The sensitivity of surface frost over a bare surface to humidity profiles and soil thermophysical properties with applications to the Jordan valley

Abstract EN

-A simple model is employed to investigate the influence of upper air moisture advection and soil thermophysical properties on the minimum ground temperature experienced in the Jordan Valley during relatively calm and clear winter weather conditions.

The predicted ground minimum temperatures appear to fit the observed values quite well.

It is evident from the present analysis that moisture modifactions at lower tropospheric levels are important to the resultant minimum temperatures; moisture modifications at upper levels are of little significance to the ground minima.

Small modification in soil radiometric properties (emissivity) is less likely to produce observable impact on the ground minima because most natural surfaces have emissivities larger than 0.9 .

In Contrast, small alterations to soil thermophysical properties could generate substantial effects on the ground minimum temperatures.

The present technique, in conjuction with meteorological data and high resolution thermal images, can be operationally used to delineate and assess the spatial distribution and severity of frost in the Jordan Valley during potential freezing conditions.