基于国际Argo资料中心提供的从2004年1月至2007年10月的浮标剖面资料,对西北太平洋模态水的时空变化特征进行分析。结合WOA01(the World Ocean Atlas 2001)资料,选定模态水主要形成区(30°～35°N,140°～155°E)作为...基于国际Argo资料中心提供的从2004年1月至2007年10月的浮标剖面资料,对西北太平洋模态水的时空变化特征进行分析。结合WOA01(the World Ocean Atlas 2001)资料,选定模态水主要形成区(30°～35°N,140°～155°E)作为研究区域,利用3月份的平均资料,给出西北太平洋模态水的空间结构为:北边界位于34.5°N附近,南边界可达30°N以南,东边界位于151.5°E,西边界可达140°E以西,深度为350m以浅。通过对模态水核心区的逐月资料分析,揭示了其温度、盐度等的季节变化,并提出一种判别模态水范围的盐度判别法。结合海平面高度异常变化,初步分析了涡旋对模态水的影响,发现涡旋只能暂时改变核心区模态水的温盐结构,之后该区域模态水将基本恢复到正常状态。根据模态水2004-2007年的水文数据特点,发现在过去4a中模态水性质基本稳定,变化很小。展开更多
采用来自大洋环流模式ECCO2(the estimating the circulation and climate of the ocean,phase II project)的再分析数据对1992-2019年北太平洋副热带西部模态水(subtropical mode water,STMW)的年代际变化特征及机制进行了分析。结果表...采用来自大洋环流模式ECCO2(the estimating the circulation and climate of the ocean,phase II project)的再分析数据对1992-2019年北太平洋副热带西部模态水(subtropical mode water,STMW)的年代际变化特征及机制进行了分析。结果表明:STMW形成体积具有显著的年代际变化,于1992-1997年、2000-2005年和2011-2017年期间为正异常,而于1998-1999年和2006-2010年期间为负异常,由晚冬生成区混合层体积的年代际变化引起。STMW形成厚度和面积均呈现类似的年代际变化。合成分析表明,STMW形成体积正异常期间,黑潮延伸体上游南侧STMW生成区,海表涡动能相对负异常期间减小,同时预先层结相对负异常期间减弱,并伴随着海表高度异常。通过混合层收支分析发现,混合层形成体积年代际变化与海洋预先层结调控的混合层底卷吸作用变化同步且大小相当,而与海气形成率变化无关。增强(减弱)的海洋预先层结通过调控STMW形成区冬季混合层底卷吸过程,阻碍(促进)冬季混合层加深,最终使得STMW形成体积减少(增加)。进一步分析表明,STMW形成体积年代际变化受与太平洋年代际涛动相关的风应力旋度异常的远场调控。展开更多
In order to optimize the design of a 12.5 m deepwater channel project and protect the ecological environment, it is necessary to study the habitat evaluation of species in the engineered area. A coupled eco-hydrodynam...In order to optimize the design of a 12.5 m deepwater channel project and protect the ecological environment, it is necessary to study the habitat evaluation of species in the engineered area. A coupled eco-hydrodynamic model, which combines a hydrodynamic model （ADCIRC） and a habitat suitability index （HSI） model is developed for target fish （Coilia nasus） and benthos （Corbicula fluminea） in the Yangtze River in order to predict the ecological changes and optimize the regulation scheme. Based on the existing research concerning the characteristics of Coilia nasus and Corbicula fluminea, the relationship between the target species and water environment factors is established. The verification results of tidal level, velocity and biological density show that the proposed coupling model performs well when predicting ecological suitability in the studied region. The results indicate a slight improvement in the potential habitat availability for the two species studied as the natural hydraulic conditions change after the deep-water channel regulation works.展开更多
Using a crop-water-salinity production function and a soil-water-salinity dynamic model, optimal irrigation scheduling was developed to maximize net return per irrigated area. Plot and field experiments were used to o...Using a crop-water-salinity production function and a soil-water-salinity dynamic model, optimal irrigation scheduling was developed to maximize net return per irrigated area. Plot and field experiments were used to obtain the crop water sensitivity index, the salinity sensitivity index, and other parameters. Using data collected during 35 years to calculate the 10-day mean precipitation and evaporation, the variation in soil salinity concentrations and in the yields of winter wheat and cotton were simulated for 49 irrigation scheduling that were combined from 7 irrigation schemes over 3 irrigation dates and 7 salinity concentrations of saline irrigation water (fresh water and 6 levels of saline water). Comparison of predicted results with irrigation data obtained from a large area of the field showed that the model was valid and reliable. Based on the analysis of the investment cost of the irrigation that employed deep tube wells or shallow tube wells, a saline water irrigation schedule and a corresponding strategy for groundwater development and utilization were proposed. For wheat or cotton, if the salinity concentration was higher than 7.0 g L-1 in groundwater, irrigation was needed with only fresh water; if about 5.0 g L-1, irrigation was required twice with fresh water and once with saline water; and if not higher than 3.0 g L-1, irrigation could be solely with saline water.展开更多
From the synopical CTD sections in the WOCE PR11 repeated cruises, the South Pacific Subtropical Mode Water (SPSTMW) has been identified in the region of the Tasman Front Extension (TFE) around 29?S to the east of Aus...From the synopical CTD sections in the WOCE PR11 repeated cruises, the South Pacific Subtropical Mode Water (SPSTMW) has been identified in the region of the Tasman Front Extension (TFE) around 29?S to the east of Australia. In the depth range of 150-250 m, the SPSTMW appears as a thermostad with vertical temperature gradient lower than 1.6℃(100 m)-1 and a tem- perature range of 16.5-19.5℃ and as a pycnostad with PV lower than 2×10-10 m-1 s-1 and a potential density range of 25.4-26.0 kg m-3. Like the subtropical mode waters in the North Atlantic and North Pacific, the formation of the SPSTMW is associated with the convective mixing during the austral wintertime as manifested from the time series of the Argo floats. And cold water entrains into the mixed layer with the deepening mixed layer from September to the middle of October. During the wintertime formation process, mesoscale eddies prevailing in the TFE region play an important role in the SPSTMW formation, and have a great effect on the SPSTMW distribution in the next year. The deeper (shallower) mixed layer in wintertime, consistent with the depressed (uplifted) permanent thermocline, is formed by the anticyclonic (cyclonic) eddies, and the substantial mode water thicker than 50 m is mainly found in the region of the anticyclonic eddies where the permanent thermocline is deeper than 450 m.展开更多
文摘基于国际Argo资料中心提供的从2004年1月至2007年10月的浮标剖面资料,对西北太平洋模态水的时空变化特征进行分析。结合WOA01(the World Ocean Atlas 2001)资料,选定模态水主要形成区(30°～35°N,140°～155°E)作为研究区域,利用3月份的平均资料,给出西北太平洋模态水的空间结构为:北边界位于34.5°N附近,南边界可达30°N以南,东边界位于151.5°E,西边界可达140°E以西,深度为350m以浅。通过对模态水核心区的逐月资料分析,揭示了其温度、盐度等的季节变化,并提出一种判别模态水范围的盐度判别法。结合海平面高度异常变化,初步分析了涡旋对模态水的影响,发现涡旋只能暂时改变核心区模态水的温盐结构,之后该区域模态水将基本恢复到正常状态。根据模态水2004-2007年的水文数据特点,发现在过去4a中模态水性质基本稳定,变化很小。
文摘采用来自大洋环流模式ECCO2(the estimating the circulation and climate of the ocean,phase II project)的再分析数据对1992-2019年北太平洋副热带西部模态水(subtropical mode water,STMW)的年代际变化特征及机制进行了分析。结果表明:STMW形成体积具有显著的年代际变化,于1992-1997年、2000-2005年和2011-2017年期间为正异常,而于1998-1999年和2006-2010年期间为负异常,由晚冬生成区混合层体积的年代际变化引起。STMW形成厚度和面积均呈现类似的年代际变化。合成分析表明,STMW形成体积正异常期间,黑潮延伸体上游南侧STMW生成区,海表涡动能相对负异常期间减小,同时预先层结相对负异常期间减弱,并伴随着海表高度异常。通过混合层收支分析发现,混合层形成体积年代际变化与海洋预先层结调控的混合层底卷吸作用变化同步且大小相当,而与海气形成率变化无关。增强(减弱)的海洋预先层结通过调控STMW形成区冬季混合层底卷吸过程,阻碍(促进)冬季混合层加深,最终使得STMW形成体积减少(增加)。进一步分析表明,STMW形成体积年代际变化受与太平洋年代际涛动相关的风应力旋度异常的远场调控。
基金The National Natural Science Foundation of China(No.51209040,51279134)the Natural Science Foundation of Jiangsu Province(No.BK2012341)
文摘In order to optimize the design of a 12.5 m deepwater channel project and protect the ecological environment, it is necessary to study the habitat evaluation of species in the engineered area. A coupled eco-hydrodynamic model, which combines a hydrodynamic model （ADCIRC） and a habitat suitability index （HSI） model is developed for target fish （Coilia nasus） and benthos （Corbicula fluminea） in the Yangtze River in order to predict the ecological changes and optimize the regulation scheme. Based on the existing research concerning the characteristics of Coilia nasus and Corbicula fluminea, the relationship between the target species and water environment factors is established. The verification results of tidal level, velocity and biological density show that the proposed coupling model performs well when predicting ecological suitability in the studied region. The results indicate a slight improvement in the potential habitat availability for the two species studied as the natural hydraulic conditions change after the deep-water channel regulation works.
基金Project supported by the National Natural Science Foundation of China (Nos. 50339030 and 90202001).
文摘Using a crop-water-salinity production function and a soil-water-salinity dynamic model, optimal irrigation scheduling was developed to maximize net return per irrigated area. Plot and field experiments were used to obtain the crop water sensitivity index, the salinity sensitivity index, and other parameters. Using data collected during 35 years to calculate the 10-day mean precipitation and evaporation, the variation in soil salinity concentrations and in the yields of winter wheat and cotton were simulated for 49 irrigation scheduling that were combined from 7 irrigation schemes over 3 irrigation dates and 7 salinity concentrations of saline irrigation water (fresh water and 6 levels of saline water). Comparison of predicted results with irrigation data obtained from a large area of the field showed that the model was valid and reliable. Based on the analysis of the investment cost of the irrigation that employed deep tube wells or shallow tube wells, a saline water irrigation schedule and a corresponding strategy for groundwater development and utilization were proposed. For wheat or cotton, if the salinity concentration was higher than 7.0 g L-1 in groundwater, irrigation was needed with only fresh water; if about 5.0 g L-1, irrigation was required twice with fresh water and once with saline water; and if not higher than 3.0 g L-1, irrigation could be solely with saline water.
基金This study was supported by the Chinese Natural Science Foundation of China(NSFC)(Nos.40276009 and 90411010)
文摘From the synopical CTD sections in the WOCE PR11 repeated cruises, the South Pacific Subtropical Mode Water (SPSTMW) has been identified in the region of the Tasman Front Extension (TFE) around 29?S to the east of Australia. In the depth range of 150-250 m, the SPSTMW appears as a thermostad with vertical temperature gradient lower than 1.6℃(100 m)-1 and a tem- perature range of 16.5-19.5℃ and as a pycnostad with PV lower than 2×10-10 m-1 s-1 and a potential density range of 25.4-26.0 kg m-3. Like the subtropical mode waters in the North Atlantic and North Pacific, the formation of the SPSTMW is associated with the convective mixing during the austral wintertime as manifested from the time series of the Argo floats. And cold water entrains into the mixed layer with the deepening mixed layer from September to the middle of October. During the wintertime formation process, mesoscale eddies prevailing in the TFE region play an important role in the SPSTMW formation, and have a great effect on the SPSTMW distribution in the next year. The deeper (shallower) mixed layer in wintertime, consistent with the depressed (uplifted) permanent thermocline, is formed by the anticyclonic (cyclonic) eddies, and the substantial mode water thicker than 50 m is mainly found in the region of the anticyclonic eddies where the permanent thermocline is deeper than 450 m.
