doi:10.1007/s00376-015-5024-8

Alfieri L., P. Claps, P. D’dorico F. Laio, and T. M. Over, 2008: An analysis of soil moisture feedback on convective and stratiform precipitation. Journal of Hydrometeorology,9, 280-291, doi: 10.1175/2007JHM863.1.10.1175/2007JHM863.1

c49c95f6-36e8-4195-869e-8b5d0d91ad20

d89a7f0418f491adf47cc2c7f019eb60

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F201995690_An_Analysis_of_the_Soil_Moisture_Feedback_on_Convective_and_Stratiform_Precipitation%3Fev%3Dauth_pub

refpaperuri:(34b566f474b46439d7ae0b3608261d8c)

http://www.researchgate.net/publication/201995690_An_Analysis_of_the_Soil_Moisture_Feedback_on_Convective_and_Stratiform_Precipitation?ev=auth_pubAbstract Land tmosphere interactions in midlatitude continental regions are particularly active during the warm season. It is still unclear whether and under what circumstances these interactions may involve positive or negative feedbacks between soil moisture conditions and rainfall occurrence. Assessing such feedbacks is crucially important to a better understanding of the role of land surface conditions on the regional dynamics of the water cycle. This work investigates the relationship between soil moisture and subsequent precipitation at the daily time scale in a midlatitude continental region. Sounding data from 16 locations across the midwestern United States are used to calculate two indices of atmospheric instability鈥攏amely, the convective available potential energy (CAPE) and the convective inhibition (CIN). These indices are used to classify rainfall as convective or stratiform. Correlation analyses and uniformity tests are then carried out separately for these two rainfall categories, to assess the dependence of rainfall occurrence on antecedent soil moisture conditions, using simulated soil moisture values. The analysis suggests that most of the positive correlation observed between soil moisture and subsequent precipitation is due to the autocorrelation of long stratiform events. The authors found both areas with positive and areas with negative feedback on convective precipitation. This behavior is likely due to the contrasting effects of soil moisture conditions on convective phenomena through changes in surface temperature and the supply of water vapor to the overlying air column. No significant correlation is found between daily rainfall intensity and antecedent simulated soil moisture conditions either for convective or stratiform rainfall.

Amenu G. G., P. Kumar, X. Z. Liang, 2005: Interannual variability of deep-layer hydrologic memory and mechanisms of its influence on surface energy fluxes. J.Climate, 18, 5024- 5045.10.1175/JCLI3590.1

6411535dd3246b9e1f995baa0ed09cb1

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F260259384_Interannual_Variability_of_Deep-Layer_Hydrologic_Memory_and_Mechanisms_of_Its_Influence_on_Surface_Energy_Fluxes

http://www.researchgate.net/publication/260259384_Interannual_Variability_of_Deep-Layer_Hydrologic_Memory_and_Mechanisms_of_Its_Influence_on_Surface_Energy_FluxesThe characteristics of deep-layer terrestrial memory are explored using observed soil moisture data and simulated soil temperature from the Illinois Climate Network stations. Both soil moisture and soil temperature are characterized by exponential decay in amplitude, linear lag in phase, and increasing persistence with depth. Using spectral analysis, four dominant low-frequency modes are identified in the soil moisture variability. These signals have periods of about 12, 17, 34, and 60 months, which correspond to annual cycle, (4/3) ENSO, quasi-biennial (QB) ENSO, and quasi-quadrennial (QQ) ENSO signals, respectively. For deep layers, the interannual modes are dominant over the annual cycle, and vice versa for the near-surface layer. There are inherently two mechanisms by which deep-layer moisture impacts the surface fluxes. First, its temporal variability sets the lower boundary condition for the transfer of moisture and heat fluxes from the surface. Second, this temporal variability influences the uptake of moisture by plant roots, resulting in the variability of the transpiration and, therefore, the entire energy balance. Initial results suggest that this second mechanism may be more predominant.

Collini E. A., E. H. Berbery, V. R. Barros, and M. E. Pyle, 2008: How does soil moisture influence the early stages of the South American monsoon? J. Climate,15, 195-213, doi: 10.1175/ 2007JCLI1846.1.10.1175/2007JCLI1846.1

d90d813a5c39c460671e2a5d832984a1

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F252575821_How_Does_Soil_Moisture_Influence_the_Early_Stages_of_the_South_American_Monsoon

http://www.researchgate.net/publication/252575821_How_Does_Soil_Moisture_Influence_the_Early_Stages_of_the_South_American_MonsoonABSTRACT This article discusses the feedbacks between soil moisture and precipitation during the early stages of the South American monsoon. The system achieves maximum precipitation over the southern Amazon basin and the Brazilian highlands during the austral summer. Monsoon changes are associated with the large-scale dynamics, but during its early stages, when the surface is not sufficiently wet, soil moisture anomalies may also modulate the development of precipitation. To investigate this, sensitivity experiments to initial soil moisture conditions were performed using month-long simulations with the regional mesoscale Eta model. Examination of the control simulations shows that they reproduce all major features and magnitudes of the South American circulation and precipitation patterns, particularly those of the monsoon. The surface sensible and latent heat fluxes, as well as precipitation, have a diurnal cycle whose phase is consistent with previous observational studies. The convective inhibition is smallest at the time of the precipitation maximum, but the convective available potential energy exhibits an unrealistic morning maximum that may result from an early boundary layer mixing. The sensitivity experiments show that precipitation is more responsive to reductions of soil moisture than to increases, suggesting that although the soil is not too wet, it is sufficiently humid to easily reach levels where soil moisture anomalies stop being effective in altering the evapotranspiration and other surface and boundary layer variables. Two mechanisms by which soil moisture has a positive feedback with precipitation are discussed. First, the reduction of initial soil moisture leads to a smaller latent heat flux and a larger sensible heat flux, and both contribute to a larger Bowen ratio.' The smaller evapotranspiration and increased sensible heat flux lead to a drier and warmer boundary layer, which in turn reduces the atmospheric instability. Second, the deeper (and drier) boundary layer is related to a stronger and higher South American low-level jet (SALIJ). However, because of the lesser moisture content, the SALLJ carries less moisture to the monsoon region, as evidenced by the reduced moisture fluxes and their convergence. The two mechanisms - reduced convective instability and reduced moisture flux convergence - act concurrently to diminish the core monsoon precipitation.

Dickinson R. E., A. Henderson-Sellers, 1988: Modelling tropical deforestation: A study of GCM land-surface parametrizations. Quart. J. Roy. Meteor. Soc., 114, 439- 462.10.1256/smsqj.48008

af465290870a3e7ad9a3ffde43733641

http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1002%2Fqj.49711448009%2Fpdf

http://onlinelibrary.wiley.com/doi/10.1002/qj.49711448009/pdfABSTRACT Inclusion of a land-surface scheme with a vegetation canopy into a version of the NCAR Community Climate Model (CCM) with a diurnal as well as a seasonal cycle permits an exploratory study of the possible effects of tropical deforestation. In a 13-month integration that assumes that all of the Amazon tropical forest in South American is replaced by impoverished grassland, surface hydrological and temperature effects dominate the response. Reduced mixing and less interception and evaporation from the canopy cause runoff to increase and surface temperatures to rise by 3-5 K. The period of driest soil is increased in the model from one month to several, but the possibility that this change is random cannot be excluded. Increased temperatures and drier soil could have a detrimental impact on survival of the remaining forest and on attempts at cultivation in deforested areas. -from Authors

Dirmeyer P. A., J. Shukla, 1993: Observational and modeling studies of the influence of soil moisture anomalies on the atmospheric circulation. Predictions of Interannual Climate Variations, J. Shukla, Ed., NATO Series I, Vol. 6, Springer-Verlag, 1- 23.

Dirmeyer P. A., 2011: The terrestrial segment of soil moisture-climate coupling. Geophys. Res. Letts., 38,L16702, doi: 10.1029/2011GL048268.

Douville H., 2002: Influence of soil moisture on the Asian and African monsoons. Part II: Interannual variability. J.Climate, 15, 701- 720.10.1175/1520-0442(2002)0152.0.CO;2

0e2c46828fbc37b9cec96128d3938ab7

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F249611238_Influence_of_Soil_Moisture_on_the_Asian_and_African_Monsoons._Part_II_Interannual_Variability

http://www.researchgate.net/publication/249611238_Influence_of_Soil_Moisture_on_the_Asian_and_African_Monsoons._Part_II_Interannual_VariabilityAbstract The relevance of soil moisture (SM) for simulating the interannual climate variability has not been much investigated until recently. Much more attention has been paid on SST anomalies, especially in the Tropics where the El Ni帽o鈥揝outhern Oscillation represents the main mode of variability. In the present study, ensembles of atmospheric integrations based on the Action de Recherche Petit Echelle Grande Echelle (ARPEGE) climate model have been performed for two summer seasons: 1987 and 1988, respectively. The aim is to compare the relative impacts of using realistic boundary conditions of SST and SM on the simulated variability of the Asian and African monsoons. Besides control runs with interactive SM, sensitivity tests have been done in which SM is relaxed toward a state-of-the-art SM climatology, either globally or regionally over the monsoon domain. The simulations indicate that the variations of the Asian monsoon between 1987 and 1988 are mainly driven by SST anomalies. This result might be explained by the strong teleconnection with the ENSO and by a weak SM鈥損recipitation feedback over south Asia (Part I of the study). The influence of SM is more obvious over Africa. The model needs both realistic SST and SM boundary conditions to simulate the observed variability of the Sahelian monsoon rainfall. The positive impact of the SM relaxation is not only due to a local mechanism whereby larger surface evaporation leads to larger precipitation. The best results are obtained when the relaxation is applied globally, suggesting that remote SM impacts also contribute to the improved simulation of the precipitation variability. A relationship between the Sahelian rainfall anomalies and the meridional wind anomalies over North Africa points out the possible influence of the Northern Hemisphere midlatitudes. The comparison of the low- and midtropospheric anomalies in the various pairs of experiments indicates that SM anomalies can trigger stationary waves over Europe, and thereby promote the intrusion of dry air from the midlatitudes into the Tropics. The study therefore emphasizes the relevance of SM for seasonal climate predictions, at least in summer in the Northern Hemisphere, and shows a dynamical interaction between the Tropics and extratropics.

Douville H., F. Chauvin, and H. Broqua, 2001: Influence of soil moisture on the Asian and African monsoons. Part I: Mean monsoon and daily precipitation. J.Climate, 14, 2381- 2403.10.1175/1520-0442(2001)0142.0.CO;2

80ca8546b8a744e691d5b21df6bd3242

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F249611307_Influence_of_Soil_Moisture_on_the_Asian_and_African_Monsoons._Part_I_Mean_Monsoon_and_Daily_Precipitation

http://www.researchgate.net/publication/249611307_Influence_of_Soil_Moisture_on_the_Asian_and_African_Monsoons._Part_I_Mean_Monsoon_and_Daily_PrecipitationAbstract Soil moisture responds to precipitation variability but also affects precipitation through evaporation. This two-way interaction has often been referred to as a positive feedback, since the water added to the land surface during a precipitation event leads to increased evaporation, and this in turn can lead to further rainfall. Various numerical experiments have suggested that this feedback has a major influence on tropical climate variability from the synoptic to the interannual timescale. In the present study, ensembles of seasonal simulations (March eptember) have been performed in order to investigate the sensitivity of the Asian and African monsoon rainfall to regional soil moisture anomalies. After a control experiment with free-running soil moisture, other ensembles have been performed in which the soil water content is strongly constrained over a limited area, either south Asia or Sudan ahel. Besides idealized simulations in which soil moisture is limited by the value at the wilting point or at the field capacity, more realistic experiments are relaxed toward the Global Soil Wetness Project (GSWP) soil moisture climatology. The results show a different sensitivity of the Asian and African monsoons to the land surface hydrology. Whereas African rainfall increases with increasing soil moisture, such a clear and homogeneous response is not found over the Indian subcontinent. Precipitation does increase over northern India as a consequence of wetter surface conditions, but the increased evaporation is counterbalanced by a reduced moisture convergence when averaging the results over the whole Indian peninsula. This contrasted behavior is partly related to the more dynamical and chaotic nature of the Asian monsoon, for which moisture convergence is about 2 times that found over Sudan鈥揝ahel so that water recycling has a weaker influence on seasonal rainfall. It is also due to a different response of the frequency distribution of daily precipitation, and particularly to an increased number of strong convective events with decreasing soil moisture over India. Part II of the study will investigate how soil moisture also affects the interannual variability of the Asian and African monsoons.

Hansen M. C., R. S. DeFries, J. R. G. Townshend, and R. Sohlberg, 2000: Global land cover classification at 1 km spatial resolution using a classification tree approach. Int. J. Remote Sens., 21, 1331- 1364.10.1080/014311600210209

904df2501344b744d86289aa6b8f9985

http%3A%2F%2Fwww.tandfonline.com%2Fdoi%2Fabs%2F10.1080%2F014311600210209

http://www.tandfonline.com/doi/abs/10.1080/014311600210209ABSTRACT This paper on reports the production of a 1 km spatial resolution land cover classification using data for 1992-1993 from the Advanced Very High Resolution Radiometer (AVHRR). This map will be included as an at-launch product of the Moderate Resolution Imaging Spectroradiometer (MODIS) to serve as an input for several algorithms requiring knowledge of land cover type. The methodology was derived from a similar effort to create a product at 8 km spatial resolution, where high resolution data sets were interpreted in order to derive a coarse-resolution training data set. A set of 37 294 x 1 km pixels was used within a hierarchical tree structure to classify the AVHRR data into 12 classes. The approach taken involved a hierarchy of pair-wise class trees where a logic based on vegetation form was applied until all classes were depicted. Multitemporal AVHRR metrics were used to predict class memberships. Minimum annual red reflectance, peak annual Normalized Difference Vegetation Index (NDVI), and minimum channel three brightness temperature were among the most used metrics. Depictions of forests and woodlands, and areas of mechanized agriculture are in general agreement with other sources of information, while classes such as low biomass agriculture and high-latitude broadleaf forest are not. Comparisons of the final product with regional digital land cover maps derived from high-resolution remotely sensed data reveal general agreement, except for apparently poor depictions of temperate pastures within areas of agriculture. Distinguishing between forest and non-forest was achieved with agreements ranging from 81 to 92% for these regional subsets. The agreements for all classes varied from an average of 65% when viewing all pixels to an average of 82% when viewing only those 1 km pixels consisting of greater than 90% one class within the high-resolution data sets.

Hirschi, M., Coauthors, 2011: Observational evidence for soil-moisture impact on hot extremes in southeastern Europe. Nature Geoscience,4, 17-21, doi: 10.1038/ngeo1032.10.1038/ngeo1032

cd503f31ed103b91daafb99f039b4f52

http%3A%2F%2Fwww.nature.com%2Fngeo%2Fjournal%2Fv4%2Fn1%2Fabs%2Fngeo1032.html

http://www.nature.com/ngeo/journal/v4/n1/abs/ngeo1032.htmlABSTRACT Climate change is expected to affect not only the means of climatic variables, but also their variabilities(1,2) and extremes such as heat waves(2-6). In particular, modelling studies have postulated a possible impact of soil-moisture deficit and drought on hot extremes(7-11). Such effects could be responsible for impending changes in the occurrence of heat waves in Europe(7). Here we analyse observational indices based on measurements at 275 meteorological stations in central and southeastern Europe, and on publicly available gridded observations(12). We find a relationship between soil-moisture deficit, as expressed by the standardized precipitation index(13), and summer hot extremes in southeastern Europe. This relationship is stronger for the high end of the distribution of temperature extremes. We compare our results with simulations of current climate models and find that the models correctly represent the soil-moisture impacts on temperature extremes in southeastern Europe, but overestimate them in central Europe. Given the memory associated with soil moisture storage, our findings may help with climate-change-adaptation measures, such as early-warning and prediction tools for extreme heat waves

Kalnay E., M. Kanamitsu, and W. E. Baker, 1990: Global numerical weather prediction at the National Meteorological Center. Bull. Amer. Meteor. Soc., 71, 1410- 1428.10.1175/1520-0477(1990)071<1410:GNWPAT>2.0.CO;2

40f5a2ec457a88ff64e71c267422105d

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F234407529_Global_Numerical_Weather_Prediction_at_the_National_Meteorological_Center

http://www.researchgate.net/publication/234407529_Global_Numerical_Weather_Prediction_at_the_National_Meteorological_CenterAbstract In this paper we describe the global numerical weather prediction system of the National Meteorological Center, and review recent improvements, the evolution in skill, and current research projects and plans.

Kanae S., Y. Hirabayashi, T. Yamada, and T. Oki, 2006: Influence of "realistic" land surface wetness on predictability of seasonal precipitation in Boreal summer. J.Climate, 19, 1450- 1460.10.1175/JCLI3686.1

60985f61-7ca2-4cb0-8e4e-19a22f19d71b

b03cf69110519641aa25bb44274d23a8

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F242396955_Influence_of_Realistic%27%27_Land_Surface_Wetness_on_Predictability_of_Seasonal_Precipitation_in_Boreal_Summer

refpaperuri:(b864125bf6b8687f67b1415b99707447)

http://www.researchgate.net/publication/242396955_Influence_of_Realistic''_Land_Surface_Wetness_on_Predictability_of_Seasonal_Precipitation_in_Boreal_SummerOutputs from two ensembles of atmospheric model simulations for 195107070598 define the influence of 070705realistic070705 land surface wetness on seasonal precipitation predictability in boreal summer. The ensembles consist of one forced with observed sea surface temperatures (SSTs) and the other forced with realistic land surface wetness as well as SSTs. Predictability was determined from correlations between the time series of simulated and observed precipitation. The ratio of forced variance to total variance determined potential predictability. Predictability occurred over some land areas adjacent to tropical oceans without land wetness forcing. On the other hand, because of the chaotic nature of the atmosphere, considerable parts of the land areas of the globe did not even show potential predictability with both land wetness and SST forcings. The use of land wetness forcing enhanced predictability over semiarid regions. Such semiarid regions are generally characterized by a negative correlation between fluxes of latent heat and sensible heat from the land surface, and are 070705water-regulating070705 areas where soil moisture plays a governing role in land070705atmosphere interactions. Actual seasonal prediction may be possible in these regions if slowly varying surface conditions can be estimated in advance. In contrast, some land regions (e.g., south of the Sahel, the Amazon, and Indochina) showed little predictability despite high potential predictability. These regions are mostly characterized by a positive correlation between the surface fluxes, and are 070705radiation-regulating070705 areas where the atmosphere plays a leading role. Improvements in predictability for these regions may require further improvements in model physics.

Kanamitsu, M., Coauthors, 1991: Recent changes implemented into the global forecast system at NMC. Wea.Forecasting, 6, 425- 435.10.1175/1520-0434(1991)0062.0.CO;2

0667b287c4c4ad1b126ece33ac2702f0

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F238307210_Recent_Changes_Implemented_into_the_Global_Forecast_System_at_NMC

http://www.researchgate.net/publication/238307210_Recent_Changes_Implemented_into_the_Global_Forecast_System_at_NMCAbstract A number of improvements were implemented on 6 March 1991 into the National Meteorological Center's global model, which is used in the global data assimilation system (GDAS), the aviation (AVN) forecast, and the medium-range forecast (MRF): The horizontal resolution of the forecast model was increased from triangular truncation T80 to T126, which corresponds to an equivalent increase in grid resolution from 160 km to 105 km. The use of enhanced orography has been discontinued and replaced by mean orography. A new marine-stratus parameterization was introduced. A new mass-conservation constraint was implemented. The horizontal diffusion in the medium scales was reduced by adopting the Leith formulation. A new, more accurate sea-surface temperature analysis is now used. In this note, we discuss each of the changes and briefly review the new model performance.

Kim J.-E., S.-Y. Hong, 2007: Impact of soil moisture anomalies on summer rainfall over East Asia: A regional climate model study. J.Climate, 20, 5732- 5743.10.1175/2006JCLI1358.1

5f8a2915-fa96-449b-8e40-f659e999f025

76e37f2a6a2cb94b8730e181f6bbeef1

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F242483106_Impact_of_Soil_Moisture_Anomalies_on_Summer_Rainfall_over_East_Asia_A_Regional_Climate_Model_Study

refpaperuri:(b227ca3c2ded65c129f76d567a441d1f)

http://www.researchgate.net/publication/242483106_Impact_of_Soil_Moisture_Anomalies_on_Summer_Rainfall_over_East_Asia_A_Regional_Climate_Model_StudyAbstract Numerous modeling studies have shown that soil moisture anomalies in later spring have a significant effect on the summer rainfall anomalies in North America. On the other hand, the role of soil moisture in forming monsoonal precipitation in East Asia has not been identified. This study attempts to clarify the importance of soil moisture on the summer rainfall in late spring in East Asia. The National Centers for Environmental Prediction (NCEP) Regional Spectral Model (RSM) is utilized for 3-month (June–August) simulations in 1998 (above-normal precipitation year) and 1997 (below-normal precipitation year). Initial and boundary conditions are derived from the NCEP–Department of Energy (DOE) reanalysis. The control run uses the initial soil moisture from the reanalysis, whereas it is set as a saturation and wilting point for “wet” and “dry” experiments, respectively. The impact of soil moisture anomalies on the simulated summer rainfall in East Asia is not significant. The change in precipitation between the wet and dry experiments is about 10%. A conflict between the local feedback of soil moisture and a change in large-scale circulations associated with the summertime monsoonal circulation in East Asia can be attributed as a reason for this anomaly. It is found that enhanced (suppressed) evaporation from the soil to the atmosphere in wet (dry) initial soil moisture reduces (increases) the land–sea contrast between East Asia and the Pacific Ocean, leading to a weakened sensitivity of the monsoonal circulations to the initial soil moisture. It can be concluded that the impact of the initial soil moisture is significant on the dynamic circulation in East Asia.

Koster, R. D., Coauthors, 2004: Regions of strong coupling between soil moisture and precipitation. Science, 305, 1138- 1140.10.1126/science.1100217

15326351

2248f930ac46c13f0bd21d54795b293b

http%3A%2F%2Fmed.wanfangdata.com.cn%2FPaper%2FDetail%2FPeriodicalPaper_PM15326351

http://med.wanfangdata.com.cn/Paper/Detail/PeriodicalPaper_PM15326351Previous estimates of land-atmosphere interaction (the impact of soil moisture on precipitation) have been limited by a lack of observational data and by the model dependence of computational estimates. To counter the second limitation, a dozen climate-modeling groups have recently performed the same highly controlled numerical experiment as part of a coordinated comparison project. This allows a multimodel estimation of the regions on Earth where precipitation is affected by soil moisture anomalies during Northern Hemisphere summer. Potential benefits of this estimation may include improved seasonal rainfall forecasts.

Li Z. X., T. J. Zhou, H. S. Chen, D. H. Ni, and R. H. Zhang, 2015: Modelling the effect of soil moisture variability on summer precipitation variability over East Asia. Int. J. Climatol., 35, 879- 887.10.1002/joc.4023

09e217b8b09476b056aef3d6d61f23ca

http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1002%2Fjoc.4023%2Ffull

http://onlinelibrary.wiley.com/doi/10.1002/joc.4023/fullABSTRACT The potential role of surface soil moisture (SSM) in improving the simulation of interannual East Asian summer precipitation is investigated using a coupled land-atmosphere climate model, the Community Atmosphere Model version 3 (CAM3). Forced by specified observational sea surface temperature (SST), two ensemble simulations for 22 boreal-summer seasons (1979–2000) are conducted, one with interannually varying SSM (SSM inter ) forcing and another with climatological SSM (SSM clim ) forcing. Results show that, relative to the SSM clim run, interannual variability of East Asian summer precipitation is better simulated in the SSM inter run over the mid- and high-latitudes of East Asia, especially in northwest China, where the correlation coefficient between precipitation simulated and observed from the Climate Prediction Center Merged Analysis of Precipitation (CMAP) is increased from 0.12 to 0.56 during 1979–2000. Meanwhile, positive relationships between anomalies of local soil evaporation and summer precipitation in northwest China can be better reproduced in the SSM inter run than in the SSM clim run. Possible mechanisms for the improved simulations of the interannual summer precipitation variability in northwest China are analysed; the improvement is resulted from the reasonable reproduction of anomalous atmospheric circulation in Siberia and Iranian plateau.

Liu, L, R. H. Zhang, Z. Y. Zuo, 2014: Intercomparison of spring soil moisture among multiple reanalysis data sets over eastern China. J. Geophys. Res.,119, doi: 10.1002/ 2013JD020940.10.1002/2013JD020940

5bedb865e080276de3c92b635f389d80

http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1002%2F2013JD020940%2Fabstract

http://onlinelibrary.wiley.com/doi/10.1002/2013JD020940/abstractSpring soil moisture in different reanalysis data sets is intercompared Spatial and temporal characteristics of soil moisture of China are revealed The reasons causing the differences of reanalysis soil moisture are investigated Spring soil moisture in different reanalysis data sets is intercompared Spatial and temporal characteristics of soil moisture of China are revealed The reasons causing the differences of reanalysis soil moisture are investigated

Ma Z. G., H. L. Wei, and C. B. Fu, 2000: Relationship between regional soil moisture variation and climatic variability over East China. Acta Meteorologica Sinica, 58, 278- 287. (in Chinese)ff65cf88ffcfa1954b5b2bd2ec976ad3

http%3A%2F%2Fen.cnki.com.cn%2FArticle_en%2FCJFDTOTAL-QXXB200003002.htm

http://en.cnki.com.cn/Article_en/CJFDTOTAL-QXXB200003002.htmBased on the data of soil moisture, precipitation and temperature every ten-day over the east of China from 1981 to 1991, their trend, interannual variability and relationship among them were analyzed. The results indicate the notable trend of soll moisture, pre-cipitation and air temperature, positive correlation between soil moisture in every layer and precipitation, and negative correlation soil moisture and air temperature can be found, the correlation coefficient reaches the testing of degree of confidence of 0. 01. Al-so the results mean the data is useful for analyzing the relationship between soil mois-ture and climate change.

Mahfouf J. -F., 1991: Analysis of soil moisture from near-surface parameters: A feasibility study. J. Appl. Meteor., 30, 1534- 1547.10.1175/1520-0450(1991)0302.0.CO;2

86eae10840eda9e5c09a376a52a277e3

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F249606597_Analysis_of_Soil_Moisture_from_Near-Surface_Parameters_A_Feasibility_Study

http://www.researchgate.net/publication/249606597_Analysis_of_Soil_Moisture_from_Near-Surface_Parameters_A_Feasibility_StudyAbstract The main purpose of this paper is to demonstrate that it is possible to estimate soil moisture from the evolution of atmospheric parameters near the surface (temperature and relative humidity) if a realistic surface transfer model is available. Two methods to initialize soil moisture in meteorological models are then proposed: a variational method where the optimal soil moisture minimizes a penality function and a sequential method consisting of a set of predictions and static corrections of soil moisture. The algorithms are examined with a one-dimensional model including a detailed land-surface parameterization. A feasibility study is undertaken using the HAPEX-MOBILHY dataset where soil moisture has been measured together with atmospheric parameters. It is demonstrated that for three 48-h clear-sky periods the two methods are able to converge rapidly toward a realistic soil moisture content starting from arbitrary values.

Meehl G. A., 1994: Influence of the land surface in the Asian summer monsoon: External conditions versus internal feedbacks. J.Climate, 7, 1033- 1049.10.1175/1520-0442(1994)0072.0.CO;2

4b3e7bd786db915d46aad7c89d3f56f6

http%3A%2F%2Fonlinelibrary.wiley.com%2Fresolve%2Freference%2FADS%3Fid%3D1994JCli....7.1033M

http://onlinelibrary.wiley.com/resolve/reference/ADS?id=1994JCli....7.1033MAbstract The basic concept of land-sea temperature contrast and the strength of the Asian summer monsoon is investigated here by comparing the relative contributions of external conditions (involving surface albedo) and internal feedbacks (involving soil moisture) in a number of atmospheric general circulation model (GCM) mean climate simulations and in a GCM sensitivity experiment. All models are run with the same long-term mean sea surface temperatures so that only land-surface conditions affect the land-sea temperature contrast. There is a surprising consistency among the various models such that stronger summer monsoons (defined as high area-averaged precipitation over south Asia) are associated with greater land-sea temperature contrast (i.e., higher land temperatures), lower sea level pressure over land, less snow cover, and greater soil moisture. In a sensitivity study with land albedos uniformly raised from 0. 13 to 0.20 in one of the models, the winter-spring-summer sequence over southern Asia shows that there is a high sensitivity to the specified land albedos. Lower land albedos are associated with warmer land temperatures, greater land-sea temperature contrast, and a stronger Asian summer monsoon. There is also a positive feedback between soil moisture and precipitation (increased soil moisture provides a surface moisture source for further precipitation).

Meng L., D. Long, S. M. Quiring, and Y. J. Shen, 2014: Statistical analysis of the relationship between spring soil moisture and summer precipitation in East China. Inter. J. Climatol., 34, 1511- 1523.10.1002/joc.3780

debffbc7ff043ca4e78bb4044375be5a

http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1002%2Fjoc.3780%2Fabstract

http://onlinelibrary.wiley.com/doi/10.1002/joc.3780/abstractABSTRACT The relationship between spring soil moisture (SM) and summer precipitation in East China (EC) was examined using monthly temperature and precipitation data and ERA-40 SM data. EC was divided into five different climate regions to investigate how SM-precipitation correlations vary under different climatic conditions. Both local and remote impacts of spring SM in EC were assessed. It was found that spring SM had significant correlations with summer precipitation in the East, Southeast, and Southwest regions, but not in the Northwest and Northeast region. This is possibly because correlations between summer precipitation and temperature (as a surrogate to SM–evaporation relationship) were statistically significant in the first three regions, but not in the Northwest and Northeast regions. Statistically significant positive correlations between SM and summer precipitation were found in the East and Southeast regions and statistically significant negative correlations were in the Southwest region. The negative SM-precipitation relationship is possibly because the Southwest region is primarily an energy-controlled regime. Significant SM-precipitation correlations were usually associated with strong SM persistence and precipitation autocorrelation. Our results suggest that strong correlation between spring SM and summer precipitation might be due to the combination of SM–precipitation interactions and precipitation autocorrelation. Our study also demonstrated that there are strong temporal variations in SM–precipitation relationships in the regions where significant correlations occurred. May SM had significant positive correlations (approximately 0.6) with summer precipitation over most of the study period in East region. Strong negative correlation (approximately 610.6) was found in Southwest during 1980s-1990s due to strong SM persistence and strong precipitation autocorrelation in the same period. This suggested that SM–precipitation relationships vary over time even in regions with strong coupling. Multivariate regression analysis demonstrated that SM persistence had the largest contribution to summer precipitation variation in East region and April precipitation was the dominant predictor of summer precipitation variations in Southeast and Southwest regions. Statistical analysis of SM and precipitation relationships should consider both SM persistence and precipitation autocorrelation. Results from this study can be used to improve the predictability of droughts.

Sch盲r, C., D. L眉thi, U. Beyerle, E. Heise, 1999: The soil-precipitation feedback: A process study with a regional climate model. J.Climate, 12, 722- 736.10.1175/1520-0442(1999)012<0722:TSPFAP>2.0.CO;2

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http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F202000635_The_soil-precipitation_feedback_a_process_study_with_a_regional_climate_model

refpaperuri:(16cee649732b21510dc11005ae926acc)

http://www.researchgate.net/publication/202000635_The_soil-precipitation_feedback_a_process_study_with_a_regional_climate_modelMonth-long integrations with a regional climate model covering Europe and the Northern Atlantic are utilized to study the sensitivity of the summertime European precipitation climate with respect to the continental-scale soil moisture content. Experiments are conducted for July 1990 and 1993. For each of the two months, the control experiment with the initial soil water distribution derived from the operational ECMWF analysis is compared against two sensitivity experiments with dry and wet initial soil moisture distributions. The results demonstrate that summertime European precipitation climate in a belt ;1000 km wide between the wet Atlantic and the dry Mediterranean climate heavily depends upon the soil moisture content. In this belt, changes in monthly mean precipitation amount to about half of the changes in mean evapotranspiration. Budget analysis of water substance over selected subdomains demonstrate that the simulated sensitivity cannot be interpreted with the classical recycling mechanism, that is, the surplus of precipitation that falls over wet (as compared to dry) soils does not directly derive from evapotranspiration. Rather, the surplus of precipitation primarily originates from water vapor extracted from the ambient atmospheric flow. Thus, the soil--precipitation feedback must rely on some indirect mechanism, whereby wet soils increase the efficiency of convective precipitation processes. In order to isolate the physical mechanisms underlying the soil--precipitation feedback, a detailed analysis including an investigation of the mean diurnal cycle throughout the integration period is performed. The key elements of the feedback are the following. First, wet soils (small Bowen ratios) imply the buildup of a comparatively shallow boundary layer. The surface fluxes of heat and moisture are thus concentrated into a comparatively small volume of air, leading to the buildup of high values of low-level moist entropy, thereby providing a...

Seller P. J., Y. Mintz, Y. C. Sud, and A. Dalcher, 1986: A simple biosphere model (SiB) for use within general circulation models. J. Atmos. Sci., 43, 505- 531.10.1175/1520-0469(1986)0432.0.CO;2

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http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F23616366_A_simple_biosphere_model_%28SiB%29_for_use_within_general_circulation_models

refpaperuri:(a95392ee7d4a0ad0f57ff0ecec81773a)

http://www.researchgate.net/publication/23616366_A_simple_biosphere_model_(SiB)_for_use_within_general_circulation_modelsA simple but realistic biosphere model has been developed for calculating the transfer of energy, mass and momentum between the atmosphere and the vegetated surface of the earth. The model is designed for use in atmospheric general circulation models. The vegetation in each terrestrial model grid area is represented by two distinct layers, either or both of which may be present or absent at any given location and time. The upper vegetation layer represents the perennial canopy of trees or shrubs, while the lower layer represents the annual ground cover of grasses and other herbaceous species. The local coverage of each vegetation layer may be fractional or complete but as the individual vegetation elements are considered to be evenly spaced, their root systems are assumed to extend uniformly throughout the entire grid area. The Simple Biosphere (SiB) has seven prognostic physical-state variables: two temperatures (one for the canopy and one for the ground cover and soil surface); two interception water stores (one for the canopy and one for the ground cover); and three soil moisture stores (two of which can be reached by the vegetation root systems and one underlying recharge layer into and out of which moisture is transferred more» only by hydraulic diffusion and gravitational drainage). 芦less

Thiaw W. M., K. C. Mo, 2005: Impact of sea surface temperature and soil moisture on seasonal rainfall prediction over the Sahel. J.Climate, 18, 5330- 5343.10.1175/JCLI3552.1

8f85fe341b06c9e4c6e4ee31a731bf28

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F238561257_Impact_of_Sea_Surface_Temperature_and_Soil_Moisture_on_Seasonal_Rainfall_Prediction_over_the_Sahel

http://www.researchgate.net/publication/238561257_Impact_of_Sea_Surface_Temperature_and_Soil_Moisture_on_Seasonal_Rainfall_Prediction_over_the_SahelAbstract The ensemble rainfall forecasts over the Sahel for July鈥揝eptember (JAS) from the NCEP Coupled Forecast System (CFS) were evaluated for the period 1981鈥2002. The comparison with the gauge-based precipitation analysis indicates that the predicted Sahel rainfall is light and exhibits little interannual variability. The rain belt is shifted about 4掳 southward. One major source of rainfall errors comes from the erroneous sea surface temperature (SST) forecasts. The systematic SST error pattern has positive errors in the North Pacific and the North Atlantic and negative errors in the tropical Pacific and the southern oceans. It resembles the decadal SST mode, which has a significant influence on rainfall over the Sahel. Because the systematic SST errors were not corrected during the forecasts, persistent errors serve as an additional forcing to the atmosphere. The second source of error is from the soil moisture feedback, which contributes to the southward shift of rainfall and dryness over West Africa. This was demonstrated by the comparison between simulations (SIMs) and the Atmospheric Model Intercomparison Project (AMIP) run. Both are forced with observed SSTs. The SIMs initialized at the end of June have realistic soil moisture and do not show the southward shift of rainfall. The AMIP, which predicts soil moisture, maintains the dryness through the summer over the Sahel. For AMIP, the decreased rainfall is contributed by the decreased evaporation ( E ) due to the dry soil and the shift of the large temperature gradients southward. In response, the African easterly jet (AEJ) shifts southward. Since this jet is the primary source of energy for the African waves and their associated mesoscale convective systems, these too shift southward. This negative feedback contributes to increased dryness over the Sahel.

Vivoni E. R., K. Tai, and D. J. Gochis, 2009: Effects of initial soil moisture on rainfall generation and subsequent hydrologic response during the North American monsoon. Journal of Hydrometeorology,10, 644-664, doi: 10.1175/2008JHM 1069.1.10.1175/2008JHM1069.1

16be7c30775b0b376d88c007adbe563d

http%3A%2F%2Fwww.cabdirect.org%2Fabstracts%2F20093230242.html

http://www.cabdirect.org/abstracts/20093230242.htmlAbstract Through the use of a mesoscale meteorological model and distributed hydrologic model, the effects of initial soil moisture on rainfall generation, streamflow, and evapotranspiration during the North American monsoon are examined. A collection of atmospheric fields is simulated by varying initial soil moisture in the meteorological model. Analysis of the simulated rainfall fields shows that the total rainfall, intensity, and spatial coverage increase with higher soil moisture. Hydrologic simulations forced by the meteorological fields are performed using two scenarios: (i) fixed soil moisture initializations obtained via a drainage experiment in the hydrologic model and (ii) adjusted initializations to match conditions in the two models. The scenarios indicate that the runoff ratio increases with higher rainfall, although a change is observed from a linear (fixed initialization) to a nonlinear response (adjusted initialization). Variations in basin response are attributed to controls exerted by rainfall, soil, and vegetation properties for varying initial conditions. Antecedent wetness significantly influences the runoff response through the interplay of different runoff generation mechanisms and also controls the evapotranspiration process. The authors conclude that a regional increase in initial soil moisture promotes rainfall generation, streamflow, and evapotranspiration for this warm-season case study.

Wei J. F., R. E. Dickinson, and H. S. Chen, 2008: A negative soil moisture-precipitation relationship and its causes. Journal of Hydrometeorology, 9, 1364- 1376.10.1175/2008JHM955.1

7ed26af4-b931-411c-9ccb-bb76551e192b

cb5c68bf3f9545e39c66b63606f4f850

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F230758459_A_Negative_Soil_Moisture-Precipitation_Relationship_and_Its_Causes

refpaperuri:(89101296de0086f69a1da88db4093127)

http://www.researchgate.net/publication/230758459_A_Negative_Soil_Moisture-Precipitation_Relationship_and_Its_CausesABSTRACT This study examines a lagged soil moisture-precipitation (S-P) correlation for 24 yr of boreal summer (1979-2002) from the 40-yr ECMWF Re-Analysis (ERA-40), the NCEP-Department of Energy (DOE) reanalysis 2 (R-2), the North American Regional Reanalysis (NARR), 10 yr (1986-95) of data from phase 2 of the Global Soil Wetness Project (GSWP-2), and two 24-yr model simulations with the NCAR Community Atmosphere Model version 3.1 (CAM3). The different datasets and model simulations all show a similar negative-dominant S-P correlation pattern with wet areas having more significantly negative correlations than the dry areas. The experiments with CAM3 show that this correlation pattern is not caused by the soil moisture feedback. Rather, the combined effect of the precipitation variability and the memory of soil moisture is the main reason for this correlation pattern. Theoretical analysis confirms this conclusion and shows that the correlation pattern is related to both the precipitation spectrum and the time scale of soil moisture retention. This study suggests that the attribution of lagged correlations of precipitation with soil moisture or related variables should be done cautiously.

Wu R. G., J. L. Kinter III, 2009: Analysis of relationship of U. S. droughts with SST and soil moisture: Distinguishing the time scale of droughts . J. Climate,22, 4520-4538, doi: 10.1175/2009JCLI2841.1.10.1175/2009JCLI2841.1

6c7a038b-7f2a-4de4-ace8-1885c11bfac3

1637889a80c10f809a3055ac53d2e99a

http%3A%2F%2Fwww.cabdirect.org%2Fabstracts%2F20093259190.html

refpaperuri:(f29bf9fa222be198a49a3f22532f3920)

http://www.cabdirect.org/abstracts/20093259190.htmlAbstract The impacts of droughts depend on how long droughts persist and the reasons why droughts extend to different time scales may be different. The present study distinguishes the time scale of droughts based on the standardized precipitation index and analyzes the relationship of boreal summer U.S. droughts with sea surface temperature (SST) and soil moisture. It is found that the roles of remote SST forcing and local soil moisture differ significantly for long-term and short-term droughts in the U.S. Great Plains and Southwest. For short-term droughts (鈮3 months), simultaneous remote SST forcing plays an important role with an additional contribution from soil moisture. For medium-term and long-term droughts (鈮6 months), both simultaneous and antecedent SST forcing contribute to droughts, and the soil moisture is important for the persistence of droughts through a positive feedback to precipitation. The antecedent remote SST forcing contributes to droughts through soil moisture and evaporation changes. The tropical Pacific SST is the dominant remote forcing for U.S. droughts. The most notable impacts of the tropical Pacific SST are found in the Southwest with extensions to the Great Plains. Tropical Indian Ocean SST forcing has a notable influence on medium-term and long-term U.S. droughts. The relationships between tropical Indian and Pacific Ocean SST and boreal summer U.S. droughts have undergone obvious long-term changes, especially for the Great Plains droughts.

Xue Y. K., F. J. Zeng, and C. A. Schlosser, 1996: SSiB and its sensitivity to soil properties閳ユ柡锟芥摐 case study using HAPEX-Mobilhy data. Global and Planetary Change, 13, 183- 194.10.1016/0921-8181(95)00045-3

f5f54b91-289c-4a17-a610-bf912addeaa6

5b488372c94be1e1185a9a47e9ee20f3

http%3A%2F%2Fwww.sciencedirect.com%2Fscience%2Farticle%2Fpii%2F0921818195000453

refpaperuri:(e12b2bd9669af24530abb264fcf40c05)

http://www.sciencedirect.com/science/article/pii/0921818195000453In this paper, SSiB's development and some of its major parameterizations in the model are briefly reviewed. The soil moisture parameterizations, which are a key element in the model, are comprehensively described.The sensitivity study shows that hydraulic conductivity at saturation, B parameter, and wilting point have a profound impact on the simulation of soil moisture, but with different features. Both hydraulic conductivity at saturation and B parameter influence the soil moisture simulation by changing the soil hydraulic conductivity and the field capacity. The changes in equilibrium soil water content in this study are consistent with the changes in field capacity. The wilting point affects the soil moisture through vegetation transpiration.Through these sensitivity studies, improvements in modeling the soil moisture content of HAPEX-Mobilhy data are made. The soil moisture simulations at six Russian sites are also re-examined. After applying the results from the sensitivity studies of the HAPEX-Mobilhy data, the soil moisture simulation of the Russian data is significantly improved.

Xue Y. K., H. -M. H. Juang, W.-P. Li, S. Prince, R. DeFries, Y. Jiao, and R. Vasic, 2004: Role of land surface processes in monsoon development: East Asia and West Africa. J. Geophys. Res., 109, D03105, doi: 10.1029/2003JD003556.10.1029/2003JD003556

0be8fd82d8b22ead8b270953c125d84d

http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1029%2F2003JD003556%2Ffull

http://onlinelibrary.wiley.com/doi/10.1029/2003JD003556/full[1] Evidence is presented that exchanges of water and energy between the vegetation and the atmosphere play an important role in east Asian and West African monsoon development and are among the most important mechanisms governing the development of the monsoon. The results were obtained by conducting simulations for five months of 1987 using a general circulation model (GCM) coupled with two different land surface parameterizations, with and without explicit vegetation representations, referred to as the GCM/vegetation and the GCM/soil, respectively. The two land surface models produced similar results at the planetary scale but substantial differences at regional scales, especially in the monsoon regions and some of the large continental areas. In the simulation with GCM/soil, the east Asian summer monsoon moisture transport and precipitation were too strong in the premonsoon season, and an important east Asian monsoon feature, the abrupt monsoon northward jump, was unclear. In the GCM/vegetation simulation, the abrupt northward jump and other monsoon evolution processes were simulated, such as the large-scale turning of the low-level airflow during the early monsoon stage in both regions. With improved initial soil moisture and vegetation maps, the intensity and spatial distribution of the summer precipitation were also improved. The two land surface representations produced different longitudinal and latitudinal sensible heat gradients at the surface that, in turn, influenced the low-level temperature and pressure gradients, wind flow (through geostrophic balance), and moisture transport. It is suggested that the great east-west thermal gradient may contribute to the abrupt northward jump and the latitudinal heating gradient may contribute to the clockwise and counterclockwise turning of the low-level wind. The results showed that under unstable atmospheric conditions, not only low-frequency mean forcings from the land surface, such as monthly mean albedo, but also the perturbation processes of vegetation were important to the monsoon evolution, affecting its intensity, the spatial distribution of precipitation, and associated circulation at the continental scale.

Xue Y., P. J. Sellers, J. L. Kinter III, and J. Shukla, 1991: A simplified biosphere model for global climate studies. J.Climate, 4, 345- 364.10.1175/1520-0442(1991)004<0345:ASBMFG>2.0.CO;2

2cec60786f1e8a214837c0752dc1fcd0

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F23833274_A_simplified_biosphere_model_for_global_climate_studies

http://www.researchgate.net/publication/23833274_A_simplified_biosphere_model_for_global_climate_studiesABSTRACT A comprehensive analysis of the simple biosphere model (SIB) of Sellers et al. (1986) is performed in an effort to bridge the gap between the typical hydrological treatment of the land surface biosphere and the conventional general circulation model treatment, which is specified through a single parameter. Approximations are developed that stimulate the effects of reduced soil moisture more simply, maintaining the essence of the biophysical concepts utilized in SIB. Comparing the reduced parameter biosphere with those from the original formulation in a GCM and a zero-dimensional model shows the simplified version to reproduce the original results quite closely.

Yang R., M. J. Fennessy, and J. Shukla, 1994: The influence of initial of soil wetness on medium-range surface weather forecasts. Mon. Wea. Rev., 122, 471- 485.10.1175/1520-0493(1994)1222.0.CO;2

21fdaeed-f80a-41ba-8a47-c73b21b213af

6687460aba391435848bd2853a3613da

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F249620951_The_Influence_of_Initial_Soil_Wetness_on_Medium-Range_Surface_Weather_Forecasts

refpaperuri:(158e3591b8233ce0e9cf78597f4d5b3f)

http://www.researchgate.net/publication/249620951_The_Influence_of_Initial_Soil_Wetness_on_Medium-Range_Surface_Weather_ForecastsAbstract The influence of initial soil wetness on surface weather forecasts was quantitatively assessed through the use of the Center for Ocean–Land–Atmosphere Interactions (COLA) general circulation model with an advanced simple biosphere model. The sensitivity of the COLA GCM to changes in initial soil wetness (ISW) is determined by repeating three 10-day integrations with the same initial and boundary conditions as the control runs except the values of ISW, which are revised at 69 model grid points covering much of the continental United States. It is found that the relationship between the changes in the 5-day mean forecasts of surface air temperature and surface specific humidity and the changes in ISW depends upon vegetation type and the values of ISW, and is approximated by regression equations. With the ISW revised based on these regression equations, the first 5-day mean surface air temperature and mean surface relative humidity forecast errors over the relatively dry western portion of the domain are reduced from 2.9° to 1.1°C and from 15% to 7.6%, respectively. Somewhat smaller surface forecast improvements occur for the following 5 days. The impact on the upper atmosphere is small and is largely confined to lower levels. It is also found that the model soil wetness has strong persistence. Therefore, additional forecast experiments are carried out in which the initial soil wetness for a 10-day integration is revised based on the surface forecast errors for the preceding 5-day mean. This results in a reduction of the first 5-day mean surface air temperature and surface relative humidity forecast errors from 2.4° to 1.3°C and from 15% to 8%, respectively, averaged over the dry region. This study suggests the importance of accurate initial soil wetness for medium-range surface weather forecasts. The regression method developed in this study could be readily used operationally to initialize the soil wetness field for medium-range forecasting.

Yang S., K. -M. Lau, 1998: Influences of sea surface temperature and ground wetness on Asian summer monsoon. J.Climate, 11, 3230- 3246.10.1175/1520-0442(1998)011<3230:IOSSTA>2.0.CO;2

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a109151418d415e70d85a8c6ed93c571

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F246469024_Influences_of_Sea_Surface_Temperature_and_Ground_Wetness_onAsian_Summer_Monsoon

refpaperuri:(bbcad17d9a46f8058a3588c23f1a777a)

http://www.researchgate.net/publication/246469024_Influences_of_Sea_Surface_Temperature_and_Ground_Wetness_onAsian_Summer_MonsoonABSTRACT The authors have conducted a series of experiments with a general circulation model to understand the influences of sea surface temperature (SST) and ground wetness (GW) (measured by snow amount and soil moisture content) on the Asian summer monsoon. The experiments are designed to illustrate the dominant features of monsoon response to SST and GW forcings and to delineate the relative importance of each forcing function in contributing to the variability of the monsoon.Results indicate that ocean basin-scale SST anomalies exert a stronger control on the interannual variability of the monsoon compared to GW anomalies. The impact of SST anomalies on the monsoon appears nonlinear with respect to warm and cold events. The monsoon is weakened during the warm events but changes less noticeably during the cold events. The diminution of monsoon circulation associated with the warm SST anomalies is accompanied by a broad-scale reduction in water vapor convergence and monsoon rainfall.Results also indicate that, following wet land surface conditions (enhanced snow and soil moisture) in the Asian continent during previous cold seasons, the summer monsoon becomes moderately weaker. Antecedent land surface processes mainly influence the early part of the monsoon. Wetter and colder conditions occur in the Asian continent during warm SST events. This results in reduced land-sea thermal contrast, which reinforces the weak monsoon anomalies produced initially by warm SST forcing. These interactive forcings are also responsible for the changes in the winter-spring westerlies over subtropical Asia, which are key precursory signals for the subsequent summer monsoon.It should be pointed out that this study is conducted for the climate decade of 1979-88 only. The general robustness of the results needs to be explored by further investigations. In addition, chaotic features may have affected the results because of sampling errors.

Yeh T.-C., R. T. Wetherald, and S. Manabe, 1984: The effect of soil moisture on the short-term climate and hydrology change閳ユ柡锟芥摐 numerical experiment. Mon. Wea. Rev., 112, 474- 490.

You X. T., T. N. Xiong, T. Yasunari, and H. L. Tanaka, 2000: The impact of the ground wetness anomalies in spring on the climate of following months. Chinese J. Atmos. Sci., 24, 660- 668. (in Chinese)bf6d6d508af27e45b880d5e7a95c9c1a

http%3A%2F%2Fwww.jourlib.org%2Fpaper%2F1557728

http://www.jourlib.org/paper/1557728The impact of anomalous ground wetness (GW) in spring over Asian mid-latitudes on the monthly climatic parameters in the following four months is investigated with a GCM experiment. The main results are summarized as follows: the effect of positive GW anomalies on the monthly climatic parameters is the weakest for the first following month and the strongest for the third following months; the positive anomalous GW leads to decreases of both height and temperature in the whole troposphere over most mid-high latitudes of Asia for all following four months, to developments of both the depressions in mid-high latitudes and the subtropical high, and thus to intensification of the westerly jet; and some evidences of teleconnection remarkably appear in the atmospheric circulation over the east coast of North America.

Zampieri M., F. D'Andrea R. Vautard, P. Ciais, N. De Noblet-Decoudr茅, and P. Yiou, 2009: Hot European summers and the role of soil moisture in the propagation of Mediterranean drought. J. Climate,22, 4747-4758, doi: 10.1175/2009JCLI 2568.1.10.1175/2009JCLI2568.1

641679d4bd76b35b3d711aef36799d26

http%3A%2F%2Fwww.cabdirect.org%2Fabstracts%2F20093283571.html

http://www.cabdirect.org/abstracts/20093283571.htmlABSTRACT Drought in spring and early summer has been shown to precede anomalous hot summer temperature. In particular, drought in the Mediterranean region has been recently shown to precede and to contribute to the development of extreme heat in continental Europe. In this paper, this mechanism is investigated by per- forming integrations of a regional mesoscale model at the scale of the European continent in order to re- produce hot summer inception, starting with different initial values of soil moisture south of 468N. The mesoscale model is driven by the large-scale atmospheric conditions corresponding to the 10 hottest summers on record from the European Climate Assessment dataset. A northward progression of heat and drought from late spring to summer is observed from the Mediterranean regions, which leads to a further increase of temperature during summer in temperate continental Europe. Dry air formed over dry soils in the Medi- terranean region induces less convection and diminished cloudiness, which gets transported northward by occasional southerly wind, increasing northward temperature and vegetation evaporative demand. Later in the season, drier soils have been established in western and central Europe where they further amplify the warming through two main feedback mechanisms: 1) higher sensible heat emissions and 2) favored upper-air anticyclonic circulation. Drier soils in southern Europe accelerate the northward propagation of heat and drying, increasing the probability of strong heat wave episodes in the middle or the end of the summer.

Zhan Y. L., Z. H. Lin, 2011: The relationship between June precipitation over mid-lower reaches of the Yangtze River Basin and spring soil moisture over the East Asian monsoon region. Acta Meteorologica Sinica, 25, 355- 363.10.1007/s13351-011-0310-6

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e6c9b5d02d6bfac71a602d45377d84f6

http%3A%2F%2Flink.springer.com%2F10.1007%2Fs13351-011-0310-6

refpaperuri:(c34f4da0f142f3f63c28460a97af9c3d)

http://d.wanfangdata.com.cn/Periodical_qxxb-e201103010.aspxUsing the US Climate Prediction Center (CPC) soil moisture dataset and the observed precipitation over China together with the NCEP/NCAR reanalysis wind and air temperature,the relationship between June precipitation over mid-lower reaches of the Yangtze River basin (MLR-YRB) and spring soil moisture over the East Asian monsoon region was explored,with the signal of the ENSO effect on precipitation removed.A significant positive correlation was found between the mean June precipitation and the preceding soil moisture over the MRL YRB.The possible response mechanism for this relationship was also investigated.It is found that when the soil over the MRL-YRB is wetter (drier) than normal in April and May,the air temperature in the lower troposphere over this region in May is lower (higher) than normal,and this temperature effect leads to a decrease (increase) in the temperature contrast between the land and the sea.Generally,a decrease (increase) in the land-sea temperature contrast leads to weaker (stronger) East Asian summer monsoon in June.Southerly (northerly) wind anomalies at 850 hPa then show up in the south of the Yangtze River basin while northerly (southerly) wind anomalies dominate in the north.These anomalies lead to the convergence (divergence) of wind and water vapor and hence gives rise to more (less) precipitation in June over the MLR-YRB.

Zhang R. H., A. Sumi, 2002: Moisture circulation over East Asia during El Ni帽o episode in northern winter, spring and autumn. J. Meteor. Soc.Japan, 80, 213- 227.10.2151/jmsj.80.213

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cea86a88dc7604ae2df8bcdd0d70b2e5

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F250139732_Moisture_Circulation_over_East_Asia_during_El_Nino_Episode_in_Northern_Winter_Spring_and_Autumn

refpaperuri:(dd9337565e43d151884840aaae8ea43f)

http://www.researchgate.net/publication/250139732_Moisture_Circulation_over_East_Asia_during_El_Nino_Episode_in_Northern_Winter_Spring_and_AutumnDiagnostic analysis is made to investigate features of the moisture circulation over East Asian during the El Nino episode in northern winter, spring and autumn. It is found that in all these seasons, the anomalies of precipitation in China, atmospheric precipitable water, water vapor transport and moisture divergence over East Asia in the El Nino mature phase, differ from those in the rest of the phases. In the El Nino mature phase, positive precipitation anomalies occur in the southern part of China. More northeastward water vapor transport appears around the southeastern coast of East Asia, where moisture converges, and precipitable water is above normal, which are consistent with the precipitation anomalies. The physical process through which El Nino affects the East Asian climate, is also identified. Differing from the rest of the phases in the El Nino episode, the mature phase is characterized by strong convective cooling anomalies in the atmosphere, in the area (0-15掳N 110掳E-150掳E) over the western tropical Pacific. As a Rossby wave response of the tropical atmosphere to the cooling anomalies, an anomalous low-level anticyclone forms to the north of the maritime continent. This anticyclonic anomaly not only transports more water vapor to the area around the southeastern coast of East Asia, but also strengthens the western Pacific subtropical high, and shifts it to the south of the mainland China, which are favorable for more precipitation in the southern part of China.

Zhang R. H., Z. Y. Zuo, 2011: Impact of spring soil moisture on surface energy balance and summer monsoon circulation over East Asia and precipitation in East China. J.Climate, 24, 3309- 3322.10.1175/2011JCLI4084.1

4e1c05b0ce038a8a1c04d2c3d3c0aeba

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F262007278_Impact_of_Spring_Soil_Moisture_on_Surface_Energy_Balance_and_Summer_Monsoon_Circulation_over_East_Asia_and_Precipitation_in_East_China

http://www.researchgate.net/publication/262007278_Impact_of_Spring_Soil_Moisture_on_Surface_Energy_Balance_and_Summer_Monsoon_Circulation_over_East_Asia_and_Precipitation_in_East_ChinaAbstract Numerous studies have been conducted on the impact of soil moisture on the climate, but few studies have attempted to diagnose the linkage between soil moisture and climate variability using observational data. Here, using both observed and reanalysis data, the spring (April鈥揗ay) soil moisture is found to have a significant impact on the summer (June鈥揂ugust) monsoon circulation over East Asia and precipitation in east China by changing surface thermal conditions. In particular, the spring soil moisture over a vast region from the lower and middle reaches of the Yangtze River valley to north China (the YRNC region) is significantly correlated to the summer precipitation in east China. When the YRNC region has a wetter soil in spring, northeast China and the lower and middle reaches of the Yangtze River valley would have abnormally higher precipitation in summer, while the region south of the Yangtze River valley would have abnormally lower precipitation. An analysis of the physical processes linking the spring soil moisture to the summer precipitation indicates that the soil moisture anomaly across the YRNC region has a major impact on the surface energy balance. Abnormally wet soil would increase surface evaporation and hence decrease surface air temperature ( T a ). The reduced T a in late spring would narrow the land ea temperature difference, resulting in the weakened East Asian monsoon in an abnormally strengthened western Pacific subtropical high that is also located farther south than its normal position. This would then enhance precipitation in the Yangtze River valley. Conversely, the abnormally weakened East Asian summer monsoon allows the western Pacific subtropical high to wander to south of the Yangtze River Valley, resulting in an abnormally reduced precipitation in the southern part of the country in east China.

Zhang R. H., A. Sumi, and M. Kimoto, 1999: A diagnostic study of the impact of El Nino on the precipitation in China. Adv. Atmos. Sci.,16, 229-241, doi: 10.1007/BF02973084 .e2f47c2d-312e-4490-a05a-1abe2744ae7f

014527ac8838d6c47c53a590bc972bcc

http%3A%2F%2Fwww.cnki.com.cn%2FArticle%2FCJFDTotal-DQJZ199902004.htm

refpaperuri:(f11d963098268b0c48cc7790860683fc)

http://www.cnki.com.cn/Article/CJFDTotal-DQJZ199902004.htm1.IntroductionEINifioisthemostoutstandinginterannualvariabilityintheocean.Itiswellknownthattheheatsourcedrivingtheatmosphericgeneralcirculationismainlywithinthetropics.EINinooccursinthetropicalPacificandthewarmingoftheoceanduringtheEINinocancoveralar...

Zuo Z. Y., R. H. Zhang, 2007: The spring soil moisture and the summer rainfall in eastern China. Chinese Science Bulletin, 52, 3310- 3312.10.1007/s11434-007-0442-3

99becb10c2584f5954723c66ed752103

http%3A%2F%2Fd.wanfangdata.com.cn%2FPeriodical_kxtb-e200723022.aspx

http://d.wanfangdata.com.cn/Periodical_kxtb-e200723022.aspxThe relation between the soil moisture in spring and the rainfall in summer in eastern China is investi- gated. Results show that the summer rainfall in eastern China is closely related to the spring soil moisture in the area from North China to the lower reaches of Yangtze River (NCYR). When spring soil moisture anomalies over NCYR are positive, the summer precipitation exhibits positive anomalies in Northeast China and the lower reaches of Yangtze River, and negative anomalies in southern China and North China. The higher soil moisture over NCYR cools land surface and reduces the land-sea tem- perature gradient, which weakens East Asian summer monsoon. The western Pacific Subtropical High (WPSH) is located to the south and shifts westward, resulting in more rainfall in the lower reaches of Yangtze River and less in southern China and North China.

Zuo Z. Y., R. H. Zhang, 2009: Temporal and spatial features of the soil moisture in boreal spring in eastern China. Science in China (D), 52, 269- 278.10.1007/s11430-009-0011-5

72344c63578fc2eec2f64a8f5f410d5f

http%3A%2F%2Flink.springer.com%2F10.1007%2Fs11430-009-0011-5

http://www.cnki.com.cn/Article/CJFDTotal-JDXG200902014.htmSoil moisture data of 45 years from European Center for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) and the in situ observational data are used to study the temporal and spatial characteristics of the soil moisture in boreal spring in the area to the east of 100掳E in China. Results show that ERA-40 soil moisture well reproduces the temporal and spatial features of observations. ERA-40 data capture the spatial pattern that the soils in Northeast China and Southwest China are wetter than those in Inner Mongolia and North China and represent the inter-annual variability in ob-servations. The dry trends of spring soil moisture are evident over the whole eastern China. It is espe-cially prominent for the dry trend in southwest China where the spring soil from surface to deep-layer show drying and the trend became significant after the 1980s. The dry trend in Northeast China is weak after early 1970s in near-surface layer but aggravates after latel 1970s in deep layers. In the mid-latitude zone, the inter-annual variation of spring soil is robust and shows no dry trend except in deep-layer after 1988.