Spectral Kernel

The dataset comprises two NetCDF files containing spectral kernels computed under different atmospheric conditions: spectral_kernel_monthly_climatology_clearsky.nc — clear-sky conditions spectral_kernel_monthly_climatology_allsky.nc — all-sky conditions Each file provides the partial derivatives of spectral radiance (computed at nadir) with respect to seven key atmospheric variables: Surface temperature - unit [mW/(m²·cm⁻¹· sr ·K) ] Air temperature - unit [mW/(m²·cm⁻¹· sr ·K ) ] Water vapor concentration - unit [mW/(m²·cm⁻¹·sr ppmv) ] Ozone - unit [mW/(m²·cm⁻¹·sr ppmv) ] Carbon dioxide - unit [mW/(m²·cm⁻¹·sr ppmv) ] Methane - unit [mW/(m²·cm⁻¹·sr ppmv) ] Nitrous oxide - unit [mW/(m²·cm⁻¹·sr ppmv) ] The kernels were computed using the RTTOV radiative transfer model, based on monthly mean ERA5 atmospheric profiles and standard forcing datasets used for historical CMIP6 simulations for the years 2008, 2009, and 2010. These results were then averaged over the three years to produce monthly climatological mean spectral kernels, spanning the spectral range of the IASI instrument. The spectral resolution is 10 cm⁻¹, covering the IASI range from 650 to 2750 cm⁻¹. In addition to the regular spectral grid, the dataset includes high-resolution spectral kernels for a selected set of IASI channels that are particularly sensitive to specific climate variables at different atmospheric levels (667.75, 700.25, 710.25, 721.25, 728.50, 739.00, 871.25, 901.50, 1014.50, 1041.00, 1326.75, 1381.75, 1400.50, 1596.25 cm⁻¹).These channels were selected to capture sensitivity to climate-relevant variations across different altitudes.