ESA Permafrost Climate Change Initiative (Permafrost_cci): Permafrost active layer thickness for the Northern Hemisphere, v5.0

It forms part of the second version of their Climate Research Data Package (CRDP v4). It is derived from a thermal model driven and constrained by satellite data.

Grid products of CDRP v4 are released in annual files, covering the start to the end of the Julian year. The maximum depth of seasonal thaw is provided, which corresponds to the active layer thickness. Case A: It covers the Northern Hemisphere (north of 30°N) for the period 2003-2023 based on MODIS Land Surface temperature merged with downscaled ERA5 reanalysis near-surface air temperature data.e.g. ESACCI-PERMAFROST-L4-ALT-MODISLST_CRYOGRID-AREA4_PP-****-fv05.0.ncCase B: It covers the Northern Hemisphere (north of 30°N) for the period 1997-2002 based on downscaled ERA5 reanalysis near-surface air temperature data which are bias-corrected with the Case A product for the overlap period 2003-2023 using a pixel-specific statistics for each day of the year.e.g. ESACCI-PERMAFROST-L4-ALT-ERA5_MODISLST_BIASCORRECTED-AREA4_PP-****-fv05.0.nc