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Diurnal temperature range for a doubled carbon dioxide concentration experiment: Analysis of possible physical mechanisms
Author(s) -
Verdecchia M.,
Visconti G.,
Giorgi F.,
Marinucci M. R.
Publication year - 1994
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/94gl00188
Subject(s) - environmental science , water content , atmospheric sciences , carbon dioxide , precipitation , greenhouse gas , sensible heat , diurnal temperature variation , latent heat , daytime , moisture , diurnal cycle , flux (metallurgy) , climatology , materials science , chemistry , meteorology , geology , physics , oceanography , geotechnical engineering , organic chemistry , metallurgy , composite material
An analysis of the results of a climate simulation for a doubling of atmospheric carbon dioxide concentration over the European region is reported. Physical mechanisms are sought which could explain possible changes in the diurnal temperature range (DTR) under conditions of increased atmospheric greenhouse gas content. We show that an important contribution to changes in DTR is given by soil moisture. In areas where soil moisture increases due to an increase in precipitation there is a positive change in latent heat flux and a decrease in sensible heat flux. As a result, in areas with increasing soil moisture, the increase in maximum daytime temperature will be smaller than that in minimum temperature, thereby causing a decrease in the DTR. The opposite occurs for areas which undergo soil drying. This process amplifies the effect of cloud changes on surface solar and infrared radiation and dominates the direct effect of downward infrared radiation associated with increasing greenhouse gas concentration. Because the soil water content is largely controlled by precipitation, our results are consistent with early observational findings of negative correlation between changes in precipitation and in diurnal temperature range.