关键词: ＭＯＤＩＳ, 气溶胶光学厚度, 时空变化, 能见度, 北疆地区

Abstract: Spatio-temporal distribution and variation of the aerosol optical depth (AOD) in North Xinjiang in 2000 - 2013 was analyzed using MODIS aerosol products various in resolution, and compared with the corresponding visibility data available for correlation analysis. Results show that spatially the mean AOD of the area in the past 14 years was high in the centre and low along the rim; The annual mean AOD of prefecture-level cities in the high-value region was 0.335, about 1.33 times as high as that of North Xinjiang, and was the highest in Kuitun; the annual mean AOD of prefecture-level cities in the sub-high value region was 0.202, about 0.8 times as high as that of North Xinjiang and was the lowest in Tacheng; and there was no prefecture-level city in the low value region. Temporally, the annual mean AOD of North Xinjiang varied between 0.221 and 0.283 in the past 14 years, peaking in 2003 and bottoming in 2005; Within a year, AOD was the highest in Spring and the lowest in Autumn. For years, AODs in all the four seasons displayed a declining trend, and the drop in winter was the most significant; the monthly mean AOD of North Xinjiang varied between 0.186 and 0.395 in the past 14 years, peaking in February and bottoming in October. A significantly negative relationship was observed between monthly mean AOD and monthly mean visibility in Tacheng and Altay (P＜0.05), while a reverse one was between the two in Urumqi and Shihezi (P＜0.05).

Key words: MODIS, AOD, spatio-temporal variation, visibility, North Xinjiang