Vertical Correlation Functions for Temperature and Relative Humidity Errors
NAVAL RESEARCH LAB MONTEREY CA DATA ASSIMILATION SECTION
Pagination or Media Count:
This report gives the details and results of any investigation into the properties of the temperature and relative humidity errors from the Navy Operational Global Atmospheric Prediction System for a four-month period from March-June 1998. The spatial covariance data for temperature and for relative humidity was fit using eight different approximation functionsweighting methods. From these, two were chosen as giving good estimates of the parameters and variances of the prediction and observation errors and were used in further investigations. The vertical correlation between temperature errors at different levels and relative humidity errors at different levels was approximated using a combination of functional fitting and transformation of the pressure levels. The cross-covariance between temperature and relative humidity errors at various pressure levels were approximated in two ways 1 by directly computing and approximating the cross-covariance data, and 2 by approximating variance of the difference of normalized data. The latter led to more consistent results. There are numerous figures illustrating the results obtained and tables give the pertinent data.