TWP/SMET/C2 - Temperature Sensor Failed, Data Missing

The T/RH sensor on Nauru failed and was replaced (only the temperature sensor failed).

• Temperature maximum(temp_max)
• temp_sd
• Temperature minimum(temp_min)
• Mean Air Temperature or Hardware Error(temp_mean)

• Mean Air Temperature or Hardware Error(temp_mean)
• temp_sd
• Temperature maximum(temp_max)
• Temperature minimum(temp_min)

TWP/SMET/C2 - Upper wind sensor failed

The upper wind speed sensor failed.  Wind speeds were reported as 0 m/s and wind direction 
data was not in agreement with the lower wind sensor. Anemometer was replaced.

• up_dir_vec_avg
• up_spd_min
• up_spd_arith_avg
• up_dir_sd
• up_spd_sd
• up_spd_max
• up_spd_vec_avg

TWP/VCEIL/C2 - Power outage in I-Van resulted in Missing Data

I forgot to put in the daily report that we took the I van down yesterday to replace the 
fans in the Clary UPS. This was from 2300z on 24May03 to 0010z on 25May03. Instruments 
affected :

MPL
Ceilometer
MWR
WSI
TSI

Rex

• lon
• Third cloud base height(third_cbh)
• Second lowest cloud base height(second_cbh)
• alt
• background_light
• Backscatter(backscatter)
• receiver_sensitivity
• base_time
• status_string
• detection_status
• laser_pulse_energy
• alt_highest_signal
• filename
• laser_temperature
• range
• measurement_parameters
• status_flag
• Lowest cloud base height detected.(first_cbh)
• lat

• Raw data stream - documentation not supported

• lat
• lon
• receiver_sensitivity
• range
• sum_backscatter
• Third cloud base height(third_cbh)
• base_time
• Backscatter(backscatter)
• measurement_parameters
• tilt_angle
• laser_temperature
• laser_pulse_energy
• alt_highest_signal
• alt
• Lowest cloud base height detected.(first_cbh)
• status_string
• Vertical visibility(vertical_visibility)
• detection_status
• background_light
• Second lowest cloud base height(second_cbh)
• status_flag
• window_contamination
• time_offset
• filename

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 minimum(precip_min)
• Precipitation mean(precip_mean)
• Precipitation maximum(precip_max)
• precip_sd

TWP/SMET/C2 - Reprocess: Barometric pressure units change

Barometric pressure data during this time period is reported in hPa.  After this time, the 
data have been converted to kPa 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

TWP/SMET/C2 - Wind Speed data contain offset due to induced voltage

The marine model of the RM Young wind sensor needs twisted pair shielded cable.  The 
manufacturer did not originally supply the pigtail with twisted pair shielded cable.  Use of 
twisted pair shielded cable for the rest of the cable run to the logger was also not 
specified.  This caused an induced voltage in the wind speed line from the wind direction 
excitation.  The induced voltage varied from sensor to sensor and probably changed anytime 
the cable was replaced or parts of the wind sensor were repaired or replaced. The induced 
voltage has been seen to vary from 0.15 m/s to as much as 1.08 m/s.

• lo_spd_arith_avg
• lo_spd_min
• lo_spd_vec_avg
• up_spd_min
• up_spd_arith_avg
• lo_spd_max
• up_spd_sd
• up_spd_max
• lo_spd_sd
• up_spd_vec_avg

TWP/VCEIL/C2 - Reprocess: Incorrect serial_number and sum_backscatter fields

Attribute serial_number: In most cases, this field is not representative of the actual 
serial number of the instrument because the value did not change when an instrument changed 
locations or was replaced with a spare.
   
Variable sum_backscatter: An out-of-range condition for the "sum of detected and 
normalized backscatter" was reported as 0 instead of missing (-9999). The valid range is 0 - 
0.0999 /srad.
   
This DQR also applies to a1 level data.

• sum_backscatter