Analysis of temperature inversion in the Zhujiang River Estuaryin July 2015
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摘要
This study investigates the temperature inversion phenomenon in the Zhujiang(Pearl) River Estuary(ZRE) using hydrological data collected in a summer cruise during July 6–17, 2015. The results suggest that temperature inversion occurred primarily near the salinity front, with an average temperature difference(ΔT) of 0.42°C between the inversion layer and the underlying water. The inversion layer was approximately 4 m thick on average, with an upper boundary at a depth of 1–6 m and a lower boundary at a depth of 3–10 m. Different mechanisms and dynamic processes were responsible for temperature inversion in different parts of the study area.(1) At the salinity front in the west of the ZRE, the measurements collected by CTD(conductivity,temperature, and depth) showed that the low-salinity water mass on the inner side of the front was approximately2°C cooler than the high-salinity water mass on the outer side. Temperature inversion occurred when the cooler low-salinity water overlapped the warmer high-salinity water near the front due to the driving force of the background flow.(2) Inversion layers occurred at the mouth of the Taiping waterway as a result of varying horizontal flow between two different water masses under the effects of tides and runoff.(3) To the southwest of Hong Kong, temperature inversion occurred due to the interaction of upwelling and the salinity front.
This study investigates the temperature inversion phenomenon in the Zhujiang(Pearl) River Estuary(ZRE) using hydrological data collected in a summer cruise during July 6–17, 2015. The results suggest that temperature inversion occurred primarily near the salinity front, with an average temperature difference(ΔT) of 0.42°C between the inversion layer and the underlying water. The inversion layer was approximately 4 m thick on average, with an upper boundary at a depth of 1–6 m and a lower boundary at a depth of 3–10 m. Different mechanisms and dynamic processes were responsible for temperature inversion in different parts of the study area.(1) At the salinity front in the west of the ZRE, the measurements collected by CTD(conductivity,temperature, and depth) showed that the low-salinity water mass on the inner side of the front was approximately2°C cooler than the high-salinity water mass on the outer side. Temperature inversion occurred when the cooler low-salinity water overlapped the warmer high-salinity water near the front due to the driving force of the background flow.(2) Inversion layers occurred at the mouth of the Taiping waterway as a result of varying horizontal flow between two different water masses under the effects of tides and runoff.(3) To the southwest of Hong Kong, temperature inversion occurred due to the interaction of upwelling and the salinity front.
This study investigates the temperature inversion phenomenon in the Zhujiang(Pearl) River Estuary(ZRE) using hydrological data collected in a summer cruise during July 6–17, 2015. The results suggest that temperature inversion occurred primarily near the salinity front, with an average temperature difference(ΔT) of 0.42°C between the inversion layer and the underlying water. The inversion layer was approximately 4 m thick on average, with an upper boundary at a depth of 1–6 m and a lower boundary at a depth of 3–10 m. Different mechanisms and dynamic processes were responsible for temperature inversion in different parts of the study area.(1) At the salinity front in the west of the ZRE, the measurements collected by CTD(conductivity,temperature, and depth) showed that the low-salinity water mass on the inner side of the front was approximately2°C cooler than the high-salinity water mass on the outer side. Temperature inversion occurred when the cooler low-salinity water overlapped the warmer high-salinity water near the front due to the driving force of the background flow.(2) Inversion layers occurred at the mouth of the Taiping waterway as a result of varying horizontal flow between two different water masses under the effects of tides and runoff.(3) To the southwest of Hong Kong, temperature inversion occurred due to the interaction of upwelling and the salinity front.
引文
Akhil V P,Durand F,Lengaigne M,et al.2014.A modeling study of the processes of surface salinity seasonal cycle in the Bay of Bengal.Journal of Geophysical Research:Oceans,119(6):3926-3947,doi:10.1002/2013JC009632
Chen Xianyao,Qiao Fangli,Ge Renfeng,et al.2006.Development of subsurface warm water in the East China Sea in fall.Journal of Geophysical Research:Oceans,111(C11):C11S10
Dong Lixian,Su Jilan,Wong L A,et al.2004.Seasonal variation and dynamics of the Pearl River plume.Continental Shelf Research,24(16):1761-1777,doi:10.1016/j.csr.2004.06.006
Girishkumar M S,Ravichandran M,McPhaden M J.2013.Temperature inversions and their influence on the mixed layer heat budget during the winters of 2006-2007 and 2007-2008 in the Bay of Bengal.Journal of Geophysical Research:Oceans,118(5):2426-2437,doi:10.1002/jgrc.20192
Han Weiqing,McCreary J P Jr,Kohler K E.2001.Influence of precipitation minus evaporation and Bay of Bengal rivers on dynamics,thermodynamics,and mixed layer physics in the upper Indian Ocean.Journal of Geophysical Research:Oceans,106(C4):6895-6916,doi:10.1029/2000JC000403
Hou Weifen,Yu Cungen,Zheng Ji,et al.2010.The distribution characteristics of temperature in the offshore waters of Southern Zhejiang Province.Journal of Zhejiang Ocean University(Natural Science)(in Chinese),29(1):59-63
Lan Shufang,Gu Chuancheng,Fu Bingzhao.1993.Inversion phenomenon of temperature and salinity in the continental shelf region of East China Sea.Transactions of Oceanology and Limnology(in Chinese),3:28-34
Mao Qingwen,Shi Ping,Yin Kedong,et al.2004.Tides and tidal currents in the Pearl River Estuary.Continental Shelf Research,24(16):1797-1808,doi:10.1016/j.csr.2004.06.008
Nagata Y.1967.Shallow temperature inversions at ocean station V.Journal of the Oceanographical Society of Japan,23(4):194-200,doi:10.5928/kaiyou1942.23.194
Nagura M,Terao T,Hashizume M.2015.The role of temperature inversions in the generation of seasonal and interannual SSTvariability in the far northern Bay of Bengal.Journal of Climate,28(9):3671-3693,doi:10.1175/JCLI-D-14-00553.1
Nisha K,Rao S A,Gopalakrishna V V,et al.2009.Reduced near-surface thermal inversions in 2005-06 in the southeastern Arabian Sea(Lakshadweep Sea).Journal of Physical Oceanography,39(5):1184-1199,doi:10.1175/2008JPO3879.1
Ou Suying,Zhang Hong,Wang Dongxiao,et al.2007.Horizontal characteristics of buoyant plume off the Pearl River Estuary during summer.Journal of Coastal Research,50:652-657
Qiu Yun,Xu Jindian,Guo Xiaogang,et al.2012.Temperature inversion in the Taiwan Strait during Northeast monsoon.Haiyang Xuebao(in Chinese),34(2):13-22
Thadathil P,Gopalakrishna V V,Muraleedharan P M,et al.2002.Surface layer temperature inversion in the Bay of Bengal.Deep Sea Research Part I:Oceanographic Research Papers,49(10):1801-1818,doi:10.1016/S0967-0637(02)00044-4
Thadathil P,Gosh A K.1992.Surface layer temperature inversion in the Arabian Sea during winter.Journal of Oceanography,48(3):293-304,doi:10.1007/BF02233989
Ueno H,Yasuda I.2005.Temperature inversions in the subarctic North Pacific.Journal of Physical Oceanography,35(12):2444-2456,doi:10.1175/JPO2829.1
Wong L A,Chen J C,Xue H,et al.2003a.A model study of the circulation in the Pearl River Estuary(PRE)and its adjacent coastal waters:1.Simulations and comparison with observations.Journal of Geophysical Research:Oceans,108(C5):3156
Wong L A,Chen J C,Xue H,et al.2003b.A model study of the circulation in the Pearl River Estuary(PRE)and its adjacent coastal waters:2.Sensitivity experiments.Journal of Geophysical Research:Oceans,108(C5):3157,doi:10.1029/2002JC001452
Yan Wenbing.1991.The inversion thermocline in Taiwan Strait.Journal of Oceanography in Taiwan Strait(in Chinese),10(4):334-337
Yuan Dongliang,Li Yao,He Lei,et al.2010.An observation of the three-dimensional structure of a cross-shelf penetrating front off the Changjiang mouth.Deep Sea Research Part II:Topical Studies in Oceanography,57(19-20):1827-1834,doi:10.1016/j.dsr2.2010.04.009
Zu Tingting,Gan Jianping.2015.A numerical study of coupled estuary-shelf circulation around the Pearl River Estuary during summer:Responses to variable winds,tides and river discharge.Deep Sea Research Part II:Topical Studies in Oceanography,117:53-64,doi:10.1016/j.dsr2.2013.12.010
Zu Tingting,Wang Dongxiao,Gan Jianping,et al.2014.On the role of wind and tide in generating variability of Pearl River plume during summer in a coupled wide estuary and shelf system.Journal of Marine System,136:65-79,doi:10.1016/j.jmarsys.2014.03.005
Chen Xianyao,Qiao Fangli,Ge Renfeng,et al.2006.Development of subsurface warm water in the East China Sea in fall.Journal of Geophysical Research:Oceans,111(C11):C11S10
Dong Lixian,Su Jilan,Wong L A,et al.2004.Seasonal variation and dynamics of the Pearl River plume.Continental Shelf Research,24(16):1761-1777,doi:10.1016/j.csr.2004.06.006
Girishkumar M S,Ravichandran M,McPhaden M J.2013.Temperature inversions and their influence on the mixed layer heat budget during the winters of 2006-2007 and 2007-2008 in the Bay of Bengal.Journal of Geophysical Research:Oceans,118(5):2426-2437,doi:10.1002/jgrc.20192
Han Weiqing,McCreary J P Jr,Kohler K E.2001.Influence of precipitation minus evaporation and Bay of Bengal rivers on dynamics,thermodynamics,and mixed layer physics in the upper Indian Ocean.Journal of Geophysical Research:Oceans,106(C4):6895-6916,doi:10.1029/2000JC000403
Hou Weifen,Yu Cungen,Zheng Ji,et al.2010.The distribution characteristics of temperature in the offshore waters of Southern Zhejiang Province.Journal of Zhejiang Ocean University(Natural Science)(in Chinese),29(1):59-63
Lan Shufang,Gu Chuancheng,Fu Bingzhao.1993.Inversion phenomenon of temperature and salinity in the continental shelf region of East China Sea.Transactions of Oceanology and Limnology(in Chinese),3:28-34
Mao Qingwen,Shi Ping,Yin Kedong,et al.2004.Tides and tidal currents in the Pearl River Estuary.Continental Shelf Research,24(16):1797-1808,doi:10.1016/j.csr.2004.06.008
Nagata Y.1967.Shallow temperature inversions at ocean station V.Journal of the Oceanographical Society of Japan,23(4):194-200,doi:10.5928/kaiyou1942.23.194
Nagura M,Terao T,Hashizume M.2015.The role of temperature inversions in the generation of seasonal and interannual SSTvariability in the far northern Bay of Bengal.Journal of Climate,28(9):3671-3693,doi:10.1175/JCLI-D-14-00553.1
Nisha K,Rao S A,Gopalakrishna V V,et al.2009.Reduced near-surface thermal inversions in 2005-06 in the southeastern Arabian Sea(Lakshadweep Sea).Journal of Physical Oceanography,39(5):1184-1199,doi:10.1175/2008JPO3879.1
Ou Suying,Zhang Hong,Wang Dongxiao,et al.2007.Horizontal characteristics of buoyant plume off the Pearl River Estuary during summer.Journal of Coastal Research,50:652-657
Qiu Yun,Xu Jindian,Guo Xiaogang,et al.2012.Temperature inversion in the Taiwan Strait during Northeast monsoon.Haiyang Xuebao(in Chinese),34(2):13-22
Thadathil P,Gopalakrishna V V,Muraleedharan P M,et al.2002.Surface layer temperature inversion in the Bay of Bengal.Deep Sea Research Part I:Oceanographic Research Papers,49(10):1801-1818,doi:10.1016/S0967-0637(02)00044-4
Thadathil P,Gosh A K.1992.Surface layer temperature inversion in the Arabian Sea during winter.Journal of Oceanography,48(3):293-304,doi:10.1007/BF02233989
Ueno H,Yasuda I.2005.Temperature inversions in the subarctic North Pacific.Journal of Physical Oceanography,35(12):2444-2456,doi:10.1175/JPO2829.1
Wong L A,Chen J C,Xue H,et al.2003a.A model study of the circulation in the Pearl River Estuary(PRE)and its adjacent coastal waters:1.Simulations and comparison with observations.Journal of Geophysical Research:Oceans,108(C5):3156
Wong L A,Chen J C,Xue H,et al.2003b.A model study of the circulation in the Pearl River Estuary(PRE)and its adjacent coastal waters:2.Sensitivity experiments.Journal of Geophysical Research:Oceans,108(C5):3157,doi:10.1029/2002JC001452
Yan Wenbing.1991.The inversion thermocline in Taiwan Strait.Journal of Oceanography in Taiwan Strait(in Chinese),10(4):334-337
Yuan Dongliang,Li Yao,He Lei,et al.2010.An observation of the three-dimensional structure of a cross-shelf penetrating front off the Changjiang mouth.Deep Sea Research Part II:Topical Studies in Oceanography,57(19-20):1827-1834,doi:10.1016/j.dsr2.2010.04.009
Zu Tingting,Gan Jianping.2015.A numerical study of coupled estuary-shelf circulation around the Pearl River Estuary during summer:Responses to variable winds,tides and river discharge.Deep Sea Research Part II:Topical Studies in Oceanography,117:53-64,doi:10.1016/j.dsr2.2013.12.010
Zu Tingting,Wang Dongxiao,Gan Jianping,et al.2014.On the role of wind and tide in generating variability of Pearl River plume during summer in a coupled wide estuary and shelf system.Journal of Marine System,136:65-79,doi:10.1016/j.jmarsys.2014.03.005