| Popis: |
Convection can yield severe weather events (thunder, wind gust, tornadoes, hail, flash-flood...) which can have dramatic societal consequences. Identifying areas with potential atmospheric instabilities is hence critical to issue accurate warnings, as early as possible, to prepare population, economic actors and civil protection. The measurements from EPS-IASI and the future EUMETSAT hyperspectral infrared sounder missions IASI-NG and MTG-IRS contain information about the thermodynamic state of the atmosphere, which are important to weather forecasting. In particular, MTG-IRS will offer unparalleled data on atmospheric thermodynamic parameters with a high vertical resolution and horizontal sampling of 4 km at Nadir and temporal sampling of 30 minutes over Europe. This unprecedented system offers a significant advance in operational observation and will be a great asset to regional short-range weather forecasting and nowcasting. The hyperspectral infrared observations can be used to determine thermodynamic parameters and cloud information that can be used to supplement regional models for nowcasting, for the purpose of more accurately and quickly identifying areas of potential instability and associated weather phenomena like vertical motion, convection, precipitation, and severe storms. A number of indices is planned to be generated centrally within the L2 processing facilities of IRS, IASI and IASI-NG. It aims at ensuring continuity with other GII products, e.g. MSG and consistency with the MTG-FCI follow-up products. It is completed with a few more indices collected in the literature and from initial interactions with forecasters. We present here the results of the calculation of these indices based on real observations by IASI and on the full Earth's disk such as seen by MTG-IRS. The latter are the sub-products of the primary retrieved temperature and moisture profiles, based on realistic cloudy sky radiances simulation. |
