The distribution of hydrography and circulation in the eastern tropical Indian Ocean(ETIO) during April-May 2011 were analyzed using cruise observations,satellite observations,and historic hydrographic data.It was obs...The distribution of hydrography and circulation in the eastern tropical Indian Ocean(ETIO) during April-May 2011 were analyzed using cruise observations,satellite observations,and historic hydrographic data.It was observed that warm water(>28℃) occupies the upper 50-m layer in the ETIO.Low-salinity surface water was observed at the mouth of the Bay of Bengal(BOB),which further extends to the Arabian Sea and off Sumatra via the Sri Lanka coast and the eastern bay mouth.Arabian Sea high-salinity water(ASHSW) is carried eastward along the equator to around 90°E by the equatorial undercurrent(EUC).It also runs south of Sri Lanka(north to 3°N) and in the western bay mouth(west to 87°E) but is much shallower than its counterpart at the equator.It is suggested to be the residual of the ASHSW,which intrudes into the BOB during the preceding southwest monsoon.Our results also show that,in the south of Sri Lanka,just below this subsurface high-salinity water,very-low-salinity water(about 34.8) occurs at depths of 100-200 m.Further analysis suggests that this low-salinity water comes from the BOB.展开更多
Based on the comparison between several model outputs from CMIP5 （Coupled Model Intercomparison Project Phase-5） and the satellite rainfall mapping data of GSMaP （global satellite mapping of precipitation）, This p...Based on the comparison between several model outputs from CMIP5 （Coupled Model Intercomparison Project Phase-5） and the satellite rainfall mapping data of GSMaP （global satellite mapping of precipitation）, This paper selected MIROC4h as a future projection of rainfall in the Sittaung River basin, Myanmar, with the fine spatial resolution of 0.5°. At first, MIROC4h projection towards 2035 was corrected by using the error trend （GSMaP-MIROC4h） for nine years over-rapping of both outputs from 2006 to 2014. Assuming the seasonal autoregressive processes, future error trend at each grid point was estimated by the time series forecast of SARMAP processes using the nine years training data. Then future projection correction was done by M1ROC4h output plus error trend at each grid point to obtain the corrected MIROC4h precipitation. As a historical analysis, using the corrected precipitation in the Sittaung River basin and observed river discharge at the outlet of the river, the hydrological model （HSPF （Hydrological Simulation Program Fortran）） calibration was carried out with consideration of the water utilization data for darn/reservoir and irrigation. As a projection analysis, future simulation of hourly discharge at the outlet of Sittaung River from 2015 to 2035 was conducted by using the corrected MIROC4h precipitation. The results of projection analysis show that high risks of flood will appear in 2023 and 2028 and the risks of draught will be expected in 2019-2021.展开更多
In the past 10 years （2004-2013）, annual open cruise during late summer provided new opportunities for comprehensive studies in the Northern South China Sea （NSCS）. The 10-year field investigation program was carr...In the past 10 years （2004-2013）, annual open cruise during late summer provided new opportunities for comprehensive studies in the Northern South China Sea （NSCS）. The 10-year field investigation program was carried out by the South China Sea Institute of Oceanology, Chinese Academy of Sciences （SCSIO, CAS）. Measurements inclu- ded water mass property, ocean circulation, atmospheric structure, and chemical and biological elements. The observation data collected during these open cruises have been intensively used in the studies of marine oceanographic, meteorological, chemical, and biological processes in the NSCS. In this study, comprehensive assessment of data application in oceanographic and meteorological studies is provided： （1） the property and variability of water masses in different layers; （2） the distribution of main currents and three-dimensional structure of mesoscale eddies; and （3） atmospheric structure and its feedback to the ocean. With the continuance of open cruises, it is feasible to construct high- quality, gridded climatological marine meteorological datasets in the NSCS in the near future.展开更多
Understanding the regional hydrological response to varying CO_(2)concentration is critical for cost-benefit analysis of mitigation and adaptation polices in the near future. To characterize summer monsoon rainfall ch...Understanding the regional hydrological response to varying CO_(2)concentration is critical for cost-benefit analysis of mitigation and adaptation polices in the near future. To characterize summer monsoon rainfall change in East Asia in a changing CO_(2)pathway, we used the Community Earth System Model(CESM) with28 ensemble members in which the CO_(2)concentration increases at a rate of 1% per year until its quadrupling peak, i.e., 1468 ppm(ramp-up period), followed by a decrease of 1% per year until the present-day climate conditions, i.e., 367 ppm(ramp-down period). Although the CO_(2)concentration change is symmetric in time, the amount of summer rainfall anomaly in East Asia is increased 42% during a rampdown period than that during a ramp-up period when the two periods of the same CO_(2)concentration are compared. This asymmetrical rainfall response is mainly due to an enhanced El Ni?o-like warming pattern as well as its associated increase in the sea surface temperature in the western North Pacific during a ramp-down period. These sea surface temperature patterns enhance the atmospheric teleconnections and the local meridional circulations around East Asia, resulting in more rainfall over East Asia during a ramp-down period. This result implies that the removal of CO_(2)does not guarantee the return of regional rainfall to the previous climate state with the same CO_(2)concentration.展开更多
基金supported by the Ocean Public Welfare Scientific Research Project,State Oceanic Administration(Grant No.201005033-4)Comprehensive Fields Experiments of Oceanology in Indian Ocean in 2011(Grant No.41049903)+1 种基金the National Natural Science Foundation of China(Grant No.40806014)the National Basic Research Program of China(Grant Nos.2009CB421205 and 2011CB403502)
文摘The distribution of hydrography and circulation in the eastern tropical Indian Ocean(ETIO) during April-May 2011 were analyzed using cruise observations,satellite observations,and historic hydrographic data.It was observed that warm water(>28℃) occupies the upper 50-m layer in the ETIO.Low-salinity surface water was observed at the mouth of the Bay of Bengal(BOB),which further extends to the Arabian Sea and off Sumatra via the Sri Lanka coast and the eastern bay mouth.Arabian Sea high-salinity water(ASHSW) is carried eastward along the equator to around 90°E by the equatorial undercurrent(EUC).It also runs south of Sri Lanka(north to 3°N) and in the western bay mouth(west to 87°E) but is much shallower than its counterpart at the equator.It is suggested to be the residual of the ASHSW,which intrudes into the BOB during the preceding southwest monsoon.Our results also show that,in the south of Sri Lanka,just below this subsurface high-salinity water,very-low-salinity water(about 34.8) occurs at depths of 100-200 m.Further analysis suggests that this low-salinity water comes from the BOB.
文摘Based on the comparison between several model outputs from CMIP5 （Coupled Model Intercomparison Project Phase-5） and the satellite rainfall mapping data of GSMaP （global satellite mapping of precipitation）, This paper selected MIROC4h as a future projection of rainfall in the Sittaung River basin, Myanmar, with the fine spatial resolution of 0.5°. At first, MIROC4h projection towards 2035 was corrected by using the error trend （GSMaP-MIROC4h） for nine years over-rapping of both outputs from 2006 to 2014. Assuming the seasonal autoregressive processes, future error trend at each grid point was estimated by the time series forecast of SARMAP processes using the nine years training data. Then future projection correction was done by M1ROC4h output plus error trend at each grid point to obtain the corrected MIROC4h precipitation. As a historical analysis, using the corrected precipitation in the Sittaung River basin and observed river discharge at the outlet of the river, the hydrological model （HSPF （Hydrological Simulation Program Fortran）） calibration was carried out with consideration of the water utilization data for darn/reservoir and irrigation. As a projection analysis, future simulation of hourly discharge at the outlet of Sittaung River from 2015 to 2035 was conducted by using the corrected MIROC4h precipitation. The results of projection analysis show that high risks of flood will appear in 2023 and 2028 and the risks of draught will be expected in 2019-2021.
基金Constructive comments by three reviewers are gratefully acknowledged. Special gratitude goes to our colleagues Drs. Rui Shi, Jian Li, and Ke Huang for their help in data collection. This work was supported by the National Basic Research Program of China （2011CB403501）, the Strategic Priority Research Program of the Chinese Academy of Sciences （XDAll010403 and XDA11010 302）, Sanya and Chinese Academy of Sciences Cooperation Project （2013YD77）, the National Natural Science Foundation of China （41276024, 41206011, 41106028, 41406038, 41306012, 41306014, 41476014, 41476012 and 41406131）, the Infrastructure Facilities Project of Xisha station and Nansha station （KZCX2-EW-Y040）, and the Major National Scientific Instrument and Equipment Develop- ment Project （2012YQ12003910）.
文摘In the past 10 years （2004-2013）, annual open cruise during late summer provided new opportunities for comprehensive studies in the Northern South China Sea （NSCS）. The 10-year field investigation program was carried out by the South China Sea Institute of Oceanology, Chinese Academy of Sciences （SCSIO, CAS）. Measurements inclu- ded water mass property, ocean circulation, atmospheric structure, and chemical and biological elements. The observation data collected during these open cruises have been intensively used in the studies of marine oceanographic, meteorological, chemical, and biological processes in the NSCS. In this study, comprehensive assessment of data application in oceanographic and meteorological studies is provided： （1） the property and variability of water masses in different layers; （2） the distribution of main currents and three-dimensional structure of mesoscale eddies; and （3） atmospheric structure and its feedback to the ocean. With the continuance of open cruises, it is feasible to construct high- quality, gridded climatological marine meteorological datasets in the NSCS in the near future.
基金supported by the National Research Foundation of Korea(NRF) grant(NRF-2018R1A5A1024958)。
文摘Understanding the regional hydrological response to varying CO_(2)concentration is critical for cost-benefit analysis of mitigation and adaptation polices in the near future. To characterize summer monsoon rainfall change in East Asia in a changing CO_(2)pathway, we used the Community Earth System Model(CESM) with28 ensemble members in which the CO_(2)concentration increases at a rate of 1% per year until its quadrupling peak, i.e., 1468 ppm(ramp-up period), followed by a decrease of 1% per year until the present-day climate conditions, i.e., 367 ppm(ramp-down period). Although the CO_(2)concentration change is symmetric in time, the amount of summer rainfall anomaly in East Asia is increased 42% during a rampdown period than that during a ramp-up period when the two periods of the same CO_(2)concentration are compared. This asymmetrical rainfall response is mainly due to an enhanced El Ni?o-like warming pattern as well as its associated increase in the sea surface temperature in the western North Pacific during a ramp-down period. These sea surface temperature patterns enhance the atmospheric teleconnections and the local meridional circulations around East Asia, resulting in more rainfall over East Asia during a ramp-down period. This result implies that the removal of CO_(2)does not guarantee the return of regional rainfall to the previous climate state with the same CO_(2)concentration.
