Accepted

• Main Authors: I. Gultepe, G. A. Isaac, S. G. Cober, Inter J. Of Climatology
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2000
• Subjects: Arctic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.569.4382; http://airs-icing.org/publications/Gultepe - Ice Crystal Number Concentration Versus Temperature for Climate Studies.pdf

Ice crystal number concentration (Ni) is an important parameter, having a strong influence on the calculation of cloud optical and microphysical parameters. Cloud and precipitation parameterizations within climate and weather forecasting models, affecting the heat and moisture budget of the atmosphere, cannot be determined accurately if Ni is not estimated correctly. Previous studies of ice crystal number concentration versus temperature (T) have shown that Ni-T relationships are not unique. The present study uses observations made in the glaciated regions of stratiform clouds from two Arctic and two mid-latitude field projects to study the Ni versus temperature relationship. Scatter plots of Ni versus T at the ice particle measurement level do not show a good correlation with T for ice crystals at sizes less than 1000 µm. For a given temperature, the variation in Ni is found to be up to 2-3 orders of magnitude for ice crystals with sizes larger than approximately 100 µm. A significant Ni-T relationship is found for precipitation sized particles with sizes greater than 1000 µm. The ice particle concentration for sizes between 100 and1000 µm varied from 0.1 and 100 l-1, independent of geographic locations where the measurements were made. Based on this work, it is concluded that modeling studies should be tested for the possible variations in Ni versus T.