Dissertação
Sensibilidade às parametrizações físicas do WRF nas previsões dos parâmetros atmosféricos em shetland do sul e deception
Fecha
2013-02-05Registro en:
COMIN, Alcimoni Nelci. WRF SENSITIVITY TO THE PHYSICAL PARAMETERIZATIONS IN
THE FORECASTS OF ATMOSPHERIC PARAMETERS AT THE
SOUTH SHETLAND AND DECEPTION. 2013. 72 f. Dissertação (Mestrado em Geociências) - Universidade Federal de Santa Maria, Santa Maria, 2013.
Autor
Comin, Alcimoni Nelci
Institución
Resumen
The Weather Research and Forecasting model (WRF) was executed with high resolution and
three nested grids of 12 km, 3 km and 1 km in the South Shetland and particularly in
Deception Island s bay, during the period from 5 to 23 February 2011 at Operation Antarctica
29. Data were obtained in situ by Polar Ship Almirante Maximiano from Brazilian Navy, with
a frequency of 1 h. The measured variables are pressure, temperature, dew point temperature,
wind speed and direction. The model lateral and boundary conditions were data from NCEP
global model, with a horizontal resolution of 1o and updated every 6 hours. Two domain sizes
have been tested for the innermost grid, one with 127 and the other with 187 points in each
horizontal direction. Besides, two physical configurations have been tested, with the main
differences being snow microphysics and soil thermal diffusion. Pressure was the variable
best represented by the model, as it is the most dependent on large scale meteorological
patterns having only small dependence on the microscale. The wind direction and speed at 10
meters from the surface were also accurate, except when there were sudden fluctuations in
wind speed and direction influenced by the topography, in which case there has been an
underestimation of the speed. Thermodynamic variables have been very poorly represented by
the small inner domain, but improved appreciably when it was expanded. The simulated
temperature has an average daily cycle less intense than observed and the underestimation
increases in warmer temperatures, probably caused by snow packets in the border areas. The
dew point temperature daily average cycle followed the observations. Some observed and
simulated patterns in circulation are briefly discussed. Finally, a simulation for a 13-day
period during which there were in situ measurements at the Deception Island are presented,
showing a good performance when compared to the observations.