On the basis of snow data and AWS (Automatic Weather Station) data obtained from the Tibetan Plateau in recent years (1993 to 1999), the features of sensible heat, latent heat and net long-wave radiations are estimate...On the basis of snow data and AWS (Automatic Weather Station) data obtained from the Tibetan Plateau in recent years (1993 to 1999), the features of sensible heat, latent heat and net long-wave radiations are estimated, and their variations in more-snow year (1997/ 1998) and less-snow year (1996/ 1997) are analyzed comparatively. The relationships between snow cover of the Tibetan Plateau and plateau’s surface heating to the atmospheric heating are also discussed. The difference between more-snow and less-snow year in spring is remarkably larger than that in winter. Therefore, the effect of anomalous snow cover of the Tibetan Plateau in winter on the plateau heating appears more clearly in the following spring of anomalous snow cover. Key words Tibetan Plateau - Snow cover - Effects - Surface heat fluxes This research was supported by the National Key Programme for Developing Basic Sciences G1998040900 (I), National Natural Science Foundation of China (40075018) and Sichuan Youth Science and Technology Fund.展开更多
The radiative forcing and climate response due to black carbon（BC） in snow and/or ice were investigated by integrating observed effects of BC on snow/ice albedo into an atmospheric general circulation model（BCC AGC...The radiative forcing and climate response due to black carbon（BC） in snow and/or ice were investigated by integrating observed effects of BC on snow/ice albedo into an atmospheric general circulation model（BCC AGCM2.0.1） developed by the National Climate Center（NCC） of the China Meteorological Administration（CMA）.The results show that the global annual mean surface radiative forcing due to BC in snow/ice is ＋0.042 W m 2,with maximum forcing found over the Tibetan Plateau and regional mean forcing exceeding ＋2.8 W m 2.The global annual mean surface temperature increased 0.071 C due to BC in snow/ice.Positive surface radiative forcing was clearly shown in winter and spring and increased the surface temperature of snow/ice in the Northern Hemisphere.The surface temperatures of snow-covered areas of Eurasia and North America in winter（spring） increased by 0.83 C（0.6 C） and 0.83 C（0.46 C）,respectively.Snowmelt rates also increased greatly,leading to earlier snowmelt and peak runoff times.With the rise of surface temperatures in the Arctic,more water vapor could be released into the atmosphere,allowing easier cloud formation,which could lead to higher thermal emittance in the Arctic.However,the total cloud forcing could decrease due to increasing cloud cover,which will offset some of the positive feedback mechanism of the clouds.展开更多
利用2017年至2019年山东半岛15个沿海气象站观测资料和欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)细网格模式预报数据,采用逐日预报准确率和逐月平均差值计算方法,对地面2 m温度进行了检验,针对...利用2017年至2019年山东半岛15个沿海气象站观测资料和欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)细网格模式预报数据,采用逐日预报准确率和逐月平均差值计算方法,对地面2 m温度进行了检验,针对威海地区冷空气、冷流降雪和海雾过程分别进行了预报性能检验。结果表明:24 h时效内预报误差≤2℃时,低温预报准确率为60%~95%,高温预报准确率为50%~89%。低温预报中,北部沿海和南部沿海在3月至9月逐月平均预报误差小于1℃。冷空气过程高温预报正负差值比率相当,低温预报正差值的占比较大,最高为96%;冷流降雪过程中,高、低温预报整体以正差值为主;浓雾出现区域,模式的低温预报偏高。模式结果可为3月至9月低温预报提供较好的参考依据。展开更多
基金the National Key Programme for Developing Basic SciencesG1998040900 (I)National Natural Science Foundation of China (400750
文摘On the basis of snow data and AWS (Automatic Weather Station) data obtained from the Tibetan Plateau in recent years (1993 to 1999), the features of sensible heat, latent heat and net long-wave radiations are estimated, and their variations in more-snow year (1997/ 1998) and less-snow year (1996/ 1997) are analyzed comparatively. The relationships between snow cover of the Tibetan Plateau and plateau’s surface heating to the atmospheric heating are also discussed. The difference between more-snow and less-snow year in spring is remarkably larger than that in winter. Therefore, the effect of anomalous snow cover of the Tibetan Plateau in winter on the plateau heating appears more clearly in the following spring of anomalous snow cover. Key words Tibetan Plateau - Snow cover - Effects - Surface heat fluxes This research was supported by the National Key Programme for Developing Basic Sciences G1998040900 (I), National Natural Science Foundation of China (40075018) and Sichuan Youth Science and Technology Fund.
基金supported by the National Basic Research Program of China (Grant Nos. 2010CB955608 and 2011CB403405)the Public Meteorology Special Foundation of MOST (Grant No.GYHY200906020)
文摘The radiative forcing and climate response due to black carbon（BC） in snow and/or ice were investigated by integrating observed effects of BC on snow/ice albedo into an atmospheric general circulation model（BCC AGCM2.0.1） developed by the National Climate Center（NCC） of the China Meteorological Administration（CMA）.The results show that the global annual mean surface radiative forcing due to BC in snow/ice is ＋0.042 W m 2,with maximum forcing found over the Tibetan Plateau and regional mean forcing exceeding ＋2.8 W m 2.The global annual mean surface temperature increased 0.071 C due to BC in snow/ice.Positive surface radiative forcing was clearly shown in winter and spring and increased the surface temperature of snow/ice in the Northern Hemisphere.The surface temperatures of snow-covered areas of Eurasia and North America in winter（spring） increased by 0.83 C（0.6 C） and 0.83 C（0.46 C）,respectively.Snowmelt rates also increased greatly,leading to earlier snowmelt and peak runoff times.With the rise of surface temperatures in the Arctic,more water vapor could be released into the atmosphere,allowing easier cloud formation,which could lead to higher thermal emittance in the Arctic.However,the total cloud forcing could decrease due to increasing cloud cover,which will offset some of the positive feedback mechanism of the clouds.
文摘利用2017年至2019年山东半岛15个沿海气象站观测资料和欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)细网格模式预报数据,采用逐日预报准确率和逐月平均差值计算方法,对地面2 m温度进行了检验,针对威海地区冷空气、冷流降雪和海雾过程分别进行了预报性能检验。结果表明:24 h时效内预报误差≤2℃时,低温预报准确率为60%~95%,高温预报准确率为50%~89%。低温预报中,北部沿海和南部沿海在3月至9月逐月平均预报误差小于1℃。冷空气过程高温预报正负差值比率相当,低温预报正差值的占比较大,最高为96%;冷流降雪过程中,高、低温预报整体以正差值为主;浓雾出现区域,模式的低温预报偏高。模式结果可为3月至9月低温预报提供较好的参考依据。
