TWP/SMET/C1 - Reprocess: Skewed wind direction 1 data

Wind direction 1 data is incorrect. 
Manus SMET wind direction for Wind-1 (upper unit) was apparently skewed
from its original position as a result of checking direction calibration. 

As near as we can tell the position of the sensor was rotated clockwise
Somewhere in the range of 45-90 degrees, most likely in steps 22.5 degrees.

Data comparison performed on 3-2-00, using a small amount of data from 
this instrument.

• Raw data stream - documentation not supported

• wind1_dir_sd
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)

• Wind #1 speed vector average(wind1_spd_vec_avg)
• wind1_dir_sd
• Wind #1 direction vector average(wind1_dir_vec_avg)

TWP/SMET/C1 - Wind Direction alignment method

During RESET10 we discovered a problem with wind direction from WIND1 (upper
anemometer).  During RESET8, WIND1 was corrected by rotating the alignment
ring instead of the anemometer.  This resulted in a better agreement between
the 2 anemometers, but is not the correct way to align an anemometer. The
alignment ring was readjusted for true north and the anemometer reset in
the proper slot (the original problem).

• Raw data stream - documentation not supported

• wind1_dir_sd
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)

• Wind #1 speed vector average(wind1_spd_vec_avg)
• wind1_dir_sd
• Wind #1 direction vector average(wind1_dir_vec_avg)

TWP/C2/SMET Wind Speeds

Beginning on December 24, Anemometer #1 (there are two anemometers on
the SMET stand) occasionally reported wind speed values that were low
relative to the other sensor.  It is clear from the data that the low
reading here is the anomalous one.

• Wind #1 speed minimum(wind1_spd_min)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• wind1_dir_sd
• wind1_spd_sd
• Wind #1 speed maximum(wind1_spd_max)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Wind #1 direction vector average(wind1_dir_vec_avg)

• Raw data stream - documentation not supported

• wind1_spd_sd
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• wind1_dir_sd
• Wind #1 speed maximum(wind1_spd_max)
• Wind #1 speed minimum(wind1_spd_min)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #1 speed maximum gust(wind1_spd_max_gust)

TWP/C2/SMET Wind Speeds

Beginning on December 24, Anemometer #1 (there are two anemometers on
the SMET stand) occasionally reported wind speed values that were low
relative to the other sensor.  It is clear from the data that the low
reading here is the anomalous one.

• Wind #1 speed minimum(wind1_spd_min)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• wind1_dir_sd
• wind1_spd_sd
• Wind #1 speed maximum(wind1_spd_max)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Wind #1 direction vector average(wind1_dir_vec_avg)

• Raw data stream - documentation not supported

• wind1_spd_sd
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• wind1_dir_sd
• Wind #1 speed maximum(wind1_spd_max)
• Wind #1 speed minimum(wind1_spd_min)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #1 speed maximum gust(wind1_spd_max_gust)

TWP/C2/SMET Winds Speeds

Beginning on December 24, Anemometer #1 (there are two anemometers on
the SMET stand) occasionally reported wind speed values that were low
relative to the other sensor.  It is clear from the data that the low
reading here is the anomalous one.

• Wind #1 speed minimum(wind1_spd_min)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• wind1_dir_sd
• wind1_spd_sd
• Wind #1 speed maximum(wind1_spd_max)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Wind #1 direction vector average(wind1_dir_vec_avg)

• Raw data stream - documentation not supported

• wind1_spd_sd
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• wind1_dir_sd
• Wind #1 speed maximum(wind1_spd_max)
• Wind #1 speed minimum(wind1_spd_min)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #1 speed maximum gust(wind1_spd_max_gust)

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.

• vappress_sd
• Temperature maximum(temp_max)
• temp_sd
• Vapor pressure mean(vappress_mean)
• Temperature minimum(temp_min)
• Temperature mean(temp_mean)

• Temperature mean(temp_mean)
• temp_sd
• Vapor pressure mean(vappress_mean)
• Temperature maximum(temp_max)
• vappress_sd
• Temperature minimum(temp_min)

TWP/C2/SMET - Pressure sensitivity to rain

The pressure behaves anomalously during rain events - even very mild
ones.  Normally, the pressure undergoes a smooth semi-diurnal
oscillation with little higher frequency variability.  However, during
and shortly after rain events, the pressure signal exhibits abrupt
changes - this sort of behavior has occasionally been observed at
Manus but not with the regularity seen here.  Examples of this
behaviour occur on (date in the form YYYYMMDD):

19981212
19981215
19981216
19981217
19981223
19981224
19981225
19981230
19981231

• vappress_sd
• Vapor pressure mean(vappress_mean)
• Atmospheric pressure(atmos_pressure)

• Atmospheric pressure(atmos_pressure)
• Vapor pressure mean(vappress_mean)
• vappress_sd

TWP/SMET/C1 - Incorrect calibration for ARCS1 Wind speed

On 23 OCT 99, during Reset 8, an incorrect slope of was entered for the 
upper, windspeed1, wind speed sensor resulting in a 1% overestimate of
the wind speed.  The correct calibration was entered on 1 APR 2000 during
RESET 10.

• Raw data stream - documentation not supported

• wind1_spd_sd
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #1 speed maximum(wind1_spd_max)
• Wind #1 speed minimum(wind1_spd_min)

• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• wind1_spd_sd
• Wind #1 speed minimum(wind1_spd_min)
• Wind #1 speed maximum(wind1_spd_max)

• Raw data stream - documentation not supported

TWP/SMET/C1 - Periodic spikes in temperature and water vapor pressure

Beginning on 980212 (day #43) spikes began to occur in the surface
temperature and water vapor pressure.  These spikes occur approximately
once per hour (the spacing is very regular but occasionally an hour
is skipped).  In the one-minute averaged data, the temperature spike
lasts for only one minute and dips approximately 4-5 C below the actual
temperature.  The one-minute standard deviation is more dramatic, rising
from about 0.1 to about 35.  The one minute temperature minimum is the
most easily identifiable, each hour when the spike occurs, the minimum
is -245.84.  The vapor pressure mean jumps from about 30 to over 50 and
the standard deviation jumps from less than 1 to more than 200.  This
problem was fixed by the RESET team on 980501.

• Temperature minimum(temp_min)
• Temperature mean(temp_mean)
• vappress_sd
• Vapor pressure mean(vappress_mean)
• temp_sd
• Temperature maximum(temp_max)

• temp_sd
• vappress_sd
• Temperature mean(temp_mean)
• Vapor pressure mean(vappress_mean)
• Temperature minimum(temp_min)
• Temperature maximum(temp_max)

TWP/SMET/C1 - Elevated relative humidity

The relative humidity has been exceeding 100% with unusual regularity.
The most dramatic case occured on December 31 when the RH exceeded 100%
for 18 hours and exceeded 103.5% for 6 hours with a maximum value of
103.8%.  A PIF was submitted to propose changing this sensor. This change
occurred on August 12, 1999.

• Relative humidity mean(relh_mean)
• Relative humidity minimum(relh_min)
• relh_sd
• Relative humidity maximum(relh_max)

• Relative humidity mean(relh_mean)
• Relative humidity minimum(relh_min)
• Relative humidity maximum(relh_max)
• relh_sd

TWP/SMET/C1 - Wind speed calibration errors

Wind speed calibration factors were reversed between wind speed sensors 1 (upper) and 2 
(lower). Results in less than 1% error, but correction factors may be used.

To correct wind speed #1 (upper) add 0.03 m/s.
To correct wind speed #2 (lower) subtract 0.03 m/s.

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

• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #2 speed maximum(wind2_spd_max)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #2 speed minimum(wind2_spd_min)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• wind1_spd_sd
• Wind #1 speed minimum(wind1_spd_min)
• wind2_spd_sd
• Wind #1 speed maximum(wind1_spd_max)
• Wind #2 speed maximum gust(wind2_spd_max_gust)

TWP/SMET/C1 - precip, wind, temperature

On 10/23/01 from 4:45 to 6:45 precipitation, wind, and temperature measurements were 
directly affected by RESET14 visit activities.

• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Precipitation maximum(precip_max)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Temperature mean(temp_mean)
• Precipitation minimum(precip_min)
• Wind #1 speed minimum(wind1_spd_min)
• Wind #2 speed minimum(wind2_spd_min)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #2 speed maximum(wind2_spd_max)
• Temperature minimum(temp_min)
• wind1_spd_sd
• wind1_dir_sd
• precip_sd
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• temp_sd
• Temperature maximum(temp_max)
• Precipitation mean(precip_mean)
• wind2_dir_sd
• wind2_spd_sd
• Wind #1 speed maximum(wind1_spd_max)

• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• temp_sd
• Temperature mean(temp_mean)
• Wind #2 speed maximum(wind2_spd_max)
• Temperature minimum(temp_min)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #2 speed minimum(wind2_spd_min)
• wind2_spd_sd
• Precipitation maximum(precip_max)
• Wind #1 speed maximum(wind1_spd_max)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Precipitation mean(precip_mean)
• precip_sd
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Wind #1 speed minimum(wind1_spd_min)
• wind1_spd_sd
• wind2_dir_sd
• Temperature maximum(temp_max)
• Precipitation minimum(precip_min)
• wind1_dir_sd
• Wind #1 direction vector average(wind1_dir_vec_avg)

TWP/SMET/C2 - RH Sensor bad at Nauru

RH sensor bad from 16 Dec 2001 03 GMT to 3 Jan 2002

• relh_sd
• Relative humidity mean(relh_mean)
• Relative humidity maximum(relh_max)
• Relative humidity minimum(relh_min)

• relh_sd
• Relative humidity minimum(relh_min)
• Relative humidity mean(relh_mean)
• Relative humidity maximum(relh_max)

TWP/SMET/C1 - Sensor replacement

On 10/24/01 from 00:40 to 01:00 the T/RH probe was being replaced.

• Temperature minimum(temp_min)
• Relative humidity mean(relh_mean)
• Relative humidity minimum(relh_min)
• temp_sd
• Relative humidity maximum(relh_max)
• Temperature maximum(temp_max)
• Temperature mean(temp_mean)
• relh_sd

• temp_sd
• Temperature mean(temp_mean)
• relh_sd
• Temperature minimum(temp_min)
• Relative humidity mean(relh_mean)
• Relative humidity minimum(relh_min)
• Relative humidity maximum(relh_max)
• Temperature maximum(temp_max)

TWP/SMET/C1/C2 - Switch to new Data Header Formats not timely

On April 1, 2001 at 00:00:00 new data header with consistent variable naming conventions, 
etc were to be used for all sites, all data streams.  At the TWP sites the time of the 
movement to the new convention did not occur precisely at 00:00:00.  The following data 
files contain between 40 seconds and 20 minutes of data from 4/1/02 in the old format.  The 
delayed format change did not affect data quality in any way.

twpsmet60sC1.a1.20010401.000001.cdf
twpsmet60sC1.b1.20010401.000001.cdf
twpsmet60sC2.a1.20010401.000000.cdf
twpsmet60sC2.b1.20010401.000000.cdf

• lo_dir_vec_avg
• lo_spd_vec_avg
• up_spd_min
• up_spd_max
• Temperature mean(temp_mean)
• relh_sd
• temp_sd
• internal_voltage
• Atmospheric pressure(atmos_pressure)
• up_spd_vec_avg
• Precipitation mean(precip_mean)
• base_time
• logger_temp
• Precipitation maximum(precip_max)
• lon
• up_dir_vec_avg
• precip_sd
• lo_dir_sd
• Precipitation minimum(precip_min)
• vappress_sd
• Vapor pressure mean(vappress_mean)
• tbrg_count_total
• up_spd_arith_avg
• lat
• time_offset
• lo_spd_min
• tbrg_total
• lo_spd_max
• lo_spd_arith_avg
• up_dir_sd
• lo_spd_sd
• alt
• time
• Relative humidity mean(relh_mean)
• up_spd_sd

• up_dir_sd
• up_spd_max
• logger_temp
• time_offset
• up_spd_min
• Temperature mean(temp_mean)
• lo_spd_sd
• up_spd_sd
• tbrg_count_total
• lon
• lo_dir_vec_avg
• Precipitation maximum(precip_max)
• relh_sd
• internal_voltage
• base_time
• lo_spd_min
• Relative humidity mean(relh_mean)
• precip_sd
• tbrg_total
• temp_sd
• Vapor pressure mean(vappress_mean)
• up_spd_vec_avg
• up_dir_vec_avg
• lat
• lo_spd_max
• Atmospheric pressure(atmos_pressure)
• up_spd_arith_avg
• lo_spd_arith_avg
• lo_spd_vec_avg
• Precipitation minimum(precip_min)
• time
• alt
• vappress_sd
• Precipitation mean(precip_mean)
• lo_dir_sd

• Temperature mean(temp_mean)
• lat
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• vappress_sd
• relh_sd
• time_offset
• Vapor pressure mean(vappress_mean)
• bit_data
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• temp_sd
• internal_voltage
• Wind #2 speed maximum(wind2_spd_max)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• alt
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• external_voltage
• Wind #1 speed minimum(wind1_spd_min)
• wind1_spd_sd
• wind2_dir_sd
• Temperature maximum(temp_max)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Atmospheric pressure(atmos_pressure)
• Temperature minimum(temp_min)
• Wind #2 speed minimum(wind2_spd_min)
• lon
• Precipitation maximum(precip_max)
• Wind #1 speed maximum(wind1_spd_max)
• Precipitation mean(precip_mean)
• precip_sd
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Precipitation minimum(precip_min)
• logger_temp
• Relative humidity mean(relh_mean)
• Relative humidity maximum(relh_max)
• wind2_spd_sd
• Wind #2 direction vector average(wind2_dir_vec_avg)
• base_time
• Relative humidity minimum(relh_min)
• wind1_dir_sd

• Precipitation mean(precip_mean)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• wind2_spd_sd
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• temp_sd
• Wind #1 direction vector average(wind1_dir_vec_avg)
• precip_sd
• time_offset
• Temperature maximum(temp_max)
• internal_voltage
• Wind #2 speed minimum(wind2_spd_min)
• Atmospheric pressure(atmos_pressure)
• vappress_sd
• Relative humidity minimum(relh_min)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• lat
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Precipitation minimum(precip_min)
• Temperature minimum(temp_min)
• Wind #2 speed maximum(wind2_spd_max)
• alt
• bit_data
• wind1_spd_sd
• logger_temp
• wind1_dir_sd
• base_time
• relh_sd
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Relative humidity mean(relh_mean)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Relative humidity maximum(relh_max)
• Wind #1 speed minimum(wind1_spd_min)
• lon
• Precipitation maximum(precip_max)
• wind2_dir_sd
• Temperature mean(temp_mean)
• Wind #1 speed maximum(wind1_spd_max)
• Vapor pressure mean(vappress_mean)
• external_voltage

TWP/C2  Installation

The Nauru ARCS was installed during the period September-November
1998.  Data were being collected by the end of October, but for the
first several weeks of November, the site was undergoing considerable
change, so data from that period should be used with caution.  The
official site dedication occured on November 20.  Most on-site
activity ended following the dedication so we will consider November
20 to be the beginning of the Nauru operations.  The last members of
the installation team left Nauru on November 24.

• vappress_sd
• Wind #1 speed minimum(wind1_spd_min)
• wind1_dir_sd
• Vapor pressure mean(vappress_mean)
• wind1_spd_sd
• Temperature mean(temp_mean)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• lat
• time_offset
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• relh_sd
• temp_sd
• bit_data
• Temperature minimum(temp_min)
• internal_voltage
• Wind #2 speed minimum(wind2_spd_min)
• filename
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Atmospheric pressure(atmos_pressure)
• Precipitation mean(precip_mean)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• wind2_dir_sd
• Relative humidity maximum(relh_max)
• Relative humidity minimum(relh_min)
• Temperature maximum(temp_max)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• base_time
• logger_temp
• Precipitation maximum(precip_max)
• lon
• Wind #2 speed maximum(wind2_spd_max)
• alt
• precip_sd
• Wind #1 speed maximum(wind1_spd_max)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• external_voltage
• Precipitation minimum(precip_min)
• wind2_spd_sd
• Relative humidity mean(relh_mean)
• Wind #2 speed maximum gust(wind2_spd_max_gust)

• Raw data stream - documentation not supported

• Precipitation mean(precip_mean)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Precipitation minimum(precip_min)
• Temperature minimum(temp_min)
• Wind #2 speed maximum(wind2_spd_max)
• wind2_spd_sd
• filename
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• alt
• bit_data
• wind1_spd_sd
• logger_temp
• Wind #2 speed vector average(wind2_spd_vec_avg)
• wind1_dir_sd
• base_time
• temp_sd
• relh_sd
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Relative humidity mean(relh_mean)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Relative humidity maximum(relh_max)
• precip_sd
• time_offset
• Temperature maximum(temp_max)
• internal_voltage
• Wind #2 speed minimum(wind2_spd_min)
• Atmospheric pressure(atmos_pressure)
• Wind #1 speed minimum(wind1_spd_min)
• vappress_sd
• lon
• Precipitation maximum(precip_max)
• Relative humidity minimum(relh_min)
• wind2_dir_sd
• Temperature mean(temp_mean)
• Wind #1 speed maximum(wind1_spd_max)
• Vapor pressure mean(vappress_mean)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• lat
• external_voltage

TWP/C1 - Incorrect elevation reported in Manus Data

(From Bill Clements) We have been using 6m MSL as the station
elevation of Momote (Manus).  This was based on information
posted near the station barometer in the Momote Weather Service
Office.  It turns out that the official WMO station elevation
for Momote is 4m MSL and the upper air elevation is 5m MSL.

All Manus instruments except the sonde station are at 4m MSL.
The sonde launching station is at 5m MSL.

• alt

• alt

• alt

• alt

• alt

TWP/SMET/C3 - Lower wind direction sensor misaligned

The lower wind direction sensor (sensor #2) was misaligned and off by 15 degrees.

• wind2_dir_sd
• Wind #2 direction vector average(wind2_dir_vec_avg)

• lo_dir_sd
• lo_dir_vec_avg

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)
• Temperature mean(temp_mean)

• Temperature mean(temp_mean)
• temp_sd
• Temperature maximum(temp_max)
• Temperature minimum(temp_min)

TWP/SMET/C3 - Intermittent Pressure Sensor Failure

The Barometric Pressure sensor was intermittently failing at TWP site C3 Darwin.  At times 
there were large pressure fluctuations occurring on the order of 24 mb in a few minutes. 
 Times of large pressure fluctuations are readily apparent in the data.  At these times 
the data should be carefully analyzed before determining it's usefulness.  In between the 
periods of large fluctuations the readings appear to be stable.  It is still suggested 
that independent pressure data be obtained for comparison before use.

• Atmospheric pressure(atmos_pressure)

• Atmospheric pressure(atmos_pressure)

TWP/SMET/C1 - Reprocess: Miscalibrated windspeed2 data

A replacement anemometer (WSP2) was installed but the new anemometer calibration 
coefficients were not put into the logger. The multiplication factor was 0.09708 when it should 
have been 0.09763 (very small difference)the offset was 0.36 when it should have been 0.3 
(a difference 0.06 m/s).

• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Wind #2 speed minimum(wind2_spd_min)
• Wind #2 speed maximum(wind2_spd_max)

• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Wind #2 speed maximum(wind2_spd_max)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Wind #2 speed minimum(wind2_spd_min)

TWP/SMET/C1 - Reprocess: Lower Wind Speed incorrect

The lower wind speed sensor (sensor #2) was reporting values 10 times above the actual 
value.  During an update to the logger configuration file the calibration multiplier was 
incorrectly entered.  The multiplier inserted was .97630 when it should have been .09763.  
This caused the readings from this sensor to be incorrect.

• lo_spd_max
• lo_spd_vec_avg
• lo_spd_arith_avg
• lo_spd_min
• lo_spd_sd

• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• wind2_spd_sd
• Wind #2 speed maximum(wind2_spd_max)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Wind #2 speed minimum(wind2_spd_min)
• Wind #2 speed vector average(wind2_spd_vec_avg)

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_max
• up_spd_sd
• up_spd_vec_avg

TWP/SMET/C3 - Data reported at 15sec rather than 60s intervals

Data in these data streams should be reported at 60sec intervals, but
the logger program running during this time had the interval set to
15s.  Users will have to average the 15sec data to get 60sec data.

• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Wind #2 speed maximum(wind2_spd_max)
• wind2_spd_sd
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Precipitation mean(precip_mean)
• time_offset
• vappress_sd
• Wind #1 speed minimum(wind1_spd_min)
• wind1_dir_sd
• Temperature maximum(temp_max)
• logger_temp
• wind2_dir_sd
• Wind #2 speed vector average(wind2_spd_vec_avg)
• internal_voltage
• bit_data
• Wind #2 speed minimum(wind2_spd_min)
• Precipitation maximum(precip_max)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Atmospheric pressure(atmos_pressure)
• Relative humidity maximum(relh_max)
• Relative humidity minimum(relh_min)
• Vapor pressure mean(vappress_mean)
• temp_sd
• Temperature minimum(temp_min)
• relh_sd
• Wind #1 direction vector average(wind1_dir_vec_avg)
• external_voltage
• Precipitation minimum(precip_min)
• Temperature mean(temp_mean)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• wind1_spd_sd
• Relative humidity mean(relh_mean)
• precip_sd
• Wind #1 speed maximum(wind1_spd_max)

• lo_dir_sd
• Vapor pressure mean(vappress_mean)
• logger_temp
• up_spd_max
• up_spd_min
• precip_sd
• lo_spd_min
• temp_sd
• relh_sd
• Precipitation maximum(precip_max)
• Precipitation minimum(precip_min)
• lo_dir_vec_avg
• up_spd_sd
• lo_spd_arith_avg
• tbrg_total
• Temperature mean(temp_mean)
• Precipitation mean(precip_mean)
• up_dir_vec_avg
• tbrg_count_total
• time_offset
• Relative humidity mean(relh_mean)
• lo_spd_vec_avg
• lo_spd_sd
• Atmospheric pressure(atmos_pressure)
• up_spd_arith_avg
• lo_spd_max
• vappress_sd
• up_spd_vec_avg
• up_dir_sd
• time
• internal_voltage

TWP/SMET/C1 - Tower Lowered for Cal Activities

Tower lowered for instrument calibration

• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Relative humidity minimum(relh_min)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Precipitation maximum(precip_max)
• Relative humidity maximum(relh_max)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Temperature mean(temp_mean)
• Precipitation minimum(precip_min)
• relh_sd
• Wind #1 speed minimum(wind1_spd_min)
• Wind #2 speed minimum(wind2_spd_min)
• Wind #2 speed maximum(wind2_spd_max)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Temperature minimum(temp_min)
• vappress_sd
• Relative humidity mean(relh_mean)
• wind1_spd_sd
• wind1_dir_sd
• precip_sd
• Wind #2 speed vector average(wind2_spd_vec_avg)
• temp_sd
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Temperature maximum(temp_max)
• Precipitation mean(precip_mean)
• wind2_dir_sd
• wind2_spd_sd
• Wind #1 speed maximum(wind1_spd_max)
• Vapor pressure mean(vappress_mean)

• Raw data stream - documentation not supported

TWP/SMET/C2 - Lower wind sensor failure

The lower wind sensor failed.  Wind direction showed little or no variation, unlike the 
co-located/upper sensor.  This caused depressed wind speed values as the sensor was not 
rotating properly to orient itself parallel to the wind stream.  The sensor was replaced.

• lo_spd_arith_avg
• lo_spd_min
• lo_dir_vec_avg
• lo_spd_vec_avg
• lo_spd_max
• lo_spd_sd
• lo_dir_sd

TWP/SMET/C1 - Poor Performing Sensor

On 4/23/2004 condensation was found inside the target area of the ORG lens. A spare was 
sent and installed but did not solve the problem of high background voltage values causing 
rainrate values to be recorded during no rainfall.  Values range anywhere from 0.06 to 
0.12 mm/hr.  

A new Optical Rain Gage was installed on 01/19/2005 @ 13:30 GMT alleviating the high 
background voltage values that lead to consistent rainfall rates of around 0.11 to 0.15 mm/hr 
on a consistent basis.  

The formula used to calculate rainfall rates from the new Optical Rain Gage is:  RR 
(mm/hr) = 25(V^1.87) - 0.15.

Older model formula = 20(V^2) - 0.05

The two formulas result in comparable data.

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

TWP/SMET/C3 - Rain blocked pressure port

Atmospheric pressure values were suspect due to anomolous readings during heavy rain 
events.  Suspect blockage of port due to rainfall.  New logger and enclosure corrected problem.

• Atmospheric pressure(atmos_pressure)

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

TWP/SMET/C3 - 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.

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

TWP/SMET/C1 - RESET14 activities

RESET14 activities may have affected data in subtle ways during this
period.

• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Relative humidity maximum(relh_max)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Temperature mean(temp_mean)
• Wind #1 speed minimum(wind1_spd_min)
• Wind #2 speed maximum(wind2_spd_max)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• wind1_dir_sd
• Atmospheric pressure(atmos_pressure)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Temperature maximum(temp_max)
• wind2_dir_sd
• wind2_spd_sd
• Wind #1 speed maximum(wind1_spd_max)
• Relative humidity minimum(relh_min)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Precipitation maximum(precip_max)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Precipitation minimum(precip_min)
• relh_sd
• Wind #2 speed minimum(wind2_spd_min)
• Temperature minimum(temp_min)
• Relative humidity mean(relh_mean)
• vappress_sd
• wind1_spd_sd
• precip_sd
• Wind #2 speed vector average(wind2_spd_vec_avg)
• temp_sd
• Precipitation mean(precip_mean)
• Vapor pressure mean(vappress_mean)

• Atmospheric pressure(atmos_pressure)
• Temperature mean(temp_mean)
• Temperature minimum(temp_min)
• Wind #2 speed minimum(wind2_spd_min)
• Precipitation maximum(precip_max)
• Wind #1 speed maximum(wind1_spd_max)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Precipitation mean(precip_mean)
• precip_sd
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• vappress_sd
• relh_sd
• Vapor pressure mean(vappress_mean)
• Precipitation minimum(precip_min)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• temp_sd
• Wind #2 speed maximum(wind2_spd_max)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Relative humidity mean(relh_mean)
• Relative humidity maximum(relh_max)
• wind2_spd_sd
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Relative humidity minimum(relh_min)
• wind1_spd_sd
• Wind #1 speed minimum(wind1_spd_min)
• wind2_dir_sd
• Temperature maximum(temp_max)
• wind1_dir_sd
• Wind #1 direction vector average(wind1_dir_vec_avg)

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

TWP/SMET/C1 - 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 minimum(precip_min)
• Precipitation maximum(precip_max)
• precip_sd
• Precipitation mean(precip_mean)

TWP/SMET/C3 - Data non-representative

Tower mast was lowered for inspection.  Data during this time is non-representative.

• lo_dir_sd
• tbrg_count_total
• Vapor pressure mean(vappress_mean)
• Relative humidity mean(relh_mean)
• up_spd_max
• up_spd_min
• lo_spd_sd
• lo_spd_vec_avg
• precip_sd
• lo_spd_min
• Atmospheric pressure(atmos_pressure)
• temp_sd
• up_spd_arith_avg
• lo_spd_max
• vappress_sd
• relh_sd
• up_spd_vec_avg
• up_dir_sd
• Precipitation maximum(precip_max)
• Precipitation minimum(precip_min)
• up_spd_sd
• lo_dir_vec_avg
• lo_spd_arith_avg
• tbrg_total
• Temperature mean(temp_mean)
• Precipitation mean(precip_mean)
• up_dir_vec_avg

TWP/SMET/C2 - Upper wind direction sensor failure

The upper wind direction 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.

• up_dir_vec_avg
• up_dir_sd

TWP/SMET/C2 - Upper wind direction sensor failure

After replacement on 03/03/2005 the upper wind direction 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.

• up_dir_vec_avg
• up_dir_sd

TWP/SMET/C3 - Lower wind direction sensor failure

The lower wind direction sensor failed on 4/14 and disagrees significantly with the upper 
wind direction sensor.  The lower wind sensor reports a constant value around 0-15 
degrees since it failed.  Testing showed that excitation channel two on the logger was the 
problem.  Logger was replaced by spare.

• lo_dir_sd
• lo_dir_vec_avg

TWP/SMET/C1 - 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.  New loggers were installed 03/09/2004 @ 2243 GMT.

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

TWP/SMET/C2 - RH sensor failure

Relative humidity values were frequently over MAX value of 104% starting on 7/10/2005 
through end of period.  Sensor was replaced.

• relh_sd
• Relative humidity mean(relh_mean)

TWP/SMET/C3 - Data not representative

Tower was lowered for radiometer change and characterization. Data are not representative 
of local conditions.

• lo_dir_sd
• tbrg_count_total
• Vapor pressure mean(vappress_mean)
• Relative humidity mean(relh_mean)
• up_spd_max
• up_spd_min
• lo_spd_sd
• lo_spd_vec_avg
• precip_sd
• lo_spd_min
• Atmospheric pressure(atmos_pressure)
• temp_sd
• up_spd_arith_avg
• lo_spd_max
• vappress_sd
• relh_sd
• up_spd_vec_avg
• up_dir_sd
• Precipitation maximum(precip_max)
• Precipitation minimum(precip_min)
• up_spd_sd
• lo_dir_vec_avg
• lo_spd_arith_avg
• tbrg_total
• Temperature mean(temp_mean)
• Precipitation mean(precip_mean)
• up_dir_vec_avg

TWP/SMET/C2 - Instrument maintenance

Instrument calibration and testing were taking place for brief periods.

• vappress_sd
• lo_spd_arith_avg
• lo_dir_vec_avg
• lo_spd_vec_avg
• Vapor pressure mean(vappress_mean)
• up_spd_min
• up_dir_sd
• up_spd_max
• Temperature mean(temp_mean)
• tbrg_count_total
• Precipitation maximum(precip_max)
• up_spd_arith_avg
• lo_spd_sd
• relh_sd
• lo_spd_min
• temp_sd
• up_dir_vec_avg
• precip_sd
• Atmospheric pressure(atmos_pressure)
• lo_dir_sd
• up_spd_vec_avg
• Precipitation minimum(precip_min)
• Precipitation mean(precip_mean)
• tbrg_total
• Relative humidity mean(relh_mean)
• lo_spd_max
• up_spd_sd

TWP/SMET/C2 - ORG data incorrect

Data from the ORG was incorrect due to heavy condensation on the lens.

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

TWP/SMET/C2 - Tower down for calibration activities

Tower lowered, wind vanes spun at different frequencies, and ORG tested with electronic 
rain.

• vappress_sd
• Temperature maximum(temp_max)
• Wind #1 speed minimum(wind1_spd_min)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• wind1_dir_sd
• Vapor pressure mean(vappress_mean)
• wind1_spd_sd
• Temperature mean(temp_mean)
• Precipitation maximum(precip_max)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Wind #2 speed maximum(wind2_spd_max)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• relh_sd
• temp_sd
• Temperature minimum(temp_min)
• precip_sd
• Wind #1 speed maximum(wind1_spd_max)
• Wind #2 speed minimum(wind2_spd_min)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Precipitation mean(precip_mean)
• Precipitation minimum(precip_min)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• wind2_spd_sd
• Relative humidity mean(relh_mean)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• wind2_dir_sd
• Relative humidity maximum(relh_max)
• Relative humidity minimum(relh_min)

TWP/SMET/C3 - Upper wind sensor failure

A lightning strike destroyed the upper wind sensor.

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

TWP/SMET/C3 - RH Values Artificially High

Lightning strike caused RH readings to be higher than reasonable (130%).

• relh_sd
• Vapor pressure mean(vappress_mean)
• vappress_sd
• Relative humidity mean(relh_mean)

TWP/SMET/C3 - Instrument failure

A lightning strike caused a failure in the ORG.  Rainfall was being continually recorded.

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

TWP/SMET/C3 - ORG data noisy due to degraded ground

SMET Rain Data began to be noisy during December 2005 and the problem slowly became worse 
over time so that in February 2006 the ORG was reporting with a constant background value 
of around 0.10 mm/hr rain rate.  ORG voltage showed a near constant value above the 85mV 
threshold.  The ground for the ORG had become degraded and was lost due to corrosion.

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

TWP/SMET/C3 - Reprocessed: Lower windspeed sensor calibration error

The lower anemometer was replaced but the calibration coefficients were not changed during 
this period.  The data were reprocessed to apply the correct calibrations and the 
reprocessed data were archived in August 2008.

• lo_spd_vec_avg
• lo_spd_sd
• lo_spd_min
• lo_spd_arith_avg
• lo_spd_max

TWP/SMET/C1 - Upper wind sensor failure

The upper wind speed sensor was binding at low wind speeds.  Comparison to the lower wind 
sensor showed that the upper sensor flat-lines for long periods of time.  The upper 
anemometer was replaced.

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

TWP/SMET/C2 - Temp/RH probe failure

Temperature/RH probe failed and was replaced.

• vappress_sd
• relh_sd
• temp_sd
• Vapor pressure mean(vappress_mean)
• Relative humidity mean(relh_mean)
• Temperature mean(temp_mean)

TWP/SMET/C3 - Data not representative

The Anemometer readings were incorrect due to the tower being lowered for maintenance.

• lo_spd_sd
• lo_spd_vec_avg
• lo_spd_min
• lo_dir_sd
• up_spd_arith_avg
• lo_spd_max
• up_spd_vec_avg
• up_dir_sd
• up_spd_max
• up_spd_sd
• up_spd_min
• lo_dir_vec_avg
• lo_spd_arith_avg
• up_dir_vec_avg

TWP/SMET/C1 - 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.

• Atmospheric pressure(atmos_pressure)

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.

• Atmospheric pressure(atmos_pressure)

TWP/SMET/C3 - 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.

• Atmospheric pressure(atmos_pressure)

TWP/SMET/C1 - Reprocess: Tipping bucket rain gauge added

A tipping bucket rain gauge was added to the TWP.C1 SMET suite of instruments on 20061017. 
 Effective 20060926, two new variables (count and rain amount) were added to the end of 
the twpsmet60sC1.b1 datastream.  Between 9/26 and 10/17, 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 19961009-20060926 and data from 
19961009-20061017 will be filled with -9999 (missing).

• base_time

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/C3 - Reprocess: Tipping bucket rain gauge added

A tipping bucket rain gauge was added to the SMET suite of instruments effective 20060926. 
 Two new variables (count and rain amount) were added at the end of the twpsmet60sC1.b1 
datastream.  When reprocessing of this datastream occurs these variables will be added 
with -9999 (missing) as the value for dates prior to gauge installation.

• base_time

TWP/SMET/C2 - Barometer failure

The barometer began experiencing problems with noise resulting in incorrect data.  The 
problem becames worse over time; after 12/19/2006 @0151 GMT the barometer data is completely 
missing.  The barometer was replaced.

• Atmospheric pressure(atmos_pressure)

TWP/SMET/C3 - Barometer Data Incorrect

The barometer data was incorrect or missing due to water intrusion.

• Atmospheric pressure(atmos_pressure)

TWP/SMET/C3 - Water in enclosure

Data became erratic and unreasonable after water intrusion into the enclosure.

• relh_sd
• precip_sd
• Precipitation maximum(precip_max)
• Precipitation minimum(precip_min)
• temp_sd
• Vapor pressure mean(vappress_mean)
• Precipitation mean(precip_mean)
• Temperature mean(temp_mean)
• vappress_sd
• Relative humidity mean(relh_mean)

TWP/SMET/C1 - Upper winds failure

The upper wind instrument was inoperative resulting in constant wind direction and speed.  
A failed cable was replaced.

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

TWP/SMET/C2 - Lower windspeed sensor questionable

Lower wind speed sensor had degraded bearings.  This sensor was reporting as much as 0.4 
m/s lower values than the upper sensors when the winds were 2 m/s or below.  The sensor 
was replaced.

• lo_spd_arith_avg
• lo_spd_min
• lo_spd_vec_avg
• lo_spd_max
• lo_spd_sd

TWP/SMET/C2 - Lower Wind Sensor Direction Incorrect

Wind directions between lower and upper anemometers were displaced by approximately 45 
degrees when a new sensor was installed to replace the failing lower winde sensor.  The new 
sensor direction data incorrect.

• lo_dir_vec_avg
• lo_dir_sd

TWP/SMET/C3 - Upper wind speed artificially slow

The upper wind measurement was consistently slower by around 0.5 - 1 m/s than the lower 
wind measurement.  The bearings on the upper wind measurement were binding.

• up_spd_vec_avg
• up_spd_max
• up_spd_min
• up_spd_sd
• up_spd_arith_avg

TWP/SMET/C3 - ORG overestimated rainfall

Optical rain gauge (ORG) measured approximately 10mm higher than two co-located tipping 
bucket rain gauges and a co-located disdrometer.  The ORG is typically higher but usually 
not by an order of magnitude.

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

TWP/SMET/C2 - Lower Wind Speed Data Suspect

The lower wind speed bearings appeared to be binding at speeds below 2 m/s as it did not 
compare well with the upper wind sensor.

• lo_spd_arith_avg
• lo_spd_min
• lo_spd_vec_avg
• lo_spd_max
• lo_spd_sd

TWP/SMET/C3 - Upper Wind Sensor Data Questionable

The wind_up vs. wind_low wind directions diverged, with the differences between the two 
eventually reached 45 degrees. The Upper sensor was found to be mis-aligned and loose.

• up_spd_vec_avg
• up_spd_max
• up_spd_min
• up_spd_sd
• up_spd_arith_avg

TWP/SMET/C1 - Reprocess: ORG Data has very small rainrate values

The ORG data is collected via analog signal and not digital.  Therefore, we continuously 
collect data even when no rain is occurring.  We also capture small events such as leaves, 
large bugs, dust, etc blowing through the measurement path.  Because this discrete event 
occurs quickly the value is usually captured for 1 or 2 seconds.  This value is then 
averaged to the minute producing rainrate on the order of .009 mm/hr or less.  These values 
are not indicative of rain and should be removed from the record or summing over long 
periods can bias the climate record.  We are reprocessing the data to remove these small 
values and are adjusting the collection program to remove them before ingest.

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

TWP/SMET/C3 - Reprocess: ORG Data has very small rainrate values

The ORG data is collected via analog signal and not digital.  Therefore, we
continuously collect data even when no rain is occurring.  We also capture small events 
such as leaves, large bugs, dust, etc blowing through the measurement path.  Because this 
discrete event occurs quickly the value is usually captured for 1 or 2 seconds.  This 
value is then averaged to the minute producing rainrate on the order of .009 mm/hr or less.  

These values are not indicative of rain and should be removed from the record or summing 
over long periods can bias the climate record.  We will reprocess the data to remove these 
small values.

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

TWP/SMET/C2 - Reprocess: ORG Data has very small rainrate values

The ORG data is collected via analog signal and not digital.  Therefore, we continuously 
collect data even when no rain is occurring.  We also capture small events such as leaves, 
large bugs, dust, etc blowing through the measurement path.  Because this discrete event 
occurs quickly the value is usually captured for 1 or 2 seconds.  This value is then 
averaged to the minute producing rainrate on the order of .009 mm/hr or less.  

These values are not indicative of rain and should be removed from the record or summing 
over long periods can bias the climate record.  We will reprocess the data to remove these 
small values.

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

TWP/SMET/C3 - Lower Wind Direction Intermittently Wrong

The lower wind sensor cabling had a problem causing an intermittent connection for the 
wind direction data.

• lo_dir_sd
• lo_dir_vec_avg

TWP/SMET/C2 - ORG rainfall measurements too large

The ORG was collecting large amounts of rainfall compared to the co-located tipping bucket 
raingauge.  The cable was chewed by mice causing the wires to make contact 
intermittently mimicking rainfall.

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

TWP/SMET/C1 - ORG Precip Data Incorrect

Moisture intrusion into the sensor body allowed condensation on the lens of the ORG.  
Continual and long-term precipitation was reported during this time.

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

TWP/SMET/C3 - Upper wind speed data incorrect

Beginning on 07/08, the upper wind sensor started reporting significantly lower wind 
speeds than the lower wind sensor.  The cable connections weather proofing failed allowing 
corrosion to occur and increasing he resistance of the cables.  This in turn lowered the 
wind speeds artificially.

• up_spd_vec_avg
• up_spd_max
• up_spd_min
• up_spd_sd
• up_spd_arith_avg

TWP/SMET/C1 - Missing data

Data are missing and unrecoverable.

• up_dir_sd
• lo_spd_vec_avg
• up_spd_max
• lo_dir_vec_avg
• logger_temp
• up_dir_vec_avg
• Precipitation maximum(precip_max)
• time_offset
• up_spd_min
• Temperature mean(temp_mean)
• Precipitation minimum(precip_min)
• time
• relh_sd
• internal_voltage
• lat
• alt
• lo_spd_sd
• base_time
• lo_spd_max
• lo_spd_min
• Relative humidity mean(relh_mean)
• vappress_sd
• up_spd_sd
• tbrg_count_total
• Atmospheric pressure(atmos_pressure)
• up_spd_arith_avg
• precip_sd
• tbrg_total
• temp_sd
• Precipitation mean(precip_mean)
• lo_spd_arith_avg
• lon
• lo_dir_sd
• Vapor pressure mean(vappress_mean)
• up_spd_vec_avg

TWP/SMET/C2 - Missing data

Data are missing and unrecoverable.

• vappress_sd
• lo_spd_arith_avg
• lo_dir_vec_avg
• lo_spd_vec_avg
• Vapor pressure mean(vappress_mean)
• base_time
• up_spd_min
• up_dir_sd
• up_spd_max
• logger_temp
• Temperature mean(temp_mean)
• tbrg_count_total
• Precipitation maximum(precip_max)
• lon
• up_spd_arith_avg
• lo_spd_sd
• lat
• time_offset
• relh_sd
• lo_spd_min
• up_dir_vec_avg
• temp_sd
• alt
• internal_voltage
• precip_sd
• Atmospheric pressure(atmos_pressure)
• up_spd_vec_avg
• lo_dir_sd
• Precipitation minimum(precip_min)
• Precipitation mean(precip_mean)
• tbrg_total
• time
• Relative humidity mean(relh_mean)
• lo_spd_max
• up_spd_sd

TWP/SMET/C3 - Missing data

Data are missing and unrecoverable.

• alt
• lo_dir_sd
• lon
• base_time
• tbrg_count_total
• time_offset
• Vapor pressure mean(vappress_mean)
• Relative humidity mean(relh_mean)
• logger_temp
• up_spd_max
• up_spd_min
• lo_spd_vec_avg
• lo_spd_sd
• precip_sd
• lo_spd_min
• Atmospheric pressure(atmos_pressure)
• temp_sd
• lat
• up_spd_arith_avg
• lo_spd_max
• vappress_sd
• up_spd_vec_avg
• relh_sd
• up_dir_sd
• time
• Precipitation maximum(precip_max)
• Precipitation minimum(precip_min)
• internal_voltage
• lo_dir_vec_avg
• up_spd_sd
• lo_spd_arith_avg
• tbrg_total
• Temperature mean(temp_mean)
• Precipitation mean(precip_mean)
• up_dir_vec_avg

TWP/SMET/C1 - 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_max
• lo_spd_vec_avg
• up_spd_max
• lo_spd_arith_avg
• lo_spd_min
• up_spd_sd
• up_spd_arith_avg
• up_spd_vec_avg
• up_spd_min
• lo_spd_sd

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_max
• up_spd_sd
• lo_spd_sd
• up_spd_vec_avg

TWP/SMET/C3 - 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.

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

TWP/SMET/C2 - ORG rainrate high due to calibration.

The rainrate from the ORG was high due to calibration.  This data is not real.

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

TWP/SMET/C3 - Reprocess: Station Pressure values reported in hPa instead of kPa.

An incorrect program was entered into the datalogger.  This program did not convert the 
station pressure from hPa to kPa.  This made the values larger by a factor of 10 and caused 
the QC bit to be tripped.

• Atmospheric pressure(atmos_pressure)

TWP/SMET/C3 - Reprocess: Temperature data biased low

Due to a datalogger problem, the temperature data were biased low by 2.13 degrees C.

The data will be reprocessed.

• temp_sd
• Temperature mean(temp_mean)

TWP/SMET/C1 - Optical Rain Gage Inoperative

Beginning on 02/07/2009, the trending between the TBRG and ORG began to look poor, one 
recording precip when the other was not and vice versa.  After a while the ORG quit 
registering any precip at all.  ORG was replaced.

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

TWP/SMET/C3 - Reprocess: Temperature Biased low by 1.06 Degrees

The temperature of the SMET system was biased low by 1.06 Deg C due to a non-precision 
resistor being used int he measurement circuit.  The data will be reprocessed.  Saturation 
Vapor pressure and Vapor pressure will have to be reprocessed also.

Add 1.06 degrees to the temperature data.  

Correct Sat Vap Press using the Buck approximation:
   Es = 6.1121exp((17.502*T)/(240.97 + T) 
where T is the temperature in C.  

Correct Vapor pressure using: E = (RH*Es)/100

• temp_sd
• Vapor pressure mean(vappress_mean)
• Temperature mean(temp_mean)
• vappress_sd

TWP/SMET/C2 - Barometer data incorrect

Beginning 05/20, atmos_pressure exceeded MAX between ~21:00 and 01:00 UTC on most days.  
The inlet tube was accidentally pinched in the door of the logger enclosure artificially 
increasing the atmospheric pressure during the listed times.  Only a few hours exceeded 
max limits.

• Atmospheric pressure(atmos_pressure)

TWP/SMET/C1 - Reprocess: Barometric pressure data scaled incorrectly

The barometer data was scaled incorrectly when a new program was loaded into the 
datalogger.  The pressure data was reported as mb (hPa) instead of the standard kPa.  So, in 
essence the value was a factor of ten to large.

• Atmospheric pressure(atmos_pressure)

TWP/SMET/C2 - Induced wind speed when calm

The upper and lower wind sensors were not trending well at wind speed below 1 m/s.  Both 
sensors were showing values above 0m/s when calm.  The lightning protector was at fault 
resulting in an induced wind voltage during calm conditions.

Users should subtract any offset found (for example 0.19 m/s for upper wind speed) when 
the wind speeds are flat-lined.  The offset value was not consistent.

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

TWP/SMET/C3 - Tower Lowered for Maintenance

The tower was lowered for annual anemometer changes.  The wind data is suspect.

• lo_spd_sd
• lo_spd_vec_avg
• lo_spd_min
• lo_dir_sd
• up_spd_arith_avg
• lo_spd_max
• up_spd_vec_avg
• up_dir_sd
• up_spd_max
• up_spd_sd
• up_spd_min
• lo_dir_vec_avg
• lo_spd_arith_avg
• up_dir_vec_avg

TWP/SMET/C2 - Tower Lowered for Maintenance

Data is suspect due to the tower being lowered.

• vappress_sd
• lo_spd_arith_avg
• relh_sd
• lo_spd_min
• up_dir_vec_avg
• lo_dir_vec_avg
• temp_sd
• lo_spd_vec_avg
• Vapor pressure mean(vappress_mean)
• up_spd_min
• up_dir_sd
• up_spd_max
• Temperature mean(temp_mean)
• up_spd_vec_avg
• lo_dir_sd
• Relative humidity mean(relh_mean)
• up_spd_arith_avg
• lo_spd_max
• up_spd_sd
• lo_spd_sd

TWP/SMET/C2 - Barometer failure

The atmos_pressure values were spiking high (up to 110 kPa) from 06:00 UTC on 02/04 until 
the data went missing at 10:44 UTC on 02/06 when the barometer failed completely.

Barometer replaced 2/23.

• Atmospheric pressure(atmos_pressure)

TWP/SMET/C1 - Missing RH, Barometer, and ORG data

Atmos_pressure data suddenly went missing on 03/02 at 07:34 UTC and consequently, the 
relative humidity data flatlined. 

Furthermore, after a sudden precipitation event when the max precip rate flag was tripped 
the TBRG total has not agreed with the comparison ORG or the precip rate plot. 

A loose wire connection was fixed 3/22 restoring RH and barometer data.  A damaged cable 
was repaired 5/11 restoring ORG data.

• Precipitation minimum(precip_min)
• Relative humidity mean(relh_mean)
• relh_sd
• Atmospheric pressure(atmos_pressure)
• Precipitation maximum(precip_max)
• precip_sd
• Precipitation mean(precip_mean)

TWP/SMET/C1 - Aux (lower) wind sensor failed

The lower wind direction sensor on the C1 site was flatlining at 270 degrees throughout 
most of the daylight hours of the day. During the night the sensor appeared to be working 
fine.

• lo_spd_max
• lo_spd_vec_avg
• lo_spd_arith_avg
• lo_dir_vec_avg
• lo_spd_min
• lo_dir_sd
• lo_spd_sd

TWP/SMET/C1 - Surface pressure spike

A spike occured in the surface pressure.  The reported pressure rose as
high as 1300 hPa but returned to normal levels after 15 minutes.

• Atmospheric pressure(atmos_pressure)

Calibration interruption at TWP Nauru

Occasional calibration interuption occured while calibration SMET instruments

• logger_temp
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• time_offset
• Relative humidity maximum(relh_max)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Temperature mean(temp_mean)
• Wind #1 speed minimum(wind1_spd_min)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #2 speed maximum(wind2_spd_max)
• external_voltage
• lat
• wind1_dir_sd
• Atmospheric pressure(atmos_pressure)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Temperature maximum(temp_max)
• wind2_spd_sd
• wind2_dir_sd
• bit_data
• Wind #1 speed maximum(wind1_spd_max)
• lon
• filename
• Relative humidity minimum(relh_min)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Precipitation maximum(precip_max)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Precipitation minimum(precip_min)
• relh_sd
• internal_voltage
• Wind #2 speed minimum(wind2_spd_min)
• alt
• base_time
• Temperature minimum(temp_min)
• Relative humidity mean(relh_mean)
• vappress_sd
• wind1_spd_sd
• precip_sd
• Wind #2 speed vector average(wind2_spd_vec_avg)
• temp_sd
• Precipitation mean(precip_mean)
• Vapor pressure mean(vappress_mean)

• Raw data stream - documentation not supported

• Atmospheric pressure(atmos_pressure)
• Temperature mean(temp_mean)
• Temperature minimum(temp_min)
• Wind #2 speed minimum(wind2_spd_min)
• lon
• Precipitation maximum(precip_max)
• lat
• Wind #1 speed maximum(wind1_spd_max)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Precipitation mean(precip_mean)
• precip_sd
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• vappress_sd
• relh_sd
• time_offset
• Vapor pressure mean(vappress_mean)
• Precipitation minimum(precip_min)
• logger_temp
• bit_data
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• temp_sd
• internal_voltage
• Wind #2 speed maximum(wind2_spd_max)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Relative humidity mean(relh_mean)
• Relative humidity maximum(relh_max)
• wind2_spd_sd
• alt
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• filename
• base_time
• Wind #2 speed vector average(wind2_spd_vec_avg)
• external_voltage
• Relative humidity minimum(relh_min)
• Wind #1 speed minimum(wind1_spd_min)
• wind1_spd_sd
• wind2_dir_sd
• Temperature maximum(temp_max)
• wind1_dir_sd
• Wind #1 direction vector average(wind1_dir_vec_avg)