Type
Text
Type
Thesis
Advisor
Hameed, Sultan | Colle, Brian A | Khairoutdinov, Marat.
Date
2014-12-01
Keywords
Atmospheric sciences | marine atmospheric boundary layer, planetary boundary layer, WRF
Department
Department of Marine and Atmospheric Science.
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/76214
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
Winds, temperatures and moisture in the planetary boundary layer (PBL) are often difficult for operational models to predict given the relatively sparse observations and that most model PBL parameterizations were developed over inland locations. Coastal marine layer forecasts are important for the forecasting of severe storms and wind energy resources in the highly populated coastal marine environment of the Northeast U.S. (NEUS). Mesoscale models are known to have large biases in wind speeds and temperatures at these lower levels over coastal waters. The goal of this project is to evaluate the performance of six PBL schemes in the Weather Research and Forecasting (WRF-ARW) model version 3.4.1 in the coastal marine environment of the NEUS. This study region, stretching from the south shore of Long Island out to Cape Cod is an ideal location for an offshore wind energy grid based on such factors as regional energy demand, water depth, and available wind resource. Verification of six WRF PBL schemes (two non-local, first-order schemes and four local, TKE-order schemes) was performed using a dataset of observations at multiple levels from the Cape Wind tower in Nantucket Sound from 2003 to 2011, as well as surrounding NDBC and ASOS stations. A series of 30-hour WRF runs were conducted for 90 randomly selected days between 2003 and 2011, with initial and boundary conditions supplied by the North American Regional Reanalysis (NARR). All schemes generally displayed negative wind speed biases over the water. The cool season displayed the largest negative biases as well as a shear profile indicative of an over-mixed boundary layer. It is hypothesized that errors in the model SST field in Nantucket Sound aided in the too-stable (unstable) model MABL structures during the warm (cool) seasons and the resultant under-mixed (over-mixed) wind shear profiles. Additional model verification from three Long-EZ aircraft flights during the Improving the Mapping and Prediction of Offshore Wind Resources (IMPOWR) field campaign during strong southwesterly flow and a developing low-level jet (LLJ) supported the hypotheses. WRF simulations show that most schemes underestimated the height and magnitude of the LLJ, while overestimating the static stability below the LLJ in the vicinity of Nantucket Sound. A warmer SST field was found to improve the near-surface thermal and moisture profiles. Model runs were forced with a variety of analyses, and it was found that even for long simulations the results were more sensitive to the boundary conditions than to the PBL schemes. | 156 pages
Recommended Citation
Sienkiewicz, Matthew Joseph, "Evaluation of WRF Planetary Boundary Layer Schemes over the Coastal Waters of Southern New England" (2014). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 2151.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/2151