Based on a daily precipitation observation dataset of 743 stations in China from 1951 2004, the F distribution function is used to calculate the probability distribution of daily precipitation and to define extreme pr...Based on a daily precipitation observation dataset of 743 stations in China from 1951 2004, the F distribution function is used to calculate the probability distribution of daily precipitation and to define extreme precipitation events. Based on this, the relationship of ENSO and the frequency of extreme precipitation events is studied. Results reveal that ENSO events have impact on extreme precipitation events, with different magnitudes at different regions and seasons. In general, during winter and spring, extreme precipitation events occur more often during E1 Nino events than during La Nina events. While during summer and autumn, the opposite is found. The relationship of a two season-lag ENSO and extreme precipitation frequency shows different pattern. Extreme precipitation events occur more often in several regions if an ENSO warm phase happened in the central-eastern tropical Pacific two seasons before. No similar impacts of El Nino and La Nina on the frequency of extreme precipitation events are found.展开更多
Based on the composite result of six major the intraseasonal variation of the East Asian La Nina events during 1979-2012, the authors reveal summer monsoon (EASM) and summer rainfall in East Asia in La Nino years. D...Based on the composite result of six major the intraseasonal variation of the East Asian La Nina events during 1979-2012, the authors reveal summer monsoon (EASM) and summer rainfall in East Asia in La Nino years. Due to a higher SST over the western Pacific warm pool in the proceeding winter and spring, warm pool convection in summer is enhanced, leading to a cyclonic anomaly in the subtropical western Pacific. As a result, the western Pacific subtropical high is located more northeastward, and the seasonal march in East Asia is thus accelerated.This anomalous pattern tends to change with the seasonal march, with a maximum anomaly in July. Besides, there is less Mei-yu rainfall in the Yangtze River basin, with an earlier start and termination. The rainfall distribution in East Asia during La Nino years is characterized bya zonal pattern of less rainfall in eastern China and more rainfall over the oceanic region of the western Pacific. By comparison, a meridional pattern is found during El Nino years, with less rainfall in the tropics and more rainfall in the subtropics and midlatitudes. Therefore, the influence of La Nino on the EASM cannot be simply attributed to an antisymmetric influence of El Nino.展开更多
The interannual variability of the sea surface temperature (SST) in the South China Sea (SCS) is investigated according to its relationship with E1 Nifio/La Nifia (EN/LN) using monthly products from ICOADS. The ...The interannual variability of the sea surface temperature (SST) in the South China Sea (SCS) is investigated according to its relationship with E1 Nifio/La Nifia (EN/LN) using monthly products from ICOADS. The SCS SST bears two peaks associated with EN/LN and shows the asymmetric features. Coinciding with the mature phase of EN/LN, the first SST warming/cooling peaks in December(0)-February(1) (DJF(1)) and centers in the southern part. The major difference is in the amplitude associated with the strength of EN/LN. However, the SCS SST anomaly shows distinct difference after the mature phase of EN/LN. The EN SST warm- ing develops a mid-summer peak in June-August(1) (JJA(1)) and persists up to September-October(l), with the same amplitude of the first warming peak. Whereas the LN SST cooling peaks in May(l), it decays slowly until the end of the year, with amplitude much weaker. Comparing with SST and atmospheric circulations, the weak response and early termination of the second cooling is due to the failure of the cyclonic wind anomalies to develop in the northwest Pacific during JJA(1).展开更多
This study investigated the relationship be- tween the asymmetry in the duration of El Nifio and La Nina and the length of their decaying phases. The results suggested that the duration asymmetry comes from the long d...This study investigated the relationship be- tween the asymmetry in the duration of El Nifio and La Nina and the length of their decaying phases. The results suggested that the duration asymmetry comes from the long decaying ENSO cases rather than the short decaying ones. The evolutions of short decaying El Nino and La Nina are approximately a mirror image with a rapid decline in the following summer for the warm and cold events. However, a robust asymmetry was found in long decaying cases, with a prolonged and re-intensified La Nina in the following winter. The asymmetry for long decaying cases starts from the westward extension of the zonal wind anomalies in a mature winter, and is further contributed to by the air-sea interaction over the tropical Pacific in the following seasons.展开更多
Using the sea surface temperature (SST) predicted for the equatorial Pacific Ocean by the Flexible Global Ocean-Atmosphere-Land System Model-gamil (FGOALS-g), an analysis of the prediction errors was performed for...Using the sea surface temperature (SST) predicted for the equatorial Pacific Ocean by the Flexible Global Ocean-Atmosphere-Land System Model-gamil (FGOALS-g), an analysis of the prediction errors was performed for the seasonally dependent predictability of SST anomalies both for neutral years and for the growth/decay phase of El Nino/La Nina events. The study results indicated that for the SST predictions relating to the growth phase and the decay phase of El Nino events, the prediction errors have a seasonally dependent evolution. The largest increase in errors occurred in the spring season, which indicates that a prominent spring predictability barrier (SPB) occurs during an El Nino-Southern Oscillation (ENSO) warming episode. Furthermore, the SPB associated with the growth-phase prediction is more prominent than that associated with the decay-phase prediction. However, for the neutral years and for the growth and decay phases of La Nifia events, the SPB phenomenon was less prominent. These results indicate that the SPB phenomenon depends extensively on the ENSO events themselves. In particular, the SPB depends on the phases of the ENSO events. These results may provide useful knowledge for improving ENSO forecasting.展开更多
This study presents a detailed analysis of the asymmetric relationships between the warm/cold phase of the El Ni?o–Southern Oscillation and the typical flood/drought years in summer over Chongqing.Furthermore,its und...This study presents a detailed analysis of the asymmetric relationships between the warm/cold phase of the El Ni?o–Southern Oscillation and the typical flood/drought years in summer over Chongqing.Furthermore,its underpinning mechanisms are also explored.The results show that:(1)El Ni?o and La Ni?a have an asymmetric influence on summer precipitation in the following year over Chongqing.Generally,the composite atmospheric circulation anomalies for El Ni?o years are consistent with the composite results for typical flood years in summer over Chongqing,which indicates a tight link between typical flood years in summer over Chongqing and El Ni?o events.However,the relationship between typical drought years in summer over Chongqing and La Ni?a events is not significant.(2)From winter to the following summer,the extent of positive SST anomalies in the equatorial eastern Pacific associated with typical flood years in summer over Chongqing shrinks,whereas in the tropical Indian Ocean,the extent slightly expands.This trend indicates that the impact of El Ni?o on typical flood years in summer over Chongqing is maintained through the‘relay effect’of SSTs in the tropical Indian Ocean,which is the result of a lagged response of positive SST anomalies in the tropical Indian Ocean to El Ni?o events in winter.展开更多
By applying the historical-run outputs from 24 Coupled Model Intercomparison Project Phase 5(CMIP5) models and the NOAA Extended Reconstructed SST V3 b dataset(ERSST), the characteristics of different types of ENSO in...By applying the historical-run outputs from 24 Coupled Model Intercomparison Project Phase 5(CMIP5) models and the NOAA Extended Reconstructed SST V3 b dataset(ERSST), the characteristics of different types of ENSO in the selected CMIP5 models, including cold-season-matured Eastern Pacific(C-EP) ENSO, warmseason-matured EP(W-EP) ENSO, cold-season-matured Central Pacific(C-CP) ENSO, and warm-season-matured CP(W-CP) ENSO, were examined in comparison with those in the ERSST dataset. The results showed that, in general, consistent with observations, EP ENSO events in most of the model runs were relatively much stronger than CP ENSO events, and cold-season-matured ENSO events were relatively much more frequent than warm-season-matured ENSO events for both EP and CP ENSO events. The composite amplitudes of ENSO events in most of the models were generally weaker than in observations, particularly for EP El Ni?o and CP La Ni?a. Moreover, most of the models successfully reproduced the amplitude asymmetries between El Ni?o and La Ni?a for cold-season-matured EP and CP ENSO events, exhibiting an average stronger/weaker EP El Ni?o/La Ni?a regime and a weaker/stronger CP El Ni?o/La Ni?a regime. Most of the models, however, failed to reproduce the observed regimes of stronger/weaker W-EP El Ni?o/ La Ni?a and weaker/stronger W-CP El Ni?o/La Ni?a.展开更多
By analyzing the variability of global SST (sea surface temperature) anomalies, we propose a unified Nifio index using the surface thermal centroid anomaly of the region along the Pacific equator embraced by the 0.7...By analyzing the variability of global SST (sea surface temperature) anomalies, we propose a unified Nifio index using the surface thermal centroid anomaly of the region along the Pacific equator embraced by the 0.7~C contour line of the standard deviation of the SST anomalies and try to unify the traditional Nifio regions into a single entity. The unified Nifio region covers almost all of the traditional Nifio regions. The anomaly time series of the averaged SST over this region are closely correlated to historical Nifio indices. The anomaly time series of the zonal and meridional thermal centroid have close correlation with historical TNI (Trans-Nifio index) indices, showing differences among E1 Nifio (La Nifia) events. The meridional centroid anomaly suggests that areas of maximum temperature anomaly are moving meridionally (although slightly) with synchronous zonal movement. The zonal centroid anomalies of the unified Nifio region are found helpful in the classification of the Eastern Pacific (EP)/Central Pacific (CP) types of E1 Nifio events. More importantly, the zonal centroid anomaly shows that warm areas might move during a single warming/cooling phase. All the current Nifio indices can be well represented by a simple linear combination of unified Nifio indices, which suggests that the thermal anomaly (SSTA) and thermal centroid location anomaly of the unified Nifio region would yield a more complete image of each E1 Nifio/ La Nina event.展开更多
Methods and approaches are discussed that identify and filter off affecting factors (noise) above primary signals,based on the Adaptive-Nework-Based Fuzzy Inference System. Influences of the zonal winds in equatorial ...Methods and approaches are discussed that identify and filter off affecting factors (noise) above primary signals,based on the Adaptive-Nework-Based Fuzzy Inference System. Influences of the zonal winds in equatorial eastern and middle/western Pacific on the SSTA in the equatorial region and their contribution to the latter are diagnosed and verified with observations of a number of significant El Nio and La Nia episodes. New viewpoints are propsed. The methods of wavelet decomposition and reconstruction are used to build a predictive model based on independent domains of frequency,which shows some advantages in composite prediction and prediction validity.The methods presented above are of non-linearity, error-allowing and auto-adaptive/learning, in addition to rapid and easy access,illustrative and quantitative presentation,and analyzed results that agree generally with facts. They are useful in diagnosing and predicting the El Nio and La Nia problems that are just roughly described in dynamics.展开更多
The historical data of phytoplankton and chlorophyll a(Chl a)(1990–2002)obtained during the Chinese National Antarctic Research Expedition(CHINARE)in the Prydz Bay have been integrated.The results showed that the tem...The historical data of phytoplankton and chlorophyll a(Chl a)(1990–2002)obtained during the Chinese National Antarctic Research Expedition(CHINARE)in the Prydz Bay have been integrated.The results showed that the temperature,salinity,nutrients,and oxygen of seawater changed when El Nino/La Nina occurred.The variation of biological communities reflected the response of ecosystem to environmental changes.During El Ni?o period,Chl a concentration and phytoplankton community structure changed significantly,and the relative proportion of diatoms increased while dinoflagellates decreased.During La Ni?a period,the proportion of diatoms decreased,but the golden-brown algae and blue-green algae increased significantly.The variation of phytoplankton population directly affected the biodiversity of the bay,which were also quite sensitive to the marine environment changes.Meanwhile,the satellite remote sensing data of 2002–2011(December–March)have been used to study the temporal connection change of Chl a and phytoplankton in the Prydz Bay.We found that there were significant differences in the monthly variation characteristics of satellite remote sensing Chl a and sea surface temperature(SST),which had some links with sea ice melting and El Ni?o/La Ni?a events.We found that the start time of bloom advanced,lagged or synchronized with the changes of the SST,and we also found the occurrence time of phytoplankton bloom corresponded with the sea ice melting inner bay.To some extent,this study will help us understand the relationships between ENSO events and the phytoplankton bloom in the Southern Ocean.展开更多
Anthropogenic aerosols are effective radiative forcing agents that perturb the Earth’s climate. Major emission sources shifted from the western to eastern hemisphere around the 1980 s. An ensemble of single-forcing s...Anthropogenic aerosols are effective radiative forcing agents that perturb the Earth’s climate. Major emission sources shifted from the western to eastern hemisphere around the 1980 s. An ensemble of single-forcing simulations with an Earth System Model reveals two stages of aerosol-induced climate change in response to the global aerosol increase for 1940–1980 and the zonal shift of aerosol forcing for 1980–2020, respectively. Here, using idealized experiments with hierarchical models, we show that the aerosol increase and shift modes of aerosol-forced climate change are dynamically distinct, governed by the inter-hemispheric energy transport and basin-wide ocean–atmosphere interactions, respectively.The aerosol increase mode dominates in the motionless slab ocean model but is damped by ocean dynamics. Free of zonal-mean energy perturbation, characterized by an anomalous North Atlantic warming and North Pacific cooling, the zonal shift mode is amplified by interactive ocean dynamics through Bjerknes feedback. Both modes contribute to a La Ni?a-like pattern over the equatorial Pacific. We suggest that a global perspective that accommodates the evolving geographical distribution of aerosol emissions is vital for understanding the aerosol-forced historical climate change.展开更多
A class of coupled system of the El Nino/La Nino-Southern Oscillation (ENSO)mechanism is studied. Using the perturbed theory, the asymptotic expansions of the solution for ENSOmodel are obtained and the asymptotic beh...A class of coupled system of the El Nino/La Nino-Southern Oscillation (ENSO)mechanism is studied. Using the perturbed theory, the asymptotic expansions of the solution for ENSOmodel are obtained and the asymptotic behavior of the solution for corresponding problem isconsidered. And it is pointed out that the solution tends to the corresponding attractor as t → ∞.展开更多
基金supported by the program under Grant No.2007BAC29B04
文摘Based on a daily precipitation observation dataset of 743 stations in China from 1951 2004, the F distribution function is used to calculate the probability distribution of daily precipitation and to define extreme precipitation events. Based on this, the relationship of ENSO and the frequency of extreme precipitation events is studied. Results reveal that ENSO events have impact on extreme precipitation events, with different magnitudes at different regions and seasons. In general, during winter and spring, extreme precipitation events occur more often during E1 Nino events than during La Nina events. While during summer and autumn, the opposite is found. The relationship of a two season-lag ENSO and extreme precipitation frequency shows different pattern. Extreme precipitation events occur more often in several regions if an ENSO warm phase happened in the central-eastern tropical Pacific two seasons before. No similar impacts of El Nino and La Nina on the frequency of extreme precipitation events are found.
基金supported by the National Natural Science Foundation of China[grant number 41475052]
文摘Based on the composite result of six major the intraseasonal variation of the East Asian La Nina events during 1979-2012, the authors reveal summer monsoon (EASM) and summer rainfall in East Asia in La Nino years. Due to a higher SST over the western Pacific warm pool in the proceeding winter and spring, warm pool convection in summer is enhanced, leading to a cyclonic anomaly in the subtropical western Pacific. As a result, the western Pacific subtropical high is located more northeastward, and the seasonal march in East Asia is thus accelerated.This anomalous pattern tends to change with the seasonal march, with a maximum anomaly in July. Besides, there is less Mei-yu rainfall in the Yangtze River basin, with an earlier start and termination. The rainfall distribution in East Asia during La Nino years is characterized bya zonal pattern of less rainfall in eastern China and more rainfall over the oceanic region of the western Pacific. By comparison, a meridional pattern is found during El Nino years, with less rainfall in the tropics and more rainfall in the subtropics and midlatitudes. Therefore, the influence of La Nino on the EASM cannot be simply attributed to an antisymmetric influence of El Nino.
基金supported by the National Basic Research Program of China(2012CB955603,2010CB950302)the Chinese Academy of Sciences(XDA05090404,LT-0ZZ1202)
文摘The interannual variability of the sea surface temperature (SST) in the South China Sea (SCS) is investigated according to its relationship with E1 Nifio/La Nifia (EN/LN) using monthly products from ICOADS. The SCS SST bears two peaks associated with EN/LN and shows the asymmetric features. Coinciding with the mature phase of EN/LN, the first SST warming/cooling peaks in December(0)-February(1) (DJF(1)) and centers in the southern part. The major difference is in the amplitude associated with the strength of EN/LN. However, the SCS SST anomaly shows distinct difference after the mature phase of EN/LN. The EN SST warm- ing develops a mid-summer peak in June-August(1) (JJA(1)) and persists up to September-October(l), with the same amplitude of the first warming peak. Whereas the LN SST cooling peaks in May(l), it decays slowly until the end of the year, with amplitude much weaker. Comparing with SST and atmospheric circulations, the weak response and early termination of the second cooling is due to the failure of the cyclonic wind anomalies to develop in the northwest Pacific during JJA(1).
基金supported by the National Natural Science Foundation of China (Grant No. 41105046)
文摘This study investigated the relationship be- tween the asymmetry in the duration of El Nifio and La Nina and the length of their decaying phases. The results suggested that the duration asymmetry comes from the long decaying ENSO cases rather than the short decaying ones. The evolutions of short decaying El Nino and La Nina are approximately a mirror image with a rapid decline in the following summer for the warm and cold events. However, a robust asymmetry was found in long decaying cases, with a prolonged and re-intensified La Nina in the following winter. The asymmetry for long decaying cases starts from the westward extension of the zonal wind anomalies in a mature winter, and is further contributed to by the air-sea interaction over the tropical Pacific in the following seasons.
基金sponsored by the Knowledge Innovation Programof the Chinese Academy of Sciences (Grant No. KZCX2-YW-QN203)the National Basic Research Program of China (GrantNos. 2010CB950400 and 2007CB411800)
文摘Using the sea surface temperature (SST) predicted for the equatorial Pacific Ocean by the Flexible Global Ocean-Atmosphere-Land System Model-gamil (FGOALS-g), an analysis of the prediction errors was performed for the seasonally dependent predictability of SST anomalies both for neutral years and for the growth/decay phase of El Nino/La Nina events. The study results indicated that for the SST predictions relating to the growth phase and the decay phase of El Nino events, the prediction errors have a seasonally dependent evolution. The largest increase in errors occurred in the spring season, which indicates that a prominent spring predictability barrier (SPB) occurs during an El Nino-Southern Oscillation (ENSO) warming episode. Furthermore, the SPB associated with the growth-phase prediction is more prominent than that associated with the decay-phase prediction. However, for the neutral years and for the growth and decay phases of La Nifia events, the SPB phenomenon was less prominent. These results indicate that the SPB phenomenon depends extensively on the ENSO events themselves. In particular, the SPB depends on the phases of the ENSO events. These results may provide useful knowledge for improving ENSO forecasting.
基金This research was financially supported by the General Project of Technical Innovation and Application Demonstration in Chongqing,China[grant number cstc2018jscx-msybX0165]the Special Fund for the Development of Key Technology in Weather Forecasting of the China Meteorological Administration[grant number YBGJXM(2018)04-08]the National Natural Science Foundation of China[grant number 41875111].
文摘This study presents a detailed analysis of the asymmetric relationships between the warm/cold phase of the El Ni?o–Southern Oscillation and the typical flood/drought years in summer over Chongqing.Furthermore,its underpinning mechanisms are also explored.The results show that:(1)El Ni?o and La Ni?a have an asymmetric influence on summer precipitation in the following year over Chongqing.Generally,the composite atmospheric circulation anomalies for El Ni?o years are consistent with the composite results for typical flood years in summer over Chongqing,which indicates a tight link between typical flood years in summer over Chongqing and El Ni?o events.However,the relationship between typical drought years in summer over Chongqing and La Ni?a events is not significant.(2)From winter to the following summer,the extent of positive SST anomalies in the equatorial eastern Pacific associated with typical flood years in summer over Chongqing shrinks,whereas in the tropical Indian Ocean,the extent slightly expands.This trend indicates that the impact of El Ni?o on typical flood years in summer over Chongqing is maintained through the‘relay effect’of SSTs in the tropical Indian Ocean,which is the result of a lagged response of positive SST anomalies in the tropical Indian Ocean to El Ni?o events in winter.
基金supported by the National Basic Research Program of China (Grant Nos. 2010CB950400 and 2010CB428603)
文摘By applying the historical-run outputs from 24 Coupled Model Intercomparison Project Phase 5(CMIP5) models and the NOAA Extended Reconstructed SST V3 b dataset(ERSST), the characteristics of different types of ENSO in the selected CMIP5 models, including cold-season-matured Eastern Pacific(C-EP) ENSO, warmseason-matured EP(W-EP) ENSO, cold-season-matured Central Pacific(C-CP) ENSO, and warm-season-matured CP(W-CP) ENSO, were examined in comparison with those in the ERSST dataset. The results showed that, in general, consistent with observations, EP ENSO events in most of the model runs were relatively much stronger than CP ENSO events, and cold-season-matured ENSO events were relatively much more frequent than warm-season-matured ENSO events for both EP and CP ENSO events. The composite amplitudes of ENSO events in most of the models were generally weaker than in observations, particularly for EP El Ni?o and CP La Ni?a. Moreover, most of the models successfully reproduced the amplitude asymmetries between El Ni?o and La Ni?a for cold-season-matured EP and CP ENSO events, exhibiting an average stronger/weaker EP El Ni?o/La Ni?a regime and a weaker/stronger CP El Ni?o/La Ni?a regime. Most of the models, however, failed to reproduce the observed regimes of stronger/weaker W-EP El Ni?o/ La Ni?a and weaker/stronger W-CP El Ni?o/La Ni?a.
基金Supported by the National Basic Research Program of China(973 Program)(Nos.2012CB957704,2009CB723903)the National Natural Science Foundation of China(Nos.40506035,40876005)
文摘By analyzing the variability of global SST (sea surface temperature) anomalies, we propose a unified Nifio index using the surface thermal centroid anomaly of the region along the Pacific equator embraced by the 0.7~C contour line of the standard deviation of the SST anomalies and try to unify the traditional Nifio regions into a single entity. The unified Nifio region covers almost all of the traditional Nifio regions. The anomaly time series of the averaged SST over this region are closely correlated to historical Nifio indices. The anomaly time series of the zonal and meridional thermal centroid have close correlation with historical TNI (Trans-Nifio index) indices, showing differences among E1 Nifio (La Nifia) events. The meridional centroid anomaly suggests that areas of maximum temperature anomaly are moving meridionally (although slightly) with synchronous zonal movement. The zonal centroid anomalies of the unified Nifio region are found helpful in the classification of the Eastern Pacific (EP)/Central Pacific (CP) types of E1 Nifio events. More importantly, the zonal centroid anomaly shows that warm areas might move during a single warming/cooling phase. All the current Nifio indices can be well represented by a simple linear combination of unified Nifio indices, which suggests that the thermal anomaly (SSTA) and thermal centroid location anomaly of the unified Nifio region would yield a more complete image of each E1 Nifio/ La Nina event.
文摘Methods and approaches are discussed that identify and filter off affecting factors (noise) above primary signals,based on the Adaptive-Nework-Based Fuzzy Inference System. Influences of the zonal winds in equatorial eastern and middle/western Pacific on the SSTA in the equatorial region and their contribution to the latter are diagnosed and verified with observations of a number of significant El Nio and La Nia episodes. New viewpoints are propsed. The methods of wavelet decomposition and reconstruction are used to build a predictive model based on independent domains of frequency,which shows some advantages in composite prediction and prediction validity.The methods presented above are of non-linearity, error-allowing and auto-adaptive/learning, in addition to rapid and easy access,illustrative and quantitative presentation,and analyzed results that agree generally with facts. They are useful in diagnosing and predicting the El Nio and La Nia problems that are just roughly described in dynamics.
基金supported by the National Natural Science Foundation of China(Grant Nos.40876104,41076134,41306202,and 41376193)the Scientific Research Fund of the Second Institute,SOA(Grant Nos.JT1208,JG1217 and JG1218)
文摘The historical data of phytoplankton and chlorophyll a(Chl a)(1990–2002)obtained during the Chinese National Antarctic Research Expedition(CHINARE)in the Prydz Bay have been integrated.The results showed that the temperature,salinity,nutrients,and oxygen of seawater changed when El Nino/La Nina occurred.The variation of biological communities reflected the response of ecosystem to environmental changes.During El Ni?o period,Chl a concentration and phytoplankton community structure changed significantly,and the relative proportion of diatoms increased while dinoflagellates decreased.During La Ni?a period,the proportion of diatoms decreased,but the golden-brown algae and blue-green algae increased significantly.The variation of phytoplankton population directly affected the biodiversity of the bay,which were also quite sensitive to the marine environment changes.Meanwhile,the satellite remote sensing data of 2002–2011(December–March)have been used to study the temporal connection change of Chl a and phytoplankton in the Prydz Bay.We found that there were significant differences in the monthly variation characteristics of satellite remote sensing Chl a and sea surface temperature(SST),which had some links with sea ice melting and El Ni?o/La Ni?a events.We found that the start time of bloom advanced,lagged or synchronized with the changes of the SST,and we also found the occurrence time of phytoplankton bloom corresponded with the sea ice melting inner bay.To some extent,this study will help us understand the relationships between ENSO events and the phytoplankton bloom in the Southern Ocean.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (2016R1A1A3A04005520 and 2017K2A9A1A06056874)supported by the National Science Foundation (AGS-1934392)+1 种基金The Community Earth System Model project is supported primarily by the National Science Foundation (NSF)supported by the National Center for Atmospheric Research, which is a major facility sponsored by the NSF under Cooperative Agreement (1852977)。
文摘Anthropogenic aerosols are effective radiative forcing agents that perturb the Earth’s climate. Major emission sources shifted from the western to eastern hemisphere around the 1980 s. An ensemble of single-forcing simulations with an Earth System Model reveals two stages of aerosol-induced climate change in response to the global aerosol increase for 1940–1980 and the zonal shift of aerosol forcing for 1980–2020, respectively. Here, using idealized experiments with hierarchical models, we show that the aerosol increase and shift modes of aerosol-forced climate change are dynamically distinct, governed by the inter-hemispheric energy transport and basin-wide ocean–atmosphere interactions, respectively.The aerosol increase mode dominates in the motionless slab ocean model but is damped by ocean dynamics. Free of zonal-mean energy perturbation, characterized by an anomalous North Atlantic warming and North Pacific cooling, the zonal shift mode is amplified by interactive ocean dynamics through Bjerknes feedback. Both modes contribute to a La Ni?a-like pattern over the equatorial Pacific. We suggest that a global perspective that accommodates the evolving geographical distribution of aerosol emissions is vital for understanding the aerosol-forced historical climate change.
基金This work is supported by the National Natural Science Foundation of China (No 90211004 and 10471039)the Natural Science Foundatuon of Zhejiang Province (No 102009).
文摘A class of coupled system of the El Nino/La Nino-Southern Oscillation (ENSO)mechanism is studied. Using the perturbed theory, the asymptotic expansions of the solution for ENSOmodel are obtained and the asymptotic behavior of the solution for corresponding problem isconsidered. And it is pointed out that the solution tends to the corresponding attractor as t → ∞.