Combined studies of latitudinal and interannual variations of annual phytoplankton bloom peak in East Asian marginal seas(17°–58°N, including the northern South China Sea(SCS), Kuroshio waters, the Sea of J...Combined studies of latitudinal and interannual variations of annual phytoplankton bloom peak in East Asian marginal seas(17°–58°N, including the northern South China Sea(SCS), Kuroshio waters, the Sea of Japan and the Okhotsk Sea) are rarely. Based on satellite-retrieved ten-year(2003–2012) median timing of the annual Chlorophyll a concentration(Chl a) climax, here we report that this annual spring bloom peak generally delays from the SCS in January to the Okhotsk Sea in June at a rate of(21.20±2.86) km/d(decadal median±SD). Spring bloom is dominant feature of the phytoplankton annual cycle over these regions, except for the SCS which features winter bloom. The fluctuation of the annual peak timing is mainly within ±48 d departured from the decadal median peak date, therefore this period(the decadal median peak date ±48 d) is defined as annual spring bloom period. As sea surface temperature rises, earlier spring bloom peak timing but decreasing averaged Chl a biomass in the spring bloom period due to insufficient light is evident in the Okhotsk Sea from 2003 to 2012. For the rest of three study domains, there are no significant interannual variance trend of the peak timing and the averaged Chl a biomass. Furthermore this change of spring phytoplankton bloom timing and magnitude in the Okhotsk Sea challenges previous prediction that ocean warming would enhance algal productivity at high latitudes.展开更多
A 3- D free surface flow in open channels based on the Reynolds equations with the k-ε turbulence closure model is presented in this paper. Insted of the 'rigid lid' approximation, the solution of the free su...A 3- D free surface flow in open channels based on the Reynolds equations with the k-ε turbulence closure model is presented in this paper. Insted of the 'rigid lid' approximation, the solution of the free surface equation is implemented in the velocity-pressure iterative procedure on the basis of the conventional SIMPLE method. This model was used to compute the flow in rectangular channels with trenches dredged across the bottom. The velocity, eddy viscosity coefficient, turbulent shear stress, turbulent kinetic energy and elevation of the free surface can be obtained. The computed results are in good agreement with previous experimental data.展开更多
利用1993--2006年1～12月AIPO （The joining area of Asia and Indian-Pacific Ocean）流场数据，分析了吕宋海峡120。E断面水交换流速结构的平均月际变化特征，并计算了通过该断面的水通量，探讨了水通量及其垂向结构的月际和季节变...利用1993--2006年1～12月AIPO （The joining area of Asia and Indian-Pacific Ocean）流场数据，分析了吕宋海峡120。E断面水交换流速结构的平均月际变化特征，并计算了通过该断面的水通量，探讨了水通量及其垂向结构的月际和季节变化特征。结果表明：①在断面的南北方向，西向流和东向流分别大致以19．5°N和21．5°N线为界，二者交替相间分布，呈“两进（西向流入南海）两出（东向流出南海）”的结构；21．5°N以南的300m以深和21．5°N以北的1000m以浅海域，常年存在南海水东向流入太平洋。②上层、深层和整个断面的净水通量几乎均为西向流，净水通量冬季最大，春季和秋季次之，夏季最小。中层除12月外，其他各月的净水通量均为东向流出南海，净水通量春季最大，夏季和秋季次之，冬季最小。③整个断面的净水通量，1～5月和8～11月呈“三明治”结构，6～7月呈2层结构；12月呈单层结构，年平均呈“三明治”结构。展开更多
基金The scientific research fund of the Second Institute of Oceanography,State Oceanic Administration,China under contract No.JG1417the Public Science and Technology Research Funds Projects of Ocean under contract No.201005030the National Natural Science Foundation of China under contract Nos 41476156 and 41321004
文摘Combined studies of latitudinal and interannual variations of annual phytoplankton bloom peak in East Asian marginal seas(17°–58°N, including the northern South China Sea(SCS), Kuroshio waters, the Sea of Japan and the Okhotsk Sea) are rarely. Based on satellite-retrieved ten-year(2003–2012) median timing of the annual Chlorophyll a concentration(Chl a) climax, here we report that this annual spring bloom peak generally delays from the SCS in January to the Okhotsk Sea in June at a rate of(21.20±2.86) km/d(decadal median±SD). Spring bloom is dominant feature of the phytoplankton annual cycle over these regions, except for the SCS which features winter bloom. The fluctuation of the annual peak timing is mainly within ±48 d departured from the decadal median peak date, therefore this period(the decadal median peak date ±48 d) is defined as annual spring bloom period. As sea surface temperature rises, earlier spring bloom peak timing but decreasing averaged Chl a biomass in the spring bloom period due to insufficient light is evident in the Okhotsk Sea from 2003 to 2012. For the rest of three study domains, there are no significant interannual variance trend of the peak timing and the averaged Chl a biomass. Furthermore this change of spring phytoplankton bloom timing and magnitude in the Okhotsk Sea challenges previous prediction that ocean warming would enhance algal productivity at high latitudes.
文摘A 3- D free surface flow in open channels based on the Reynolds equations with the k-ε turbulence closure model is presented in this paper. Insted of the 'rigid lid' approximation, the solution of the free surface equation is implemented in the velocity-pressure iterative procedure on the basis of the conventional SIMPLE method. This model was used to compute the flow in rectangular channels with trenches dredged across the bottom. The velocity, eddy viscosity coefficient, turbulent shear stress, turbulent kinetic energy and elevation of the free surface can be obtained. The computed results are in good agreement with previous experimental data.
文摘利用1993--2006年1～12月AIPO （The joining area of Asia and Indian-Pacific Ocean）流场数据，分析了吕宋海峡120。E断面水交换流速结构的平均月际变化特征，并计算了通过该断面的水通量，探讨了水通量及其垂向结构的月际和季节变化特征。结果表明：①在断面的南北方向，西向流和东向流分别大致以19．5°N和21．5°N线为界，二者交替相间分布，呈“两进（西向流入南海）两出（东向流出南海）”的结构；21．5°N以南的300m以深和21．5°N以北的1000m以浅海域，常年存在南海水东向流入太平洋。②上层、深层和整个断面的净水通量几乎均为西向流，净水通量冬季最大，春季和秋季次之，夏季最小。中层除12月外，其他各月的净水通量均为东向流出南海，净水通量春季最大，夏季和秋季次之，冬季最小。③整个断面的净水通量，1～5月和8～11月呈“三明治”结构，6～7月呈2层结构；12月呈单层结构，年平均呈“三明治”结构。
