SSM/I Update (with some AMSR-E)

1. SSM/I Update(with some AMSR-E) Walt Meier

2. AMSR EASE Grid • AMSR-E Tbs gridded on the three 25 km EASE grids (NH, SH, global) • All channels produced (6, 18, 22, 36, 89 GHz) • Also in a 0.25° global grid, primarily for soil moisture community • Inverse distance squared gridding • Daily fields • Plan to make available by 2006 Fall AGU

3. AMSR EASE Images Tb (K) 100 200 300 31 December 2005, 36 GHz Horizontal

4. SSM/I Brightness Temperature and NASA Team Sea Ice Reprocessing

5. Donna Scott USO M.J. Brodzik Programmer Lynn French Writer Fran Coloma Operations Matt Savoie Programmer Jeff Smith Programmer Thanks to the Polar Stereo Team:

6. Tb Reprocessing • Tbs for 1987-1999 reprocessed to remove bad scans – completed July 2006 • Error found in some reprocessed F8 and F11 Tbs, corrected in September 2006 • Filenaming convention changed • E.g., tb_f13_20060630_v2_n85v.bin • Format changed: HDF to 2-byte flat binary, little-endian for greater compatibility with users, esp. Windows • Files not tarred or compressed, multiple file access through wuftp • Directory structure change – parameter based, not sensor based • ftp://sidads.colorado.edu/pub/DATASETS/brightness-temperatures/ssmi/ • Allows future addition of EASE Grid Tbs to same structure

7. Original Tb - 21 March 1989 Vertically Polarized 19 GHz 175 K 275 K

8. Reprocessed Tb - 21 March 1989 Vertically Polarized 19 GHz 175 K 275 K

9. Sea Ice Reprocessing • SMMR-SSM/I NASA Team, produced by Goddard • Best timeseries, but updated infrequently • SSM/I NASA Team, produced by NSIDC, same algorithm but completely separate processing from Goddard, could not be combined with Goddard • Most frequently updated, but lower quality and doesn’t include SMMR record • Sea Ice Index, NASA Team, produced by NOAA@NSIDC, modified in 2004(?) to use methodology similar to Goddard SMMR-SSM/I for monthly browse and stats of extent, area, anomalies, trends • Adapted Sea Ice Index processing to SSM/I NASA Team to produce daily, monthly data fields, consistent with Goddard so that they can be combined

10. Sea Ice Reprocessing • Done for NASA Team first • Plan to do for Bootstrap soon – when we get an update from Joey • NSIDC and Goddard products merged into one product with different processing (QC) levels • Greater continuity between products • Less ambiguity for users • Fewer tools

11. Old NRTSI 1987 - present Old tiepoints, no coastal filter, no oceanmask, HDF format Marshall Tb NSIDC Wentz Tb Goddard 1978 - 2004 New tiepoints, coastal filter, oceanmask, flat-binary format Sea Ice Index

12. New NSIDC-Goddard NASA Team • 1978 - Present • All use NRTSI-g style processing: • updated tiepoints • coastal filter • add’l weather filter (ocean or SST mask) • All share same formats, masks, overlays, tools, browse images NRT Marshall Tb Preliminary Wentz Tb Final Monthly Avg. and Browse (Sea Ice Index)

13. Flow of Products • NRT produced daily from Marshall Tbs • Preliminary produced every 3-6 months when Wentz tape arrives, ~3 month latency • Final produced at Goddard produced ~once/year, with ~1 year latency • NRT replaced by Preliminary,Preliminary replaced by Final • Only one NASA Team sea ice file for each day (except for sensor overlap periods) • If NSIDC were to take over processing from Goddard, would have only NRT and Final • Sea Ice Indexmonthly stats, browse, anomalies, etc. produced from NRT, Preliminary, or Final data

14. Current Status • Final: October 1978 – December 2005 • Preliminary: January 2006 – June 2006 • NRT: 1 July 2006 – 25 October 2006 • Sea Ice Index: Oct 1978 – Oct 2006 • DMSP SSM/I Daily and Monthly Polar Gridded Sea Ice Concentrationsfor NASA Team will go away (keeping around through Sep 2006 for users)

15. Other Changes - Products • MYI fraction no longer produced • Was done for NSIDC SSM/I • Not done for Goddard SMMR-SSM/I • MYI from NASA Team unreliable • Few users • Monthly means not computed with 0%, 5%, 15% cutoffs • Changes made to be consistent with Goddard NASA Team product

16. Other Changes - Formats • New directory structure, by parameter instead of sensor: • ftp://sidads.colorado.edu/pub/DATASETS/seaice/polar-stereo/ • Allows for extension to EASE Grid sea ice, and other sea ice product • New filename convention: • nt_YYYYMMDD_SSS_vV_H.bin • H=hem, SSS=sat (e.g., ‘f13’), V=version # • All files in consistent format with NASA Team Goddard • 1-byte flat binary with 300-byte header • little-endian for greater compatibility with users, esp. Windows • All files untarred and uncompressed, multiple file access through wuftp

17. Tools changes • New pixel area, latitude, longitude files • More precision, accuracy • One set of files for Tb and sea ice • Overlays consistent for Tb and sea ice • Display tools updated to handle new file format and filenames • Different tools for Tb and sea ice • Browse images as PNG with new color scale • Consistent with Sea Ice Index browse (also modified from original version)

18. NRT Browse Images New Old

19. Final Browse New Old

20. Sea Ice Index Browse Old New

21. Documentation Changes • Sea ice and Tb updates put into documentation • NSIDC SSM/I NASA Team page removed, only a Goddard SMMR-SSM/I NASA Team guide doc • http://nsidc.org/data/nsidc-0051.html • Some streamlining done – e.g., common grid information removed to a separate page

22. Goddard Activities • Bootstrap reprocessing – nearing completion; consistency between SMMR, SSM/I, and AMSR-E • NASA Team reprocessing – planned; will take advantages in improvements in SMMR processing • In future, transition routine processing to NSIDC? • NRT and Final product; Final created by NSIDC from Wentz tapes every 3-6 months • Consideration of cost, resources, etc.

23. Next Steps • Do the same with Bootstrap, after reprocessed update from Joey • NRT Tb files haven’t been changed • More documentation streamlining • Common sensor pages, tools pages • Update references • Ancillary updates

24. Thanks!