干旱区研究

Arid Zone Research ›› 2018, Vol. 35 ›› Issue (2): 436-443.doi: 10.13866/j.azr.2018.02.23

• Climate and Climatic Resources • Previous Articles     Next Articles

Effects of Clouds on Solar Radiation over Typical City in Arid Area

CHEN Chun-mei1, ZHONG Ke1, CHEN Yong-hang1,2, QIN Rong3, XIN Yu2, CHEN Bin4, LIU Qiong1, ZHOU Dai-yi1   

  1. 1. College of Environmental Science and Engineering,Donghua University,Shanghai 201620,China;
    2. Institute of Desert Meteorology,China Meteorological Administration,Urumqi 830002,Xinjiang,China;
    3. Xinjiang Meteorological Observatory,Urumqi 830002,Xinjiang,China;
    4. Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China
  • Received:2017-05-22 Revised:2017-08-13 Online:2018-03-15 Published:2025-11-17

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Abstract: The ecological environment in arid and semiarid areas is very fragile and sensitive to climate change.The change of solar radiation is very important to climate and ecological environment.The effects of clouds on solar radiation are significant.In this study,the effects of clouds on solar radiation over Urumqi,a typical semiarid city,were studied so as to provide a scientific basis for improving the accuracy of predicting climate change in the region using the data with high temporal and spatial resolution and the long-term series of Single Scanner Footprint TOA/Surface Fluxes and Clouds (SSF) dataset,CER_SSF_Aqua-FM3-MODIS_Edition3A dataset from the Earth’s Radiant Energy System (CERES) of NASA’s EOS (The NASA Earth Observing System).Another purpose of this study was to examine the annual and inter-annual variations of solar radiation,cloud physical properties and cloud shortwave radiative forcing over Urumqi during the period from January 2006 to December 2015.The results showed that the annual distribution curves of net surface shortwave radiation flux and the shortwave radiation flux at the top of atmosphere on clear day were unimodal.The peak values,187.5 W·m-2 and 792.3 W·m-2,occurred in June and May respectively.The cloud radiative forcing at both the top of atmosphere and on the surface were negative,i.e.-253.7 W·m-2 and -249.0 W·m-2 respectively.The annual distribution of cloud shortwave radiative forcing kept a downward trend.The inter-annual average values of cloud shortwave radiative forcing for 10 years were close to a symmetrical unimodal distribution.The peaks values,-391.3 W·m-2 and -355.0 W·m-2,occurred in July.Seasonally,the values were the highest in summer but the lowest in winter,and they were slightly higher in spring than in autumn.There was a similarity in annual variation of cloud physical parameters and cloud shortwave radiative forcing.The total cloud cover in winter was low,and its maximum value occurred in June.Cloud optical depth peak values,22 and 26.1,occurred in July and November respectively,and the minimum value (6.1) occurred in February.The maximum value (263.5 K) and the minimum value (242.6 K) of cloud equivalent temperature occurred in June and February separately.

Key words: CERES (SSF), cloud shortwave radiative forcing, cloud physical property, temporal variation, Urumqi