TWP/C2/SMET Temperature spike

There was a brief -4 C spike in the temperature at approximately
21.5 Z on December 3.  This spike also showed up in the vapor pressure
which is calculated from the temperature and relative humidity.

• Mean Air Temperature or Hardware Error(temp_mean)
• Std Dev of Air Temperature(temp_sd)
• Temperature minimum(temp_min)
• Vapor pressure standard deviation(vappress_sd)
• Temperature maximum(temp_max)
• Vapor pressure mean(vappress_mean)

• Temperature maximum(temp_max)
• Vapor pressure standard deviation(vappress_sd)
• Vapor pressure mean(vappress_mean)
• Mean Air Temperature or Hardware Error(temp_mean)
• Std Dev of Air Temperature(temp_sd)
• Temperature minimum(temp_min)

TWP/SMET/C2 - Negative rainfall rates

Due to limitations of the Zeno dataloggers all voltage measurements
from the optical rain gauge (ORG) were converted to rainfall rates. 
This resulted in negative values for rain rates.  Any value below
0.10 mm/hr should be considered to be 0 mm/hr.  New dataloggers 
alleviated this problem.

• Precipitation maximum(precip_max)
• Precipitation mean(precip_mean)
• precipitation minimum(precip_min)
• Precipitation standard deviation(precip_sd)

TWP/SMET/C2 - Reprocess: Barometric Data Changed from hPa to kPa

Barometric pressure data was converted from hPa to kPa in order to standardize the 
measurement units among ARM sites and to conform to accepted standard units determined by the 
scientific community.

• Barometric Pressure(atmos_pressure)

TWP/SMET/C2 - Reprocess: Tipping bucket rain gauge added

A tipping bucket rain gauge was added to the TWP.C2 SMET suite of instruments on 20061129. 
Effective 20060926, two new variables (count and rain amount) were added to the end of 
the twpsmet60sC2.b1 datastream.  Between 9/26 and 11/29, the data for these two variables 
are filled with zeros.  Users should not use the data during this period as the zeros are 
not representative of the rain fall at the site.  When reprocessing of this datastream 
occurs these variables will be added for the 19981021-20060926 and data from 
19981021-20061129 will be filled with -9999 (missing).

• base time(base_time)