Relative humidity (RH) and diabatic heating rate (Q1) were stratified with 1-mm-wide bins of the precipitable water (PW) to provide information on the vertical distribution of moisture and heating. In fifth generation of ECMWF atmospheric reanalyses of the global climate (ERA5), large RH extends to the upper troposphere for large PW values, which is associated with tropical convection. The model initialization (day 0) resembles ERA5, but by day 5, all suites exhibit a dry bias in the lower troposphere (lower than 700 hPa) and a moist bias above.

Vertical profiles of relative humidity (RH; %) stratified with 1-mm-wide bins of the PW (mm) over the tropical ocean basins.

A trimodal structure of diabatic heating for PW larger than 50 mm was shown in ERA5, with one maximum around 750 hPa, one around 500 hPa, and another around 300 hPa, corresponding to shallow convection, deep convection, and stratiform process, respectively. Notice the different bias patterns shown in Suites 1 and 2 compared to Suites 3 and 4.

Vertical profiles of diabatic heating rate (Q1; K/day) stratified with 1-mm-wide bins of the PW (mm) over the tropical ocean basins.

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GMTB's Final Report