January 12, 2012
Changes to the Meteosat Second Generation Meteorological Product generation
EUMETSAT intends to introduce, on 8 February 2012, the following changes to the Meteosat Second Generation Meteorological Product generation:
- As a new product, the Normalised Difference Vegetation Index – Decadal (NDVD) will be introduced. This is a 10-day accumulation of the Normalised Difference Vegetation Index (NDVI) product. The product is accumulated over the following periods for each month:
- Days 1 to 10 of each month, disseminated on day 11 of the month
- Days 11 to 20 of each month, disseminated on day 21 of the month
- Days 21 to end of the month, disseminated on day 1 of the following month
The first NDVD product will be disseminated on 11 February 2012 at around 0:05 UTC.
Test data are available on our FTP site.
- A new algorithm of the Total Ozone (TOZ) product has been implemented. The Total Ozone product makes use of the new SEVIRI Ozone IR 9.7 mm channel and of the other IR and WV channels of SEVIRI. With the new algorithm, the TOZ product is derived as part of the Optimal Estimation Technique used for the derivation of the Global Instability Index Product. For more information on this technique, please refer to the MSG Meteorological Products Extraction Facility Algorithm Specification Document (PDF, 1.5 MB).
As the new TOZ algorithm only determines one TOZ value per segment, TOZ parameters like the standard deviation, the maximum and minimum value in the segment are not present any more in the BUFR encoded product. Note that the information in the quality parameter section of the TOZ product has changed as described in the document BUFR Descriptors for Total Ozone Product (PDF, 106 KB).
Note that this new TOZ product is the same as the one that was disseminated as ‘TOZE’ product during the trial phase that took place at the end of 2011.
Test data are available on our FTP site.
Within the Global and Regional Instability Index (GII and RII) products, the root mean square difference between the ECMWF model and observed brightness temperature is used as a parameter for the termination of the iterative process for both products. The threshold was defined as 4.0 K and has been reduced to 2.0 K. Note that the same threshold applies for the new TOZ product algorithm.
- A correction within the inter- and extrapolation routine of the prototype and operational algorithm for the determination of the Surface Emissivity maps has been implemented. This correction was required for the successful generation of the TOZ product. However, this change has a minor impact on the Cloud Mask and a very minor impact on the Active Fire Monitoring product.
- Two corrections have been implemented for the Active Fire Monitoring product:
- The first correction concerns the determination of the radius of the pixel within the Active Fire Monitoring CAP (Common Alert Protocol) product. The change only impacts e.g. pixel drawing routines that use the pixel radius for locating the pixel on the Meteosat disk.
- The second correction is on the threshold defined for the IR3.9 temperature test. Within this test the minimum difference with respect to the predicted IR3.9 brightness temperature is defined, part of which is a constant temperature difference which was set to 6 and has now been reduced to 5, in accordance with Active Fire Monitoring with MSG ATBD (EUM/MET/REP/07/0170, v2) (PDF, 1.2 MB) and the MSG Meteorological Products Extraction Facility Algorithm Specification Document (PDF, 1.5 MB). The impact is an increase of the number of possible fire detections.
- Furthermore when a product does not contain any detected fire, the dissemination of that product is stopped. Consequently, there will be no more isolated Prolog disseminated on EUMETCast without a product.
- Finally a correction is introduced for the Volcanic Ash Detection product. The change concerns the day time detection of volcanic ash, and the eruption of 22-24 May 2011 in Iceland has been used as an example for the validation.
More information will be available from the MSG Meteorological Product Operations Release Validation Report – 2 which will be published on the website in due course.
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