![]() ![]() This ensured the success of the MEIDEX sprite observations that recorded numerous events in many different geographical locations. During the ‘‘STS-107’’ mission flown in January 2003, the forecasted areas of main convective centers were transmitted daily to the crew and helped them in pointing the cameras and targeting thunderstorms. Operational skill was found to be only 43%. The 1000-m tolerance was allowed because of inevitable uncertainties underlying this method of analysis. Because the purpose was to get true alerts of potential TLE occurrences, operational forecast skill was defined as the percentage of forecasts that were accurate within 1000 m or higher than observed. The standard error in the forecast heights was 2516 m. For each convective system, the coldest cloud-top temperature was converted to height, using the NCEP–NCAR reanalysis data for the respective location and time. Cloud-top heights of 53 systems were examined on four dates in October–November 2001, using IR radiances converted to brightness temperatures. The predicted size of the convective system was typically larger than the observed size. No consistent error was found in location. Operational skill was determined as the percentage of observed cloud systems found within a 58 range in the regions that appeared on the forecast maps as having the potential to contain thunderclouds and was found to be 92%. The locations of 66 mesoscale cloud systems on Significant Weather Maps, produced for eight different dates in August 2001, were compared with satellite global IR images for these dates. ![]() To estimate the operational skill of this forecast for successfully detecting clouds with a high probability for producing TLEs, predictions for selected dates were compared with satellite observations. The forecast was based on the high-level significant weather (SIGWX) maps, commonly used for civil aviation, provided by the AWC on the Internet. Because the operational methodology was planned around a 24-h cycle, there was a need for a global forecast of areas with a high probability of massive thunderstorms that are prone to exhibit TLE activity. They are generally associated with thunderstorms and are thought to be caused by the lightning within the troposphere. Mesoscale convective systems offer a high probability for the occurrence of TLEs above active thunderstorms. Transient luminous events (TLEs) are short-lived electrical discharge that occur in the upper atmosphere. The examination was motivated by the Mediterranean Israeli Dust Experiment (MEIDEX) on the space shuttle Columbia, aimed to image transient luminous events (TLEs), such as sprites, jets, and elves, from orbit. "This paper examines the precision of location and top height of mesoscale convective systems, as forecast by the Aviation Weather Center (AWC). ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |