AbstractAbstract
Some terrestrial regions have cooled despite increases in global average near-surface air temperature. It is important to study these ‘warming holes’ to understand regional climate processes and to develop strategies to mitigate global change impacts. Many warming holes have occurred in places with changes to regional hydrology. As a consequence, increases to latent heating due to shifts in specific humidity may obscure changes due to temperature (enthalpy) when studying the full energy budget of the near surface atmosphere. We ask if known warming holes in the southeastern U.S. (SEUS), northern North American Great Plains (NNAGP), and southeastern China result from such ‘water-for-temperature’ tradeoffs using a Bayesian approach that accounts for both temporal and spatial autocorrelation in climatic variables from ERA5. The SEUS warming hole lost more energy (up to −100 J kg
−1
yr
−1
) than apparent from temperature trends alone, as it also became drier. The NNAGP exhibited the well known transition along the 100th meridian in which the semi-arid west lost enthalpy and latent heat, and the humid east gained near-surface atmospheric energy; these patterns were not apparent from temperature trends alone. Increases in latent heat of 50 J kg
−1
yr
−1
or more in the southern part of the southeastern China study area shifted significant trends in near-surface atmospheric energy further north than what was revealed by temperature trends alone. The magnitude of trends in latent heat often exceeded those of enthalpy across all study areas, emphasizing the importance of incorporating water and a more complete depiction of the energy balance into studies of regional climate.
