Rain volume estimation over areas using satellite and radar data

The feasibility of rain volume estimation over fixed and floating areas was investigated using rapid scan satellite data following a technique recently developed with radar data, called the Area Time Integral (ATI) technique. The radar and rapid scan GOES satellite data were collected during the Cooperative Convective Precipitation Experiment (CCOPE) and North Dakota Cloud Modification Project (NDCMP). Six multicell clusters and cells were analyzed to the present time. A two-cycle oscillation emphasizing the multicell character of the clusters is demonstrated. Three clusters were selected on each day, 12 June and 2 July. The 12 June clusters occurred during the daytime, while the 2 July clusters during the nighttime. A total of 86 time steps of radar and 79 time steps of satellite images were analyzed. There were approximately 12-min time intervals between radar scans on the average

Rain volume estimation over areas using satellite and radar data

The analysis of 18 convective clusters demonstrates that the extension of the Area-Time-Integral (ATI) technique to the use of satellite data is possible. The differences of the internal structures of the radar reflectivity features, and of the satellite features, give rise to differences in estimating rain volumes by delineating area; however, by focusing upon the area integrated over the lifetime of the storm, it is suggested that some of the errors produced by the differences in the cloud geometries as viewed by radar or satellite are minimized. The results are good and future developments should consider data from different climatic regions and should allow for implementation of the technique in a general circulation model

Sur l’instabilité dynamique barocline. Le calcul de la quantité d’eau condensée prévue pour un intervalle de 24 heures dans une atmosphère barocline instable non-adiabatique

On dynamic instability developing in baroclinal models of the atmosphere. The use of baroclinal models to ascertain dynamic instability due to the interaction of mechanical and thermal factors. Determination of open atmosphere geopotential, or of surface pressure, by the consideration of eddying trends, that is conversion of potential energy into kinetic energy. Correlations between mechanical and thermal factors in the open atmosphere in south-eastern Europe for short-term weather forecasting purposes. Quantitative rainfall and wind direction forecasting.On présente une méthode de calcul des quantités d'eau condensée prévues dans les conditions d'une atmosphère barocline instable. Les mouvements verticaux calculés sont dus à l'état non-stationnaire de l'atmosphère et à la convergence dans la couche adjacente au sol. On perfectionne une méthode proposée par Batchourina et Tourketti en établissant des courbes de régression qui permettent d'évaluer les variations individuelles de la température de l'air de manière différenciée dans deux couches atmosphériques et suivant la direction de la circulation influencée ou non par des chaînes de montagnes. Il est montré que la méthode fournit des résultats satisfaisants dans la prévision des précipitations pour 24 h.Doneaud A., Besleaga N., Stoïan Rodica. Sur l’instabilité dynamique barocline. Le calcul de la quantité d’eau condensée prévue pour un intervalle de 24 heures dans une atmosphère barocline instable non-adiabatique. In: Les instabilités en hydraulique et en mécanique des fluides. Compte rendu des huitièmes journées de l'hydraulique. Lille, 8-10 juin 1964. Tome 2, 1965