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Wind, temperature and humidity distribution at some cold fronts over SE. England
Author(s) -
Miles M. K.
Publication year - 1962
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49708837708
Subject(s) - cold front , humidity , warm front , meteorology , apparent temperature , front (military) , atmospheric sciences , temperature gradient , geology , air temperature , lapse rate , relative humidity , environmental science , climatology , geography
Recent evidence from frequent radar‐sonde soundings at Crawley (Sussex) has been studied along with earlier published evidence to establish that a marked fall in humidity occurs directly above the front in a more or less random sample of cold fronts crossing southern England. This usually happens at levels above 700 mb and without a corresponding fall of temperature or any considerable change in wind direction at these levels. Evidence from trajectories shows that the dry warm air is drawn from a cold source and warmed dynamically before it enters the frontal zone. At this stage it is usually moving faster than, and in the same direction, as the warm moist air and this contributes to the formation of a marked humidity gradient at the junction of the two air masses. The air may sometimes be ascending at this junction, but there is no clear evidence that a wedge of cold air (where it exists) has anything to do with the vertical motion.