Format of clim file:
filled driver data for each site based on a nearest neighbor type 
regression of each tower to all other ChEAS towers

localmet has time step of 1 hour
localmet-2d has time step of half-daily (variable)
10yr is filled for all 10 years (1997-2007), otherwise it is filled only 
for years where flux data are measured for the site

Columns:
Location - default is 0, for Sipnet
Year
Day of Year
Hour
Length of time period (days) - hourly is 1/24
Mean air temperature (degrees C)
Mean soil temperature (degrees C)
Total Incoming PAR (mol/m2/time step)
  to convert hourly data to umol/m2/s, mutiply by 1e6/3600 (277.778)
Total Precip (mm / timestep) - *NEEDS MORE QC*
Mean VPD (Pa)
Mean VPD_soil with respect to Soil T (Pa)
Mean Vapor pressure (Pa)
Mean Windspeed (m/s)
Mean soil wetness (fraction sat) - *DATA IS SUSPECT AT MOST SITES*