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NOAA Polar Orbiter Data User's Guide

Section 5.0
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5.0 NESDIS Operational Products

SSB presently archives several different types of NESDIS operational polar orbiter products. The products include atmospheric soundings, sea surface temperatures, heat budget, mapped/gridded AVHRR data, TOVS and AVHRR Level 1b data (which have been previously described in Sections 2, 3, and 4), and total and profile ozone data. Tables 5.0-1 through 5 contain a detailed list of the specific NESDIS products which are available. The sounding products in Table 5.0-1 are known as the TOVS sounding products which are described in Section 5.1. The sea surface temperature products in Table 5.0-2 are produced from quantitative processing of digital radiometric measurements (AVHRR) and are described in Section 5.2. The mapped GAC products contained in Table 5.0-3 (Polar Stereographic and Mercator GAC mosaics) are described in Section 5.3. Heat budget products listed in Table 5.0-4 are described in Section 5.4. The ozone products generated from the Solar Backscattered Ultraviolet Radiometer Version 2 (SBUV/2) and listed in Table 5.0-5 are described in Section 5.5.

The TOVS sounding product information is derived from the three TOVS instruments. These instruments consist of the HIRS/2, MSU, and SSU sensors (described in previous sections) which measure the intensity of the upwelling radiation in the various spectral intervals that occur at maxima over broad layers and depths of the atmosphere. These radiance measurements are processed into Earth-located, calibrated radiance values, "clear" radiances (radiances corrected for cloud effects and angle of view), estimates of water vapor in three atmospheric layers (converted to precipitable water in these layers), mean temperatures for selected atmospheric layers, tropopause height and temperature estimates, and geopotential thickness of selected atmospheric layers.

The digital AVHRR data are processed into the quantitative products of global sea surface temperatures and global radiation budget estimates.

The GAC infrared and visible data are processed into a basic set of sea surface temperature (SST) observations at 8-km resolution (50-km prior to November 17, l981) over the global oceans. All observations are values which have been integrated over an 8-km diameter spot, however, they have a variable spacing, ranging from 8-km (contiguous) in the U.S. coastal waters to 25-km in the open ocean. This data base is further processed to generate gridded analyses at the regional, global, and local scales. The Regional-Scale analyses (50 km resolution) are over five selected regions on a 0.5 degree latitude/longitude grid. The Global-Scale analysis covers the global oceans at 100-km resolution (1 degree latitude/longitude grid) and the Local-Scale analyses are at 14-km resolution (0.125 degree latitude/longitude grid) over eight selected regions.

The Radiation Budget archive consists of six types of similar data. One type is the Monthly Radiation Budget consisting of daily values of day flux, night flux, absorbed solar energy, and available solar energy for a month. These data are available in Polar Stereographic and Mercator projections. Another type of Radiation Budget product is the Seasonal Radiation Budget which has the same daily radiation fields as the Monthly Radiation Budget product. But, in addition to Polar Stereographic and Mercator projections, there is a smaller (45x45) polar chip included and, the data range over a three-month season. A subset of the Seasonal Radiation Budget product is now available for ten years in the Mercator format, and is called the Ten-year Mercator Radiation Budget product. The fourth type of Radiation Budget product is the Monthly Mean Radiation Budget which contains monthly averages for the above mentioned radiation fields. These data are also available in Polar Stereographic and Mercator projections. The fifth and sixth types of radiation budget data products are the seasonal mean and annual mean. The seasonal mean product are averages over each season while the annual mean product are averages calculated over each calendar year.

The gridded AVHRR products consist of mosaics of orbital passes of unmapped data and the mapped AVHRR products consist of Mercator and Polar Stereographic map projections. The mapped mosaics are of daytime visible and infrared, and nighttime infrared imagery. Note that as of June 24, l985, the Mercator mosaics became available in digital form in addition to the already available Polar Stereographic mosaics.

There are three types of SBUV/2 ozone products. They are the 1B Capture product, the Historical Instruments file product and the Product Master File product.

Table 5.0-1. TOVS Sounding Products on CCT.
Product Description Accuracy Goals Coverage/Spatial Resolution
Layer-mean temperatures (K) for the layers listed below:
surface - 850 mb; 850-700 mb; 700-500 mb; 500-400 mb; 400-300 mb; 300-200 mb; 200-100 mb; 100-70 mb; 70-50 mb; 50-30 mb; 30-10 mb; 10-5 mb; 5-2 mb; 2-1 mb; 1-0.4 mb.		 Surface-850 mb: ± 2.5K; 850-tropopause: ± 2.25K; tropopause-2 mb: ± 3K; 2-4 mb: ± 3.5K Global coverage. Nominal 250 km near the subsatellite track. Spacing and resolution increase with scan angle. Resolution will be fixed at 250 km nominal.
Layer precipitable water (mm) for these layers:
surface-700 mb; 700-500 mb; above 500 mb		 ± 30% Same as above.
Tropopause pressure (mb) and temperature Pressure: ± 50 mb; temperature: ± 2.5 degrees Same as above.
Total ozone (Dobson units) ± 15% tropical; ± 50% polar Same as above.
Equivalent blackbody temperatures (K) for 20 HIRS/2 stratospheric channels, 4 MSU channels, and 3 SSU channels ± 2K Same as above.
Cloud cover ± 20% Same as above.

Table 5.0-2. Sea Surface Temperature Products.
Product Description Accuracy Goals Spatial Resolution/Geographical coverage Format/Schedule
1) Sea Surface Temperature Observations ± 1.5 degrees C absolute; ± 1.5 degrees C relative 8 km (nominal/Global) CCT - weekly
2) Sea Surface Temperature Regional-Scale Analysis See above. 0.5 degree lat/long grid (50 km); 5 regions Image - weekly;
CCT - monthly
3) Sea Surface Temperature Global-Scale See above. 1 degree lat/long grid (100 km) Contour chart - weekly;
CCT- bimonthly;
Image - daily
4) Sea Surface Temperature Local-Scale Analysis See above. 0.125 degree lat/long grid (14 km); 8 regions 2 CCTs - monthly; Image - daily
5) Sea Surface Temperature Monthly Mean See above. Global 2.5 degrees lat/long grid (250 km) CCT - yearly; Contour chart - monthly

Table 5.0-3. Mapped/Gridded AVHRR Product.
Product Description Accuracy Goals Coverage/Spatial resolution Format/Schedule
1) Hemisphere Mapped GAC Polar mosaics IR and VIS mosaics Nominal ± 5 km for Polar and Mercator mapping location Northern/Southern Hemispheres 1024 x 1024; 14.8 km at Equator; 29.6 km at poles Mapped imagery - CCT daily
2) Mercator Mapped GAC mosaics IR/VIS See above. 360 degree longitude; 40N-40S; 9.8 km at Equator, increasing poleward Mapped imagery CCT daily (beginning May 31, 1985)
3) Polar Mapped GAC composites IR/VIS (minimum Brightness/maximum temperatures) See above. North/South polar Regions 1024 x 1024 Mapped - conforms to 7 day compositing period
4) Pass-by-pass Gridded GAC imagery VIS/IR (one satellite) Nominal ± 5 km grid placement Global 4 km Gridded imagery - orbit by orbit
5) Imagery from LAC data: both recorded and Direct Readout (ungridded) n/a Recorded data: selectable; two 11.5 minute segments/orbit. Direct Readout Continental U.S. Imagery - recorded: variable two 11.5 minute segments/orbit. Direct Readout all Continental U.S.

Table 5.0-4. Radiation Budget Products.
Product Description Accuracy Goals Coverage/Spatial Resolution Format/Schedule
Monthly Radiation Budget Parameters ± 7 W/m2 reflected outgoing energy Global;
Observations are 50km		 CCT (January 1979 to present)
a. 2.5 x 2.5 degree Mercator map array
b. 125 x 125 polar map array
2 times/day IR flux; 1 time/day reflected energy; monthly (time average)
1. Daytime Longwave Flux ± 7 W/m2 Global See above.
2. Nighttime Longwave Flux ± 7 W/m2 Global See above.
3. Absorbed Solar Radiation ± 7 W/m2 Global See above.
4. Available Solar Energy (calculated field to be included in output form) ± 7 W/m2 Global See above.
Seasonal Radiation Budget Parameters ± 7 W/m2 Global CCT (June 1974 to present)
a. 125 x 125 Polar Stereo map array
b. 45 x 45 Polar Stereo chip array
c. 144 x 72 (2.5 x 2.5 degree) Mercator array
Daily data for a 3-month season
1. Daytime Outgoing Longwave ± 7 W/m2 Global See above.
2. Absorbed Solar Energy ± 7 W/m2 Global See above.
3. Available Solar Energy ± 7 W/m2 Global See above.
4. Nighttime Outgoing Longwave ± 7 W/m2 Global See above.
10-year Mercator Heat Budget Parameters ± 7 W/m2 Global CCT
a. 144 x 72 (2.5 x 2.5 degree) Mercator map array
Daily data for 10 years. (June 1974 - March 1978, January 1979 - February 1986)
1. Daytime Outgoing Longwave ± 7 W/m2 Global See above.
2. Absorbed Solar Energy ± 7 W/m2 Global See above.
3. Available Solar Energy ± 7 W/m2 Global See above.
4. Nighttime Outgoing Longwave ± 7 W/m2 Global See above.
Monthly Mean Heat Budget Parameters ± 7 W/m2 Global CCT (January 1979 to present)
a. 144 x 72 (2.5 x 2.5 degree) Mercator map array
b. 125 x 125 Polar Stereo map array
1. Daytime IR Flux ± 7 W/m2 Global See above.
2. Nighttime IR Flux ± 7 W/m2 Global See above.
3. Absorbed Solar Energy ± 7 W/m2 Global See above.
4. Available Solar Energy ± 7 W/m2 Global See above.

Table 5.0-5. SBUV/2 Ozone Products.
Product Description Accuracy Goals Coverage/Spatial Resolution
Total Ozone (Dobson units) 1% Global
Layer Ozone (Dobson units), layers: 5% Global
Layer number Pressure range (mb)
1 surface - 250
2 250 - 125
3 125 - 63
4 63 - 31
5 31 - 16
6 16 - 8
7 8 - 4
8 4 - 2
9 2 - 1
10 1 - 0.5
11 0.5 - 0.25
12 0.25 - 0.1
Level Ozone (micrograms/gram), levels:

5%

 Global
Level number Pressure (mb)
1 0.3
2 0.4
3 0.5
4 0.7
5 1.0
6 1.5
7 2
8 3
9 4
10 5
11 7
12 10
13 15
14 20
15 30
16 40
17 50
18 70
19 100

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