Comment on “Moist Static Energy Transport Trends in Four Global Reanalyses: Are They Downgradient?” by Clark et al. (2022)

Given the key role that atmospheric heat transport plays in Earth's climate system, efforts to document its changes over the satellite era are valuable. Clark et al. (2022, https://doi.org/10.1029/2022GL098822) calculated trends in atmospheric heat transport among four reanalysis data sets and found substantial disagreements between data sets. However, after accounting for the lack of mass‐conservation in reanalysis data sets, we find much smaller magnitude trends, with much better agreement among reanalyses. This highlights the importance of mass corrections when calculating atmospheric heat transport. Plain Language Summary Atmospheric heat transport plays an important role in our climate system. Reanalysis data sets provide our best representation of how atmospheric heat transport has changed over the last 40 years. A previous study used four different reanalysis data sets to explore how atmospheric heat transport has changed. They found very large changes that disagreed between data sets. We repeat their calculations, but account for known inaccuracies in the reanalysis data sets and find much better agreement between the data sets. Key Points It is necessary to account for the lack of mass conservation in reanalysis data sets when calculating atmospheric heat transport Clark et al. (2022) found large trends in atmospheric heat transport that differed among reanalysis data sets due to unrealistic mass fluxes Trends in atmospheric heat transport are similar among reanalysis data sets once a mass correction is applied