Description
Three Doppler C-band weather radars will be used for the program. The radars will (1) continuously collect information on natural cloud characteristics, (2) help direct the operations with the cloud physics aircraft, and (3) provide general information to Saudi weather forecast personnel. NCAR will implement analysis and display software systems (e.g. TITAN/CIDD/CTREC), along with possible hardware upgrades necessary for ingesting high-quality radar data. Similar efforts were required in the UAE for their network of five radars.
An essential part of the radar analysis will be to determine the number of storms occurring over the Kingdom of Saudi Arabia. This is important in order to understand (1) the number of storms that occur naturally in the various regions around Saudi Arabia, (2) the length of time that might be necessary in order to perform a later randomized experiment that would quantitatively describe the potential rainfall increase from seeding, (3) to assess the operational aircraft needs in treating these storms in a timely manner, and (4) to conduct a very preliminary estimate the overall area rainfall increases that might be possible from seeding. Using TITAN, the typical lifetimes, sizes, and intensities of rain events will be determined, in order to compare the Arabian storm climatology to those observed in other parts of the world.
The dynamical organization of storms responsible for the bulk of the rainfall will also be documented. The significant rainstorms are likely to be convective in nature (isolated storms as well as embedded), but stratiform rain also occurs. Past studies have indicated that the latter is usually not a suitable candidate for seeding. Among the convective storms, it is important to find out whether they are organized in individual convective units, or whether they often occur in organized lines. If there are a lot of line storms, then it may be necessary to adopt a different method of objectively characterizing the convective unit from what has been used in other recent seeding projects.
