Relationship between temperature and precipitable water changes over tropical oceans

We use observations, climate models and reanalysis output to examine the relationship between changes in temperature and changes in precipitable water. In climate models these variables are highly correlated over the tropical oceans, with a similar scaling ratio for interannual and decadal time scales. This result is consistent with the most recently developed satellite datasets. In contrast, scaling rations based either on an earlier version of the satellite measurements or reanalysis show scaling ratios that are inconsistent with models, and are dependent on time scale. These results demonstrate that climate model output is useful for evaluating differences between divergent observational datasets.