Upper Circumpolar Deep Water(UCDW)and North Pacifi c Deep Water(NPDW)coexist in the upper deep layer(i.e.,with a 1.2-2.0-℃potential temperature range and a 2000-4100-dbar pressure range)of the Eastern Philippine Sea....Upper Circumpolar Deep Water(UCDW)and North Pacifi c Deep Water(NPDW)coexist in the upper deep layer(i.e.,with a 1.2-2.0-℃potential temperature range and a 2000-4100-dbar pressure range)of the Eastern Philippine Sea.They have similar properties in potential temperature and salinity,while have a signifi cant diff erence in dissolved silicate.Based on the repeated observations along a 137°E transect from the World Ocean Database(WOD18),this study revealed the interannual variability of dissolved silicate in the upper deep layer of the Eastern Philippine Sea.Dissolved silicate increased in 1995,1996,2005,2006,and 2007,and decreased in 1997,2000,2001,2002,and 2004.Composition analysis showed that the large diff erence between positive and negative dissolved silicate anomalies occurred mainly at~15°N and north of 25°N,with the concentration reaching 4.25μmol/g.Further analysis indicated that the interannual dissolved silicate variability was related to the zonal current variation in the upper deep layer.The relatively strong(weak)westward current transport increased(decreased)NPDW to the Eastern Philippine Sea,thereby resulting in increased(decreased)dissolved silicate.展开更多
The evolution of thermohaline structure at the upper ocean during three tropical cyclones(TCs)in the Northwest Pacific was studied in this study based on successive observation by two new-style underwater gliders duri...The evolution of thermohaline structure at the upper ocean during three tropical cyclones(TCs)in the Northwest Pacific was studied in this study based on successive observation by two new-style underwater gliders during fall 2018.These remote-controllable gliders with CTD sensor enabled us to explore high frequency responses of temperature,salinity,mixed and barrier layers in the upper ocean to severe TCs in this area.Results showed that three significant cooling-to-warming and stratification destructing-to-reconstructing processes at the mixed layer occurred during the lives of three TCs.The maximal cooling of SST all reached≥0.5℃although TCs with different intensities had different minimal distances to the observed area.Under potential impacts of solar radiation,tide and inertial motions,the mixed layer depth possessed significant high-frequency fluctuations during TC periods.In addition,barrier layers appeared and vanished quickly during TCs,accompanied with varied temperature inversion processes.展开更多
基金Supported by the National Key Research and Development Program of China(No.2018YFC0309800)the National Natural Science Foundation of China(Nos.42176021,91858203)+1 种基金the Open Project Program of State Key Laboratory of Tropical Oceanography(No.LTOZZ2001)the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(No.GML2019ZD0304)。
文摘Upper Circumpolar Deep Water(UCDW)and North Pacifi c Deep Water(NPDW)coexist in the upper deep layer(i.e.,with a 1.2-2.0-℃potential temperature range and a 2000-4100-dbar pressure range)of the Eastern Philippine Sea.They have similar properties in potential temperature and salinity,while have a signifi cant diff erence in dissolved silicate.Based on the repeated observations along a 137°E transect from the World Ocean Database(WOD18),this study revealed the interannual variability of dissolved silicate in the upper deep layer of the Eastern Philippine Sea.Dissolved silicate increased in 1995,1996,2005,2006,and 2007,and decreased in 1997,2000,2001,2002,and 2004.Composition analysis showed that the large diff erence between positive and negative dissolved silicate anomalies occurred mainly at~15°N and north of 25°N,with the concentration reaching 4.25μmol/g.Further analysis indicated that the interannual dissolved silicate variability was related to the zonal current variation in the upper deep layer.The relatively strong(weak)westward current transport increased(decreased)NPDW to the Eastern Philippine Sea,thereby resulting in increased(decreased)dissolved silicate.
基金The National Key R&D Program of China under contract No.2018YFC0309800the National Natural Science Foundation of China under contract Nos 41666001,41576006,41676015 and U1709202+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences under contract No.XDA13030302the Chinese Academy of Sciences Frontier Basic Research Project under contract No.QYJC201910
文摘The evolution of thermohaline structure at the upper ocean during three tropical cyclones(TCs)in the Northwest Pacific was studied in this study based on successive observation by two new-style underwater gliders during fall 2018.These remote-controllable gliders with CTD sensor enabled us to explore high frequency responses of temperature,salinity,mixed and barrier layers in the upper ocean to severe TCs in this area.Results showed that three significant cooling-to-warming and stratification destructing-to-reconstructing processes at the mixed layer occurred during the lives of three TCs.The maximal cooling of SST all reached≥0.5℃although TCs with different intensities had different minimal distances to the observed area.Under potential impacts of solar radiation,tide and inertial motions,the mixed layer depth possessed significant high-frequency fluctuations during TC periods.In addition,barrier layers appeared and vanished quickly during TCs,accompanied with varied temperature inversion processes.
