太阳活动对全球气候的影响一直是人们关心的热门话题,尤其是太阳活动对海温和降水的影响吸引更多学者的目光.本文通过研究全球0~700 m海温对太阳射电通量(Solar Radio Flux,缩写为SRF)的响应,发现全球海温对太阳活动响应具有空间分布不...太阳活动对全球气候的影响一直是人们关心的热门话题,尤其是太阳活动对海温和降水的影响吸引更多学者的目光.本文通过研究全球0~700 m海温对太阳射电通量(Solar Radio Flux,缩写为SRF)的响应,发现全球海温对太阳活动响应具有空间分布不均匀性特征,显著响应的地区集中在太平洋和南大西洋,显著响应的层次主要在0~200 m.利用响应太阳活动显著区域的海温资料,定义一个响应太阳活动的海温异常指数,研究该指数与同期和滞后1年全球冬夏季降水的相关分布,发现指数高时夏季热带中太平洋降水增多,南北半球中高纬地区降水增加,呈带状分布,南极地区降水显著减少;我国江南东部地区、青藏高原和山东半岛降水减少.冬季热带中部太平洋和东南太平洋地区降水增多,赤道西太平洋降水明显偏少,北极地区降水显著偏多,热带西太平洋和孟加拉湾降水减少,南北两个半球中高纬度地区降水增多;我国华南地区广西和广东西部、海南一带降水增多,东北地区降水减少,青藏高原地区降水显著增加.当海温异常指数低时,情况相反.研究结果表明,海温异常通过影响降水放大了太阳活动的作用.由此推测,在考虑夏季降水的预测问题时,由太阳活动引起的太平洋和大西洋海温异常对降水的影响应该引起重视.展开更多
The Lancang–Mekong River basin(LMRB) is under increasing threat from global warming. In this paper, the projection of future climate in the LMRB is explored by focusing on the temperature change and extreme temperatu...The Lancang–Mekong River basin(LMRB) is under increasing threat from global warming. In this paper, the projection of future climate in the LMRB is explored by focusing on the temperature change and extreme temperature events. First, the authors evaluate the bias of temperature simulated by the Weather Research and Forecasting model. Then, correction is made for the simulation by comparing with observation based on the non-parametric quantile mapping using robust empirical quantiles(RQUANT) method. Furthermore, using the corrected model results, the future climate projections of temperature and extreme temperature events in this basin during 2016–35, 2046–65, and 2080–99 are analyzed. The study shows that RQUANT can effectively reduce the bias of simulation results. After correction, the simulation can capture the spatial features and trends of mean temperature over the LMRB, as well as the extreme temperature events. Besides, it can reproduce the spatial and temporal distributions of the major modes. In the future, the temperature will keep increasing, and the warming in the southern basin will be more intense in the wet season than the dry season. The number of extreme high-temperature days exhibits an increasing trend, while the number of extreme low-temperature days shows a decreasing trend. Based on empirical orthogonal function analysis, the dominant feature of temperature over this basin shows a consistent change. The second mode shows a seesaw pattern.展开更多
Based on satellite altimeter and reanalysis data,this paper studies the relationships between the intensity of the Kuroshio current in the East China Sea（ECS） and the East Asian winter monsoon（EAWM）.The mechanisms...Based on satellite altimeter and reanalysis data,this paper studies the relationships between the intensity of the Kuroshio current in the East China Sea（ECS） and the East Asian winter monsoon（EAWM）.The mechanisms of their possible interaction are also discussed.Results indicate that adjacent transects show consistent variations,and on an interannual timescale,when the EAWM is anomalously strong（weak）,the downstream Kuroshio in the ECS is suppressed（enhanced） in the following year from February to April.This phenomenon can be attributed to both the dynamic effect（i.e.,Ekman transport） and the thermal effect of the EAWM.When the EAWM strengthens（weakens）,the midstream and downstream Kuroshio in the ECS are also suppressed（intensified） during the following year from October to December.The mechanisms vary for these effects.The EAWM exerts its influence on the Kuroshio＇s intensity in the following year through the tropospheric biennial oscillation（TBO）,and oceanic forcing is dominant during this time.The air-sea interaction is modulated by the relative strength of the EAWM and the Kuroshio in the ECS.The non-equivalence of spatial scales between the monsoon and the Kuroshio determines that their interactions are aided by processes with a smaller spatial scale,i.e.,local wind stress and heating at the sea surface.展开更多
Mid-latitude air-sea interaction is an important topic that attracts a considerable amount of research interest. The Kuroshio Extension(KE) is one of the main western boundary currents and plays a critical role in the...Mid-latitude air-sea interaction is an important topic that attracts a considerable amount of research interest. The Kuroshio Extension(KE) is one of the main western boundary currents and plays a critical role in the mid-latitude atmospheric circulation. This paper uses the NCEP/NCAR reanalysis and Hadley sea surface temperature datasets to investigate the influence of oceanic fronts in the KE region on surface air temperature in North America over the period 1949–2014. A significant correlation was found between the KE front intensity and the temperatures over North America in autumn and winter. A strong(weak) KE front anomaly in autumn is associated with an increasing(decreasing) surface temperature over western North America but a decreasing(increasing) surface temperature over eastern North America. In winter, central North America warms(cools) when the KE front is strong(weak). The response of the atmospheric circulation, including wind in the high and low troposphere, troughs, and ridges, to the strengthening(weakening) of the KE front is the main cause of these changes in surface temperature.展开更多
文摘太阳活动对全球气候的影响一直是人们关心的热门话题,尤其是太阳活动对海温和降水的影响吸引更多学者的目光.本文通过研究全球0~700 m海温对太阳射电通量(Solar Radio Flux,缩写为SRF)的响应,发现全球海温对太阳活动响应具有空间分布不均匀性特征,显著响应的地区集中在太平洋和南大西洋,显著响应的层次主要在0~200 m.利用响应太阳活动显著区域的海温资料,定义一个响应太阳活动的海温异常指数,研究该指数与同期和滞后1年全球冬夏季降水的相关分布,发现指数高时夏季热带中太平洋降水增多,南北半球中高纬地区降水增加,呈带状分布,南极地区降水显著减少;我国江南东部地区、青藏高原和山东半岛降水减少.冬季热带中部太平洋和东南太平洋地区降水增多,赤道西太平洋降水明显偏少,北极地区降水显著偏多,热带西太平洋和孟加拉湾降水减少,南北两个半球中高纬度地区降水增多;我国华南地区广西和广东西部、海南一带降水增多,东北地区降水减少,青藏高原地区降水显著增加.当海温异常指数低时,情况相反.研究结果表明,海温异常通过影响降水放大了太阳活动的作用.由此推测,在考虑夏季降水的预测问题时,由太阳活动引起的太平洋和大西洋海温异常对降水的影响应该引起重视.
基金This work was supported by the External Cooperation Program of Bureau of International Co-operation,Chinese Academy of Sciences[grant number GJHZ1729]the Key Program of the Natural Science Foundation of Yunnan Province of China[grant number 2016FA041].
文摘The Lancang–Mekong River basin(LMRB) is under increasing threat from global warming. In this paper, the projection of future climate in the LMRB is explored by focusing on the temperature change and extreme temperature events. First, the authors evaluate the bias of temperature simulated by the Weather Research and Forecasting model. Then, correction is made for the simulation by comparing with observation based on the non-parametric quantile mapping using robust empirical quantiles(RQUANT) method. Furthermore, using the corrected model results, the future climate projections of temperature and extreme temperature events in this basin during 2016–35, 2046–65, and 2080–99 are analyzed. The study shows that RQUANT can effectively reduce the bias of simulation results. After correction, the simulation can capture the spatial features and trends of mean temperature over the LMRB, as well as the extreme temperature events. Besides, it can reproduce the spatial and temporal distributions of the major modes. In the future, the temperature will keep increasing, and the warming in the southern basin will be more intense in the wet season than the dry season. The number of extreme high-temperature days exhibits an increasing trend, while the number of extreme low-temperature days shows a decreasing trend. Based on empirical orthogonal function analysis, the dominant feature of temperature over this basin shows a consistent change. The second mode shows a seesaw pattern.
基金The National Basic Research Program(973 program)of China under contract No.2013CB956200the National Natural Science Foundation of China under contract Nos 41490642 and 41605051
文摘Based on satellite altimeter and reanalysis data,this paper studies the relationships between the intensity of the Kuroshio current in the East China Sea（ECS） and the East Asian winter monsoon（EAWM）.The mechanisms of their possible interaction are also discussed.Results indicate that adjacent transects show consistent variations,and on an interannual timescale,when the EAWM is anomalously strong（weak）,the downstream Kuroshio in the ECS is suppressed（enhanced） in the following year from February to April.This phenomenon can be attributed to both the dynamic effect（i.e.,Ekman transport） and the thermal effect of the EAWM.When the EAWM strengthens（weakens）,the midstream and downstream Kuroshio in the ECS are also suppressed（intensified） during the following year from October to December.The mechanisms vary for these effects.The EAWM exerts its influence on the Kuroshio＇s intensity in the following year through the tropospheric biennial oscillation（TBO）,and oceanic forcing is dominant during this time.The air-sea interaction is modulated by the relative strength of the EAWM and the Kuroshio in the ECS.The non-equivalence of spatial scales between the monsoon and the Kuroshio determines that their interactions are aided by processes with a smaller spatial scale,i.e.,local wind stress and heating at the sea surface.
基金supported in part by the National Natural Science Foundation of China(Nos.41490642,41690640 and 41665004)
文摘Mid-latitude air-sea interaction is an important topic that attracts a considerable amount of research interest. The Kuroshio Extension(KE) is one of the main western boundary currents and plays a critical role in the mid-latitude atmospheric circulation. This paper uses the NCEP/NCAR reanalysis and Hadley sea surface temperature datasets to investigate the influence of oceanic fronts in the KE region on surface air temperature in North America over the period 1949–2014. A significant correlation was found between the KE front intensity and the temperatures over North America in autumn and winter. A strong(weak) KE front anomaly in autumn is associated with an increasing(decreasing) surface temperature over western North America but a decreasing(increasing) surface temperature over eastern North America. In winter, central North America warms(cools) when the KE front is strong(weak). The response of the atmospheric circulation, including wind in the high and low troposphere, troughs, and ridges, to the strengthening(weakening) of the KE front is the main cause of these changes in surface temperature.
基金Supported by the National Basic Research Program of China(Grant No.2003CB415101)the Climate Change Program of China Meteorological Administration(Grant No.CCSF2007-23)
