The Deposition Characterisitics of Radiation Fog Water in Winter of Nanjing
The intensive field observation experiments were conducted in the northern suburb of Nanjing from November 15 to December 29 in 2007.We used an ultrasonic anemometer-thermometer in combination with a size-resolving cloud droplet spectrometer capable of providing number counts in 20 droplet size classes.Our study focuses on the physical characteristics of fog and quantifying the fog deposition flux by using direct eddy covariance flux measurements,as well as the fog water deposition differences between radiation and advection fog.The resullts are as follows:The fog water deposition flux during the mature stage of radiation fog could be 90%of the to-tal deposition flux.Droplet sizes above 20 μm contributed mostly to the fog deposition,which was mainly gravity settling and it was 82% of the total deposition flux,while the turbulent deposition was relatively small.Droplet sizes below 7 μm and above 40 μm con-tributed little to the overall deposition flux.The fog water deposition flux depended linearly on liquid water content of the fog,which in-dicated that the liquid water content of the fog influenced directly on the deposition flux.In the development stage of radiation fog, there was obvious fluctuation of fog water flux due to intensive turbulence,while for advection fog there wasn’t this phenomenon.
Nanjingfogfog water depositionfogwater fluxeddy covariance
NETL
NSTL
万方数据
维普
