In recent decades, the typical E1 Nifio events with the warmest SSTs in the tropical eastern Pacific have become less common, and a different of E1 Nifio with the wannest SSTs in the central the east and west by coole...In recent decades, the typical E1 Nifio events with the warmest SSTs in the tropical eastern Pacific have become less common, and a different of E1 Nifio with the wannest SSTs in the central the east and west by cooler Pacific, which is flanked on SSTs, has become more frequent. The more recent type of E1 Nifio was referred to as central Pacific E1 Nifio, warm pool E1 Nifio, or dateline E1 Nifio, or the E1 Nifio Modoki. Central Pacific E1 Nifio links to a different tropical-to-extratropical teleconnection and exerts different impacts on climate, and several clas- sification approaches have been proposed. In this study, a new classification approach is proposed, which is based on the linear combination （sum or difference） of the two leading Empirical Orthogonal Functions （EOFs） of tropi- cal Pacific Ocean sea surface temperature anomaly （SSTA）, and the typical E1 Nifio index （TENI） and the central E1 Nifio index （CENI） are able to be derived by projecting the observed SSTA onto these combinations. This classification not only reflects the characteristics of non-orthogonality between the two types of events but also yields one period peaking at approximate two to seven years. In particular, this classification can distin- guish the different impacts of the two types of events on rainfall in the following summer in East China. The typi- cal E1 Nifio events tend to induce intensified rainfall in the Yangtze River valley, whereas the central Pacific El Nifio tends to induce intensified rainfall in the Huaihe River valley. Thus, the present approach may be appropriate for studying the impact of different types of E1 Nifio on the East Asian climate.展开更多
A simple approach that considers both internal decadal variability and the effect of anthropogenic forcing is developed to predict the decadal components of global sea surface temperatures (SSTs) for the three decades...A simple approach that considers both internal decadal variability and the effect of anthropogenic forcing is developed to predict the decadal components of global sea surface temperatures (SSTs) for the three decades 2011-2040. The internal decadal component is derived by harmonic wave expansion analyses based on the quasiperiodic evolution of the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO), as obtained from observational SST datasets. Furthermore, the external decadal component induced by anthropogenic forcing is assessed with a second-order fit based on the ensemble of projected SSTs in the experiments with multiple coupled climate models associated with the third Coupled Model Intercomparison Project (CMIP3) under the Intergovernmental Panels on Climate Change (IPCC) Special Reports on Emissions Scenario (SRES) A1B. A validation for the years from 2002 to 2010 based on a comparison of the predicted and the observed SST and their spatial correlation, as well as the root mean square error (RMSE), suggests that the approach is reasonable overall. In addition, the predicted results over the 50°S-50°N global band, the Indian Ocean, the western Pacific Ocean, the tropical eastern Pacific Ocean, and the North and the South Atlantic Ocean are presented.展开更多
The quality of regional ocean reanalysis data for ＂the joining area of Asia and the Indian-Pacific Ocean （AIPO）＂ has been assessed from the perspective of ENSO-related ocean signals. The results derived from the A...The quality of regional ocean reanalysis data for ＂the joining area of Asia and the Indian-Pacific Ocean （AIPO）＂ has been assessed from the perspective of ENSO-related ocean signals. The results derived from the AIPO reanalysis, including SST, sea surface height （SSH）, and subsurface ocean temperature and currents, are compared with those of Hadley Center Sea Ice and Sea Surface Temperature （HadlSST） data set and Simple Ocean Data Assimilation （SODA） reanalysis data. Both the spatial pattern and the characteristics of evolution of the ENSO-related ocean temperature anomalies are well reproduced by the AIPO reanalysis data. The physical processes proposed to explain the life cycle of ENSO, including the delayed oscillator mechanism, recharge-discharge mechanism, and the zonal advection feedback, are reasonably represented in this dataset. However, the westward Rossby wave signal in 1992 is not obvious in the AIPO data, and the magnitude of the heat content anomalies is different from that of the SODA data. The reason for the discrepancies may lie in the different mod- els and methods for data assimilation and differences in wind stress forcing. The results demonstrate the high reliability of the AIPO reanalysis data in describing ENSO signals, implying its potential application value in ENSO- related studies.展开更多
基金supported by the Nationa Basic Research Program of China, "Oceanic circulation, structure characteristics, variation mechanisms, and climate effects of thewarm pool in the tropical Pacific", under Grant 2012CB417403
文摘In recent decades, the typical E1 Nifio events with the warmest SSTs in the tropical eastern Pacific have become less common, and a different of E1 Nifio with the wannest SSTs in the central the east and west by cooler Pacific, which is flanked on SSTs, has become more frequent. The more recent type of E1 Nifio was referred to as central Pacific E1 Nifio, warm pool E1 Nifio, or dateline E1 Nifio, or the E1 Nifio Modoki. Central Pacific E1 Nifio links to a different tropical-to-extratropical teleconnection and exerts different impacts on climate, and several clas- sification approaches have been proposed. In this study, a new classification approach is proposed, which is based on the linear combination （sum or difference） of the two leading Empirical Orthogonal Functions （EOFs） of tropi- cal Pacific Ocean sea surface temperature anomaly （SSTA）, and the typical E1 Nifio index （TENI） and the central E1 Nifio index （CENI） are able to be derived by projecting the observed SSTA onto these combinations. This classification not only reflects the characteristics of non-orthogonality between the two types of events but also yields one period peaking at approximate two to seven years. In particular, this classification can distin- guish the different impacts of the two types of events on rainfall in the following summer in East China. The typi- cal E1 Nifio events tend to induce intensified rainfall in the Yangtze River valley, whereas the central Pacific El Nifio tends to induce intensified rainfall in the Huaihe River valley. Thus, the present approach may be appropriate for studying the impact of different types of E1 Nifio on the East Asian climate.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDA05090406 and XDA05110203)the special projects of the China Meteorological Administration(Grant No.GYHY201006022)contribution to the DecCen and Blue Arc projects funded by the Research Council of Norway and to the Centre for Climate Dynamics at the Bjerknes Centre
文摘A simple approach that considers both internal decadal variability and the effect of anthropogenic forcing is developed to predict the decadal components of global sea surface temperatures (SSTs) for the three decades 2011-2040. The internal decadal component is derived by harmonic wave expansion analyses based on the quasiperiodic evolution of the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO), as obtained from observational SST datasets. Furthermore, the external decadal component induced by anthropogenic forcing is assessed with a second-order fit based on the ensemble of projected SSTs in the experiments with multiple coupled climate models associated with the third Coupled Model Intercomparison Project (CMIP3) under the Intergovernmental Panels on Climate Change (IPCC) Special Reports on Emissions Scenario (SRES) A1B. A validation for the years from 2002 to 2010 based on a comparison of the predicted and the observed SST and their spatial correlation, as well as the root mean square error (RMSE), suggests that the approach is reasonable overall. In addition, the predicted results over the 50°S-50°N global band, the Indian Ocean, the western Pacific Ocean, the tropical eastern Pacific Ocean, and the North and the South Atlantic Ocean are presented.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KZCX2-YW-Q11-04)the Public Science and Technology Research Funds Projects of Ocean (Grant No. 201105019-3)the National Basic Research Program of China (Grant No. 2010CB951904)
文摘The quality of regional ocean reanalysis data for ＂the joining area of Asia and the Indian-Pacific Ocean （AIPO）＂ has been assessed from the perspective of ENSO-related ocean signals. The results derived from the AIPO reanalysis, including SST, sea surface height （SSH）, and subsurface ocean temperature and currents, are compared with those of Hadley Center Sea Ice and Sea Surface Temperature （HadlSST） data set and Simple Ocean Data Assimilation （SODA） reanalysis data. Both the spatial pattern and the characteristics of evolution of the ENSO-related ocean temperature anomalies are well reproduced by the AIPO reanalysis data. The physical processes proposed to explain the life cycle of ENSO, including the delayed oscillator mechanism, recharge-discharge mechanism, and the zonal advection feedback, are reasonably represented in this dataset. However, the westward Rossby wave signal in 1992 is not obvious in the AIPO data, and the magnitude of the heat content anomalies is different from that of the SODA data. The reason for the discrepancies may lie in the different mod- els and methods for data assimilation and differences in wind stress forcing. The results demonstrate the high reliability of the AIPO reanalysis data in describing ENSO signals, implying its potential application value in ENSO- related studies.
