Leicester Telecon 2

Gary Corlett and Chris Merchant by telephone
2 Nov 2010

GC has circulated the draft Data Access Requirements Document round the project team, for comments and completion of some missing/difficult-to-source information about data sets. Replies are solicited for 10 Nov, the Met Office input being key. CM asked GC specifically to request also the DMI and met.no colleagues to review the sea ice / high latitude contents of the data being sought.

Key problem/uncertainty is the best source for AVHRR. First look shows >1 K differences in retrieved SST when using SCOPE-CM BTs compared to NOAA GAC, and also scan-line striping. Use of the cloud information seemed feasible: there are obvious failures to detect cloud in the SCOPE-CM data that are absent from NOAA GAC, but the reverse is also true. It was agreed that a telecon between Leicester (GC), Edinburgh (Mark Filipiak) and the SCOPE CM contact is needed to address the following:

1. Why the BTs are different by >1 K in clear sky areas in the mean.
2. Why there is striping relative to GAC, and if this striping is reasonably known to be zero-mean.
3. Realistic time scale for obtaining the full SCOPE CM data set.
4. Where SCOPE CM source their NOAA GAC input.

CM has commented on GC's Product Validation Plan Table of Contents, and it was agreed to stick to the contractual contents, except that a section introducing the Multi-sensor Match-up Dataset is essential for the document to make sense.

Argo matches with AATSR and further SEVIRI matches from Meteo France have been obtained at Leicester since last discussion. Access to the Edinburgh cluster is problematic so far -- GC and Mark F will work on this.

Regarding aerosol data, agreed solution is as follows. GC has found http://www.temis.nl/airpollution/absaai/, which offers daily GOME-2 Absorbing Aerosol Index in TOMS-like format. We will use TOMS, GOME-1, TOMS, OMI & GOME-2 to cover as much as we can from 01/08/1991 to 31/12/2010 (long-term record) and then GOME-2 (if available) for 01/10/2011 to 31/03/2012 (short-term demonstration). Overlap where possible between sensors (up to one year) to do some basic AAI intercomparisons with TOMS as well. This means there will be roughly 7 months of data missing from 24/11/1994 (the last METEOR 3 file, although the data starts to degrade a few weeks prior to this date) to 01/07/1995 (the start of GOME-1, although there are a few odd days of missing GOME-1 data). For the Pinatubo aerosol, we'll use the SAGE II data monthly means for the period 01/08/1991 to at least the end of 1994 to look for stratospheric aerosol correlations during the Mount Pinatubo eruption.

CM will attend the NASA SST meeting, and will use the opportunity to discuss AVHRR data sourcing. CM will not attend the next AATSR QWG (no funding and it is not in UK), but in any case, the AATSR SAG meeting the following week looks very pertinent and will summarize some of the same ground.

DONM Tue 16 Nov, 10.00