The modeling responses of heat budget in the Eastern China Seas to global warming

2020 ◽  
Author(s):  
Di Tian
Keyword(s):  
Heat Flux ◽  
Solar Radiation ◽  
Heat Transport ◽  
Heat Budget ◽  
Eastern China ◽  
Surface Wind ◽  
Shelf Break ◽  
China Seas ◽  
Heat Gain ◽  
Eastern China Seas

<p>Impacts of climate change on heat budget in the Eastern China Seas (ECSs) are estimated under the historical, RCP4.5 and RCP8.5 scenarios using an atmosphere-ocean coupled regional climate model system (REMO/MPIOM). Solar radiation contributes the largest heat source of the ECSs. The heat gain achieved by solar radiation is overruled by thermal radiation, latent heat flux and sensible heat flux released at the ocean surface. The air-sea heat exchange thus cools the ECSs, whereas an overall warming is found for the ECSs. An increased oceanic heat transport by ocean currents balances this reduced heat supply by the sea surface heat fluxes. In particular, the water transport through Taiwan Strait brings the largest amount of heat into the ECSs. Despite of an inward heat transport onto the ECS shelf caused by the Kuroshio intrusion occurring northeast of Taiwan, overall, the shelf break section acts as a heat sink for the ECSs. The net heat gain/loss by the Tsushima Strait is marginal. Under the climate projection scenarios, the net heat loss from the shelf break section reduces, probably associated with the change in surface wind. Thus the net heat transported into the ECSs through the lateral boundaries increases slightly under these scenarios, leading to an overall warming of the ECSs, relative to 20C run. Noteworthy, the warmer SST, along with strengthened wind, further enhances the surface evaporation, providing a negative feedback onto the net effect of oceanic transport.</p>

Heat budget responses of the eastern China seas to global warming in a coupled atmosphere-ocean model

2019 ◽  
Vol 79 (2) ◽  
pp. 109-126
Author(s):  
D Tian ◽  
J Su ◽  
F Zhou ◽  
B Mayer ◽  
D Sein ◽  
...  
Keyword(s):  
Global Warming ◽  
Heat Budget ◽  
Eastern China ◽  
Ocean Model ◽  
China Seas ◽  
Eastern China Seas

scholarly journals Thermal Regime of Ice Covered Swedish Lakes

1996 ◽  
Vol 27 (1-2) ◽  
pp. 39-56 ◽  
Author(s):  
Lars Bengtsson ◽  
Thorbjörn Svensson
Keyword(s):  
Heat Flux ◽  
Solar Radiation ◽  
Heat Source ◽  
Lake Water ◽  
Heat Budget ◽  
Heat Content ◽  
Heat Fluxes ◽  
Late Winter ◽  
Temperature Profiles ◽  
Early Winter

Temperature conditions and heat fluxes in ice covered lakes are discussed analyzing measurements in eight Swedish lakes. Heat fluxes from sediments and heat fluxes from water to ice are determined from temperature profiles. The contribution of solar radiation is estimated from heat-budget calculations. It is found that the heat content of most of the lakes changes very little when they are ice covered, but that the lake-water temperature slightly increases. All heat fluxes are small. The heat flux from the sediments is the highest flux in early winter, but is later in the winter balanced by the heat loss from the water to the underside of the ice. Solar radiation is an important heat source in late winter, when the snow cover is thin.

scholarly journals Satellite views of seasonal and inter-annual variability of phytoplankton blooms in the eastern China seas over the past 14 yr (1998–2011)

2013 ◽  
Vol 10 (1) ◽  
pp. 111-155 ◽  
Author(s):  
X. Q. He ◽  
Y. Bai ◽  
D. L. Pan ◽  
C.-T. A. Chen ◽  
Q. Chen ◽  
...  
Keyword(s):  
Yellow Sea ◽  
Annual Variation ◽  
Bohai Sea ◽  
Eastern China ◽  
Chlorophyll Concentration ◽  
The Yellow Sea ◽  
China Seas ◽  
Phytoplankton Blooms ◽  
The Changjiang Estuary ◽  
Eastern China Seas

Abstract. The eastern China seas are one of the largest marginal seas in the world, where high primary productivity and phytoplankton blooms are often observed. However, to date, little is known about the spatial and temporal variability of phytoplankton blooms in these areas due to the difficulty of the monitoring of bloom events by field measurement. In this study, 14-yr time series of satellite ocean color data from the Sea-Viewing Wide Field-of-view Sensor (SeaWiFS) and the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite have been used to investigate the seasonal and inter-annual variability and long-term changes of phytoplankton blooms in the eastern China seas. We validated and calibrated the satellite-derive chlorophyll concentration in the eastern China seas based on extensive data sets from two large cruises. Overestimation of satellite-derive chlorophyll concentration caused by high water turbidity was found to be less than 10 μg L−1. This level can be used as a safe threshold for the identification of a phytoplankton bloom in a marginal sea with turbid waters. Annually, blooms mostly occur in the Changjiang Estuary and along the coasts of Zhejiang. The coasts of the northern Yellow Sea and Bohai Sea also have high-frequency blooms. The blooms have significant seasonal variation, with most of the blooms occurring in the spring (April–June) and summer (July–September). This study revealed a doubling in bloom intensity in the Yellow Sea and Bohai Sea during the past 14 yr (1998–2011), yet surprisingly, there has been no decadal increase or decrease of bloom intensity in despite of significant inter-annual variation in the Changjiang Estuary. The time series in situ datasets show that both the nitrate and phosphate concentrations increase more than twofold from 1998 to 2005. This might be the reason for the doubling of bloom intensity in the Yellow Sea and Bohai Sea. In addition, the ENSO and PDO can affect the inter-annual variation of bloom intensity in the eastern China seas.

scholarly journals Satellite views of the seasonal and interannual variability of phytoplankton blooms in the eastern China seas over the past 14 yr (1998–2011)

2013 ◽  
Vol 10 (7) ◽  
pp. 4721-4739 ◽  
Author(s):  
X. He ◽  
Y. Bai ◽  
D. Pan ◽  
C.-T. A. Chen ◽  
Q. Cheng ◽  
...  
Keyword(s):  
Yellow Sea ◽  
Bohai Sea ◽  
Eastern China ◽  
The Yellow Sea ◽  
China Seas ◽  
Phytoplankton Blooms ◽  
Chl A ◽  
The Past ◽  
Eastern China Seas

Abstract. The eastern China seas are some of the largest marginal seas in the world, where high primary productivity and phytoplankton blooms are often observed. However, little is known about their systematic variation of phytoplankton blooms on large spatial and long temporal scales due to the difficulty of monitoring bloom events by field measurement. In this study, we investigated the seasonal and interannual variability and long-term changes in phytoplankton blooms in the eastern China seas using a 14 yr (1998–2011) time series of satellite ocean colour data. To ensure a proper satellite dataset to figure out the bloom events, we validated and corrected the satellite-derived chlorophyll concentration (chl a) using extensive in situ datasets from two large cruises. The correlation coefficients between the satellite retrieval data and the in situ chl a on the logarithmic scale were 0.85 and 0.72 for the SeaWiFS and Aqua/MODIS data, respectively. Although satellites generally overestimate the chl a, especially in highly turbid waters, both the in situ and satellite data show that the overestimation of satellite-derived chl a has an upper limit value (10 μg L−1), which can be used as a threshold for the identification of phytoplankton blooms to avoid the false blooms resulting from turbid waters. Taking 10 μg L−1 as the threshold, we present the spatial-temporal variability of phytoplankton blooms in the eastern China seas over the past 14 yr. Most blooms occur in the Changjiang Estuary and along the coasts of Zhejiang, with a maximal frequency of 20% (about 73 days per year). The coasts of the northern Yellow Sea and the Bohai Sea also have high-frequency blooms (up to 20%). The blooms show significant seasonal variation, with most occurring in spring (April–June) and summer (July–September). The study also revealed a doubling in bloom intensity in the Yellow Sea and Bohai Sea during the past 14 yr. The nutrient supply in the eastern China seas might be a major controlling factor in bloom variation. The time series in situ nutrient datasets show that both the nitrate and phosphate concentrations increased more than twofold between 1998 and 2005 in the Yellow Sea. This might be the reason for the doubling of the bloom intensity index in the Yellow Sea and Bohai Sea. In contrast, there has been no significant long-term increase or decrease in the Changjiang Estuary, which might be regulated by the Changjiang River discharge. These results offer a foundation for the study of the influence of phytoplankton blooms on the carbon flux estimation and biogeochemical processes in the eastern China seas.

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