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Data Product Description

Data for Rel. 4-IP is available for order from the LaRC/ASDC. Detailed documentation of this release is available within the Algorithm Theoretical Basis Document (ATBD).

Each data file contains an entire month of global fields of the parameters described below. The data files are available in netCDF-4 in various temporal levels by month.

The following diagram gives a general idea on how file names are constructed for the data set.

Cartoon of how to construct file names

Shortwave fluxes and associated fields

  • TOA insolation
  • TOA all-sky upward flux
  • TOA clear-sky upward flux
  • TOA pristine-sky upward flux
  • Surface all-sky upward flux
  • Surface clear-sky upward flux
  • Surface all-sky downward flux
  • Surface clear-sky downward flux
  • Surface pristine-sky downward flux
  • Surface all-sky diffuse downward flux
  • Solar zenith angle
  • Total cloud fraction
  • Par
  • Flux fill flag

Longwave fluxes and associated fields

  • TOA all-sky upward flux
  • TOA clear-sky upward flux
  • TOA pristine-sky upward flux
  • Surface all-sky upward flux
  • Surface clear-sky upward flux
  • Surface all-sky downward flux
  • Surface clear-sky downward flux
  • Surface pristine-sky downward flux
  • Tropopause all-sky upward flux
  • Tropopause clear-sky upward flux
  • Tropopause pristine-sky upward flux
  • Tropopause all-sky downward flux
  • Tropopause clear-sky downward flux
  • Tropopause pristine-sky downward flux
  • 200 hPa all-sky upward flux
  • 200 hPa clear-sky upward flux
  • 200 hPa pristine-sky upward flux
  • 200 hPa all-sky downward flux
  • 200 hPa clear-sky downward flux
  • 200 hPa pristine-sky downward flux
  • 500 hPa all-sky upward flux
  • 500 hPa clear-sky upward flux
  • 500 hPa pristine-sky upward flux
  • 500 hPa all-sky downward flux
  • 500 hPa clear-sky downward flux
  • 500 hPa pristine-sky downward flux
  • Flux fill flag
  • Day/night flag (3-hourly only)

Ancillary fields

Fields are only available as 3-hourly.

  • Surface skin temperature
  • Temperature at 2 meters
  • Specific humidity at 2 meters
  • Total column precipitable water
  • Snow and ice land coverage percent
  • Day/Night flag (day=1, night=0)
  • Total cloud area fraction
  • Total cloud top pressure
  • Total cloud top temperature
  • Total cloud optical Depth
  • Surface Pressure
  • Total column ozone
  • Longwave Surface Emissivity for 12 Fu-Liou bands

Cloud fields for ice or water cloud fields for high, middle, and low levels:

  • Cloud area fraction
  • Cloud optical depth
  • Cloud particle size
  • Cloud top temperature
  • Cloud top pressure
  • Cloud base pressure
  • Cloud water or ice content
  • Cloud thickness
  • Fill method flag for cloud data

Derivable fields

While not directly offered in the data files, the following can be derived from the available fields:

Parameter Procedure
Net Longwave Flux Radiation at Earth’s Surface, (NLF)s [W/m2] From the downward LW flux (DLF) and upward LW flux (ULF) as:

(NLF)s = (DLF)s – (ULF)s
Net fluxes can be computed for the clear-sky and all-sky conditions.
Longwave Cloud Radiative Effect, (LWCRE) at the surface, (>0, energy to the surface increased by clouds) [W/m2] From the Surface all-sky downward LW flux all(DLF)s and Surface clear-sky downward flux LW Flux clr(DLF)s as:

LWCREs= all(DLF)s – clr(DLF)s
Longwave Cloud Radiative Effect, (LWCRE) at the TOA, (primarily >0, clouds remit at colder temperatures, energy stays in atmosphere) [W/m2] From the TOA all-sky upward LW flux all(ULF)toa and TOA clear-sky upward LW flux clr(ULF)toa as:

LWCREtoa= clr(ULF)toa – all(ULF)toa
Net Longwave Flux of the Atmosphere, (NLF)atm, [W/m2] From the Net Longwave Flux at TOA (NLF)TOA and the Net Longwave Flux at surface (NLF)s as:

(NLF)atm = (NLF)TOA – (NLF)s
Surface Albedo (dimensionless) From Surface all-sky upward SW flux, all(USF)s and Surface all-sky downward SW flux , all(DSF)s as:

Surface Albedo = all(USF)s / all(DSF)s
SW cloud radiative forcing, (SWCRF), at the surface [W/m2] From all-sky surface downward flux (FALL) and clear-sky surface downward fluxes (FCLR) as:

SWCRF = FALL – FCLR
Shortwave Cloud Radiative Effect, (SWCRE) at TOA, (primarily <0, clouds reflect energy out of the atmosphere) [W/m2] From the TOA all-sky upward SW flux all(USF)toa and TOA clear-sky upward SW flux clr(USF)toa as:

SWCREtoa= clr(USF)toa – all(USF)toa
Shortwave Cloud Radiative Effect, (SWCRE) at the surface, (primarily <0, clouds prevent energy from reaching surface) [W/m2] From Surface All Sky Downward Shortwave Flux all(DSF)s and Surface clear-sky Downward Shortwave Flux clr(USF)s as:

SWCREs= all(DSF)s – clear(DSF)s