TWP/SMET/C2 - All data missing due to logger change

All data are missing at this site during this time period due to collection system, logger 
and enclosure change.  Data resumed after change.

• Relative humidity mean(relh_mean)
• Wind #1 direction standard deviation(wind1_dir_sd)
• Mean Air Temperature or Hardware Error(temp_mean)
• Wind #1 speed maximum(wind1_spd_max)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Wind #1 speed standard deviation(wind1_spd_sd)
• Time offset from base_time(base_time)
• Max Temperature at lowest Model Level- 1 hr(temp_max)
• east longitude for all the input platforms.(lon)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Internal Logger Temperature(logger_temp)
• Bit data. See details.(bit_data)
• Time offset of tweaks from base_time(time_offset)
• Wind #2 direction standard deviation(wind2_dir_sd)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• precipitation minimum(precip_min)
• Wind #2 speed minimum(wind2_spd_min)
• Vapor pressure mean(vappress_mean)
• Internal voltage(internal_voltage)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• Wind #2 speed maximum(wind2_spd_max)
• Wind #1 speed minimum(wind1_spd_min)
• GPS raw data filename(filename)
• Temperature standard deviation(temp_sd)
• Min Temperature at lowest Model Level- 1 hr(temp_min)
• Atmospheric pressure(atmos_pressure)
• altitude above sea levelaltunits(alt)
• Relative humidity minimum(relh_min)
• Wind #2 speed standard deviation(wind2_spd_sd)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Vapor pressure standard deviation(vappress_sd)
• north latitude for all the input platforms.(lat)
• Relative humidity maximum(relh_max)
• Precipitation maximum(precip_max)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• External voltage(external_voltage)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Precipitation mean(precip_mean)
• Precipitation standard deviation(precip_sd)

TWP/SMET/C2 - connection and timing issues with new logger

Atmospheric pressure data are intermittent during this time period due to connection 
problems and program timing issues with new logger installation.  Data resumed normal 
operations after this time period.

• Atmospheric pressure(atmos_pressure)

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 - Incorrect rainrate equation used.

There are two different Optical Raingages in use at the TWP sites.  The incorrect equation 
was used at this site.  The incorrect equation is (25*(V^1.87)) - 0.15.
The correct equation is (20*(V^2)) - 0.05.  The correct equation was installed.

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

TWP/SMET/C2 - Instrument failure

Upper wind sensor failed. Wind direction was reported at a near constant value of 69 
degrees and was significantly different than the lower wind sensor's direction values. Sensor 
replaced.

• Wind #1 direction standard deviation(wind1_dir_sd)
• Wind #1 direction vector average(wind1_dir_vec_avg)

TWP/SMET/C2 - Upper wind sensor failure

After replacement on 03/03/2005 the upper wind sensor began reporting erroneous values 
again on 03/09/2005 becoming very apparent after 03/17/2005.  Wind speed data appears 
reasonable but the wind direction data do not agree well with the lower wind sensor.

• Wind #1 direction standard deviation(wind1_dir_sd)
• Wind #1 direction vector average(wind1_dir_vec_avg)

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.

• Atmospheric 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).

• Time offset from base_time(base_time)