en-us News from the NASA GES DISC http://disc.sci.gsfc.nasa.gov/AIRS/ The AIRS Project Team has discovered an error in the software that combines the daily Level 3 Product (AIRSX3STD, AIRH3STD, AIRS3STD) to create the multi-day products (AIRX3ST8, AIRX3STM, AIRH3ST8, AIRH3STM, AIRS3ST8, AIRS3STM). The total counts of all points that fall within a 1x1 deg grid cell (whether included in the final product or not) have been double-counted when creating the multi-day products.

The following fields in the L3 multi-day products are incorrect. They are off by a factor of 2. Users of these fields in the L3 multi-day products should divide the values by 2.
TotalCounts_MW_A
TotalCounts_MW_D
TotalCounts_A
TotalCounts_D

The values in these fields in the daily L3 products are correct. They are incorrect only in the multi-day L3 products. /news/detailed_story.html?ii=263 2008-07-18 Young-In Won is the lead author of a presentation analyzing the effect of solar variability on MLS and AIRS atmospheric temperature measurements. This research will be presented at the 37th COSPAR Scientific Assembly in Montreal, Canada, July 13-16. http://disc.sci.gsfc.nasa.gov/news/COSPAR_meeting_presentation.shtml 2008-07-09 To address the AMSU-A channel 4 noise problem, the AIRS science team delivered a new processing algorithm V5.2. It applies to AIRS+AMSU-A Level-2 (AIRX2*) and Level-3 (AIRX3*) products. Previous to October 1,2007 they will remain as V5.0. Beginning October 1, 2007, the products will be V5.2. http://disc.sci.gsfc.nasa.gov/AIRS/documentation/notices/Notice_20080229.shtml 2008-04-24 AMSU-A Channel 4 NeDT continues to degrade, reaching 3K by the beginning of December, 2007. The condition is now significantly impacting the yield of the operational version 5 AMSU+AIRS retrieval products. Please the the PDF file for full text. [ALso see 2007-10-30 posting] http://disc.sci.gsfc.nasa.gov/AIRS/documentation/notices/AMSU-A_Channel_4_NeDT_Update_2007-12-20.pdf 2007-12-21 Early this past Sunday (December 2, 2007; Day 336), circumstances both onboard the spacecraft and at the EOS Operations Center led to corruption of the memory partition that holds the ground-based attitude determination (GBAD) data in the Aqua spacecraft's solid state recorder (SSR). GBAD data is the primary input used in producing PM1ATTNR. About 19 hours of GBAD data were permanently lost because nothing was written to that partition for most of Sunday.

Since late Sunday, GBAD data have been being recorded on the SSR and downlinked as usual, but the data has format problems which have prevented it from being processed at EDOS, and hence GES DISC has been unable to process PM1ATTNR.

The Earth Science Mission Operations (ESMO) Project at GSFC is working with Northrop-Grumman (the builders of the spacecraft) to correct the problem. Possible solutions are being discussed. Unfortunately, all options involve new procedures which will have to be developed and thoroughly tested. In the meantime, EDOS is working on a way to process the GBAD data that is coming down now, so that normal science data processing can resume while the SSR problem is being worked.

We recently received a set of GBAD data produced with one of those solutions; however, it's validity has yet to be established.

The ESMO Project is also investigating the possibility of reconstructing the lost GBAD data using other spacecraft telemetry and help from the Flight Dynamics Facility.

GES DISC continues AIRS NRT processing (Level-1B only) without the GBAD data for the time being. /news/detailed_story.html?ii=222 2007-12-07 The radiometric noise, NeDT, in AMSU channel 4 has recently increased significantly. At launch it was 0.12 K. Beginning in late September 2007, the rate of increase accelerated so that by the end of October the NeDT is near 1 K... http://disc.sci.gsfc.nasa.gov/AIRS/amsu_ch4_noise_increase.shtml 2007-10-30 NRT data products are currently available for Level-1B and Level-2, and are specially useful for users whose primary interest is the low latency. http://disc.sci.gsfc.nasa.gov/AIRS/documentation/notices/Notice.NRTrelease.shtml 2007-10-26 As of Aug 31 2007, GES DISC has a complete 5 year record of Collection 3 AIRS Level 1B, Level 2, and Level 3 data products. Collection 5 has succeeded Collection 3 as the AIRS baseline collection. http://disc.sci.gsfc.nasa.gov/AIRS/airs_information_updates.shtml 2007-09-05 The AIRS Project and the GES DISC are pleased to announce the release of Collection 5 of the AIRS Data Products. Collection 5, derived from the AIRS Project's latest software release, Version 5, contains many additions and refinements over AIRS Collection 3 (Version 4) data products. http://disc.sci.gsfc.nasa.gov/news/airs_v5_072507.shtml 2007-07-26 The AIRS Team has discovered a software coding error which incorrectly calculates the Version 4 Outgoing Longwave Radiation Flux product (the field, "olr", in the Level 2 Standard Product, the Level 2 Support Product and the fields "OLR_A" and "OLR_D" in all Level 3 Products). These fields should not be used for atmospheric or climate research.

The Clear-sky Outgoing Longwave Radiation Flux product (the field, "clrolr" in the Level 2 Standard Product, the Level 2 Support Product and the fields "ClrOLR_A" and "ClrOLR_D" in all Level 3 Products) is not affected by this software coding error. /news/detailed_story.html?ii=219 2006-08-03 The AIRS Science Team is pleased to release the new Version 4 products. Apart from improved algorithms, an exciting addition is the gridded AIRS level 3 products. Three types of level 3 products will be available: daily, 8-day and monthly means. Also, see Level 3 features from JPL. http://disc.gsfc.nasa.gov/AIRS/documentation/v4_docs/v4_docs_list.shtml 2005-04-26