SARS流行期的天气学尺度分析

本文以香港和北京为例,对SARS流行期的天气特征做了事件相关分析和统计分析.研究发现,在SARS流行期,SARS疫情高发可能与大约8日前的气温日较差阶段性降低有关系.但是当气温日较差过程发生趋势性变化时,疫情过程的响应时间为5～10天.SARS疫情高发还可能与8日前空气相对湿度偏低有关系,同时也与11～12日前的相对湿度峰值有关.前者较多的表现在香港,后者较多表现在北京.初步认为,略低于相对湿度75%的某个值附近,相对湿度对于疫情发展有促进作用;相对湿度具有二重性.空气污染有助于SARS病毒的扩散传染,它的影响滞后期在8～10天.

AN ANALYSIS OF SARS EPIDEMIC WITH WEATHER SCALE

Research has showed that SARS virus demands feasible condition to survive. This implies that under non-control condition of prevalence the epidemic situation could be relative with climate and weather. In this paper the authors analyze the weather characters while SARS was on its prevalence in Beijing and Hong Kong to find out and to prove these relations. It leads to the conclusion that the epidemic situation process responsed in 5～10 days after the diurnal temperature range process changes constitutionally. Event analysis shows that 8～9 days before an outbreak of SARS cases there was generally a local minimum of relative air humidity that almost bellow 75%. But often, the local maximum of relative air humidity appeard 11～12 days before. Taking the data from Beijing, the regression analysis gets a high r of 0.94 when the relative air humidity 8 days ago, the diurnal temperature range 8 days ago and the exponent of the accumulation of SARS cases 10～14 days ago were considered as the independent variables. It approves the relation between SARS and the former 2 weather factor. But further regression analysis posts that relative air humidity 11 days ago acts contrarily. The authors think the SARS tends to prevail when the relative air humidity is around a certain value just below 75%. As a major index of weather factors, air temperature is found out to have no obvious effect on the epidemic situation. But air pollution helps to spread SARS, its effect may lag 8～10 days behind. From the above analysis, a supposition is put forward that SARS virus could survive well outdoor in a condition of stable air temperature (which means small diurnal temperature range) and stable relative air humidity