秋分晨阴，A.Cu , A.5t 自南，65°，房中66°。上
南京秋分展阴， A. Cu , A.5t 自南， 650 ， 房中660 。上
午阴，下午微雨，晚阴。犹闻促织，未闻黄莺也，不见燕子。
方俊赴河南。剃头。
晨六点起。近日腹又患泻， 应酬多， 于消化有不良影响。八点至地理所。作函与汪胡帧，介绍周宗梭。复得汪电话，知渠巳电邀周宗泼矣。阅Richard Ha由horne著Nature of Geography ，述地理学历史甚详。十二点回。睡一小时。二点至南大前剃头铺剃头。回。徐近之、九章相继来。与孟和谈。五点洗浴。
H. R. Byers: Principal Results of a Comprehensive Investigation of the Structureand Dynamics of the Thunderstorm, Tellus , Nov. , 1949 , pp.6- 18.在1945 年， US Weather Bureau , Air Force , Navy & National Advisory Committeefor Aeronautics 组织研究雷雨。1946 年在Florida 研究， 1947 年在SW Ohio 研究。
报告是R. R. Braham , 1. J. Battan , H. 1. Harriilton , H. M. Moses 著， 1950 年初出版，计3∞ pp. , US Government Printing Office 称” Thundemtom” 。
雷雨可分三期: ( 1) Cumulus stage , (2) Mature stage, (3) Dissipating st吨e。
在第一时期不降雨， 气流上升。第二时期开始下雨。When the size and concentrationof the drops or ice crystals becomes so great that they can no longer be supported bythe existing updraft. The drag exerted by the precipitation upon the ascending air is animportant factor in fonning a downdraft and , as a maller of observed fact , the beginningof rain at the surface & the initial appearance of downdraft are coincidental : 在此时期，updraft still persists , greatest at the highest levels up to 25 ， α泪， Low T. are associatedW1也downdraft. Above 26; 000′ , no direct observations have been made , but radar日记. 1 950 年187echo returned, it is concluded that the size & number of particles 缸e large to hts. asgreat 臼60 ，仅)().在第三期， Downdraft spreads the entire 缸ea. A thunderstonn usuallyconsists of 3 or more cells adjacent to each other. Average duration of rain 25′. In pr臼S山e curve there 町e the”n。四.. and the “dome”. Pressure nose was detected by butone station per cell in Ohio , indicating that max. diameter of 5 miles , probably due tothe weight ‘of suspended and 也lling water, and a lack of balance between convergence& divergence. ln humidity curve there is a sharp decre且se in the midst of downpour to60- 70%. The T.. of rain water is several degrees lower than ambient 时.第一次电闪见时，要云顶到- 20 0 C levelo Radar 可以测上升气流，故可以预告Hail o mean m阻ht.of 雷雨，用Radar 量得37 ， 5∞’ 。
寄周宗竣函