利用遥感监测青藏高原上空臭氧总量30 a的变化

利用多源卫星遥感数据,分析了自1979年以来青藏高原上空臭氧总量的时空动态特征.结果表明,青藏高原上空的臭氧总量还在持续下降,而且下降速度高于全球和北半球平均水平,青藏高原、全球和北半球每年大约平均减少0.23%、0.19%、0.12%.但是自2000年后,下降的速度有所减缓,1979～1989、1990～1999和2000～2008年3个时期每年减少大约分别为0.51%、0.49%、0.31%.30a来青藏高原上空臭氧总量低于240DU的天数有34d.在2005年后,没有出现大面积的臭氧总量低值区(低于240DU);臭氧总量的季节变化呈正弦曲线变化,最大和最小值分别出现在3和10月,平均值分别大约为304.59和265.45DU.但是每年的极小值常出现在11月或12月.臭氧总量波动最大和最小分别出现在2月和9月,标准差为17.28和5.88DU;臭氧总量与海拔高度呈反相关,低值区出现在高海拔的上空,特别是在青藏高原区,与同纬度圈的平均值相比,青藏高原臭氧总量大约低了19DU,形成臭氧低谷.

Variation of Total Ozone over Tibetain Plateau During 30 Years Monitored by Remotely Sensed Data

This paper is study on the temporal and spatial dynamics characteristics of total ozone over Tibetain Plateau from 1979 using multi-resource remote sensing. The findings indicate that the total ozone over Tibetain Plateau is continuously decreasing. The decreasing rate is larger than the global and northern hemisphere average, and the average annual decreasing rates are about 0.23%, 0.19% and 0.12% for Tibetain Plateau, global and northern hemisphere average respectively. However, the decreasing rate is lessening after 2000. The decreasing rates each year are about 0.51%, 0.49% and 0.31% during the 3 stages of 1979-1989, 1990-1999 and 2000-2008. The days of total ozone over Tibetain Plateau lower than 240 DU is up to 34 d, and there is not largely lower ozone (lower than 240 DU) area after 2005; the seasonal variation of total ozone present sinusoidal, the largest and smallest value appear in March and October, the average values are about 304.59 and 265.45 DU respectively. But the smallest of daily value are often appears in November or December. The largest and smallest fluctuation of total ozone appear in February and September with the standard deviation of 17.28 and 5.88 DU respectively; the total ozone and altitude is inversely relationship, lower ozone appear over higher altitude areas, especially, over Tibetain Plateau region. Compare with the average total ozone over the same latitude, the total ozone over Tibetain Plateau is lower with about 19 DU, and give birth to an ozone valley.