The upper-ocean responses to Typhoon Megi （2010） are investigated using data from ARGO floats and the satellite TMI. The experiments are conducted using a three-dimensional Princeton Ocean Model （POM） to assess th...The upper-ocean responses to Typhoon Megi （2010） are investigated using data from ARGO floats and the satellite TMI. The experiments are conducted using a three-dimensional Princeton Ocean Model （POM） to assess the storm, which affected the Northwest Pacific Ocean （NWP） and the South China Sea （SCS）. Results show that the upwelling and entrainment experiment together account for 93% of the SST anomalies, where typhoon-induced upwelling may cause strong ocean cooling. In addition, the anomalous SST cooling is stronger in the SCS than in the NWP. The most striking feature of the ocean response is the presence of a two-layer inertial wave in the SCS--a feature that is absent in the NWE The near-inertial oscillations can be generated as typhoon wakes, which have maximum flow velocity in the surface mixed layer and may last for a few days, after the typhoon＇s passage. Along the typhoon tracks, the horizontal currents in the upper ocean show a series of alternating negative and positive anomalies emanating from the typhoon.展开更多
Winter coastal upwelling off northwest Borneo in the South China Sea （SCS） is investigated by using satellite data, climatological temperature and salinity fields and reanalysis data. The upwelling forms in Decem- b...Winter coastal upwelling off northwest Borneo in the South China Sea （SCS） is investigated by using satellite data, climatological temperature and salinity fields and reanalysis data. The upwelling forms in Decem- ber, matures in January, starts to decay in February and almost disappears in March. Both Ekman trans- port induced by the alongshore winter monsoon and Ekman pumping due to orographic wind stress curl are favorable for the upwelling. Transport estimates demonstrate that the month-to-month variability of Ekman transport and Ekman pumping are both consistent with that of winter coastal upwelling, but Ek- man transport is two times larger than Ekman pumping in January and February. Under the influence of E1 Nino-Southern Oscillation （ENSO）, the upwelling shows remarkable interannual variability： during winter of El Nino （La Nina） years, an anticyclonic （a cyclonic） wind anomaly is established in the SCS, which behaves a northeasterly （southwesterly） anomaly and a positive （negative） wind stress curl anomaly off the north- west Borneo coast, enhancing （reducing） the upwelling and causing anomalous surface cooling （warming） and higher （lower） chlorophyll concentration. The sea surface temperature anomaly （SSTA） associated with ENSO off the northwest Borneo coast has an opposite phase to that off southeast Vietnam, resulting in a SSTA seesaw pattern in the southern SCS in winter.展开更多
The Pearl River Mouth Basin, which is situated on the northern margin of the South China Sea, has attracted great attention not only because of its tectonic setting but also because of its abundant hydrocarbon resourc...The Pearl River Mouth Basin, which is situated on the northern margin of the South China Sea, has attracted great attention not only because of its tectonic setting but also because of its abundant hydrocarbon resources. We have analyzed the Cenozoic tectonic subsidence history of 4 drilled wells and 43 artificial wells from the Zhu 1 Sub-basin of the Pearl River Mouth Basin by back-stripping, using newly interpreted seismic profiles. We also calculated the average tectonic sub- sidence rates of the four sags in the Zhu 1 Sub-basin. The rifting and post-rifting stages are separated by abrupt changes in the tectonic subsidence curves and average subsidence rates. In the eastem sags of the Zhu 1 Sub- basin, tectonic subsidence started to slow at ca. 30 Ma, compared with ca. 23.8 Ma in the western sags. This probably corresponds to the timing of break-up and suggests that tiffing in the Pearl River Mouth Basin ended earlier in the eastern sags than in the western sags. Anomalously accelerated tectonic subsidence occurred at 17.5-16.4 Ma during the post-tiffing stage, with average subsidence rates as high as 301.9 m/Myr. This distin- guishes the Pearl River Mouth Basin from classical Atlantic passive continental marginal basins, which demonstrate exponentially decaying post-rift tectonic subsidence.展开更多
Based on the analysis of tropical cyclone （TC） database in the Northwest Pacific （NWP） from 1945 to 2008, we not only extract the temporal variation of TC intensity and frequency, but also give their spatial distr...Based on the analysis of tropical cyclone （TC） database in the Northwest Pacific （NWP） from 1945 to 2008, we not only extract the temporal variation of TC intensity and frequency, but also give their spatial distribution both in the NWP and in the South China Sea （SCS）. The results show that there is an observational increase of TC activities, which manifests as the enhancement of the power dissipation index （PDI） and the growth of TC frequency, especially for typhoons and strong typhoons. The inbomogeneous spatial distributions of TC frequency and intensity are also provided both in the NWP and in the SCS. For example, the region of Zhongsha Islands and Dongsha Islands in the SCS （15°-22°N, 115° - 120°E）, west to the Philippine Islands is the place with frequent occurrence of strong typhoons, among which the wind speed of 7 TCs in 64 years exceeds 60 m/s.展开更多
基金supported by the National Key Basic Research and Development Plan(Grant No.2015CB953900)the National Natural Science Foundation of China(Grant No.41176005)+1 种基金the Public Science and Technology Research Funds Projects of the Ocean(Grant No.GYHY201105018)the China R&D Special Fund for Public Welfare Industry(GYHY 201306016)
文摘The upper-ocean responses to Typhoon Megi （2010） are investigated using data from ARGO floats and the satellite TMI. The experiments are conducted using a three-dimensional Princeton Ocean Model （POM） to assess the storm, which affected the Northwest Pacific Ocean （NWP） and the South China Sea （SCS）. Results show that the upwelling and entrainment experiment together account for 93% of the SST anomalies, where typhoon-induced upwelling may cause strong ocean cooling. In addition, the anomalous SST cooling is stronger in the SCS than in the NWP. The most striking feature of the ocean response is the presence of a two-layer inertial wave in the SCS--a feature that is absent in the NWE The near-inertial oscillations can be generated as typhoon wakes, which have maximum flow velocity in the surface mixed layer and may last for a few days, after the typhoon＇s passage. Along the typhoon tracks, the horizontal currents in the upper ocean show a series of alternating negative and positive anomalies emanating from the typhoon.
基金The National Natural Science Foundation of China under contract No.91128212the National Natural Science Foundation of China under contract No.41306024+3 种基金the National Basic Research Program of China under contract No.2013CB430301the National Science Fund of China for Distinguished Young Scholars(NSFDYS)under contract No.41125019the Project of Global Change and Air-Sea Interaction under con-tract No.GASI-03-01-03-03the Basic Research Program of Second Institute of Oceanography,State Oceanic Administration of China under contract No.JT1301
文摘Winter coastal upwelling off northwest Borneo in the South China Sea （SCS） is investigated by using satellite data, climatological temperature and salinity fields and reanalysis data. The upwelling forms in Decem- ber, matures in January, starts to decay in February and almost disappears in March. Both Ekman trans- port induced by the alongshore winter monsoon and Ekman pumping due to orographic wind stress curl are favorable for the upwelling. Transport estimates demonstrate that the month-to-month variability of Ekman transport and Ekman pumping are both consistent with that of winter coastal upwelling, but Ek- man transport is two times larger than Ekman pumping in January and February. Under the influence of E1 Nino-Southern Oscillation （ENSO）, the upwelling shows remarkable interannual variability： during winter of El Nino （La Nina） years, an anticyclonic （a cyclonic） wind anomaly is established in the SCS, which behaves a northeasterly （southwesterly） anomaly and a positive （negative） wind stress curl anomaly off the north- west Borneo coast, enhancing （reducing） the upwelling and causing anomalous surface cooling （warming） and higher （lower） chlorophyll concentration. The sea surface temperature anomaly （SSTA） associated with ENSO off the northwest Borneo coast has an opposite phase to that off southeast Vietnam, resulting in a SSTA seesaw pattern in the southern SCS in winter.
文摘The Pearl River Mouth Basin, which is situated on the northern margin of the South China Sea, has attracted great attention not only because of its tectonic setting but also because of its abundant hydrocarbon resources. We have analyzed the Cenozoic tectonic subsidence history of 4 drilled wells and 43 artificial wells from the Zhu 1 Sub-basin of the Pearl River Mouth Basin by back-stripping, using newly interpreted seismic profiles. We also calculated the average tectonic sub- sidence rates of the four sags in the Zhu 1 Sub-basin. The rifting and post-rifting stages are separated by abrupt changes in the tectonic subsidence curves and average subsidence rates. In the eastem sags of the Zhu 1 Sub- basin, tectonic subsidence started to slow at ca. 30 Ma, compared with ca. 23.8 Ma in the western sags. This probably corresponds to the timing of break-up and suggests that tiffing in the Pearl River Mouth Basin ended earlier in the eastern sags than in the western sags. Anomalously accelerated tectonic subsidence occurred at 17.5-16.4 Ma during the post-tiffing stage, with average subsidence rates as high as 301.9 m/Myr. This distin- guishes the Pearl River Mouth Basin from classical Atlantic passive continental marginal basins, which demonstrate exponentially decaying post-rift tectonic subsidence.
基金supported by the National High Technology Research and Development Program of China(863 Program,Grant No.2006AA09A103-4)the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KJCX-YW-L02)
文摘Based on the analysis of tropical cyclone （TC） database in the Northwest Pacific （NWP） from 1945 to 2008, we not only extract the temporal variation of TC intensity and frequency, but also give their spatial distribution both in the NWP and in the South China Sea （SCS）. The results show that there is an observational increase of TC activities, which manifests as the enhancement of the power dissipation index （PDI） and the growth of TC frequency, especially for typhoons and strong typhoons. The inbomogeneous spatial distributions of TC frequency and intensity are also provided both in the NWP and in the SCS. For example, the region of Zhongsha Islands and Dongsha Islands in the SCS （15°-22°N, 115° - 120°E）, west to the Philippine Islands is the place with frequent occurrence of strong typhoons, among which the wind speed of 7 TCs in 64 years exceeds 60 m/s.
