NASA Goddard Earth Sciences (GES), Data Information Service Center (DISC), Distributed Active and Archive Center (DAAC), Greenbelt, MD - USA

Gilberto Vicente, Jianchun Qin (JCQ), Jason Li, Irina Gerasimov, Andrey Savtchenkohttp://disc.gsfc.nasa.gov

Overview of GES DAAC Services and Tools Functionality

S u m m a r yThis poster describes the web-enabled subsetting

services currently available at the GES DISC/DAAC that provide functions for all the Level 1B and Level 2 data products from the AIRS/AMSU/HSB instruments. The on-line services allow users to access the data in interoperable, personalized, real-time, on-demand and on-the-fly manners. The input file can be subsetted by channels only, by parameters only or by channels and parameters.

The GES DISC subsetting web-based systems are:

On-Demand Subset system - ODS

Places orders to the long term tape archive, where all data for the missions durations are kept. Users receive email notification when the subset data are ready for pick-up or have been pushed to the User's host.

On-the-fly system OTF

Works with the GES DISC Data Pool only. It is a disk cache of 50 TB of rolling archive, where the data are available for instant download. All data have certain retention time and are replaced with new one as soon as the retention time expires.

The fine resolution data holdings expire in just several weeks because of the large data volumes and the limited disk space. Many coarser resolution data, like AMSU radiances and the upcoming Level-3 products, will be kept for more than one year before being replaced. The advantage of this subset service is that it is instantaneous, and the only wait time is that of the data download.

Three major types of AIRS data subsets are available:

1. Level 1B Channel/Variable subset

OTF for Infrared geolocated and calibrated radiances OTF for Visible/Near Infrared geolocated and calibrated radiances OTF for AMSU-A1 & AMSU-A2 combined, geolocated and calibrated

brightness temperature ODS for Infrared geolocated and calibrated radiances (coming soon) ODS for Visible/Near Infrared geolocated and calibrated radiances

(coming soon) ODS for AMSU-A1 & AMSU-A2 combined, geolocated and calibrated

brightness temperature (coming soon)

2. AIRS Level 2 Parameter subset

OTF for Standard final retrieval product in 28 standard pressure levels

OTF for Cloud-Cleared IR radiancesODS for Standard final retrieval product in 28 standard pressure

levels (coming soon) ODS for Cloud-Cleared IR radiances (coming soon)

3. AIRS Level 3 Parameter and Spatial subset

OTF Parameter subsetting (coming soon) OTF Spatial subsetting (coming soon) Acknowledgements: To all GES DAAC data support teams.

This work is supported by the NASA/GSFC Earth Science Enterprise.

Client’s Browser

Internet

F T P

WebLogic

DataPool(Online Disk Cache)

HSE Subsetter

DISC-DAAC Subsetting ServiceDISC-DAAC Subsetting Service

Channels Available for Subsetting ServicesChannels Available for Subsetting ServicesUsers can either specify any channel for the subsetting request or choose a pre-defined set as shown in the table below (Courtesy of Evan Manning, NASA/JPL). This will make it easier for selecting all channels in various frequency ranges.

AMSU and IR Channels Subsetting ExamplesAMSU and IR Channels Subsetting Examples

Algorithm of on-the-fly SubsettingAlgorithm of on-the-fly SubsettingThe core functionality of the HDF-EOS Web-Based Subsetter (HEW), which is developed by the University of Alabama in Huntsville (UAH), has been extracted into a stand-alone callable function known as the HDF-EOS Subsetting Engine (HSE). The AIRS Level-1B and Level-2 subsetter makes use of HSE and can be incorporated into any application that needs to perform HDF-EOS subsetting. The subsetter populates a subsetting criteria data structure which contains the information the HSE needs to operate. This data structure is passed to the HSE which then uses the information to locate and subset the input files into the output files. The output files are then deliver to end user via FTP.

HardwareModule

FrequencyRange

Channel Numbers

Number ofChannels

Comments

All 649.61 - 2665.24cm-1 1 - 2378 323 The Numerical Weather Prediction sets

M-12 649.61 - 681.99cm-1 1 - 130 130 Long-wave temperature sounding

M-11 687.60 - 728.44cm-1 131-274 143 Long-wave temperature sounding

M-10 728.06 - 781.88cm-1 275 - 441 166 Long-wave surface

M-09 789.26 - 852.43cm-1 442 - 608 166 Long-wave surface

M-08 851.49 - 903.78cm-1 609 - 769 160 Long-wave surface

M-07 911.24 - 974.29cm-1 770 - 936 166 Long-wave surface

M-06 973.82 - 1046.20cm-1 937 - 1103 166 Ozone

M-05 1056.10 - 1136.66cm-1 1104 - 1262 158 Long-wave surface, Ozone

M-04d 1216.97 - 1272.59cm-1 1263 - 1368 105 Water vapor

M-04c 1284.35 - 1338.86cm-1 1369 - 1462 93 Water vapor, methane

M-03 1338.16 - 1443.07cm-1 1463 - 1654 191 Water vapor

M-04b 1460.27 - 1527.00cm-1 1655 - 1760 105 Water vapor

M-04a 1541.10 - 1613.86cm-1 1761 - 1864 103 Water vapor

M-02b 2181.50 - 2325.06cm-1 1865 - 2014 149 Shortwave temperature sounding, CO

M-01b 2299.80 - 2422.85cm-1 2015 - 2144 129 Shortwave temperature sounding

M-02a 2446.20 - 2569.75cm-1 2145 - 2260 115 Shortwave Surface

M-01a 2541.90 - 2665.24cm-1 2261 - 2378 117 Shortwave Surface

Parameters Available for Subsetting ServicesParameters Available for Subsetting ServicesSurface Skin Temperature Long-wave surface, Ozone

Surface Air Temperature Microwave Emissivity

Atmospheric Temperature Total Cloud Liquid Water

Water Vapor Mass Mixing Ratio Cloud Top Temperature

Total Precipitable Water Vapor Cloud Top Pressure

Ozone Volume Mixing Ratio Effective Cloud Fraction

Total Ozone Burden Geopotential Heights at Std Pressure Level

Spectral IR Surface Emissivities Geopotential Heights of Surface

Spectral IR Surface Bi-direct Reflectivity Microwave Surface Brightness