The corrections are independent of the land - surface air temperature data. (ipcc.ch)
Below are charts of each of the stations with air temperature data beginning in 1991. (waclimate.net)
WMO - «Because the data with respect to in - situ surface air temperature across Africa is sparse, a oneyear regional assessment for Africa could not be based on any of the three standard global surface air temperature data sets from NOAANCDC, NASA - GISS or HadCRUT4 Instead, the combination of the Global Historical Climatology Network and the Climate Anomaly Monitoring System (CAMS GHCN) by NOAA's Earth System Research Laboratory was used to estimate s (wattsupwiththat.com)