September 15, 2010
Major improvement to the EPS IASI Sounding products service
Starting 14 September 2010, the new 'day-2' version of the IASI level 2 product processing chain is put in operational service.
The plots represent the statistics of differences between IASI temperature profiles and co-located ECMWF forecast fields, above ocean in the inter-tropical zone. Red lines correspond to the previous operational product, black lines to the new product. Dashed lines show the mean difference, solid lines the root-mean-square. (Click to enlarge)
The most intensive computations taking place in the EPS ground segment provide the IASI sounding products, which include temperature and humidity profiles and surface temperatures, cloud properties, ozone, trace gases and emissivity. Those products are derived in Near Real Time and disseminated under a timeliness constraint of 3h from data sensing, on EUMETCast and on the WMO GTS. The products are also available from the Data Centre.
The new version sees major improvements in the quality of the land surface temperatures, ozone and carbon monoxide total columns (in the trace gases products): those products are reaching an operational validity status. Important improvements also concern the quality of the temperature profiles retrieved in clear sky conditions, the cloud properties, and the quality flags in the product. As the temperature and humidity profiles are provided for cloud-free pixels, the size of the TWT product is expected to decrease. Also note that, within the Trace Gases (TRG) product, CO and N2O are available at a reduced spatial sampling, due to non-uniformity of the instrument response.
Surface emissivity, partial column ozone, trace gases aside from CO: N2O, CH4, CO2, are produced with a pre-operational validity status and development and validation efforts will continue.