Detecting shifts in tropical moisture imbalances with satellite‐derived isotope ratios in water vapor Journal of Geophysical Research: Atmospheres

As global temperatures rise, regional differences in evaporation ( E) and precipitation ( P) are likely to become more disparate, causing the drier E-dominated regions of the tropics to become drier and the wetter P-dominated regions to become wetter. Models suggest that such intensi fication of the water cycle should already be taking place; however, quantitatively verifying these changes is complicated by inherent difficulties in measuring EandPwith suf ficient spatial coverage and resolution. This paper presents a new metric for tracking changes in regional moisture imbalances (e.g., E-P)b yd e fining δDq—the isotope ratio normalized to a reference water vapor concentration of 4 mmol mol/C01—and evaluates its ef ficacy using both