Comparison of AIRS gravity wave observations with ISSI model simulations
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1) Overview of comparisons:

  o List of overpasses to be analyzed:
    - 2010-10-09, 05:09 UTC
    - 2010-10-09, 18:36 UTC
    - 2010-10-10, 04:13 UTC
    - 2010-10-14, 18:54 UTC
    - 2010-10-16, 18:42 UTC
    - 2010-10-17, 04:19 UTC

  o Additional overpasses looking at South Georgia:
    - 2010-10-11, 03:18 UTC
    - 2010-10-16, 17:03 UTC
    - 2010-10-17, 02:41 UTC (overpass may be out of model domain)

  o Most recent comparisons for ISSI OSSE:
    - comp_airs_icon_v2.* = comparison with ICON simulations (Catrin and Olaf)
    - comp_airs_ifs_v2.* = comparison with IFS simulations (Inna)
    - comp_airs_um_v2.* = comparison with UM simulations (Annelize)
    - comp_airs_wrf_v2.* = comparison with WRF simulations (Chris)

  o Add-ons and sensitivity tests:
    - comp_airs_ifs_kernel_midl.* = convolution with mid-latitude kernel function rather than non-linear RTM
    - comp_airs_ifs_kernel_pwin.* = convolution with polar winter kernel function rather than non-linear RTM
    - comp_airs_ifs_raydz.* = finer vertical sampling in RTM raytracer (100 m instead of 500 m)
    - comp_airs_ifs_slant.* = assumption of vertical profiles rather than slant profiles in RTM
    - comp_airs_icon_v2_init.* = initialization experiment for ICON
    - comp_airs_ifs_v2_init.* = initialization experiment for IFS

2) Plots and data files:

  o pdf-files:
    - panels showing all plots of real or simulated brightness temperature (BT) perturbations and corresponding variances per model
    - panels include cross-sections of perturbations at 55°S and 65°S (symbols are individual AIRS footprints, curves are 1° x 1° averages)

  o zip-files:
    - sub-directories per AIRS overpass and channel set (4.3 micron data as well as 15 micron "low" and "high" data)
    - vertical coverage: 4 micron = 30...40 km of altitude, 15 micron "low" = 25 km of altitude, 15 micron "high" = 40 km of altitude
      (plots of kernel functions and sensitivity curves: https://datapub.fz-juelich.de/slcs/airs/gravity_waves/data/kernel.pdf)
      (plots of noise estimates of AIRS channel sets: https://datapub.fz-juelich.de/slcs/airs/gravity_waves/data/noise.pdf)
    - there may be one or two sub-directories per AIRS overpass (for one or two of the neighboring output time steps of the models)
    - wave_airs.tab = ASCII file containing real BT perturbations from AIRS
    - wave_model.tab = ASCII file containing simulated BT perturbations from model
    - wave_airs.nc = netCDF file containing real BT perturbations from AIRS
    - wave_model.nc = netCDF file containing simulated BT perturbations from model
    - gw_*.png = maps of real and simulated BT perturbations
    - var_*.png = maps of real and simulated BT variances
    - cross_*.png = cross-sections of BT perturbations at 55°S and 65°S