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PoDAG XXV, 26 Oct 2006 1 SSM/I Update (with some AMSR-E) Walt Meier.

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Presentation on theme: "PoDAG XXV, 26 Oct 2006 1 SSM/I Update (with some AMSR-E) Walt Meier."— Presentation transcript:

1 PoDAG XXV, 26 Oct 2006 1 SSM/I Update (with some AMSR-E) Walt Meier

2 PoDAG XXV, 26 Oct 2006 2 AMSR EASE Grid AMSR-E T b s 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 PoDAG XXV, 26 Oct 2006 3 AMSR EASE Images T b (K) 300100200 31 December 2005, 36 GHz Horizontal

4 PoDAG XXV, 26 Oct 2006 4 SSM/I Brightness Temperature and NASA Team Sea Ice Reprocessing

5 PoDAG XXV, 26 Oct 2006 5 Thanks to the Polar Stereo Team: Donna Scott USO Lynn French Writer Fran Coloma Operations Jeff Smith Programmer Matt Savoie Programmer M.J. Brodzik Programmer

6 PoDAG XXV, 26 Oct 2006 6 T b Reprocessing T b s for 1987-1999 reprocessed to remove bad scans – completed July 2006 –Error found in some reprocessed F8 and F11 T b s, 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 T b s to same structure

7 PoDAG XXV, 26 Oct 2006 7 Original T b - 21 March 1989 Vertically Polarized 19 GHz 175 K 275 K

8 PoDAG XXV, 26 Oct 2006 8 Reprocessed T b - 21 March 1989 Vertically Polarized 19 GHz 175 K 275 K

9 PoDAG XXV, 26 Oct 2006 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 PoDAG XXV, 26 Oct 2006 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 PoDAG XXV, 26 Oct 2006 11 Old Marshall T b Wentz T b NRTSI NSIDC Goddard Sea Ice Index 1987 - present Old tiepoints, no coastal filter, no oceanmask, HDF format 1978 - 2004 New tiepoints, coastal filter, oceanmask, flat- binary format

12 PoDAG XXV, 26 Oct 2006 12 Marshall T b Wentz T b NRT Preliminary Final Monthly Avg. and Browse (Sea Ice Index) 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 NSIDC-Goddard NASA Team New

13 PoDAG XXV, 26 Oct 2006 13 Flow of Products NRT produced daily from Marshall T b s 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 Index monthly stats, browse, anomalies, etc. produced from NRT, Preliminary, or Final data

14 PoDAG XXV, 26 Oct 2006 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 Concentrations for NASA Team will go away (keeping around through Sep 2006 for users)

15 PoDAG XXV, 26 Oct 2006 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 PoDAG XXV, 26 Oct 2006 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 PoDAG XXV, 26 Oct 2006 17 Tools changes New pixel area, latitude, longitude files –More precision, accuracy –One set of files for T b and sea ice Overlays consistent for T b and sea ice Display tools updated to handle new file format and filenames –Different tools for T b and sea ice Browse images as PNG with new color scale –Consistent with Sea Ice Index browse (also modified from original version)

18 PoDAG XXV, 26 Oct 2006 18 NRT Browse Images Old New

19 PoDAG XXV, 26 Oct 2006 19 Final Browse Old New

20 PoDAG XXV, 26 Oct 2006 20 Sea Ice Index Browse OldNew

21 PoDAG XXV, 26 Oct 2006 21 Documentation Changes Sea ice and T b 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 PoDAG XXV, 26 Oct 2006 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 PoDAG XXV, 26 Oct 2006 23 Next Steps Do the same with Bootstrap, after reprocessed update from Joey NRT T b files haven’t been changed More documentation streamlining –Common sensor pages, tools pages –Update references Ancillary updates

24 PoDAG XXV, 26 Oct 2006 24 Thanks!


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