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Description:
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The current meteorological surface observation network in Texas only monitors one out of every five counties . The observation sites are nominally spaced 150 -200 km apart and report hourly measurements . For this reason , the current system is incapable of providing observations at a spatial and temporal resolution to document mesoscale weather features and provide short -range forecasting . To overcome this problem , various site spacing procedures are used to propose to fill the gaps in the monitoring system .
In this study , site spacing determination procedures based on correlation level , power spectrum , and true field error variance are used to analyze the temperature , dew point temperature , wind speed and pressure parameters over Texas . Hourly observations from 126 surface observing sites located in Texas and the adjacent states with a data coverage period varying from 6 to 21 years are considered for the study . The existence of isotropic conditions over the domain is tested by examining the spatial correlation variations of the parameters . The existence of anisotropic conditions for each parameter
resulted in the search for sub -regions within the domain . Cluster analysis indicated three separate clusters for the domain . For each cluster , the spatial correlation variations are examined and spectral analysis is applied to determine the governing scales for each parameter’s variation . Error amounts in obtaining the true Fourier coefficients are analyzed ; the highest wave number that can reasonably estimated is determined for each parameter in each cluster . Finally , the error variance in determining the true field for each parameter is examined for site spacings of 200 , 150 , 100 , 50 , and 25 km for each cluster . |