天上的冰塊

 積雨雲http://www2.hkedcity.net/sch_files/a/kws/kws-solar/public_html/typeofcloud.htm

 風切變 http://www.hkcoc.com/cycdict/key=fung.htm

 輻散氣流http://www.hko.gov.hk/education/edu01met/wxphe/ele-condiv-c.htm