*2.4. MERRA-2 Data*

The 6 hourly MERRA-2 re-analysis data (MERRA-2 inst6\_3d\_ana\_Np version 5.12.4) (https: //disc.gsfc.nasa.gov/datasets/M2I6NPANA\_V5.12.4/summary) are used to specify the atmospheric conditions [38]. The re-analysis data are available at [00, 06, 12, 18] hours with a resolution of 0.5◦ × 0.625◦ , for 42 pressure levels. Properties include sea-level pressure, surface pressure, geopotential height, air temperature, wind components, and specific humidity. Since the LST is retrieved at hourly time scale, the MERRA-2 data are linearly interpolated in time to give the atmospheric state in between the four analysis times (as needed for input to RTTOV) and linearly interpolated to 0.05◦ × 0.05◦ in space to match the formulation of this study.
