This paper describes MM90, a parallel regional weather model based on the Penn State/NCAR MM5. Parallelization of nite diierencing, horizontal interpolation, and nesting on distributed-memory (message-passing) computers is handled transparently using the RSL library package. Fortran90 modules, derived data types, dynamic memory allocation, pointers, and recursion are used, making the code modul...

(A) Numerical Modeling: To answer the first question, we perform realistic numerical simulations of the environment of a land-based tropical disturbance (an AEW comprised of an MCC and an MV) in the vicinity of the EH. The disturbance is a precursor to the eventual genesis of Hurricane Alberto of 2000 (Hill and Lin 2003). We use the COAMPS® model, provided by the Marine Meteorological Division ...

In this study, optimal parameter estimations are performed for both physical and computational parameters in a mesoscale meteorological model, and their impacts on the quantitative precipitation forecasting (QPF) are assessed for a heavy rainfall case occurred at the Korean Peninsula in June 2005. Experiments are carried out using the PSU/NCAR MM5 model and the genetic algorithm (GA) for two pa...

This paper provides a brief introduction to automatic diierentiation and relates it to the tangent linear model and adjoint approaches commonly used in meteorology. After a brief review of the forward and reverse mode of automatic diierentiation, the ADIFOR automatic diierentiation tool is introduced, and initial results of a sensitivity-enhanced version of the MM5 PSU/NCAR mesoscale weather mo...

In order to estimate the effect of an anthropogenic influence on the water balance in the Volta Basin, located in West Africa, joint regional climate–hydrology simulations were performed using the mesoscale meteorological model MM5 and the hydrological model WaSiM. The regional climate simulations show a decrease in rainfall at the beginning of the rainy season, an increase at the height of the...

The data from surface automatic weather stations show that in the area of the Llobregat delta (northeast of the Iberian Peninsula) we can observe greater precipitation than in nearby inland areas (Ordal, Collserola, Garraf), than on the other side of a massif located on the coast (Garraf) and than on the northern coast. This distribution of the precipitation could be explained by the formation ...

In a prior study, Su, Bretherton, and Chen used the Penn State/National Center for Atmospheric Research Mesoscale Model (MM5) to study the organization of deep convection in a nonrotating atmosphere over a horizontally uniform tropical ocean, with periodic boundary conditions and an imposed mean lifting. They found that convection could “self-aggregate” from small-scale initial noise into a lar...

Optical depth distributions (P(σ )) are a useful measure of radiatively important cirrus (Ci) inhomogeneity. Yet, the relationship between P(σ ) and underlying cloud physical processes remains unclear. In this study, we investigate the influence of homogeneous and heterogeneous freezing processes, ice particle growth and fallout, and mesoscale vertical velocity fluctuations on P(σ ) shape durin...