The Beijing 325-m Meteorological Tower (325MT) is used to observe the vertical variation of solar radiation. Results of the experiments indicate that the automatic radiation monitoring system, including a sun tracker ...The Beijing 325-m Meteorological Tower (325MT) is used to observe the vertical variation of solar radiation. Results of the experiments indicate that the automatic radiation monitoring system, including a sun tracker and data collection system, works well and all the specifications meet WMO observation standards. The measurement data show that there is a significant radiation decrease from 320 m to the surface, where the difference is only about 30 W m-2 on light air-pollution days, while the maximum reaches about 110 W m-2 when heavy pollution appears near the ground. The global UV radiation decreases on heavy air-pollution days and under poor visibility conditions, and the difference between 300 m and 8 m is larger than on clear days.展开更多
In this paper, we use a spectral model for the medium-range numerical weather forecast to discuss the impact of the diurnal variation of solar radiation on the medium-range weather processes. Under the tests of two ty...In this paper, we use a spectral model for the medium-range numerical weather forecast to discuss the impact of the diurnal variation of solar radiation on the medium-range weather processes. Under the tests of two typical winter and summer cases, we find that the influences of the diurnal variation of solar radiation on summer weather are really important, especially on its rainfall, surface heat transport and 500 hPa height field. On winter weather, however, the influences are very weak.展开更多
Solar radiation is an important energy source for plants on the earth and also a major component of the global energy balance. Variations in solar radiation incident at the earth’s surface profoundly affect the human...Solar radiation is an important energy source for plants on the earth and also a major component of the global energy balance. Variations in solar radiation incident at the earth’s surface profoundly affect the human and terrestrial environment, including the climate change. To provide useful information for predicting the future climate change in China, distinctive regional features in spatial and temporal variations of the surface solar radiation （SSR） and corresponding attributions （such as cloud and aerosol） are analyzed based on SSR observations and other meteorological measurements in North and East China from 1961 to 2007. Multiple models, such as the plane-parallel radiative transfer model, empirical and statistical models, and correlation and regression analysis methods are used in the study. The results are given as follows. （1） During 1961–2007, the total SSR in North China went through a process from quickly ＂dimming＂ to slowly ＂dimming＂, while in East China, a significant transition from ＂dimming＂ to ＂brightening＂ occurred. Although there are some differences between the two regional variation trends, long-term variations in SSR in the two regions are basically consistent with the observation worldwide. （2） Between the 1960s and 1980s, in both North and East China, aerosols played a critical role in the radiation dimming. However, after 1989, different variation trends of SSR occurred in North and East China, indicating that aerosols were not the dominant factor. （3） Cloud cover contributed less to the variation of SSR in North China, but was the major attribution in East China and played a promoting role in the reversal of SSR from dimming to brightening, especially in the ＂remarkable brightening＂ period, with its contribution as high as 70%.展开更多
文摘The Beijing 325-m Meteorological Tower (325MT) is used to observe the vertical variation of solar radiation. Results of the experiments indicate that the automatic radiation monitoring system, including a sun tracker and data collection system, works well and all the specifications meet WMO observation standards. The measurement data show that there is a significant radiation decrease from 320 m to the surface, where the difference is only about 30 W m-2 on light air-pollution days, while the maximum reaches about 110 W m-2 when heavy pollution appears near the ground. The global UV radiation decreases on heavy air-pollution days and under poor visibility conditions, and the difference between 300 m and 8 m is larger than on clear days.
文摘In this paper, we use a spectral model for the medium-range numerical weather forecast to discuss the impact of the diurnal variation of solar radiation on the medium-range weather processes. Under the tests of two typical winter and summer cases, we find that the influences of the diurnal variation of solar radiation on summer weather are really important, especially on its rainfall, surface heat transport and 500 hPa height field. On winter weather, however, the influences are very weak.
基金Supported by the National Key Basic Research and Development (973) Program of China (2006CB403705)Natural Science Key Research Program of Jiangsu Province (09KJA170004)Natural Science Foundation of Hebei Province (D2009001338)
文摘Solar radiation is an important energy source for plants on the earth and also a major component of the global energy balance. Variations in solar radiation incident at the earth’s surface profoundly affect the human and terrestrial environment, including the climate change. To provide useful information for predicting the future climate change in China, distinctive regional features in spatial and temporal variations of the surface solar radiation （SSR） and corresponding attributions （such as cloud and aerosol） are analyzed based on SSR observations and other meteorological measurements in North and East China from 1961 to 2007. Multiple models, such as the plane-parallel radiative transfer model, empirical and statistical models, and correlation and regression analysis methods are used in the study. The results are given as follows. （1） During 1961–2007, the total SSR in North China went through a process from quickly ＂dimming＂ to slowly ＂dimming＂, while in East China, a significant transition from ＂dimming＂ to ＂brightening＂ occurred. Although there are some differences between the two regional variation trends, long-term variations in SSR in the two regions are basically consistent with the observation worldwide. （2） Between the 1960s and 1980s, in both North and East China, aerosols played a critical role in the radiation dimming. However, after 1989, different variation trends of SSR occurred in North and East China, indicating that aerosols were not the dominant factor. （3） Cloud cover contributed less to the variation of SSR in North China, but was the major attribution in East China and played a promoting role in the reversal of SSR from dimming to brightening, especially in the ＂remarkable brightening＂ period, with its contribution as high as 70%.
