The process of air—sea fresh water exchange is included successfully in the Global— Ocean—Atmosphere Land—System model developed at the State Key Laboratory of Atmospheric Sciences and Geophysical Fluid Dynamics (...The process of air—sea fresh water exchange is included successfully in the Global— Ocean—Atmosphere Land—System model developed at the State Key Laboratory of Atmospheric Sciences and Geophysical Fluid Dynamics (LASG). The results of the coupled integration show that the climate drift has been controlled successfully. Analyses on the responses of ocean circulation to the changes of surface fresh water or salinity forcing show that the ocean spin-up stage under flux condition for salinity is the key to the implementation of air-sea fresh water flux coupling. This study also demonstrates that the Modified—Monthly—Flux—Anomaly coupling scheme (MMFA) brought forward by Yu and Zhang (1998) is suitable not only for daily air—sea heat flux coupling but also for daily fresh water flux coupling. Key words Fresh water flux - Air-sea coupling - Thermohaline circulation This work was co-supported by the National Key Project (Grant No.96-908-02-03), the Excellent National Key Laboratory Research Project (Grant No.49823002) and Chinese Academy of Sciences (CAS) under grant “ Bai Ren Ji Hua? for “Validation of Coupled Climate Models”.展开更多
Examining the descriptions of piezometric heads at two points in both the salt water and fresh water zones reveals that when the groundwater flow system is in steady state and satisfies the Dupuit assumption, the loca...Examining the descriptions of piezometric heads at two points in both the salt water and fresh water zones reveals that when the groundwater flow system is in steady state and satisfies the Dupuit assumption, the location of the fresh water-salt water interface in a homogeneous, isotropic, and unconfined coastal aquifer can be estimated based on a piezometric head of fresh water at a point in the fresh water zone （from the water table to the interface） vertically lined up with a piezometric head of salt water at a point in the salt water zone （from the interface down）. Research shows that the new method is a general relation and that both the Hubbert relation describing the location of the interface and the Ghy- ben--Herzberg relation are special cases of this method. The method requires two piezometric wells to be close to each other and each tapping into a different zone. Measurements of piezometric heads at a well cluster consisting of piezometric wells tapping separately into fresh water and salt water zones near Beihai, China at 5-day intervals for 15 months are used to illustrate the estimation of interface location. The depth of the interface for well H5 ranges from 32 to 72 m below the sea level.展开更多
This study aims, first, to examine the limit for tolerance to lower salinity by an oceanic sea skater, Halobates micans, and , second, to make it clear whether exclusively fresh water Halobatinae species, Metrocoris h...This study aims, first, to examine the limit for tolerance to lower salinity by an oceanic sea skater, Halobates micans, and , second, to make it clear whether exclusively fresh water Halobatinae species, Metrocoris histrio has salinity tolerance. Adults of H. micans were collected using Neuston Net from the starboard side of R/V MIRAI on a fixed station at 8°S, 80°E, whereas those of M. histrio were collected from a small pond filled with a spring fresh water in Kochi (33°N, 133°E), Japan. Time in survival was measured in starved condition under several salinity conditions: 0‰, 2‰, 4‰, 6‰, 8‰, 9‰ and 10‰ for H. micans;0‰, 5‰, 10‰, 12.5‰, 15‰ for M. histrio. Half of adults were in coma due to lower salinity under 10‰ and time in survival was less than 10 hours under less than 4‰ for H. micans. Time in survival was half at 5‰ of 80 hours on average at 0‰ as a control and less than 10 hours at 10‰ or higher salinity for M. histrio. Relatively flexible osmo-regulation ability by H. micans would be related to wide variety of salinity condition of surface oceanic water, whereas very limited tolerance even to lower salinity of 5‰ may be permitted by the no chances to be exposed to brackish water in natural habitats of M. histrio. This study showed that salinity tolerance of Halobatinae species would reflect, directly, the salinity condition of their habitats.展开更多
We use the U.S. Navy's Master Oceanographic Observation Data Set (MOODS) forthe Yellow Sea/ East China Sea (YES) to investigate the climatological water mass features and theseasonal and non-seasonal variabilities...We use the U.S. Navy's Master Oceanographic Observation Data Set (MOODS) forthe Yellow Sea/ East China Sea (YES) to investigate the climatological water mass features and theseasonal and non-seasonal variabilities of the thermohaline structure, and use the ComprehensiveOcean-Atmosphere Data Set (COADS) from 1945 to 1989 to investigate the linkage between the fluxes(momentum, heat, and moisture) across the air-ocean interface and the formation of the water massfeatures. After examining the major current systems and considering the local bathymetry and watermass properties, we divide YES into five regions: East China Sea (ECS) shelf, Yellow Sea (YS) Basin,Cheju bifurcation (CB) zone, Taiwan Warm Current (TWC) region, Kuroshio Current (KC) region. Thelong term mean surface heat balance corresponds to a heat loss of 30 W m^(-2) in the ESC and CBregions, a heat loss of 65 W m^(-2) in the KC and TWC regions, and a heat gain of 15 W m^(-2) in theYS region. The surface freshwater balance is defined by precipitation minus evaporation. The annualwater loss from the surface for the five subareas ranges from 1.8 to 4 cm month^(-1). The freshwater loss from the surface should be compensated for from the river run-off. The entire watercolumn of the shelf region (ECS, YS, and CB) undergoes an evident seasonal thermal cycle withmaximum values of temperature during summer and maximum mixed layer depths during winter. However,only the surface waters of the TWC and KC regions exhibit a seasonal thermal cycle.. We also foundtwo different relations between surface salinity and the Yangtze River run-off, namely, out-of-phasein the East China Sea shelf and in-phase in the Yellow Sea. This may confirm an earlier study thatthe summer fresh water discharge from the Yangtze River forms a relatively shallow, low salinityplume-like structure extending offshore on average towards the northeast.展开更多
Conductivity, temperature, and depth data collected during the summers of 2003 and 2008 were used to study upper-ocean （top 200 m） heat content in the Canada Basin. The variation of heat content with depth, heat con...Conductivity, temperature, and depth data collected during the summers of 2003 and 2008 were used to study upper-ocean （top 200 m） heat content in the Canada Basin. The variation of heat content with depth, heat content differences between the summers, principal driving factors, and horizontal spatial scale differences were analyzed. A catastrophic reduction of sea ice cover in the Canada Basin was evident in 2008 by comparison with 2003, suggesting that more solar radiation was absorbed in the upper ocean during the summer of 2008. The sea ice reduction produced more freshwater in the upper ocean. Thus, seawater properties changed. The study shows that the huge reduction of sea ice would result in two changes-widespread warming of the upper ocean, and the depth of Pacific inflow water in the basin increased substantially. Near-surface temperature maximum （NSTM） water was also analyzed as an indicator of Arctic Ocean warming.展开更多
The characteristics, pattern, hydrodynamic and hydrochemical features, and the movement pattern of the salt water-fresh water interface of the sea water intrusion and the salt water intrusion, which occur in the coast...The characteristics, pattern, hydrodynamic and hydrochemical features, and the movement pattern of the salt water-fresh water interface of the sea water intrusion and the salt water intrusion, which occur in the coastal area of Laizhou Bay in Shandong Province, are analysed. The characteristics of the two kinds of intrusion are compared as well. A three-dimensional sea water intrusion model to describe the sea water intrusion with a transitional zone 1.56.0 km wide in the phreatic aquifer and a solute transport model describing the behavior of cations exchange in the process of sea water intrusion are established.展开更多
文摘The process of air—sea fresh water exchange is included successfully in the Global— Ocean—Atmosphere Land—System model developed at the State Key Laboratory of Atmospheric Sciences and Geophysical Fluid Dynamics (LASG). The results of the coupled integration show that the climate drift has been controlled successfully. Analyses on the responses of ocean circulation to the changes of surface fresh water or salinity forcing show that the ocean spin-up stage under flux condition for salinity is the key to the implementation of air-sea fresh water flux coupling. This study also demonstrates that the Modified—Monthly—Flux—Anomaly coupling scheme (MMFA) brought forward by Yu and Zhang (1998) is suitable not only for daily air—sea heat flux coupling but also for daily fresh water flux coupling. Key words Fresh water flux - Air-sea coupling - Thermohaline circulation This work was co-supported by the National Key Project (Grant No.96-908-02-03), the Excellent National Key Laboratory Research Project (Grant No.49823002) and Chinese Academy of Sciences (CAS) under grant “ Bai Ren Ji Hua? for “Validation of Coupled Climate Models”.
基金supported by the Fund for the Special Research of Doctorate Subjects of the Ministry of Education of China (No.20070491522)
文摘Examining the descriptions of piezometric heads at two points in both the salt water and fresh water zones reveals that when the groundwater flow system is in steady state and satisfies the Dupuit assumption, the location of the fresh water-salt water interface in a homogeneous, isotropic, and unconfined coastal aquifer can be estimated based on a piezometric head of fresh water at a point in the fresh water zone （from the water table to the interface） vertically lined up with a piezometric head of salt water at a point in the salt water zone （from the interface down）. Research shows that the new method is a general relation and that both the Hubbert relation describing the location of the interface and the Ghy- ben--Herzberg relation are special cases of this method. The method requires two piezometric wells to be close to each other and each tapping into a different zone. Measurements of piezometric heads at a well cluster consisting of piezometric wells tapping separately into fresh water and salt water zones near Beihai, China at 5-day intervals for 15 months are used to illustrate the estimation of interface location. The depth of the interface for well H5 ranges from 32 to 72 m below the sea level.
文摘This study aims, first, to examine the limit for tolerance to lower salinity by an oceanic sea skater, Halobates micans, and , second, to make it clear whether exclusively fresh water Halobatinae species, Metrocoris histrio has salinity tolerance. Adults of H. micans were collected using Neuston Net from the starboard side of R/V MIRAI on a fixed station at 8°S, 80°E, whereas those of M. histrio were collected from a small pond filled with a spring fresh water in Kochi (33°N, 133°E), Japan. Time in survival was measured in starved condition under several salinity conditions: 0‰, 2‰, 4‰, 6‰, 8‰, 9‰ and 10‰ for H. micans;0‰, 5‰, 10‰, 12.5‰, 15‰ for M. histrio. Half of adults were in coma due to lower salinity under 10‰ and time in survival was less than 10 hours under less than 4‰ for H. micans. Time in survival was half at 5‰ of 80 hours on average at 0‰ as a control and less than 10 hours at 10‰ or higher salinity for M. histrio. Relatively flexible osmo-regulation ability by H. micans would be related to wide variety of salinity condition of surface oceanic water, whereas very limited tolerance even to lower salinity of 5‰ may be permitted by the no chances to be exposed to brackish water in natural habitats of M. histrio. This study showed that salinity tolerance of Halobatinae species would reflect, directly, the salinity condition of their habitats.
文摘We use the U.S. Navy's Master Oceanographic Observation Data Set (MOODS) forthe Yellow Sea/ East China Sea (YES) to investigate the climatological water mass features and theseasonal and non-seasonal variabilities of the thermohaline structure, and use the ComprehensiveOcean-Atmosphere Data Set (COADS) from 1945 to 1989 to investigate the linkage between the fluxes(momentum, heat, and moisture) across the air-ocean interface and the formation of the water massfeatures. After examining the major current systems and considering the local bathymetry and watermass properties, we divide YES into five regions: East China Sea (ECS) shelf, Yellow Sea (YS) Basin,Cheju bifurcation (CB) zone, Taiwan Warm Current (TWC) region, Kuroshio Current (KC) region. Thelong term mean surface heat balance corresponds to a heat loss of 30 W m^(-2) in the ESC and CBregions, a heat loss of 65 W m^(-2) in the KC and TWC regions, and a heat gain of 15 W m^(-2) in theYS region. The surface freshwater balance is defined by precipitation minus evaporation. The annualwater loss from the surface for the five subareas ranges from 1.8 to 4 cm month^(-1). The freshwater loss from the surface should be compensated for from the river run-off. The entire watercolumn of the shelf region (ECS, YS, and CB) undergoes an evident seasonal thermal cycle withmaximum values of temperature during summer and maximum mixed layer depths during winter. However,only the surface waters of the TWC and KC regions exhibit a seasonal thermal cycle.. We also foundtwo different relations between surface salinity and the Yangtze River run-off, namely, out-of-phasein the East China Sea shelf and in-phase in the Yellow Sea. This may confirm an earlier study thatthe summer fresh water discharge from the Yangtze River forms a relatively shallow, low salinityplume-like structure extending offshore on average towards the northeast.
基金supported by the Global Change Research Program of China (Grant no. 2010CB951403)the National Natural Science Foundation of China (Grant no.40631006, for the project "Arctic circumpolar current structure and its contribution to the climate change")
文摘Conductivity, temperature, and depth data collected during the summers of 2003 and 2008 were used to study upper-ocean （top 200 m） heat content in the Canada Basin. The variation of heat content with depth, heat content differences between the summers, principal driving factors, and horizontal spatial scale differences were analyzed. A catastrophic reduction of sea ice cover in the Canada Basin was evident in 2008 by comparison with 2003, suggesting that more solar radiation was absorbed in the upper ocean during the summer of 2008. The sea ice reduction produced more freshwater in the upper ocean. Thus, seawater properties changed. The study shows that the huge reduction of sea ice would result in two changes-widespread warming of the upper ocean, and the depth of Pacific inflow water in the basin increased substantially. Near-surface temperature maximum （NSTM） water was also analyzed as an indicator of Arctic Ocean warming.
文摘The characteristics, pattern, hydrodynamic and hydrochemical features, and the movement pattern of the salt water-fresh water interface of the sea water intrusion and the salt water intrusion, which occur in the coastal area of Laizhou Bay in Shandong Province, are analysed. The characteristics of the two kinds of intrusion are compared as well. A three-dimensional sea water intrusion model to describe the sea water intrusion with a transitional zone 1.56.0 km wide in the phreatic aquifer and a solute transport model describing the behavior of cations exchange in the process of sea water intrusion are established.
