Document Type

Thesis

Abstract

A comparison between two Mesoscale models, Colorado State University Regional Atmospheric Model System (RAMS) version 4.4 coupled with the Land‐Ecosystem– Atmosphere Feedback Model (LEAF2) and Penn State/NCAR’s Mesoscale Model (MM5) coupled with NOAH Land Surface Model, was conducted in order to assess the sensitivity of forecasted boundary layer variables to anomalous volumetric soil moistures. The study elaborates on the findings of Quintanar et al. (2008) using the study’s experimental design as a template for our numerical model comparison. The experiments were conducted using the same synoptic events examined by Quintanar et al. (2008): June 11, June 17 and June 22, 2006. For each event, six simulations were conducted with RAMS and MM5 in which volumetric soil moisture was increase and decreased by 0.05, 0.10, and 0.15 m3m‐3. The simulations were initialized with 1x1 degree FNL‐Reanalysis data and a horizontal grid resolution of 12km. Each resulting simulation was individually analyzed. Overall, RAMS simulations presented a greater sensitivity and variability when forecasting precipitation and PBL parameters. Both models were able to capture the distribution and accumulation of precipitation with respect to NARR for the CTRL runs. However, during the sensitivity studies, RAMS fails to accurately position precipitation and other parameters such as equivalent potential temperature and vertical wind.

Advisor(s) or Committee Chair

Professor Rezaul Mahmood

Disciplines

Astrophysics and Astronomy