Procedure
First, we collected hourly data
from ECONET stations in North Carolina. Overall, there are currently 37 ECONET
stations across the state; however 15 of the stations either didn't have enough
data, or had too many bogus observations. We ultimately kept the stations that
had at least 7 years of data, as that would give us enough observations to
obtain more accurate statistics. The data period that we chose was from 2003 to
2009.
We retrieved the data from the
State Climate Office's CRONOS Database and saved each file in Excel format. For
each station, we created scatter plots of solar radiation versus air
temperature, soil temperature, and relative humidity. We then calculated the
correlation between solar radiation and the other 3 parameters using Excel's
correlation function. We copied all of the correlation values into a single
Excel spreadsheet, and then converted the spreadsheet to a shapefile using
ArcCatalog. ArcCatalog is a program within ArcGIS that allows you to organize
spatial data. We then used ArcMap to display our correlations.