Premium
Understanding the effects of atmospheric circulation in the relationships between water vapor and temperature through theoretical analyses
Author(s) -
Lu Er
Publication year - 2007
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 - 10.1029/2007gl029727
Subject(s) - water vapor , atmosphere (unit) , relative humidity , evaporation , atmospheric temperature range , humidity , atmospheric sciences , vapour pressure of water , vapor pressure , environmental science , thermodynamics , chemistry , meteorology , physics
Theoretical analyses are provided to understand the effects of the atmospheric circulation in the relationships between water vapor and temperature. Relative humidity ( r ) analysis indicates that when temperature variation range Δ T ≡ T 2 − T 1 is larger than D r ≡ 13 ln( r 1 / r 2 ), a measure of the decrease of r over the temperature range, strong positive correlations can be expected between water vapor and temperature. Dynamic process analysis reveals, with expressing the change of water vapor as Δ W = f Δ T + B ( f > 0 and B represents atmospheric dynamic effect), the dual effects of the atmospheric circulation in the water vapor‐temperature relationships. When Δ T is large so that f Δ T > ∣ B ∣, the thermodynamic effect of the earth‐atmosphere is more important; the thermally induced atmospheric circulation and the evaporation tend to establish strong positive correlations between water vapor and temperature. When Δ T is small so that f Δ T < ∣ B ∣, the dynamic effect of the atmosphere is more important; the dynamic water vapor convergence and divergence make water vapor and temperature have weak correlations.