doi:10.1007/s00376-015-5058-y

Ahlgrimm M., R. Forbes, 2014: Improving the representation of low clouds and drizzle in the ECMWF model based on ARM observations from the Azores. Mon. Wea. Rev., 142, 668- 685.10.1175/MWR-D-13-00153.1

c53e9fdf-33ee-4370-988d-02ad176a50de

c2d516365a45b95bc22319957c04e3ab

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F266383218_Improving_the_representation_of_low_clouds_and_drizzle_in_the_ECMWF_model_based_on_ARM_observations_from_the_Azores

refpaperuri:(508c63b60f224b6804f3d75207189375)

http://www.researchgate.net/publication/266383218_Improving_the_representation_of_low_clouds_and_drizzle_in_the_ECMWF_model_based_on_ARM_observations_from_the_AzoresAbstract In this study, the representation of marine boundary layer clouds is investigated in the ECMWF model using observations from the Atmospheric Radiation Measurement (ARM) mobile facility deployment to Graciosa Island in the North Atlantic. Systematic errors in the occurrence of clouds, liquid water path, precipitation, and surface radiation are assessed in the operational model for a 19-month-long period. Boundary layer clouds were the most frequently observed cloud type but were underestimated by 10% in the model. Systematic but partially compensating surface radiation errors exist and can be linked to opposing cloud cover and liquid water path errors in broken (shallow cumulus) and overcast (stratocumulus) low-cloud regimes, consistent with previously reported results from the continental ARM Southern Great Plains (SGP) site. Occurrence of precipitation is overestimated by a factor of 1.5 at cloud base and by a factor of 2 at the surface, suggesting deficiencies in both the warm-rain formation and subcloud evaporation parameterizations. A single-column version of the ECMWF model is used to test combined changes to the parameterizations of boundary layer, autoconversion/accretion, and rain evaporation processes at Graciosa. Low-cloud occurrence, liquid water path, radiation biases, and precipitation occurrence are all significantly improved when compared to the ARM observations. Initial results from the modified parameterizations in the full model show improvement in the global top-of-the-atmosphere shortwave radiation, suggesting the reduced errors in the comparison at Graciosa are more widely applicable to boundary layer cloud around the globe.

Aydin K., J. Singh, 2004: Cloud ice crystal classification using a 95-GHz polarimetric radar. J. Atmos. Oceanic Technol., 21, 1679- 1688.10.1175/JTECH1671.1

a7b0a4cf-6625-46e6-a476-1558c8e8e605

3d8c5b82a3154860c2302a39ca8a4f83

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F249604509_Cloud_Ice_Crystal_Classification_Using_a_95GHz_Polarimetric_Radar

refpaperuri:(c612c557d246bba531ea3db3d0183c34)

http://www.researchgate.net/publication/249604509_Cloud_Ice_Crystal_Classification_Using_a_95GHz_Polarimetric_RadarAbstract Two algorithms are presented for ice crystal classification using 95-GHz polarimetric radar observables and air temperature ( T ). Both are based on a fuzzy logic scheme. Ice crystals are classified as columnar crystals (CC), planar crystals (PC), mixtures of PC and small- to medium-sized aggregates and/or lightly to moderately rimed PC (PSAR), medium- to large-sized aggregates of PC, or densely rimed PC, or graupel-like snow or small lumpy graupel (PLARG), and graupel larger than about 2 mm (G). The 1D algorithm makes use of Z h , Z dr , LDR hv , and T, while the 2D algorithm incorporates the three radar observables in pairs, ( Z dr , Z h ), (LDR hv , Z h ), and ( Z dr , LDR hv ), plus the temperature T. The range of values for each observable or pair of observables is derived from extensive modeling studies conducted earlier. The algorithms are tested using side-looking radar measurements from an aircraft, which was also equipped with particle probes producing simultaneous and nearly collocated shadow images of cloud ice crystals. The classification results from both algorithms agreed very well with the particle images. The two algorithms were in agreement by 89% in one case and 97% in the remaining three cases considered here. The most effective observable in the 1D algorithm was Z dr , and in the 2D algorithm the pair ( Z dr , Z h ). LDR hv had negligible effect in the 1D classification algorithm for the cases considered here. The temperature T was mainly effective in separating columnar crystals from the rest. The advantage of the 2D algorithm over the 1D algorithm was that it significantly reduced the dependence on T in two out of the four cases.

Brown P. R. A., A. J. Illingworth, A. J. Heymsfield, G. M. McFarquhar, K. A. Browning, and M. Gosset, 1995: The role of spaceborne millimeter-wave radar in the global monitoring of ice cloud. J. Appl. Meteor., 34, 2346- 2366.10.1175/1520-0450(1995)034<2346:TROSMW>2.0.CO;2

9378f3f6-641e-49ee-82b0-8c278aef5eef

812dc4ad605d83370e04908c4ec3e3de

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F249606617_The_Role_of_Spaceborne_Millimeter-Wave_Radar_in_the_Global_Monitoring_of_Ice_Cloud

refpaperuri:(15521550e8c4860534cc1892db9a8f76)

http://www.researchgate.net/publication/249606617_The_Role_of_Spaceborne_Millimeter-Wave_Radar_in_the_Global_Monitoring_of_Ice_CloudAbstract The purpose of this paper is to assess the potential of a spaceborne 94-GHz radar for providing useful measurements of the vertical distribution and water content of ice clouds on a global scale. Calculations of longwave (LW) fluxes for a number of model ice clouds are performed. These are used to determine the minimum cloud optical depth that will cause changes in the outgoing longwave radiation or flux divergence within a cloud layer greatear than 10 W m 612 , and in surface downward LW flux greater than 5 W m 612 , compared to the clear-sky value. These optical depth values are used as the definition of a “radiatively significant” cloud. Different “thresholds of radiative significance” are calculated for each of the three radiation parameters and also for tropical and midlatitude cirrus clouds. Extensive observational datasets of ice crystal size spectra from midlatitude and tropical cirrus are then used to assess the capability of a radar to meet these measurement requirements. A radar with a threshold of 6130 dBZ should detect 99% (92%) of “radiatively significant” clouds in the midlatitudes (Tropics). This detection efficiency may be reduced significantly for tropical clouds at very low temperatures (6180°C). The LW flux calculations are also used to establish the required accuracy within which the optical depth should be known in order to estimate LW fluxes or flux divergence to within specified limits of accuracy. Accuracy requirements are also expressed in terms of ice water content (IWC) because of the need to validate cloud parameterization schemes in general circulation models (GCMs). Estimates of IWC derived using radar alone and also using additional information to define the mean crystal size are considered. With crystal size information available, the IWC for samples with a horizontal scale of 1022 km may be obtained with a bias of less than 8%. For IWC larger than 0.01 g m 613 , the random error is in the range +50% to 6135%, whereas for a value of 0.001 g m 613 the random error increases to between +80% and 6145%. This level of accuracy also represents the best that may be achieved for estimates of the cloud optical depth and meets the requirements derived from LW flux calculations. In the absence of independent particle size information, the random error is within the range +85% to 6155% for IWC greater than 0.01 g m 613 . For the same IWC range, the estimated bias is few than ±15%. This accuracy is sufficient to provide useful constraints on GCM cloud parameteriation schemes.

Clothiaux E. E., M. A. Miller, B. A. Albrecht, T. P. Ackerman, J. Verlinde, D. M. Babb, R. M. Peters, and W. J. Syrett, 1995: An evaluation of a 94-GHz radar for remote sensing of cloud properties. J. Atmos. Oceanic Technol., 12, 201- 229.10.1175/1520-0426(1995)012<0201:AEOAGR>2.0.CO;2

f69d3e54-69a3-4c34-b3ff-7d9994320363

3e1b853e1211287158ccc0a9805968fc

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F234351192_An_Evaluation_of_a_94-GHz_Radar_for_Remote_Sensing_of_Cloud_Properties

refpaperuri:(0009d67011de61962c899e0e7836add1)

http://www.researchgate.net/publication/234351192_An_Evaluation_of_a_94-GHz_Radar_for_Remote_Sensing_of_Cloud_PropertiesAbstract The performance of a 94-GHz radar is evaluated for a variety of cloud conditions. Descriptions of the radar hardware, signal processing, and calibration provide an overview of the radar's capabilities. An important component of the signal processing is the application of two cloud-mask schemes to the data to provide objective estimates of cloud boundaries and to detect significant returns that would otherwise be discarded if a simple threshold method for delectability was applied to the return power. Realistic profiles of atmospheric pressure, temperature, and water vapor are used in a radiative transfer model to address clear-sky attenuation. A physically relevant study of beam extinction and backscattering by clouds is attempted by modeling cloud drop size distributions with a gamma distribution over a range of number concentrations, particle mean diameters, and distribution shape factors; cloud liquid water contents and mean drop size diameters reported in the literature are analyzed in this context. Results of observations of a number of cloud structures, including marine strato- cumulus, cirrus, and stratus and cirrus associated with a midlatitude cyclone are described.

Clothiaux E. E., T. P. Ackerman, G. G. Mace, K. P. Moran, R. T. Marchand , M. A. Miller, and B. E. Martner, 2000: Objective determination of cloud heights and radar reflectivities using a combination of active remote Sensors at the ARM CART Sites. J. Appl. Meteor., 39, 645- 665.3e1820d5-5cc4-4be6-8979-f1394315131f/s?wd=paperuri%3A%283c45307a9ef203f333cce4c6fe06c847%29&filter=sc_long_sign&sc_ks_para=q%3D2000%3A%20Objective%20determination%20of%20cloud%20heights%20and%20radar%20reflectivities%20using%20a%20combination%20of%20active%20remote%20sensors%20at%20the%20ARM%20CART%20sites&tn=SE_baiduxueshu_c1gjeupa&ie=utf-8

Fuller W. H., M. T. Osborn, and W. M. Hunt, 1988: 48-inch lidar aerosol measurements taken at the Langley research center-May 1974 to December 1987. NASA Reference Publication, 1209.e979fe1ed0f23f9bde5f80cb983c9c99

http://www.researchgate.net/publication/24332087_The_48-inch_lidar_aerosol_measurements_taken_at_the_Langley_Research_Center

http://www.researchgate.net/publication/24332087_The_48-inch_lidar_aerosol_measurements_taken_at_the_Langley_Research_CenterABSTRACT This report presents lidar data taken between July 1991 and December 1992 using a ground-based 48-inch lidar instrument at the Langley Research Center in Hampton, Virginia. Seventy lidar profiles (approximately one per week) were obtained during this period, which began less than 1 month after the eruption of the Mount Pinatubo volcano in the Philippines. Plots of backscattering ratio as a function of altitude are presented for each data set along with tables containing numerical values of the backscattering ratio and backscattering coefficient versus altitude. The enhanced aerosol backscattering seen in the profiles highlights the influence of the Mount Pinatubo eruption on the stratospheric aerosol loading over Hampton. The long-term record of the profiles gives a picture of the evolution of the aerosol cloud, which reached maximum loading approximately 8 months after the eruption and then started to decrease gradually. NASA RP-1209 discusses 48-inch lidar aerosol measurements taken at the Langley Research Center from May 1974 to December 1987.

Hogan R. J., A. J. Illingworth, 2000: Deriving cloud overlap statistics from radar. Quart. J. Roy. Meteor. Soc., 126, 2903- 2009.10.1002/qj.49712656914

5362ae66-515d-4197-8be2-3cbacf4b6851

82df4376a5f3eb4ca38f4ec135f8a8f5

http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1002%2Fqj.49712656914%2Ffull

refpaperuri:(b84f82ee3eb58252dd750f91d3c03385)

http://onlinelibrary.wiley.com/doi/10.1002/qj.49712656914/fullABSTRACT The predictions of general-circulation models (GCMs) are sensitive to the assumed cloud overlap within a vertical column of model grid boxes, but until now no reliable observations of the degree of cloud overlap have been available. In this note we derive the overlap characteristics of clouds from 71 days of high vertical resolution 94 GHz cloud radar data in the UK. It is found that, contrary to the assumption made in most models, vertically continuous clouds tend not to be maximally overlapped. Rather, the overlap of clouds at two levels tends to fall rapidly as their vertical separation is increased, and for levels more than 4 km apart, overlap is essentially random. A simple inverse-exponential expression for the degree of overlap as a function of level separation is proposed that could, once results become available from a variety of other locations and seasons, be implemented in current GCMs with relatively little difficulty.

Hollars S., Q. Fu, J. Comstock, and T. Ackerman, 2004: Comparison of cloud-top height retrievals from ground-based 35 GHz MMCR and GMS-5 satellite observations at ARM TWP Manus site. Atmospheric Research, 72, 169- 186.10.1016/j.atmosres.2004.03.015

2de48cb1-a935-4e52-b94b-943de3e4398d

465ca84566f471a8c1b0820a7c9e45f5

http%3A%2F%2Fwww.sciencedirect.com%2Fscience%2Farticle%2Fpii%2FS0169809504000717

refpaperuri:(5aefb6091a1178c156f0f2b27070857d)

http://www.sciencedirect.com/science/article/pii/S0169809504000717Retrievals of cloud-top heights from the ARM 35 GHz Millimeter Wave Cloud Radar (MMCR) located on Manus Island are compared to those from the GMS-5 satellite as a means to evaluate the accuracy of both MMCR and GMS-5 retrievals, as well as to ascertain their limitations. Comparisons are carried out for retrievals of both single-layer and multilayer clouds as seen by radar, but only for satellite-detected clouds with 100% amount within a 0.3 x 0.3degrees domain centered at the ARM site of one cloud type (i.e., low, middle, or high). Mean differences, with 95% confidence limits, between radar- and satellite-retrieved cloud-top heights (i.e., radar-retrieved cloud-top heights-satellite-retrieved cloud-top heights) are 0.3 +/- 0.3 km for single-layer clouds and -0.7 +/- 0.3 km for multilayer clouds. The study reveals that for thick clouds (i.e., cloud base less than or equal to 1 km and cloud thickness greater than or equal to 10 km), which are representative of convective towers with no/light precipitation as well as thick anvil clouds, retrievals from the MMCR agree well with those from satellite with mean differences of 0.0 +/- 0.4 and -0.2 +/- 0.3 km for single-layer and multilayer clouds, respectively. For clouds of lesser thickness, mean cloud-top heights derived from satellite are lower than those derived from radar by as much as 2.0 km. It is also shown that for convective clouds with heavy precipitation, MMCR retrievals underestimate the cloud-top heights significantly. (C) 2004 Elsevier B.V. All rights reserved.

Illingworth, A. J., Coauthors, 2007: Cloudnet. Bull. Amer. Meteor. Soc., 88, 883- 898.10.1175/BAMS-88-6-883

28bcb2b3-8c5b-45f5-9511-667d44cdd162

66db9286b9e93d844da1ede0ec238ef4

http://www.researchgate.net/publication/216674059_Cloudnet_-_Continuous_evaluation_of_cloud_profiles_in_seven_operational_models_using_ground-based_observations?ev=prf_cit

http://www.researchgate.net/publication/216674059_Cloudnet_-_Continuous_evaluation_of_cloud_profiles_in_seven_operational_models_using_ground-based_observations?ev=prf_citAbstract The Cloudnet project aims to provide a systematic evaluation of clouds in forecast and climate models by comparing the model output with continuous ground-based observations of the vertical profiles of cloud properties. In the models, the properties of clouds are simplified and expressed in terms of the fraction of the model grid box, which is filled with cloud, together with the liquid and ice water content of the clouds. These models must get the clouds right if they are to correctly represent both their radiative properties and their key role in the production of precipitation, but there are few observations of the vertical profiles of the cloud properties that show whether or not they are successful. Cloud profiles derived from cloud radars, ceilometers, and dual-frequency microwave radiometers operated at three sites in France, Netherlands, and the United Kingdom for several years have been compared with the clouds in seven European models. The advantage of this continuous appraisal is that the feedback on how new versions of models are performing is provided in quasieal time, as opposed to the much longer time scale needed for in-depth analysis of complex field studies. Here, two occasions are identified when the introduction of new versions of the ECMWF and Mto-France models leads to an immediate improvement in the representation of the clouds and also provides statistics on the performance of the seven models. The Cloudnet analysis scheme is currently being expanded to include sites outside Europe and further operational forecasting and climate models.

Kent G. S., S. K. Schaffner, 1988: Analysis of atmospheric dynamics and radiative properties for understanding weather and climate, task 1, 10 \upmum backscatter modeling. STC Tech. Rep. 2175, prepared for NASA under contract NAS1-18252.

Kneifel S., M. Maahn, G. Peters, and C. Simmer, 2011: Observation of snowfall with a low-power FM-CW K-band radar (Micro Rain Radar). Meteor. Atmos. Phys., 113, 75- 87.10.1007/s00703-011-0142-z

d8ceb000-1f03-4ab2-b995-1a5265e773ea

0c30fa55869ceac7e10b7a9c15ccb933

http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fb2100mqrr7033570%2F

refpaperuri:(73b288e359ef988816824806a093352d)

http://www.springerlink.com/content/b2100mqrr7033570/Quantifying snowfall intensity especially under arctic conditions is a challenge because wind and snow drift deteriorate estimates obtained from both ground-based gauges and disdrometers. Ground-based remote sensing with active instruments might be a solution because they can measure well above drifting snow and do not suffer from flow distortions by the instrument. Clear disadvantages are, however, the dependency of e.g. radar returns on snow habit which might lead to similar large uncertainties. Moreover, high sensitivity radars are still far too costly to operate in a network and under harsh conditions. In this paper we compare returns from a low-cost, low-power vertically pointing FM-CW radar (Micro Rain Radar, MRR) operating at 24.1 GHz with returns from a 35.5 GHz cloud radar (MIRA36) for dry snowfall during a 6-month observation period at an Alpine station (Environmental Research Station Schneefernerhaus, UFS) at 2,650 m height above sea level. The goal was to quantify the potential and limitations of the MRR in relation to what is achievable by a cloud radar. The operational MRR procedures to derive standard radar variables like effective reflectivity factor ( Z) or the mean Doppler velocity ( W) had to be modified for snowfall since the MRR was originally designed for rain observations. Since the radar returns from snowfall are weaker than from comparable rainfall, the behavior of the MRR close to its detection threshold has been analyzed and a method is proposed to quantify the noise level of the MRR based on clear sky observations. By converting the resulting MRR- Z into 35.5 GHz equivalent Z values, a remaining difference below 1 dBz with slightly higher values close to the noise threshold could be obtained. Due to the much higher sensitivity of MIRA36, the transition of the MRR from the true signal to noise can be observed, which agrees well with the independent clear sky noise estimate. The mean Doppler velocity differences between both radars are below 0.3 ms. The distribution of Z values from MIRA36 are finally used to estimate the uncertainty of retrieved snowfall and snow accumulation with the MRR. At UFS low snowfall rates missed by the MRR are negligible when comparing snow accumulation, which were mainly caused by intensities between 0.1 and 0.8 mm h. The MRR overestimates the total snow accumulation by about 7%. This error is much smaller than the error caused by uncertain Z-snowfall rate relations, which would affect the MIRA36 estimated to a similar degree.

Kobayashi F., T. Takano, and T. Takamura, 2011: Isolated cumulonimbus initiation observed by 95-GHz FM-CW radar, X-band radar, and photogrammetry in the Kanto region, Japan. SOLA, 7, 125- 128.10.2151/sola.2011-032

b44895cb-1497-4588-950e-bc4cbebb66f6

f923923b9c53a142b56acc763ef087e6

http%3A%2F%2Fci.nii.ac.jp%2Fnaid%2F130004448546

refpaperuri:(91487b4b30eb13bbc4d226c76f4097a4)

http://ci.nii.ac.jp/naid/130004448546Simultaneous observations of cumulonimbi using the 95-GHz FM-CW cloud radar, the X-band radar, and photogrammetry were carried out during the summer of 2010 in the Kanto region, Japan. An isolated cumulonimbus developed above the cloud radar site after 16:00 Japan Standard Time (JST) on 24 July 2010. A continuous generation of turrets was observed and a total of four turrets formed. The growth rates of the turrets were quite different. The first radar echo of the X-band radar was detected at 3 km above ground level (AGL), three minutes after turret 1 reached its maximum height. Turret 2, generated above the cloud radar, reached 10 km AGL and had a growth rate of 8 m s-1. The cloud radar detected echoes approximately two minutes after the generation of turret 2. The intermittent echo pattern observed by the cloud radar denotes fine structures in the cumulonimbus.

Kollias P., E. E. Clothiaux, M. A. Miller, B. A. Albrecht, G. L. Stephens, and T. P. Ackerman, 2007a: Millimeter-wavelength radars: New frontier in atmospheric cloud and precipitation research. Bull. Amer. Meteor. Soc., 88, 1608- 1624.10.1175/BAMS-88-10-1608

f55fe536-0798-476d-a82d-c99ca2060088

4ec07a674f0409ee1a21a372702eb0bb

http://www.researchgate.net/publication/228666652_Millimeter-Wavelength_Radars_New_Frontier_in_Atmospheric_Cloud_and_Precipitation_Research

http://www.researchgate.net/publication/228666652_Millimeter-Wavelength_Radars_New_Frontier_in_Atmospheric_Cloud_and_Precipitation_ResearchAbstract During the past 20 yr there has been substantial progress on the development and application of millimeter-wavelength (3.2 and 8.6 mm, corresponding to frequencies of 94 and 35 GHz) radars in atmospheric cloud research, boosted by continuous advancements in radar technology and the need to better understand clouds and their role in the Earth's climate. Applications of millimeter-wavelength radars range from detailed cloud and precipitation process studies to long-term monitoring activities that strive to improve our understanding of cloud processes over a wide range of spatial and temporal scales. These activities are the result of a long period of successful research, starting from the 1980s, in which research tools and sophisticated retrieval techniques were developed, tested, and evaluated in field experiments. This paper presents a cohesive, chronological overview of millimeter-wavelength radar advancements during this period and describes the potential of new applications of millimeter-wavelength radars on sophisticated platforms and the benefits of both lower- and higher-frequency radars for cloud and precipitation research.

Kollias P., G. Tselioudis, and B. A. Albrecht, 2007b: Cloud climatology at the Southern Great Plains and the layer structure, drizzle, and atmospheric modes of continental stratus. J. Geophys. Res., 112,D09116, doi: 10.1029/2006JD007307.10.1029/2006JD007307

89c6a496-d9f5-4365-a775-22064b9c7afb

678e1fe7495c0cfefa1a243a2780e740

http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1029%2F2006JD007307%2Fabstract

refpaperuri:(3ff07ffc8d97f7141ff4cec778d5904b)

http://onlinelibrary.wiley.com/doi/10.1029/2006JD007307/abstract[1] Long-term (6.5 years) cloud observations from the Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) climate research facility in Oklahoma are used to develop detailed cloud climatology. Clouds are classified with respect to their altitude (low, middle, and high), vertical development, and the presence of multilayer clouds. Single-layered cirrus, middle or low clouds were observed a total of 23% of the time the MilliMeter Cloud Radar (MMCR) was operating, and multilayer clouds were observed 20.5% of the time. Boundary layer clouds exhibit the strongest seasonal variability because of continental stratus associated with midlatitude frontal systems. Cirrus clouds are the most frequently observed cloud type and exhibit strong seasonal variability in cloud base height (higher cloud base during the summer months) and relatively constant cloud fraction. The majority of middle-level clouds are shallow with vertical extent less than 1 km. No strong seasonal cycle in the fractional coverage of multilayer clouds is observed. Continental stratus clouds exhibit strong seasonal variability with maximum occurrence during the cold seasons. Nondrizzling stratus clouds exhibit a bimodal seasonal variability with maximum occurrences in the fall and spring, while drizzling stratus occur most frequently in the winter. Thermodynamic and dynamic variables from soundings and the European Centre for Medium-Range Weather Forecasts Model (ECMWF) analyses at the SGP site illustrate an interesting coupling between strong large-scale forcing and the formation of single-layered (no other cloud layer is present) continental stratus clouds. Single-layered stratus clouds (drizzling and nondrizzling) exhibit a strong correlation with positive at 500 mbar and strong northerly flow.

Mace G. G., C. Jakob, and K. P. Moran, 1998: Validation of hydrometeor occurrence predicted by the ECMWF model using millimeter wave radar data. Geophys. Res. Lett., 25, 1645- 1648.10.1029/98GL00845

b629ac84-2cae-4f9e-8540-b5f92bea020a

7b4aaf2a74da68641b7e0df8026a46b9

http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1029%2F98GL00845%2Fabstract

refpaperuri:(e45e5d101945904f1e5928742ab97599)

http://onlinelibrary.wiley.com/doi/10.1029/98GL00845/abstractABSTRACT Validation of hydrometeor prediction by global models is an important issue as it pertains to the accuracy of climate predictions. In this study we use data from a continuously operating millimeter wave radar at a research site in north central Oklahoma, USA to validate output from the operational ECMWF forecast model. We demonstrate that the ECMWF model shows good overall skill at predicting the vertical distribution of the clouds and precipitation that occurred over this site during winter 1997. However, we also show that the model tended to predict the onset of deep cloud events too soon, made the layers too deep and predicted dissipation somewhat later than observed.

METRI/KMA, 2009: Development of meteorological data processing system of communication, ocean and meteorological satellite. 846 pp.

Moran K. P., B. E. Martner, M. J. Post, R. A. Kropfli, D. C. Welsh, and K. B. Widener, 1998: An unattended cloud-profiling radar for use in climate research. Bull. Amer. Meteor. Soc., 79, 443- 455.10.1175/1520-0477(1998)079<0443:AUCPRF>2.0.CO;2

b2c09796-6864-47a8-934f-588f1d9f42e8

88b4ba46aabc493aeeb31cb98bc0e7f8

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F253533024_An_Unattended_Cloud-Profiling_Radar_for_Use_in_Climate_Research

refpaperuri:(07b869bf0142341037a9298275b42b44)

http://www.researchgate.net/publication/253533024_An_Unattended_Cloud-Profiling_Radar_for_Use_in_Climate_ResearchPresents a study utilizing a millimeter-wave cloud radar (MMCR) for observations in climate research. Description of MMCR; Application of the radar; Indication of the study; Discussion on findings.

O'Connor, E. J., R. J. Hogan, A. J. Illingworth, 2005: Retrieving stratocumulus drizzle parameters using Doppler radar and lidar. J. Appl. Meteor., 44, 14- 27.10.1175/JAM-2181.1

3e760ea2-2294-49ff-a86d-a416ff02f36a

c077a264840d35e2bc0332ee4e263f7b

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F43155443_Retrieving_stratocumulus_drizzle_parameters_using_Doppler_radar_and_lidar

refpaperuri:(dc07849fac8f15301074072fa8296e82)

http://www.researchgate.net/publication/43155443_Retrieving_stratocumulus_drizzle_parameters_using_Doppler_radar_and_lidarABSTRACT Stratocumulus is one of the most common cloud types globally, with a profound effect on the earth's radiation budget, and the drizzle process is fundamental in understanding the evolution of these boundary layer clouds. In this paper a combination of 94-GHz Doppler radar and backscatter lidar is used to investigate the microphysical properties of drizzle falling below the base of stratocumulus clouds. The ratio of the radar to lidar backscatter power is proportional to the fourth power of mean size, and so potentially it can provide an accurate size estimate. Information about the shape of the drop size distribution is then inferred from the Doppler spectral width. The algorithm estimates vertical profiles of drizzle parameters such as liquid water content, liquid water flux, and vertical air velocity, assuming that the drizzle size spectrum may be represented by a gamma distribution. The depletion time scale of cloud liquid water through the drizzle process can be estimated when the liquid water path of the cloud is available from microwave radiometers, and observations suggest that this time scale varies from a few days in light drizzle to a few hours in strong drizzle events. Radar and lidar observations from Chilbolton (in southern England) and aircraft size spectra taken during the Atlantic Stratocumulus Transition Experiment have both been used to derive the following power-law relationship between liquid water flux (LWF) (g m-2 s-1) and radar reflectivity (Z) (mm6 m-3): LWF = 0.0093Z0.69. This relation is valid for frequencies up to 94 GHz and therefore would allow a forthcoming spaceborne radar to measure liquid water flux around the globe to within a factor of 2 for values of Z above -20 dBZ.

Oh S. B., H. Y. Won, J. C. Ha, and K. Y. Chung, 2014: Comparison of cloud top height observed by a Ka-band cloud radar and COMS. Atmosphere, 24, 39- 48. (in Korean)

Sakurai N., K. Iwanami, T. Maesaka, S. I. Suzuki, S. Shimizu, R. Misumi, D. S. Kim, and M. Maki, 2012: Case study of misoscale convective echo behavior associated with cumulonimbus development observed by Ka-band Doppler radar in the Kanto region, Japan.SOLA, 8, 107- 110.10.2151/sola.2012-027

f64a5987-e609-44e5-801e-6b2a16fc464d

f0e78beb12d27ba436ded05f0f5d4cdf

http://www.researchgate.net/publication/273668341_Case_Study_of_Misoscale_Convective_Echo_Behavior_Associated_with_Cumulonimbus_Development_Observed_by_Ka-band_Doppler_Radar_in_the_Kanto_Region_Japan

http://www.researchgate.net/publication/273668341_Case_Study_of_Misoscale_Convective_Echo_Behavior_Associated_with_Cumulonimbus_Development_Observed_by_Ka-band_Doppler_Radar_in_the_Kanto_Region_JapanSimultaneous observations of cumulonimbi by a Ka-band Doppler radar (KaDR) and an X-band polarimetric Doppler radar (MP-X) were performed during the summer of 2011 in the Kanto region, Japan to study the process of cumulonimbus initiation and development. A cumulonimbus developed up to 12 km above sea level (ASL) in the mountainous western part of the Kanto region on the morning of 18 August 2011, and its initiation and development were observed by the two radars. A misoscale convective echo which was newly detected in an RHI or PPI scan and developed vertically (RHI scan) or spatially (PPI scan) was labeled as a 'new misoscale convective echo' (NMCE). In the developing stage (DS), NMCEs occurred one after another, and the echo top height and maximum reflectivity of each individual echo gradually increased. In the first half of the DS, the NMCEs appeared between 2 and 5 km ASL. In contrast, in the second half of the DS, the NMCEs' appearance height stepped up to between 5 and 12 km ASL. These results suggest that the ascent of NMCE appearance height is one of the key factors in the prediction of deep convection, which later causes localized heavy rainfall.

Stokes G. M., S. E. Schwartz, 1994: The Atmospheric Radiation Measurement (ARM) Program: Programmatic Background and Design of the Cloud and Radiation Test Bed. Bull. Amer. Meteor. Soc., 75, 1201- 1221.10.1175/1520-0477(1994)0752.0.CO;2

f38e199a-2545-497d-9dbf-1886808898fd

cb559e9e853bfdaee1ca96431bd47f95

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F230889816_The_Atmospheric_Radiation_Measurement_%28ARM%29_Program_Programmatic_background_design_of_the_cloud_and_radiation_test_bed

refpaperuri:(dda3011ad4949adc7c4553aa7d98341a)

http://www.researchgate.net/publication/230889816_The_Atmospheric_Radiation_Measurement_(ARM)_Program_Programmatic_background_design_of_the_cloud_and_radiation_test_bedThe Atmospheric Radiation Measurement (ARM) Program, supported by the U.S. Department of Energy, is a major new program of atmospheric measurement and modeling. The program is intended to improve the understanding of processes that affect atmospheric radiation and the description of these processes in climate models. An accurate description of atmospheric radiation and its interaction with clouds and cloud processes is necessary to improve the performance of and confidence in models used to study and predict climate change. The ARM Program will employ five (this paper was prepared prior to a decision to limit the number of primary measurement sites to three) highly instrumented primary measurement sites for up to 10 years at land and ocean locations, from the Tropics to the Arctic, and will conduct observations for shorter periods at additional sites and in specialized campaigns. Quantities to be measured at these sites include longwave and shortwave radiation, the spatial and temporal distribution of clouds, water vapor, temperature, and other radiation-influencing quantities. There will be further observations of meterological variables that influence these quantities, including wind velocity, precipitation rate, surface moisture, temperature, and fluxes of sensible and latent heat. These data will be used for the prospective testing of more models of varying complexity, ranging from detailed process models to the highly parameterized description of these processes for use in general circulation models of the earth's atmosphere. This article reviews the scientific background of the ARM Program, describes the design of the program, and presents its status and plans. 31 refs., 4 figs., 5 tabs. less

Syrett W. J., B. A. Albrecht, and E. E. Clothiaux, 1995: Vertical cloud structure in a midlatitude cyclone from a 94-GHz radar. Mon. Wea. Rev., 123, 3393- 3407.10.1175/1520-0493(1995)123<3393:VCSIAM>2.0.CO;2

ac23d3d9-fc5f-4129-86f8-0581701b4ef8

98d341bfc86e5b93af3e01943815fbe5

http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F249620705_Vertical_Cloud_Structure_in_a_Midlatitude_Cyclone_from_a_94GHz_Radar

refpaperuri:(f6ece916aabc0396addfccb5ff9e7045)

http://www.researchgate.net/publication/249620705_Vertical_Cloud_Structure_in_a_Midlatitude_Cyclone_from_a_94GHz_RadarThe vertical structure of clouds associated with a developing midlatitude cyclone was studied using a 94-GHz cloud radar accompanied by a host of other surface-based instruments and rawinsondes. A thickening cirrostratus deck was observed as the storm approached. As the storm drew near, low-level moisture advection increased, and a drizzle-producing stratus deck quickly developed. A rather lengthy period of light to occasionally moderate rain accompanied the passage of the storm. When the storm pulled away to the northeast and the rain ended, the character of the stratus deck changed markedly, with no drizzle production evident. Other cloud features observed included generating cells and their resultant fallstreaks and an eye that apparently accompanied the passage of a negatively tilted upper-level trough, as evidenced by measurements from a 50-MHz wind profiler located near the cloud radar. Rawinsonde measurements showed that the cloud radar also traced the descent of the melting layer. Satellite observations indicated that attenuation often limited the ability of the radar to detect cloud top when precipitation was occurring. As a result, the radar-reported cloud tops were 2-5 km lower than those indicated from the satellite cloud-top temperatures during the heaviest precipitation. During very light precipitation and precipitation-free periods, the satellite brightness temperatures yielded slight underestimates of cloud-top height. In spite of the attenuation, the cloud radar revealed many detailed structures of the clouds of a fairly typical midlatitude cyclone and captured the entire 3-day event.

Widener K. B., J. B. Mead, 2004: W-band ARM cloud radar-Specifications and design. Proc. 14th ARM Science Team Meeting, Albuquerque, NM, Department of Energy/Office of Science. [Available online at http://www.arm.gov/\!publications/proceedings/conf14/.]9cd5acec0f409b68561aadbc23234eb1

http://www.researchgate.net/publication/228875580_W-Band_ARM_cloud_radarSpecifications_and_design

http://www.researchgate.net/publication/228875580_W-Band_ARM_cloud_radarSpecifications_and_designABSTRACT The Atmospheric Radiation Measurement (ARM) Program and ProSensing, Inc. have teamed to develop and deploy the W-band ARM Cloud Radar (WACR) at the SGP central facility. The WACR will be co-located with the ARM millimeter wave cloud radar (MMCR) with planned operation to begin in early 2005. This radar will complement the measurements of the MMCR and will aid in filtering out insect contamination in the data. In this poster we present the design goals, expected performance characteristics, and the detailed design for the WACR.

Xi B. K., X. Q. Dong, P. Minnis, and M. M. Khaiyer, 2010: A 10 year climatology of cloud fraction and vertical distribution derived from both surface and GOES observations over the DOE ARM SGP site. J. Geophys. Res., 115,D12124, doi: 10.1029/2009JD012800.10.1029/2009JD012800

ed9e337e-9a37-40e2-8418-f666e3840320

c8b860c8be7908a849c132a0a20e0c82

http://onlinelibrary.wiley.com/doi/10.1029/2009JD012800/pdf

http://onlinelibrary.wiley.com/doi/10.1029/2009JD012800/pdfABSTRACT Analysis of one decade of radar-lidar and Geostationary Operational Environmental Satellite (GOES) observations at the Department of Energy (DOE) Atmospheric Radiation Measurement Program (ARM) Southern Great Plains (SGP) site reveals that there is excellent agreement in the long-term mean cloud fractions (CFs) derived from the surface and GOES data, and the CF is independent of temporal resolution and spatial scales for grid boxes of size 0.5 to 2.5. When computed over a a 0.5 h (4 h) period, cloud frequency of occurrence (FREQ) and amount when present (AWP) derived from the point surface data agree very well with the same quantities determined from GOES for a 0.5 (2.5) region centered on the DOE ARM SGP site. The values of FREQ (AWP) derived from the radar-lidar observations at a given altitude increase (decrease) as the averaging period increases from 5 min to 6 h. Similarly, CF at a given altitude increases as the vertical resolution increases from 90 to 1000 m. The profiles of CF have distinct bimodal vertical distributions, with a lower peak between 1 and 2 km and a higher one between 8 and 11 km. The 10 year mean total CF, 46.9%, varies seasonally from a summer minimum of 39.8% to a maximum of 54.6% during the winter. The annual mean CF is 1%-2% less than that from previous studies, &tilde;48%-49%, because fewer clouds occurred during 2005 and 2006, especially during winter. The differences in single- and multilayered CFs between this study and an earlier analysis can be explained by the different temporal resolutions used in the two studies, where single-layered CFs decrease but multilayered CFs increase from a 5 min resolution to a 1 h resolution. The vertical distribution of nighttime GOES high cloud tops agrees well with surface observations, but during the daytime, fewer high clouds are retrieved by the GOES analysis than seen from the surface observations. The FREQs for both daytime and nighttime GOES low cloud tops are significantly higher than surface observations, but the CFs are in good agreement.

Yum S. S., S. N. Oh, J. Y. Kim, C. K. Kim, and J. C. Nam, 2004: Measurements of cloud droplet size spectra using a forward scattering spectrometer probe (FSSP) in the Korean peninsula, Journal of the Korean Meteorological Society, 40, 623- 631 (in Korean).0fa11215-a0a2-40b2-a795-ba4cf296b49c

4d7d26b4b9eddda3a8520606b41c699e

http://www.dbpia.co.kr/Article/773654

http://www.dbpia.co.kr/Article/773654Forward Scattering Spectrometer Probe (FSSP) is a basic and essential instrument for in-situ measurements of cloud droplet (diameter ＜ 50 97) size distributions. As a first step towards understanding microphysical characteristics of Korean clouds for the project, Weather Modification Technique in Korea, one of the Research and Development on Meteorology and Seismology funded by the Korea Meteorological Administration, an FSSP system is imported in 2003. Measurement of cloud droplet spectra started in November 2003 at Daegwallyeong Weather Station (elevation above sea level of 840 m), which becomes the first time in Korean history to make an in-situ measurement of cloud microphysics. There are four size range settings for the FSSP and each of them is attempted. The usual size range setting of range 0 (2-47 97) for aircraft cloud droplet measurements seems to be too large for the small cloud droplets at the near cloud base altitudes such as Daegwallyeong Weather Station and lead to under-counting of activated but small (diameter ＜ 2 97) cloud droplets. Range 2 (1-16 97) is used for the temporary measurement at Anmyeon Korea Global Atmospheric Watch Observatory (KGAWO) (elevation above sea level of about 55 m) and seems to be an appropriate size range setting for the cloud/fog droplets at this place. The measured peak concentration of about 800 cm-3 is somewhat higher than typical peak cloud droplet concentration of continental clouds measured in some other places in the world.

Zhong L. Z., L. P. Liu, S. Feng, R. Ge, and Z. Zhang, 2011: A 35-GHz polarimetric Doppler radar and its application for observing clouds associated with typhoon Nuri. Adv. Atmos. Sci.,28, 945-956, doi: 10.1007/s00376-010-0073-5.

Zhong L. Z., L. P. Liu, M. Deng, and X. Zhou, 2012: Retrieving microphysical properties and air motion of cirrus clouds based on the Doppler moments method using cloud radar. Adv. Atmos. Sci.,29, 611-622, doi: 10.1007/s00376-011-0112-x.10.1007/s00376-011-0112-x

e1c30e0c-2e87-44c1-b589-241f6be9f301

4f09c8d8a52082e6325324d95a542bd3

http%3A%2F%2Fwww.springerlink.com%2Fopenurl.asp%3Fid%3Ddoi%3A10.1007%2Fs00376-011-0112-x

refpaperuri:(328adec6aea48fce0cf73d4577b5ef1e)

http://d.wanfangdata.com.cn/Periodical_dqkxjz-e201203017.aspxRadar parameters including radar reflectivity, Doppler velocity, and Doppler spectrum width were obtained from Doppler spectrum moments. The Doppler spectrum moment is the convolution of both the particle spectrum and the mean air vertical motion. Unlike strong precipitation, the motion of particles in cirrus clouds is quite close to the air motion around them. In this study, a method of Doppler moments was developed and used to retrieve cirrus cloud microphysical properties such as the mean air vertical velocity, mass-weighted diameter, effective particle size, and ice content. Ice content values were retrieved using both the Doppler spectrum method and classic Z -IWC (radar reflectivity-ice water content) relationships; however, the former is a more reasonable method.