--- - attrs: .publisher: 'Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.' .reference_type: 0 Author: "Li, Jinbao; Xie, Shang-Ping; Cook, Edward R.; Huang, Gang; D'Arrigo, Rosanne; Liu, Fei; Ma, Jian; Zheng, Xiao-Tong" DOI: 10.1038/nclimate1086 Date: 05//print Issue: 2 Journal: Nature Climate Change Pages: 114-118 Title: Interdecadal modulation of El Niño amplitude during the past millennium Volume: 1 Year: 2011 _record_number: 19630 _uuid: bbbae1eb-1f00-40e1-ae43-b7863655812f reftype: Journal Article child_publication: /article/10.1038/nclimate1086 href: https://data.globalchange.gov/reference/bbbae1eb-1f00-40e1-ae43-b7863655812f.yaml identifier: bbbae1eb-1f00-40e1-ae43-b7863655812f uri: /reference/bbbae1eb-1f00-40e1-ae43-b7863655812f - attrs: .reference_type: 0 Abstract: 'Composite temperature and precipitation anomalies during various stages of an event in the Southern Oscillation (SO) have been computed for several hundred stations across the globe. Large regions of coherent, significant signals are shown to exist for both extremes of the SO, with warm event signals generally opposite to those during cold events. In addition, during the year preceding the development of an event in the SO (year −1), climatic anomalies tend to be opposite to those during the following year (year 0). This confirms that the biennial tendency of the SO over the Pacific/Indian ocean sectors is also present in more remote regions with climatic signals related to the SO. Many of the signals are consistent enough from event to event to be useful for extended range forecasting purposes.' Author: George N. Kiladis; Henry F. Diaz DOI: 10.1175/1520-0442(1989)002<1069:GCAAWE>2.0.CO;2 Issue: 9 Journal: Journal of Climate Pages: 1069-1090 Title: Global climatic anomalies associated with extremes in the Southern Oscillation Volume: 2 Year: 1989 _record_number: 19625 _uuid: d81a06f0-65ed-4df1-9b24-eb2874f944b7 reftype: Journal Article child_publication: /article/10.1175/1520-0442(1989)002%3C1069:GCAAWE%3E2.0.CO;2 href: https://data.globalchange.gov/reference/d81a06f0-65ed-4df1-9b24-eb2874f944b7.yaml identifier: d81a06f0-65ed-4df1-9b24-eb2874f944b7 uri: /reference/d81a06f0-65ed-4df1-9b24-eb2874f944b7 - attrs: .reference_type: 0 Abstract: 'We investigate the “typical” global and large-scale regional precipitation patterns that are associated with the El Niño/Southern Oscillation (ENSO). Monthly precipitation time series from over 1700 stations are analyzed using an empirical method designed to identify regions of the globe that have precipitation variations associated with ENSO. Monthly mean ranked precipitation composites are computed over idealized 2-year ENSO episodes for all stations that include data for at least five ENSOs. The amplitude and phase of the Arm harmonic fitted to the 24-month composite values are plotted in the form of a vector for each station. When plotted on a global map, these vectors reveal both the regions of spatially coherent ENSO-related precipitation and the phase of this signal in relation to the evolution of the composite episode. Time cries of precipitation for the coherent regions identified in the harmonic vector map are examined to determine the magnitudes of the ENSO-related precipitation and the percentages of the time the identified relationship actually occurred in conjunction with ENSO episodes. This study expands previous results by placing the regional precipitation relationships into a global framework and by providing a consistent methodology for the definition of the geographical regions and the temporal phase of ENSO-related precipitation. In addition to the Pacific Ocean basin where precipitation patterns could be directly related to the ENSO, several other regions, which showed consistent ENSO-related precipitation, were identified. Specifically, four regions in Australia, two regions each in North America South America, the Indian subcontinent, and Africa and one region in Central America were all found to have coherent ENSO-related precipitation. In most of thew regions, the “season” of ENSO-related precipitation was found to be in phase with the normal annual precipitation cycle. Time series of area-averaged precipitation for the appropriate “seasons” show departures consistent with the composites occurring for at 1east 80% of the ENSO events in almost every region. The analysis further indicates that variations in precipitation related to ENSO occur as early as April of the composite episode through May of the following year.' Author: C. F. Ropelewski; M. S. Halpert DOI: 10.1175/1520-0493(1987)115<1606:GARSPP>2.0.CO;2 Issue: 8 Journal: Monthly Weather Review Pages: 1606-1626 Title: Global and regional scale precipitation patterns associated with the El Niño/Southern Oscillation Volume: 115 Year: 1987 _record_number: 19643 _uuid: e2259324-cd73-41c2-be96-a459a5021ae1 reftype: Journal Article child_publication: /article/10.1175/1520-0493(1987)115%3C1606:GARSPP%3E2.0.CO;2 href: https://data.globalchange.gov/reference/e2259324-cd73-41c2-be96-a459a5021ae1.yaml identifier: e2259324-cd73-41c2-be96-a459a5021ae1 uri: /reference/e2259324-cd73-41c2-be96-a459a5021ae1 - attrs: .reference_type: 0 Author: 'Hurrell, James W.; Deser, Clara' DOI: 10.1016/j.jmarsys.2008.11.026 Date: 8// Issue: 1 Journal: Journal of Marine Systems Keywords: NAO; Climate variability; Physical oceanographic impacts Pages: 28-41 Title: 'North Atlantic climate variability: The role of the North Atlantic oscillation' Volume: 78 Year: 2009 _record_number: 19623 _uuid: e58558a8-6072-4c71-9e2a-ad3182f9d999 reftype: Journal Article child_publication: /article/10.1016/j.jmarsys.2008.11.026 href: https://data.globalchange.gov/reference/e58558a8-6072-4c71-9e2a-ad3182f9d999.yaml identifier: e58558a8-6072-4c71-9e2a-ad3182f9d999 uri: /reference/e58558a8-6072-4c71-9e2a-ad3182f9d999 - attrs: .reference_type: 0 Abstract: 'The 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.%U ' Author: 'Thompson, David W. J.; Wallace, John M.' DOI: 10.1126/science.1058958 Issue: 5527 Journal: Science Pages: 85-89 Title: Regional climate impacts of the Northern Hemisphere annular mode Volume: 293 Year: 2001 _record_number: 19653 _uuid: eae7e119-f3d7-4ad5-9f47-5d99a2cbdd1d reftype: Journal Article child_publication: /article/10.1126/science.1058958 href: https://data.globalchange.gov/reference/eae7e119-f3d7-4ad5-9f47-5d99a2cbdd1d.yaml identifier: eae7e119-f3d7-4ad5-9f47-5d99a2cbdd1d uri: /reference/eae7e119-f3d7-4ad5-9f47-5d99a2cbdd1d - attrs: .reference_type: 0 Abstract: 'We analyse the ability of CMIP3 and CMIP5 coupled ocean–atmosphere general circulation models (CGCMs) to simulate the tropical Pacific mean state and El Niño-Southern Oscillation (ENSO). The CMIP5 multi-model ensemble displays an encouraging 30 % reduction of the pervasive cold bias in the western Pacific, but no quantum leap in ENSO performance compared to CMIP3. CMIP3 and CMIP5 can thus be considered as one large ensemble (CMIP3 + CMIP5) for multi-model ENSO analysis. The too large diversity in CMIP3 ENSO amplitude is however reduced by a factor of two in CMIP5 and the ENSO life cycle (location of surface temperature anomalies, seasonal phase locking) is modestly improved. Other fundamental ENSO characteristics such as central Pacific precipitation anomalies however remain poorly represented. The sea surface temperature (SST)-latent heat flux feedback is slightly improved in the CMIP5 ensemble but the wind-SST feedback is still underestimated by 20–50 % and the shortwave-SST feedbacks remain underestimated by a factor of two. The improvement in ENSO amplitudes might therefore result from error compensations. The ability of CMIP models to simulate the SST-shortwave feedback, a major source of erroneous ENSO in CGCMs, is further detailed. In observations, this feedback is strongly nonlinear because the real atmosphere switches from subsident (positive feedback) to convective (negative feedback) regimes under the effect of seasonal and interannual variations. Only one-third of CMIP3 + CMIP5 models reproduce this regime shift, with the other models remaining locked in one of the two regimes. The modelled shortwave feedback nonlinearity increases with ENSO amplitude and the amplitude of this feedback in the spring strongly relates with the models ability to simulate ENSO phase locking. In a final stage, a subset of metrics is proposed in order to synthesize the ability of each CMIP3 and CMIP5 models to simulate ENSO main characteristics and key atmospheric feedbacks.' Author: 'Bellenger, H.; Guilyardi, E.; Leloup, J.; Lengaigne, M.; Vialard, J.' DOI: 10.1007/s00382-013-1783-z Issue: 7 Journal: Climate Dynamics Pages: 1999-2018 Title: 'ENSO representation in climate models: From CMIP3 to CMIP5' Volume: 42 Year: 2014 _record_number: 20866 _uuid: ecf2a293-f555-4632-8f7a-1fb12c9f098e reftype: Journal Article child_publication: /article/10.1007/s00382-013-1783-z href: https://data.globalchange.gov/reference/ecf2a293-f555-4632-8f7a-1fb12c9f098e.yaml identifier: ecf2a293-f555-4632-8f7a-1fb12c9f098e uri: /reference/ecf2a293-f555-4632-8f7a-1fb12c9f098e - attrs: .reference_type: 0 Abstract: 'The historical and future relationships between two major patterns of large-scale climate variability, the North Atlantic Oscillation (NAO) and the Pacific/North America pattern (PNA), and the regional winter temperature and precipitation over the eastern United States were systemically evaluated by using 17 general circulation models (GCMs) from the Coupled Model Intercomparison Project phase 5. Empirical orthogonal function analysis was used to define the NAO and PNA. The observed spatial patterns of NAO and PNA can be reproduced by all the GCMs with slight differences in locations of the centers of action and their average magnitudes. For the correlations with regional winter temperature and precipitation over the eastern US, GCMs perform best in capturing the relationships between the NAO and winter temperature, and between the PNA and winter temperature and precipitation. The differences between the observed and simulated relationships are mainly due to displacements of the simulated NAO and PNA centers of action and differences in their magnitudes. In simulations of the future, both NAO and PNA magnitudes increase, with uncertainties related to the model response and emission scenarios. When assessing the influences of future NAO/PNA changes on regional winter temperature, it is found that the main factors are related to changes in the magnitude of the NAO Azores center and total NAO magnitude, and the longitude of the PNA center over northwestern North America, total PNA magnitude, and the magnitude of the PNA center over the southeastern US.' Author: 'Ning, Liang; Bradley, Raymond S.' DOI: 10.1007/s00382-015-2643-9 Issue: 3 Journal: Climate Dynamics Pages: 1257-1276 Title: NAO and PNA influences on winter temperature and precipitation over the eastern United States in CMIP5 GCMs Volume: 46 Year: 2016 _record_number: 20287 _uuid: ed3d1a48-a7f4-4f31-a0c2-91e438ea459d reftype: Journal Article child_publication: /article/10.1007/s00382-015-2643-9 href: https://data.globalchange.gov/reference/ed3d1a48-a7f4-4f31-a0c2-91e438ea459d.yaml identifier: ed3d1a48-a7f4-4f31-a0c2-91e438ea459d uri: /reference/ed3d1a48-a7f4-4f31-a0c2-91e438ea459d - attrs: .reference_type: 0 Abstract: 'The last decade shows increased variability in the Arctic Oscillation (AO) index for December. Over eastern North America such increased variability depended on amplification of the climatological longwave atmospheric circulation pattern. Recent negative magnitudes of the AO have increased geopotential thickness west of Greenland and cold weather in the central and eastern United States. Although the increased variance in the AO is statistically significant based on 9-yr running standard deviations from 1950 to 2014, one cannot necessarily robustly attribute the increase to steady changes in external sources (sea temperatures, sea ice) rather than a chaotic view of internal atmospheric variability; this is due to a relatively short record and a review of associated atmospheric dynamics. Although chaotic internal variability dominates the dynamics of atmospheric circulation, Arctic thermodynamic influence can reinforce the regional geopotential height pattern. Such reinforcement suggests a conditional or state dependence on whether an Arctic influence will impact subarctic severe weather, based on different circulation regimes. A key conclusion is the importance of recent variability over potential trends in Arctic and subarctic atmospheric circulation. Continued thermodynamic Arctic changes are suggested as a Bayesian prior leading to a probabilistic approach for potential subarctic weather linkages and the potential for improving seasonal forecasts.' Author: James E. Overland; Muyin Wang DOI: 10.1175/jcli-d-15-0395.1 Issue: 18 Journal: Journal of Climate Keywords: 'Arctic,Arctic Oscillation,Atmospheric circulation,Stationary waves,Teleconnections,Arctic Oscillation' Pages: 7297-7305 Title: Increased variability in the early winter subarctic North American atmospheric circulation Volume: 28 Year: 2015 _record_number: 20552 _uuid: ed68531d-2082-4da6-8803-35890cb08222 reftype: Journal Article child_publication: /article/10.1175/jcli-d-15-0395.1 href: https://data.globalchange.gov/reference/ed68531d-2082-4da6-8803-35890cb08222.yaml identifier: ed68531d-2082-4da6-8803-35890cb08222 uri: /reference/ed68531d-2082-4da6-8803-35890cb08222 - attrs: .reference_type: 0 Abstract: 'The influence of large-scale flow regimes on cool-season (November–April) northeastern U.S. (Northeast) precipitation is investigated for the period 1948–2003 from statistical and synoptic perspectives. These perspectives are addressed through (i) a statistical analysis of cool-season Northeast precipitation associated with the North Atlantic Oscillation (NAO) and Pacific–North American (PNA) regimes (one standard deviation or greater NAO or PNA daily index anomalies persisting several days), and (ii) a composite analysis of the synoptic signatures of major (two standard deviation) 24-h cool-season Northeast precipitation events occurring during NAO and PNA regimes. The statistical analysis reveals that negative PNA regimes are associated with above-average cool-season Northeast precipitation and an above-average frequency of light and moderate precipitation events, whereas the opposite associations are true for positive PNA regimes. In comparison with PNA regimes, NAO regimes are found to have relatively little influence on the amount and frequency of cool-season Northeast precipitation. The composite analysis indicates that a surface cyclone flanked by an upstream trough over the Ohio Valley and downstream ridge over eastern Canada and upper- and lower-level jets in the vicinity of the Northeast are characteristic signatures of major cool-season Northeast precipitation events occurring during NAO and PNA regimes. Negative NAO and positive PNA precipitation events, however, are associated with a more amplified trough–ridge pattern and greater implied Atlantic moisture transport by a low-level jet into the Northeast than positive NAO and negative PNA precipitation events. Furthermore, a signature of lateral upper-level jet coupling is noted only during positive and negative PNA precipitation events.' Author: Heather M. Archambault; Lance F. Bosart; Daniel Keyser; Anantha R. Aiyyer DOI: 10.1175/2007MWR2308.1 Issue: 8 Journal: Monthly Weather Review Keywords: 'Winter/cool season,Precipitation,North Atlantic Oscillation,Pacific–North American pattern/oscillation' Pages: 2945-2963 Title: Influence of large-scale flow regimes on cool-season precipitation in the northeastern United States Volume: 136 Year: 2008 _record_number: 20274 _uuid: f5711fb8-ea3b-4564-8a60-0fabd66bd173 reftype: Journal Article child_publication: /article/10.1175/2007MWR2308.1 href: https://data.globalchange.gov/reference/f5711fb8-ea3b-4564-8a60-0fabd66bd173.yaml identifier: f5711fb8-ea3b-4564-8a60-0fabd66bd173 uri: /reference/f5711fb8-ea3b-4564-8a60-0fabd66bd173 - attrs: .reference_type: 0 Author: 'Yu, Jin-Yi; Zou, Yuhao; Kim, Seon Tae; Lee, Tong' DOI: 10.1029/2012GL052483 Issue: 15 Journal: Geophysical Research Letters Keywords: CP El Niño; EP El Niño; US winter temperatures; 1616 Climate variability; 1630 Impacts of global change; 3305 Climate change and variability; 4522 ENSO Pages: L15702 Title: The changing impact of El Niño on US winter temperatures Volume: 39 Year: 2012 _record_number: 19663 _uuid: ff7033b4-13c2-4cf2-8ba2-c0b81affa2b4 reftype: Journal Article child_publication: /article/10.1029/2012GL052483 href: https://data.globalchange.gov/reference/ff7033b4-13c2-4cf2-8ba2-c0b81affa2b4.yaml identifier: ff7033b4-13c2-4cf2-8ba2-c0b81affa2b4 uri: /reference/ff7033b4-13c2-4cf2-8ba2-c0b81affa2b4