doi:10.1007/s00376-017-7028-z

Allan R., T. Ansell, 2006: A new globally complete monthly historical gridded mean sea level pressure dataset (HadSLP2): 1850-2004.J. Climate,19,5816-5842, https://doi.org/10.1175/JCLI3937.1.

10.1175/JCLI3937.1

d44c3a0167c2587043914d0ce0b1b468

http%3A%2F%2Fwww.readcube.com%2Farticles%2F10.1175%2FJCLI3937.1

http://journals.ametsoc.org/doi/abs/10.1175/JCLI3937.1An upgraded version of the Hadley Centre's monthly historical mean sea level pressure (MSLP) dataset (HadSLP2) is presented. HadSLP2 covers the period from 1850 to date, and is based on numerous terrestrial and marine data compilations. Each terrestrial pressure series used in HadSLP2 underwent a series of quality control tests, and erroneous or suspect values were either corrected, where possible, or removed. Marine observations from the International Comprehensive Ocean Atmosphere Data Set were quality controlled (assessed against climatology and near neighbors) and then gridded. The final gridded form of HadSLP2 was created by blending together the processed terrestrial and gridded marine MSLP data. MSLP fields were made spatially complete using reduced-space optimal interpolation. Gridpoint error estimates were also produced. HadSLP2 was found to have generally stronger subtropical anticyclones and higher-latitude features across the Northern Hemisphere than an earlier product (HadSLPI). During the austral winter, however, it appears that the pressures in the southern Atlantic and Indian Ocean midlatitude regions are too high; this is seen in comparisons with both HadSLP1 and the 40-yr ECMWF Re-Analysis (ERA-40). Over regions of high altitude, HadSLP2 and ERA-40 showed consistent differences suggestive of potential biases in the reanalysis model, though the region over the Himalayas in HadSLP2 is biased compared with HadSLP1 and improvements are required in this region. Consistent differences were also observed in regions of sparse data, particularly over the higher latitudes of the Southern Ocean and in the southeastern Pacific. Unlike the earlier HadSLP1 product, error estimates are available with HadSLP2 to guide the user in these regions of low confidence. An evaluation of major phenomena in the climate system using HadSLP2 provided further validation of the dataset. Important climatic features/indices such as the North Atlantic Oscillation, Arctic Oscillation, North Pacific index, Southern Oscillation index, Trans-Polar index, Antarctic Oscillation, Antarctic Circumpolar Wave, East Asian Summer Monsoon index, and the Siberian High index have all been resolved in HadSLP2, with extensions back to the mid-nineteenth century.

Andrews D. G., 1987: On the interpretation of the eliassen-palm flux divergence.Quart. J. Roy. Meteor. Soc.,113(475),323-338, https://doi.org/10.1002/qj.49711347518.

10.1002/qj.49711347518

27c3328c114ccb3e5c3386d3944e5c9f

http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1002%2Fqj.49711347518%2Ffull

http://doi.wiley.com/10.1002/qj.49711347518New expressions are presented for the wave-activity density and the non-conservative source of wave activity in the small amplitude Eliassen-Palm theorem for the primitive equations in log(pressure) and isentropic coordinates. These expressions involve Ertel's potential vorticity, and include versions that are of Eulerian form.The theoretical results are used as a basis for investigating the interpretation of the Eliassen-Palm flux divergence in terms of physical wave properties. Implications for modelling and observational studies of planetary waves are discussed and connections with stability theory and the definition of orthogonality of normal modes are mentioned.

Castanheira J. M., H.-F. Graf, 2003: North Pacific-North Atlantic relationships under stratospheric control? J.Geophys. Res.,108,ACL 11-1-ACL 11-10, https://doi.org/10.1029/2002JD002754.

10.1029/2002JD002754

2071cb28929f7e3a11dcdee0d0d07743

http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1029%2F2002JD002754%2Ffull

http://adsabs.harvard.edu/abs/2002EGSGA..27.6603CAn analysis of monthly mean atmospheric sea level pressure data from NCEP reanal- ysis (1948-2000) shows a significant anticorrelation between pressure in the northern North Atlantic and North Pacific only if the stratospheric circulation is in the "strong polar vortex" regime, but not when the vortex is weak. Since general circulation mod- els in most cases are biased towards the strong vortex regime, they tend to reproduce this anticorrelation already in the mean. This allows an explanation for the results of some works that obtain a correlation between PNA and NAO greater in simulation experiments than in the observations.

Dickinson R. E., 1968: Planetary Rossby waves propagating vertically through weak westerly wind wave guides. J. Atmos. Sci., 25, 984-1002, https://doi.org/10.1175/1520-0469 (1968)025<0984:PRWPVT>2.0,CO;2.

10.1175/1520-0469(1968)0252.0.CO;2

23bbe7d8816e1025b52805db03a4fcec

http%3A%2F%2Fadsabs.harvard.edu%2Fabs%2F1968JAtS...25..984D

http://journals.ametsoc.org/doi/abs/10.1175/1520-0469%281968%29025%3C0984%3APRWPVT%3E2.0.CO%3B2The role of horizontal wind shears in the vertical propagation of planetary Rossby waves is investigated using an adiabatic linear model. We discuss wave guides formed by regions of weak westerly wind. If the wave guide is formed by trapping of waves between strong westerlies and/or the geometric poles, the ducting occurs as a wave propagation in discrete normal modes of the internal wave guide. On the other hand, for wave guides formed by one or more lines of zero wind, waves are absorbed rather than reflected at the zero wind line so that there are no normal modes of the wave guide. Disturbances excited in the lower stratosphere in the equatorial zero wind wave guide will terminate somewhere in the equatorial stratosphere, but eddy motions may be maintained in the tropics at higher levels by leakage from the Aleutian high planetary wave propagating vertically in a polar wave guide. The Aleutian high should he significantly attenuated by such leakage. The theory of zero wind line absorption suggests a planetary wave coupling with the biennial oscillation.

Garreaud R. D., 2007: Precipitation and circulation covariability in the extratropics.J. Climate,20(18),4789-4797, https://doi.org/10.1175/JCLI4257.1.

10.1175/JCLI4257.1

f018095afeec8e0874e0af1ecd7454a8

http%3A%2F%2Fadsabs.harvard.edu%2Fabs%2F2007JCli...20.4789G

http://journals.ametsoc.org/doi/abs/10.1175/JCLI4257.1Extratropical precipitation is primarily produced by cold and warm fronts associated with surface cyclones and upper-level troughs. The growth of these midlatitude storms is partially controlled by the dry baroclinicity of the troposphere, which in turn can be roughly quantified by the intensity of the upper-level zonal flow. Orographic rainfall, an important component of the precipitation in several midlatitude regions, is also partially determined by the intensity of the cross-mountain midlevel winds. Thus, at monthly and longer time scales, variations of precipitation and zonal flow aloft (as well as wind shear) at a given location should exhibit some degree of coherence. In this work the local covariability of these variables is documented over intermonthly and interannual time scales, using global precipitation products and atmospheric reanalysis from 1979 to 2004. The spatial correspondence between the precipitation and two indices of synoptic activity in the extratropics is also documented. The local correlation (r0) between monthly anomalies of precipitation and upper-level (300 hPa) zonal flow varies in space, from moderately and even highly significant values (r0 090304 0.3 to 0.7) over the midlatitude oceans to near zero over the interior of continental areas. Broadly similar results are found when considering the monthly variance of the high-pass-filtered meridional wind (an index of eddy activity) or the midlevel Eady growth rate. The local correlation map between precipitation and low-level (850 hPa) zonal flow is similar to its upper-level counterpart, but the correlations over open ocean are somewhat weaker, while orographic effects show up more clearly. The correlations are positive and large upstream of the major north09“south-oriented mountain ranges, as strong westerlies promote upslope rain in addition to storm-related precipitation. In contrast, the correlation tends to be negative downstream of the ranges, as strong westerlies enhance the rain shadow effects over the lee side.

Häkkinen, S., P. B. Rhines, D. L. Worthen, 2011: Atmospheric blocking and Atlantic Multidecadal Ocean variability.Science,334,655-659, https://doi.org/10.1126/science.1205683.

10.1126/science.1205683

22053046

6e18240803eb40f14feb04f620393b08

http%3A%2F%2Fwww.jstor.org%2Fstable%2F41351640

http://www.sciencemag.org/cgi/doi/10.1126/science.1205683Abstract Atmospheric blocking over the northern North Atlantic, which involves isolation of large regions of air from the westerly circulation for 5 days or more, influences fundamentally the ocean circulation and upper ocean properties by affecting wind patterns. Winters with clusters of more frequent blocking between Greenland and western Europe correspond to a warmer, more saline subpolar ocean. The correspondence between blocked westerly winds and warm ocean holds in recent decadal episodes (especially 1996 to 2010). It also describes much longer time scale Atlantic multidecadal ocean variability (AMV), including the extreme pre-greenhouse-gas northern warming of the 1930s to 1960s. The space-time structure of the wind forcing associated with a blocked regime leads to weaker ocean gyres and weaker heat exchange, both of which contribute to the warm phase of AMV.

Harris I., P. D. Jones, T. J. Osborn, and D. H. Lister, 2014: Updated high-resolution grids of monthly climatic observations-the CRU TS3.10 Dataset. International Journal of Climatology,34(3),623-642, https://doi.org/10.1002/joc.3711.

10.1002/joc.3711

e2795603b39ca772a29510810a516f17

http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1002%2Fjoc.3711%2Fpdf

http://doi.wiley.com/10.1002/joc.3711This paper describes the construction of an updated gridded climate dataset (referred to as CRU TS3.10) from monthly observations at meteorological stations across the world's land areas. Station anomalies (from 1961 to 1990 means) were interpolated into 0.5º latitude/longitude grid cells covering the global land surface (excluding Antarctica), and combined with an existing climatology to obtain absolute monthly values. The dataset includes six mostly independent climate variables (mean temperature, diurnal temperature range, precipitation, wet-day frequency, vapour pressure and cloud cover). Maximum and minimum temperatures have been arithmetically derived from these. Secondary variables (frost day frequency and potential evapotranspiration) have been estimated from the six primary variables using well-known formulae. Time series for hemispheric averages and 20 large sub-continental scale regions were calculated (for mean, maximum and minimum temperature and precipitation totals) and compared to a number of similar gridded products. The new dataset compares very favourably, with the major deviations mostly in regions and/or time periods with sparser observational data. CRU TS3.10 includes diagnostics associated with each interpolated value that indicates the number of stations used in the interpolation, allowing determination of the reliability of values in an objective way. This gridded product will be publicly available, including the input station series (http://www.cru.uea.ac.uk/ and http://badc.nerc.ac.uk/data/cru/). 2013 Royal Meteorological Society

Honda M., H. Nakamura, 2001: Interannual seesaw between the Aleutian and Icelandic lows. Part II: Its significance in the interannual variability over the wintertime Northern Hemisphere. J. Climate, 14, 4512-4529, https://doi.org/10.1175/1520-0442(2001)014<4512:ISBTAA>2.0,CO;2.

Honda M., H. Nakamura, J. Ukita, I. Kousaka, and K. Takeuchi, 2001: Interannual seesaw between the Aleutian and Icelandic lows. Part I: Seasonal dependence and life cycle. J. Climate, 14, 1029-1042, https://doi.org/10.1175/1520-0442(2001)014<1029:ISBTAA>2.0,CO;2.

Honda M., Y. Kushnir, H. Nakamura, S. Yamane, and S. E. Zebiak, 2005a: Formation,mechanisms,and predictability of the Aleutian-Icelandic low seesaw in ensemble AGCM simulations. J. Climate,18, 1423-1434,https://doi.org/10.1175/JCLI3353.1.

Honda M., S. Yamane, and H. Nakamura, 2005b: Impacts of the Aleutian-Icelandic low seesaw on surface climate during the twentieth century.J. Climate,18(14),2793-2802, https://doi.org/10.1175/JCLI3419.1.

10.1175/JCLI3419.1

fd1f65eb4f2158b8dca596f6579cce10

http%3A%2F%2Fadsabs.harvard.edu%2Fabs%2F2005JCli...18.2793H

http://journals.ametsoc.org/doi/abs/10.1175/JCLI3419.1Abstract An interannual seesaw between the intensities of the Icelandic and Aleutian lows and its impact on surface climate observed during the twentieth century are investigated. In a recent period from the late 1960s to the early 1990s, their seesaw relationship was particularly apparent in late winter. The associated anomalies in surface air temperature were significant in many regions over the extratropical Northern Hemisphere except in central portions of the continents. The seesaw also modified the ocean–atmosphere exchange of heat and moisture extensively over the North Atlantic and North Pacific by changing evaporation and precipitation. Since the seesaw formation was triggered by eastward propagation of stationary Rossby wave trains from the North Pacific into the North Atlantic, anomalous circulation over the North Pacific in January was identified as a good precursor for February surface air temperatures in the Euro–Atlantic sector during that period. The seesaw relationship between the two low...

Kalnay, E., Coauthors, 1996: The NCEP/NCAR 40-year reanalysis project. Bull. Amer. Meteor. Soc., 77, 437-471, https://doi.org/10.1175/1520-0477(1996)077 <0437:TNYRP>2.0,CO;2.

10.1175/1520-0477(1996)077<0437:TNYRP>2.0.CO;2

9bfeacc7ab553b364e43408563ad850b

http%3A%2F%2Fintl-icb.oxfordjournals.org%2Fexternal-ref%3Faccess_num%3D10.1175%2F1520-0477%281996%290772.0.CO%3B2%26amp%3Blink_type%3DDOI

http://journals.ametsoc.org/doi/abs/10.1175/1520-0477%281996%29077%3C0437%3ATNYRP%3E2.0.CO%3B2

Kaplan A., M. A. Cane, Y. Kushnir, A. C. Clement, M. B. Blumenthal, and B. Rajagopalan, 1998: Analyses of global sea surface temperature 1856-1991.J. Geophys. Res.,103,18 567-18 589, https://doi.org/10.1029/97JC01736.

10.1029/97JC01736

17a0641d8f21e698d600b0b023977c69

http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1029%2F97JC01736%2Ffull%3FscrollTo%3Dreferences

http://doi.wiley.com/10.1029/97JC01736Global analyses of monthly sea surface temperature (SST) anomalies from 1856 to 1991 are produced using three statistically based methods: optimal smoothing (OS), the Kaiman filter (KF) and optimal interpolation (OI). Each of these is accompanied by estimates of the error covariance of the analyzed fields. The spatial covariance function these methods require is estimated from the available data; the timemarching model is a first-order autoregressive model again estimated from data. The data input for the analyses are monthly anomalies from the United Kingdom Meteorological Office historical sea surface temperature data set (MOHSST5) [Parker et al., 1994] of the Global Ocean Surface Temperature Atlas (GOSTA) [Bottomley et al., 1990]. These analyses are compared with each other, with GOSTA, and with an analysis generated by projection (P) onto a set of empirical orthogonal functions (as in Smith et al. [1996]). In theory, the quality of the analyses should rank in the order OS, KF, OI, P, and GOSTA. It is found that the first four give comparable results in the data-rich periods (1951-1991), but at times when data is sparse the first three differ significantly from P and GOSTA. At these times the latter two often have extreme and fluctuating values, prima facie evidence of error. The statistical schemes are also verified against data not used in any of the analyses (proxy records derived from corals and air temperature records from coastal and island stations). We also present evidence that the analysis error estimates are indeed indicative of the quality of the products. At most times the OS and KF products are close to the OI product, but at times of especially poor coverage their use of information from other times is advantageous. The methods appear to reconstruct the major features of the global SST field from very sparse data. Comparison with other indications of the El Niño-Southern Oscillation cycle show that the analyses provide usable information on interannual variability as far back as the 1860s.

Kerr R. A., 2000: A North Atlantic climate pacemaker for the centuries.Science,288,1984-1986, https://doi.org/10.1126/science.288.5473.1984.

10.1126/science.288.5473.1984

17835110

79a588566eccc20d99c2a1030043a243

http%3A%2F%2Fonlinelibrary.wiley.com%2Fresolve%2Freference%2FPMED%3Fid%3D17835110

http://www.sciencemag.org/cgi/doi/10.1126/science.288.5473.1984Although El Ni09o and La Ni09a are the largest single sources of global interannual climate variability, climate shifts on longer time scales than El Ni09o's 2 to 7 years are also drawing the attention of researchers. On multidecadal time scales of 40 to 80 years, a restless North Atlantic seems to be at work, alternately countering and enhancing humankind's alterations of climate. The evidence for this is turning up in such records as tree rings, ice cores, and corals.

Li S. L., G. T. Bates, 2007: Influence of the Atlantic multidecadal oscillation on the winter climate of East China.Adv. Atmos. Sci.,24(1),126-135, https://doi.org/10.1007/s00376-007-0126-6.

10.1007/s00376-007-0126-6

bccca0cb470212275f14af8e90e8ae65

http%3A%2F%2Fwww.cqvip.com%2FMain%2FDetail.aspx%3Fid%3D23633572

http://link.springer.com/10.1007/s00376-007-0126-6正The Atlantic Multidecadal Oscillation (AMO), the multidecadal variation of North Atlantic sea surface temperature (SST), exhibits an oscillation with a period of 65-80 years and an amplitude of 0.4℃. Observational composite analyses reveal that the warm phase AMO is linked to warmer winters in East

Liu J., J. A. Curry, H. Wang, M. Song, and R. M. Horton, 2012: Impact of declining Arctic sea ice on winter snowfall.Proceedings of the National Academy of Sciences of the United States of America,109,4074-4079, 1114910109.https://doi.org/10.1073/pnas.

10.1073/pnas.1114910109

22371563

e869b196cae446b30762b978476557d4

http%3A%2F%2Fwww.jstor.org%2Fstable%2F41507098

http://www.pnas.org/cgi/doi/10.1073/pnas.1114910109While the Arctic region has been warming strongly in recent decades, anomalously large snowfall in recent winters has affected large parts of North America, Europe, and east Asia. Here we demonstrate that the decrease in autumn Arctic sea ice area is linked to changes in the winter Northern Hemisphere atmospheric circulation that have some resemblance to the negative phase of the winter Arctic oscillation. However, the atmospheric circulation change linked to the reduction of sea ice shows much broader meridional meanders in midlatitudes and clearly different interannual variability than the classical Arctic oscillation. This circulation change results in more frequent episodes of blocking patterns that lead to increased cold surges over large parts of northern continents. Moreover, the increase in atmospheric water vapor content in the Arctic region during late autumn and winter driven locally by the reduction of sea ice provides enhanced moisture sources, supporting increased heavy snowfall in Europe during early winter and the northeastern and midwestern United States during winter. We conclude that the recent decline of Arctic sea ice has played a critical role in recent cold and snowy winters.

Lu R. Y., B. W. Dong, and H. Ding, 2006: Impact of the Atlantic Multidecadal Oscillation on the Asian summer monsoon. Geophys. Res. Lett. 33(24), https://doi.org/10.1029/2006GL027655.

10.1029/2006GL027655

52398184b237301b9bb60b677c2aa390

http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1029%2F2006GL027655%2Fpdf

http://onlinelibrary.wiley.com/doi/10.1029/2006GL027655/pdfThe impact of the Atlantic Multidecadal Oscillation (AMO) on the Asian summer monsoon is investigated using a coupled atmosphere-ocean global general circulation model by imposing the AMO-associated sea surface temperature anomalies in the Atlantic as boundary forcing, and allowing atmosphere-ocean interactions outside the Atlantic. The positive AMO phase, characterized by anomalous warm North Atlantic and cold South Atlantic, leads to strong Southeast and east Asian summer monsoons, and late withdrawal of the Indian summer monsoon. These changes of monsoons are mainly through coupled atmosphere-ocean feedbacks in the western Pacific and Indian Oceans and tropospheric temperature changes over Eurasia in response to the imposed forcing in the Atlantic. The results are in agreement with the observed climate changes in China corresponded to the AMO phases. They suggest a non-local mechanism for the Asian summer monsoon variability and provide an alternative view to understanding its interdecadal variation during the twentieth century.

Nakamura H., M. Honda, 2002: Interannual seesaw between the Aleutian and Icelandic lows Part III: Its influence upon the stratospheric variability.J. Meteor. Soc. Japan,80(4B),1051-1067, https://doi.org/10.2151/jmsj.80.1051.

10.2151/jmsj.80.1051

http://joi.jlc.jst.go.jp/JST.JSTAGE/jmsj/80.1051?from=CrossRef

Nishii K., H. Nakamura, and Y. J. Orsolini, 2011: Geographical dependence observed in blocking high influence on the stratospheric variability through enhancement and suppression of upward planetary-wave propagation.J. Climate,24(24),6408-6423, https://doi.org/10.1175/JCLI-D-10-05021.1.

10.1175/JCLI-D-10-05021.1

183381a16429fb893c42b07f71b21a0c

http%3A%2F%2Fadsabs.harvard.edu%2Fabs%2F2011JCli...24.6408N

http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-10-05021.1Previous studies have suggested the importance of blocking high (BH) development for the occurrence of stratospheric sudden warming (SSW), while there is a recent study that failed to identify their statistical linkage. Through composite analysis applied to high-amplitude anticyclonic anomaly events observed around every grid point over the extratropical Northern Hemisphere, the present study reveals a distinct geographical dependence of BH influence on the upward propagation of planetary waves (PWs) into the stratosphere. Tropospheric BHs that develop over the Euro-Atlantic sector tend to enhance upward PW propagation, leading to the warming in the polar stratosphere and, in some cases, to major SSW events. In contrast, the upward PW propagation tends to be suppressed by BHs developing over the western Pacific and the Far East, resulting in the polar stratospheric cooling. This dependence is found to arise mainly from the sensitivity of the interference between the climatological PWs and upward-propagating Rossby wave packets emanating from BHs to their geographical locations. This study also reveals that whether a BH over the eastern Pacific and Alaska can enhance or reduce the upward PW propagation is case dependent. It is suggested that BHs that induce the stratospheric cooling can weaken the statistical relationship between BHs and SSWs.

Omrani N.-E., N. S. Keenlyside, J. Bader, and E. Manzini, 2014: Stratosphere key for wintertime atmospheric response to warm Atlantic decadal conditions.Climate Dyn.,42,649-663, https://doi.org/10.1007/s00382-013-1860-3.

10.1007/s00382-013-1860-3

9687bf74387cfd236248754b7d3d2abb

http%3A%2F%2Flink.springer.com%2F10.1007%2Fs00382-013-1860-3

http://link.springer.com/10.1007/s00382-013-1860-3There is evidence that the observed changes in winter North Atlantic Oscillation (NAO) drive a significant portion of Atlantic Multi Decadal Variability (AMV). However, whether the observed decadal NAO changes can be forced by the ocean is controversial. There is also evidence that artificially imposed multi-decadal stratospheric changes can impact the troposphere in winter. But the origins of such stratospheric changes are still unclear, especially in early to mid winter, where the radiative ozone-impact is negligible. Here we show, through observational analysis and atmospheric model experiments, that large-scale Atlantic warming associated with AMV drives high-latitude precursory stratospheric warming in early to mid winter that propagates downward resulting in a negative tropospheric NAO in late winter. The mechanism involves stratosphere/troposphere dynamical coupling, and can be simulated to a large extent, but only with a stratosphere resolving model (i.e., high-top). Further analysis shows that this precursory stratospheric response can be explained by the shift of the daily extremes toward more major stratospheric warming events. This shift cannot be simulated with the atmospheric (low-top) model configuration that poorly resolves the stratosphere and implements a sponge layer in upper model levels. While the potential role of the stratosphere in multi-decadal NAO and Atlantic meridional overturning circulation changes has been recognised, our results show that the stratosphere is an essential element of extra-tropical atmospheric response to ocean variability. Our findings suggest that the use of stratosphere resolving models should improve the simulation, prediction, and projection of extra-tropical climate, and lead to a better understanding of natural and anthropogenic climate change.

Orsolini Y. J., 2004: Seesaw fluctuations in ozone between the North Pacific and North Atlantic.J. Meteor. Soc. Japan,82(3),941-949, 2004. 941.https://doi.org/10.2151/jmsj.

10.2151/jmsj.2004.941

http://joi.jlc.jst.go.jp/JST.JSTAGE/jmsj/2004.941?from=CrossRef

Orsolini Y. J., N. G. Kvamst闁帮拷, I. T. Kindem, M. Honda, and H. Nakamura, 2008: Influence of the Aleutian-Icelandic low seesaw and ENSO onto the Stratosphere in ensemble winter hindcasts.J. Meteor. Soc. Japan,86(5),817-825, https://doi.org/10.2151/jmsj.86.817.

10.2151/jmsj.86.817

19dd4bba2fe2498008ce895e845b8359

http%3A%2F%2Fci.nii.ac.jp%2Fnaid%2F110006991218

http://joi.jlc.jst.go.jp/JST.JSTAGE/jmsj/86.817?from=CrossRefUsing an ensemble of wintertime hindcasts with a high-resolution (T106L60) Atmospheric General Circulation Model (AGCM) forced by observed sea surface temperatures (SSTs) and extending into the stratosphere, we investigate the formation and lifecycle of the Aleutian-Icelandic low Seesaw (AIS) during the 1978 to 1993 period. The AIS has been newly proposed to be an important mode of variability, linking the major wintertime surface lows, the Icelandic Low and the Aleutian Low, in late winter, and thereby linking climate variability over the North Pacific and the North Atlantic. We demonstrate for the first time with a stratosphere-troposphere model, that a coherent, ensemble-mean AIS extension into the stratosphere exists, where its presence modulates ultra-long planetary wave propagation and the polar night jet intensity. The model AIS peaks in February, when the Aleutian and Icelandic Low anti-correlation maximizes at -0.59. The AIS provides a new way to describe the El Niño-Southern Oscillation (ENSO) phenomenon influence into the stratosphere. For example, El-Nino conditions correspond to a deeper than normal Aleutian Low, extending its influence into the Icelandic sector as an AIS negative phase (weakened Icelandic Low), hence enhanced planetary wave vertical propagation and a weakened stratospheric polar vortex. This maturation of the AIS in late winter explains the intra-seasonal variability of the stratospheric response to ENSO, which peaks in late winter. Internal model variability is large and enhanced potential predictability is found primarily in the western hemisphere, with a western Atlantic maxima being more pronounced in the stratosphere than in the upper troposphere.

Peings Y., G. Magnusdottir, 2014: Forcing of the wintertime atmospheric circulation by the multidecadal fluctuations of the North Atlantic ocean,Environmental Research Letters,9(3),034018, https://doi.org/10.1088/1748-9326/9/3/034018.

10.1088/1748-9326/9/3/034018

9b1c9024c7198675b4ac73193d07d04b

http%3A%2F%2Fadsabs.harvard.edu%2Fabs%2F2014ERL.....9c4018P

http://stacks.iop.org/1748-9326/9/i=3/a=034018?key=crossref.78c09fa6ee45935be9d64175d1959d01The North Atlantic sea surface temperature exhibits fluctuations on the multidecadal time scale, a phenomenon known as the Atlantic Multidecadal Oscillation (AMO). This letter demonstrates that the multidecadal fluctuations of the wintertime North Atlantic Oscillation (NAO) are tied to the AMO, with an opposite-signed relationship between the polarities of the AMO and the NAO. Our statistical analyses suggest that the AMO signal precedes the NAO by 10-15 years with an interesting predictability window for decadal forecasting. The AMO footprint is also detected in the multidecadal variability of the intraseasonal weather regimes of the North Atlantic sector. This observational evidence is robust over the entire 20th century and it is supported by numerical experiments with an atmospheric global climate model. The simulations suggest that the AMO-related SST anomalies induce the atmospheric anomalies by shifting the atmospheric baroclinic zone over the North Atlantic basin. As in observations, the positive phase of the AMO results in more frequent negative NAO - and blocking episodes in winter that promote the occurrence of cold extreme temperatures over the eastern United States and Europe. Thus, it is plausible that the AMO plays a role in the recent resurgence of severe winter weather in these regions and that wintertime cold extremes will be promoted as long as the AMO remains positive. 2014 IOP Publishing Ltd.

Peings Y., G. Magnusdottir, 2016: Wintertime atmospheric response to Atlantic multidecadal variability: Effect of stratospheric representation and ocean-atmosphere coupling.Climate Dyn.,47,1029-1047, https://doi.org/10.1007/s00382-015-2887-4.

10.1007/s00382-015-2887-4

6b4ddb4fb9836c7d2a39332a9f3192a8

http%3A%2F%2Flink.springer.com%2F10.1007%2Fs00382-015-2887-4

http://link.springer.com/10.1007/s00382-015-2887-4The impact of the Atlantic multidecadal variability (AMV) on the wintertime atmosphere circulation is investigated using three different configurations of the Community Atmospheric Model version 5 (CAM5). Realistic SST and sea ice anomalies associated with the AMV in observations are prescribed in CAM5 (low-top model) and WACCM5 (high-top model) to assess the dependence of the results on the representation of the stratosphere. In a third experiment, the role of ocean-atmosphere feedback is investigated by coupling CAM5 to a slab-ocean model in which the AMV forcing is prescribed through oceanic heat flux anomalies. The three experiments give consistent results concerning the response of the NAO in winter, with a negative NAO signal in response to a warming of the North Atlantic ocean. This response is found in early winter when the high-top model is used, and in late winter with the low-top model. With the slab-ocean, the negative NAO response is more persistent in winter and shifted eastward over the continent due to the damping of the atmospheric response over the North Atlantic ocean. Additional experiments suggest that both tropical and extratropical SST anomalies are needed to obtain a significant modulation of the NAO, with small influence of sea ice anomalies. Warm tropical SST anomalies induce a northward shift of the ITCZ and a Rossby-wave response that is reinforced in the mid-latitudes by the extratropical SST anomalies through eddy-mean flow interactions. This modeling study supports that the positive phase of the AMV promotes the negative NAO in winter, while illustrating the impacts of the stratosphere and of the ocean-atmosphere feedbacks in the spatial pattern and timing of this response.

Plumb R. A., 1985: On the three-dimensional propagation of stationary waves. J. Atmos. Sci., 42, 217-229, https://doi.org/10.1175/1520-0469(1985)042<0217:OTTDPO>2.0,CO;2.

10.1175/1520-0469(1985)042<0217:OTTDPO>2.0.CO;2

ccdb9bc2c2853e3ba3d7632e5f9db2c5

http%3A%2F%2Fadsabs.harvard.edu%2Fabs%2F1985jats...42..217p

http://journals.ametsoc.org/doi/abs/10.1175/1520-0469%281985%29042%3C0217%3AOTTDPO%3E2.0.CO%3B2A locally applicable (nonzonally-averaged) conservation relation is derived for quasi-geostrophic stationary waves on a zonal flow, a generalization of the Eliassen-Palm relation. The flux which appears in this relation constitutes, it is argued, a useful diagnostic of the three-dimensional propagation of stationary wave activity. This is illustrated by application to a simple theoretical model of a forced Rossby wave train and to a Northern Hemisphere winter climatology. Results of the latter procedure suggest that the major forcing of the stationary wave field derives from the orographic effects of the Tibetan plateau and from nonorographic effects (diabatic heating and/or interaction with transient eddies) in the western North Atlantic and North Pacific Oceans and Siberia. No evidence is found in the data for wave trains of tropical origin; forcing by the orographic effects of the Rocky mountains seems to be of secondary importance.

Reichler T., J. Kim, E. Manzini, and J. Kröger, 2012: A stratospheric connection to Atlantic climate variability.Nature Geoscience,5(11),783-787, https://doi.org/10.1038/ngeo1586.

10.1038/ngeo1586

dd8ef745da79b475b6f15308b68e2c7b

http%3A%2F%2Fwww.nature.com%2Fngeo%2Fjournal%2Fv5%2Fn11%2Fabs%2Fngeo1586.html

http://www.nature.com/doifinder/10.1038/ngeo1586It is well recognized that the stratosphere is connected to tropospheric weather and climate. In particular, extreme stratospheric circulation events and their dynamical feedback on the troposphere are known to play a major role1. However, what is not known to date is whether the state of the stratosphere also matters for the ocean and its circulation. Previous research suggests co-variability of decadal stratospheric flow variations and conditions in the North Atlantic Ocean, but such findings are based on short simulations with only one climate model2. Here we report that over the past 30 years the stratosphere and the Atlantic thermohaline circulation underwent low-frequency variations that were similar to each other.

Schneider U., A. Becker, P. Finger, A. Meyer-Christoffer B. Rudolf, and M. Ziese, 2015: GPCC Full Data Reanalysis Version 7.0 at 1.0: Monthly Land-Surface Precipitation from Rain-Gauges built on GTS based and Historic Data, https://doi.org/10.5065/D6000072.

Sun J., B. Tan, 2013: Mechanism of the wintertime Aleutian low-Icelandic low seesaw.Geophys. Res. Lett.,40(15),4103-4108, https://doi.org/10.1002/grl.50770.

10.1002/grl.50770

cd7dc4217aad74a745a7d58e0ae56f3b

http%3A%2F%2Fadsabs.harvard.edu%2Fabs%2F2013GeoRL..40.4103S

http://doi.wiley.com/10.1002/grl.50770The driving mechanism for the wintertime (December-March) Aleutian Low-Icelandic Low (AL-IL) seesaw is investigated with National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis data for 1948-2009. It is shown that the AL and the IL are dynamically linked through the eastern Pacific wave train (EPW) and that both the EPWs and the stratospheric polar vortex are found to work cooperatively to produce a significant AL-IL seesaw. In general, it is found that wave reflection by the polar vortex is crucial for the formation of the AL-IL seesaw. However, when the EPWs are extremely strong, the AL-IL seesaw appears to be caused primarily by horizontal wave propagation. It is further shown that the Pacific center of the traditional Arctic Oscillation pattern is present when the AL-IL seesaw is active, but it disappears when the AL-IL seesaw is absent.

Tang Q. H., X. J. Zhang, X. H. Yang, and J. A. Francis, 2013: Cold winter extremes in northern continents linked to Arctic sea ice loss,Environmental Research Letters,8(1),014036, https://doi.org/10.1088/1748-9326/8/1/014036.

10.1088/1748-9326/8/1/014036

4a2689c416c3793196f6b65170ec673d

http%3A%2F%2Fadsabs.harvard.edu%2Fabs%2F2013ERL.....8a4036T

http://stacks.iop.org/1748-9326/8/i=1/a=014036?key=crossref.3b07e12952c5b61acb8cedc9b207e051中国科学院机构知识库(中国科学院机构知识库网格（CAS IR GRID）)以发展机构知识能力和知识管理能力为目标，快速实现对本机构知识资产的收集、长期保存、合理传播利用，积极建设对知识内容进行捕获、转化、传播、利用和审计的能力，逐步建设包括知识内容分析、关系分析和能力审计在内的知识服务能力，开展综合知识管理。

Thompson, D. W. J, J. M. Wallace, 2001: Regional climate impacts of the Northern Hemisphere annular mode.Science,293(5527),85-89, https://doi.org/10.1126/science.1058958.

10.1126/science.1058958

11441178

aae3355072278d18ed2819f35c5dc39d

http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpubmed%2F11441178

http://www.sciencemag.org/cgi/doi/10.1126/science.1058958The Northern Hemisphere annular mode (NAM) (also known as the North Atlantic Oscillation) is shown to exert a strong influence on wintertime climate, not only over the Euro-Atlantic half of the hemisphere as documented in previous studies, but over the Pacific half as well. It affects not only the mean conditions, but also the day-to-day variability, modulating the intensity of mid-latitude storms and the frequency of occurrence of high-latitude blocking and cold air outbreaks throughout the hemisphere. The recent trend in the NAM toward its high-index polarity with stronger subpolar westerlies has tended to reduce the severity of winter weather over most middle- and high-latitude Northern Hemisphere continental regions.

Wallace J. M., D. S. Gutzler, 1981: Teleconnections in the geopotential height field during the Northern Hemisphere winter.Monthly Weather Review,109(4),784-812, https://doi.org/10.1175/1520-0493(1981)109<0784:TITGHF>2.0.CO;210.1175/1520-0493(1981)109<0784:TITGHF>2.0.CO;2

3544b322a43213a44a5bb1db36c9aad9

http%3A%2F%2Fwww.bioone.org%2Fservlet%2Flinkout%3Fsuffix%3Di0276-4741-32-4-431-Wallace1%26amp%3Bdbid%3D16%26amp%3Bdoi%3D10.1659%252FMRD-JOURNAL-D-12-00062.1%26amp%3Bkey%3D10.1175%252F1520-0493%281981%291092.0.CO%253B2

http://journals.ametsoc.org/doi/abs/10.1175/1520-0493%281981%29109%3C0784%3ATITGHF%3E2.0.CO%3B2