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Contents:




outgoing LW radiationOutgoing Longwave Radiant Flux from ERBE

This dataset is a collection of monthly means of outgoing longwave radiation derived from the Earth Radiation Budget Experiment (ERBE) scanning instruments aboard the ERBS, NOAA-9, and NOAA-10 satellites. It was created from regional, zonal and global gridded averages (ERBE S-4G) data product, and covers the years 1986 - 1988. More years are expected to be added as data is regridded, please refer to the DAAC Outgoing Longwave Radiant Flux FTP site.

The Earth Radiation Budget Experiment is a system of satellites designed to measure the Earth's energy balance. Its goal is to provide accurate measurements of incoming solar radiation and shortwave radiation reflected or emitted from the Earth back into space. The Earth's radiation budget is the primary indicator of global climate change. The absorbed shortwave radiation (incident minus reflected) fuels the Earth's climate and biosphere systems. The longwave radiation represents the exhaust heat emitted to space. It can be used to estimate the insulating effect of the atmosphere (the greenhouse effect). It is also a useful indicator of cloud amount and activity.

Documentation available on CD-ROM


The data is available on Volume 3 of the CIDC CD set.


solar irradiance Solar Irradiance

Total solar irradiances are presented for the period November 16, 1978 through December 31, 1997. The measurement program is continuing and additional years will be added as they become available. This irradiance provides the energy that powers the Earth's climate and biosphere. It had long been suspected that the solar energy emitted towards the Earth varied with time but this was not definitely demonstrated until accurate, self-calibrating pyrheliometers flown on satellites began to regularly monitor the Sun (Hickey et al., 1980). The measured solar variations are of the order of fractions of a percent and atmospheric transmission problems had previously limited the accuracy of ground based measurements ( Willson, 1984). Data from four experiments are included here: The Nimbus-7 Earth Radiation Budget (ERB) measurements (November 1978 - December 1993), the Active Cavity Radiometer Irradiance Monitor I (ACRIM I) measurements (February 1980 - July 1989) on the Solar Maximum Mission (SMM), the solar monitor measurements (October 1984 - June 1996) on the Earth Radiation Budget Satellite (ERBS), and the ACRIM II measurements (October 1991 - December 1996) on the Upper Atmosphere Research Satellite (UARS). ACRIM I & II was replaced by the final version which now runs through December 1997. Both daily and monthly mean values are given from the Nimbus-7 ERB (Hoyt et al., 1992), ACRIM I & II (Willson, 1994), and the ERBS/ERBE (Lee, 1995) measurement programs, and cover the area of the solar disk. For ease of comparison all the measurements are converted to the value that would be obtained at the mean annual Earth to Sun distance.

Documentation available on CD-ROM


The data is available on Volume 3 of the CIDC CD set.


ISCCP C2Clouds from ISCCP C2

Clouds play an important role in the climate change by affecting the heat exchange between the Sun, Earth and atmosphere. They also modulate the solar irradiance incident on the Earth's surface (the insolation) and this affects the productivity of plants both on land and in the water as well as the surface temperature and heat budget. Numerous efforts to form cloud climatologies from both surface and satellite observations have been made. At present the most important of these is the ongoing International Satellite Cloud Climatology Project (ISCCP), established in 1982 as part of the World Climate Research Program (WCRP). A combination of satellite-measured radiances, ice/snow cover datasets and TOVS atmospheric temperature/humidity are used by ISCCP to produce a global dataset on cloud and surface variables. Operational data collection and processing for ISCCP have been underway since July 1983. An overview of the project and the data products is given in Rossow and Schiffer (1991); the algorithm and its effectiveness are described by Rossow and Garder (1993a&b) while Rossow et al. (1993) compare the resulting products to other cloud climatologies. The ISCCP C2-series data products, briefly described here (more extensively in Rossow et al. (1996)), are gridded data averaged over each month. These data (spanning over the period July 1983 to June 1991) are originally produced on an equal area map grids which has a constant 2.5° latitude increments and variable longitude increments ranging from 2.5° at the equator to 120° at the pole. The Goddard DAAC has regridded these datasets to 1° x 1° equal angle grid for inclusion in the Interdisciplinary data collection.

Documentation available on CD-ROM


The data is available on Volume 3 of the CIDC CD set.


ISCCP D2New Clouds from ISCCP D2

Cloud cover is an extremely important climate parameter. Although only some clouds bring precipitation, all affect the heat exchange between the Sun, Earth and cold space, and they are also quite variable in time, from region to region, and in the effects they produce. Clouds modulate the solar irradiance incident on the Earth's surface (the insolation) and this affects the productivity of plants both on land and in the water as well as the surface temperature and heat budget. Numerous efforts to produce cloud climatologies from both surface and satellite observations have been made. At present the most important of these is the ongoing International Satellite Cloud Climatology Project (ISCCP). A combination of satellite-measured radiances, TOVS atmospheric temperature/humidity and ice/snow data are used by ISCCP to produce a global dataset on cloud and surface variables. An overview of the Project and the data products is given in Rossow and Schiffer (1991); the algorithm and its effectiveness are described by Rossow and Garder (1993a&b) while Rossow et al. (1993) compare the resulting products to other cloud climatologies. The ISCCP D-series, which is described more extensively in Rossow et al. (1996), is a revised version of the C-series dataset. The ISCCP D2-series products are gridded data averaged over each month. These datasets (presently covering the period 1986-1987 & 1989-1992) are originally produced on an equal area map grids which has a constant 2.5° latitude increments and variable longitude increments ranging from 2.5° at the equator to 120° at the pole. The Goddard DAAC has regridded a subset (36 out of the original 130 parameters) of these dataset to 1° x 1° equal angle grid for inclusion in the Climatology Interdisciplinary Data Collection (CIDC).

Documentation available on CD-ROM


The data is available on Volume 3 of the CIDC CD set.


surface radiationSurface Radiation Budget from NASA Langley

The surface radiation budget (SRB) is a basic climate and biosphere parameter which affects the surface heat and moisture budget as well as biological productivity. This dataset covers the spectral range of 0.2-50 micrometers, and is divided into two regions: shortwave (SW, 0.2-5.0 micrometers) and thermal longwave (LW, 5.0-50 micrometers). Both the downward and net radiation at the surface are given. It consists of monthly means covering the period (July 1983-June 1991) and was developed by the Radiation Sciences Branch of the Atmospheric Sciences Division at NASA Langley Research Center, Hampton, Virginia. The irradiances are calculated using computationally fast radiative transfer algorithms whose primary input data come from the International Satellite Cloud Climatology Project (ISCCP) C1 products (Darnell et al., 1996; Rossow and Schiffer, 1991). This dataset, like the ISCCP products, was developed on an equal area world grid (about 280 km by 280 km). The data has been regridded to a 1° x 1° grid for easy comparison with the other Climatology Interdisciplinary Data Collection parameters. There have been extensive validation efforts, including comparisons with surface measurements (Gupta et al., 1993a; Whitlock et al., 1995; and Darnell et al., 1996). Pinker et al. (1995) discuss a number of research fields in which this data will be very useful. The Global Energy and Water-cycle Experiment (GEWEX) SRB Project chose the Langley short- and long-wave SRB algorithms as one pair of two shortwave and two longwave algorithms to produce SRB fluxes for the twelve year study period (July'83 through June'95).

Documentation available on CD-ROM


The data is available on Volume 3 of the CIDC CD set.


surface irradianceSurface Solar Irradiance from NASA GISS

The surface solar irradiance (250-4000 nm) is a basic climate and biosphere parameter which affects the surface temperature and photosynthesis in both marine and land plants. It is also important to geochemical cycling because both biological and photochemical processes strongly perturb distributions of chemical species on land and in the ocean. Clouds are a major modulator of the surface solar irradiance. Bishop and Rossow (1991) developed a fast radiative transfer algorithm for calculating the downwelling surface solar irradiance which uses the total cloud amount from the International Satellite Cloud Climatology Project (ISCCP) as an important input parameter. Their algorithm has gone through three versions, reprocessing using the version 3 algorithm is in progress. Eight years (July '83 - June '91) of monthly downward surface solar irradiance (W/m2) calculated using version 2 algorithm are presented here. The original data was on a 2.5° x 2.5° grid, which has been interpolated to a 1° x 1° grid.

Documentation available on CD-ROM


The data is available on Volume 3 of the CIDC CD set.