A new regional coupled ocean–atmosphere model,WRF4-LICOM,was used to investigate the impacts of regional air–sea coupling on the simulation of the western North Pacific summer monsoon(WNPSM),with a focus on the norm...A new regional coupled ocean–atmosphere model,WRF4-LICOM,was used to investigate the impacts of regional air–sea coupling on the simulation of the western North Pacific summer monsoon(WNPSM),with a focus on the normal WNPSM year 2005.Compared to WRF4,WRF4-LICOM improved the simulation of the summer mean monsoon rainfall,circulations,sea surface net heat fluxes,and propagations of the daily rainband over the WNP.The major differences between the models were found over the northern South China Sea and east of the Philippines.The warmer SST reduced the gross moist stability of the atmosphere and increased the upward latent heat flux,and then drove local ascending anomalies,which led to the increase of rainfall in WRF4-LICOM.The resultant enhanced atmospheric heating drove a low-level anomalous cyclone to its northwest,which reduced the simulated circulation biases in the stand-alone WRF4 model.The local observed daily SST over the WNP was a response to the overlying summer monsoon.In the WRF4 model,the modeled atmosphere exhibited passive response to the underlying daily SST anomalies.With the inclusion of regional air–sea coupling,the simulated daily SST–rainfall relationship was significantly improved.WRF4-LICOM is recommended for future dynamical downscaling of simulations and projections over this region.展开更多
Sea ice conditions in the Bohai Sea of China are sensitive to large-scale climatic variations. On the basis of CLARA-A1-SAL data, the albedo variations are examined in space and time in the winter（December, January a...Sea ice conditions in the Bohai Sea of China are sensitive to large-scale climatic variations. On the basis of CLARA-A1-SAL data, the albedo variations are examined in space and time in the winter（December, January and February） from 1992 to 2008 in the Bohai Sea sea ice region. Time series data of the sea ice concentration（SIC）, the sea ice extent（SIE） and the sea surface temperature（SST） are used to analyze their relationship with the albedo. The sea ice albedo changed in volatility appears along with time, the trend is not obvious and increases very slightly during the study period at a rate of 0.388% per decade over the Bohai Sea sea ice region.The interannual variation is between 9.93% and 14.50%, and the average albedo is 11.79%. The sea ice albedo in years with heavy sea ice coverage, 1999, 2000 and 2005, is significantly higher than that in other years; in years with light sea ice coverage, 1994, 1998, 2001 and 2006, has low values. For the monthly albedo, the increasing trend（at a rate of 0.988% per decade） in December is distinctly higher than that in January and February. The mean albedo in January（12.90%） is also distinctly higher than that in the other two months. The albedo is significantly positively correlated with the SIC and is significantly negatively correlated with the SST（significance level 90%）.展开更多
Research on carrying capacity, aiming at maintaining the limited ability of the Earth＇s life supporting system to sustain human development, requires a comprehensive and ecosystem-based approach to monitor and assess...Research on carrying capacity, aiming at maintaining the limited ability of the Earth＇s life supporting system to sustain human development, requires a comprehensive and ecosystem-based approach to monitor and assess the localized sustainability of coupled social and ecological systems. A definition termed the ecosystem-based carrying capacity of island（EBCCI） was developed in this paper of which the indices of fundamental and realized carrying capacities of island（FCCI and RCCI） were highlighted to emphasize the inter-dependencies between social systems and ecological systems. In order to avoid the difficulties and uncertainties of direct assessment, the related assessment model was established on the basis of synthetic evaluation of inherent and external factors affecting the EBCCI. The southern Miaodao Archipelago（SMA） located in the intersection of the Bohai Sea and the Yellow Sea, China, was taken as a typical example to acquire integrated recognition of the island ecosystem and its carrying capacity so as to discuss its sustainable development. The index scores of FCCI and RCCI in the SMA were 0.818 5 and 0.712 9 out of 1.0, respectively, with acceptable uncertainties. The results showed a relatively well capacity to sustain progress and relatively well realization of the carrying capacity of island ecosystem, owing to a well capacity of ecologically regulating, general performance of both ecologically supporting and resource provisioning, and a relatively high level of social supporting system. The study implied that it was critical to optimize the inter-dependencies and to sustain the relative balance between social systems and ecological systems so as to improve the RCCI and further facilitate the sustainability of SMA. The approach proposed in this paper provides a powerful tool which is well applicative to the regional level of an oceanic island or archipelago to study the sustainable development and can be further popularized to the coastal zone.展开更多
A successful simulation of the western North Pacific summer monsoon needs a regional ocean–atmosphere coupled model(ROAM). How the performance of ROAM relies on the oceanic component model remains unknown. In this st...A successful simulation of the western North Pacific summer monsoon needs a regional ocean–atmosphere coupled model(ROAM). How the performance of ROAM relies on the oceanic component model remains unknown. In this study, the authors investigated the effects of different oceanic components on the simulation of western North Pacific(WNP) summer monsoon in a ROAM. Three cases of simulations were performed, viz. the summer of 1998(El Nin o decaying phase), 2004(El Nin o developing phase), and 1993(the non-ENSO phase). Results show that the coupled simulations for different ENSO phases exhibit improvements in the simulation of location of Meiyu rainband and spatial distribution of monsoon low-level flow over WNP, whereas the systemic cold biases of sea surface air temperature are further increased. The coupled simulations with different oceanic components show similar performance, which is not ENSO phase dependent. For the case of the summer of 1998, a slightly stronger western Pacific subtropical high and colder sea surface air temperature are found in the simulation with colder sea surface temperature(SST) biases. The colder SST biases are partly contributed by the ocean dynamics processes because the sea surface net flux favors a warmer SST. This study suggests that the dependence of performance of ROAM over WNP on oceanic models is much weaker than that on atmospheric models.展开更多
基金jointly supported by the National Natural Science Foundation of China grant number 41875132The National Key Research and Development Program of China grant number 2018YFA0606003。
文摘A new regional coupled ocean–atmosphere model,WRF4-LICOM,was used to investigate the impacts of regional air–sea coupling on the simulation of the western North Pacific summer monsoon(WNPSM),with a focus on the normal WNPSM year 2005.Compared to WRF4,WRF4-LICOM improved the simulation of the summer mean monsoon rainfall,circulations,sea surface net heat fluxes,and propagations of the daily rainband over the WNP.The major differences between the models were found over the northern South China Sea and east of the Philippines.The warmer SST reduced the gross moist stability of the atmosphere and increased the upward latent heat flux,and then drove local ascending anomalies,which led to the increase of rainfall in WRF4-LICOM.The resultant enhanced atmospheric heating drove a low-level anomalous cyclone to its northwest,which reduced the simulated circulation biases in the stand-alone WRF4 model.The local observed daily SST over the WNP was a response to the overlying summer monsoon.In the WRF4 model,the modeled atmosphere exhibited passive response to the underlying daily SST anomalies.With the inclusion of regional air–sea coupling,the simulated daily SST–rainfall relationship was significantly improved.WRF4-LICOM is recommended for future dynamical downscaling of simulations and projections over this region.
文摘Sea ice conditions in the Bohai Sea of China are sensitive to large-scale climatic variations. On the basis of CLARA-A1-SAL data, the albedo variations are examined in space and time in the winter（December, January and February） from 1992 to 2008 in the Bohai Sea sea ice region. Time series data of the sea ice concentration（SIC）, the sea ice extent（SIE） and the sea surface temperature（SST） are used to analyze their relationship with the albedo. The sea ice albedo changed in volatility appears along with time, the trend is not obvious and increases very slightly during the study period at a rate of 0.388% per decade over the Bohai Sea sea ice region.The interannual variation is between 9.93% and 14.50%, and the average albedo is 11.79%. The sea ice albedo in years with heavy sea ice coverage, 1999, 2000 and 2005, is significantly higher than that in other years; in years with light sea ice coverage, 1994, 1998, 2001 and 2006, has low values. For the monthly albedo, the increasing trend（at a rate of 0.988% per decade） in December is distinctly higher than that in January and February. The mean albedo in January（12.90%） is also distinctly higher than that in the other two months. The albedo is significantly positively correlated with the SIC and is significantly negatively correlated with the SST（significance level 90%）.
基金The Special Project of Science and Technology Fundamental Work from the Ministry of Science and Technology of China under contract No.2012FY112500the National Natural Science Foundation of China under contract No.41206111
文摘Research on carrying capacity, aiming at maintaining the limited ability of the Earth＇s life supporting system to sustain human development, requires a comprehensive and ecosystem-based approach to monitor and assess the localized sustainability of coupled social and ecological systems. A definition termed the ecosystem-based carrying capacity of island（EBCCI） was developed in this paper of which the indices of fundamental and realized carrying capacities of island（FCCI and RCCI） were highlighted to emphasize the inter-dependencies between social systems and ecological systems. In order to avoid the difficulties and uncertainties of direct assessment, the related assessment model was established on the basis of synthetic evaluation of inherent and external factors affecting the EBCCI. The southern Miaodao Archipelago（SMA） located in the intersection of the Bohai Sea and the Yellow Sea, China, was taken as a typical example to acquire integrated recognition of the island ecosystem and its carrying capacity so as to discuss its sustainable development. The index scores of FCCI and RCCI in the SMA were 0.818 5 and 0.712 9 out of 1.0, respectively, with acceptable uncertainties. The results showed a relatively well capacity to sustain progress and relatively well realization of the carrying capacity of island ecosystem, owing to a well capacity of ecologically regulating, general performance of both ecologically supporting and resource provisioning, and a relatively high level of social supporting system. The study implied that it was critical to optimize the inter-dependencies and to sustain the relative balance between social systems and ecological systems so as to improve the RCCI and further facilitate the sustainability of SMA. The approach proposed in this paper provides a powerful tool which is well applicative to the regional level of an oceanic island or archipelago to study the sustainable development and can be further popularized to the coastal zone.
基金supported by the National Natural Science Foundation of China(41205080)the National Basic Research Program of China(2013CB956204)+1 种基金China R&D Special Fund for Public Welfare Industry(meteorology)(GYHY201306019)Public Science and Technology Research Funds(201105019–3)
文摘A successful simulation of the western North Pacific summer monsoon needs a regional ocean–atmosphere coupled model(ROAM). How the performance of ROAM relies on the oceanic component model remains unknown. In this study, the authors investigated the effects of different oceanic components on the simulation of western North Pacific(WNP) summer monsoon in a ROAM. Three cases of simulations were performed, viz. the summer of 1998(El Nin o decaying phase), 2004(El Nin o developing phase), and 1993(the non-ENSO phase). Results show that the coupled simulations for different ENSO phases exhibit improvements in the simulation of location of Meiyu rainband and spatial distribution of monsoon low-level flow over WNP, whereas the systemic cold biases of sea surface air temperature are further increased. The coupled simulations with different oceanic components show similar performance, which is not ENSO phase dependent. For the case of the summer of 1998, a slightly stronger western Pacific subtropical high and colder sea surface air temperature are found in the simulation with colder sea surface temperature(SST) biases. The colder SST biases are partly contributed by the ocean dynamics processes because the sea surface net flux favors a warmer SST. This study suggests that the dependence of performance of ROAM over WNP on oceanic models is much weaker than that on atmospheric models.
