The Life Cycle of Valley Fog. Part I: Micrometeorological Characteristics

Open Access
Publisher Website
Google Scholar
Abstract
Extensive measurements were made of micrometeorological variables associated with eleven fogs in the Chemung River Valley near Elmira, N.Y. Temperature was measured at five levels on a 17 m tower, dew point at three levels, wind speed and direction at two levels, and net radiation and vertical wind at one level. Visibility was measured at three locations, and dew deposition and evaporation at one location near the surface. Vertical temperature distributions were also measured using an aircraft. The microphysical variables are discussed in Part II of this paper. Consistent patterns of behavior of all micrometeorological variables were observed. The formation of ground fog may be explained by radiational cooling of the surface and associated low-level heat exchange. To explain observed temperature behavior (maximum cooling rate near 100 m in the 6 h preceeding fog) and the initial formation of a thin fog layer slightly below that level, it seems necessary to invoke Defant's model of valley circulat... Abstract Extensive measurements were made of micrometeorological variables associated with eleven fogs in the Chemung River Valley near Elmira, N.Y. Temperature was measured at five levels on a 17 m tower, dew point at three levels, wind speed and direction at two levels, and net radiation and vertical wind at one level. Visibility was measured at three locations, and dew deposition and evaporation at one location near the surface. Vertical temperature distributions were also measured using an aircraft. The microphysical variables are discussed in Part II of this paper. Consistent patterns of behavior of all micrometeorological variables were observed. The formation of ground fog may be explained by radiational cooling of the surface and associated low-level heat exchange. To explain observed temperature behavior (maximum cooling rate near 100 m in the 6 h preceeding fog) and the initial formation of a thin fog layer slightly below that level, it seems necessary to invoke Defant's model of valley circulat...

This publication has 0 references indexed in Scilit: