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

• Barometric Pressure(atmos_pressure)
• Vapor pressure standard deviation(vappress_sd)
• Vapor pressure mean(vappress_mean)

• Vapor pressure standard deviation(vappress_sd)
• Vapor pressure mean(vappress_mean)
• Barometric Pressure(atmos_pressure)

TWP/SMET/C1 - C1 TWP  Wind speed calibration factor problem/ Wind1

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

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

• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Wind #1 speed standard deviation(wind1_spd_sd)
• 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 arithmetic average(wind1_spd_arith_avg)

TWP/SMET/C1 - C1 SMET Incorrect wind speed calibration factors

Wind speed calibration factors were reversed between wind speed sensors 1 and 2.  Error 
results in less than a 1% error in wind speed.  A correction factor may be used.

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

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

TWP/SMET/C2 - Processing error results in missing data field

The bit_data variable is missing from the twpsmet60sC2.b1
data from 4/1/01-10/29/01 due to a processing error.  These
data are in the queue for reprocessing at low priority.

• Bit data. See details.(bit_data)

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.

• null(Raw data stream - documentation not supported)

• Wind #1 direction standard deviation(wind1_dir_sd)
• Wind #1 speed maximum(wind1_spd_max)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Wind #1 speed standard deviation(wind1_spd_sd)
• base time(base_time)
• Logger panel temperature(logger_temp)
• Wind #2 direction standard deviation(wind2_dir_sd)
• precipitation minimum(precip_min)
• Wind #2 speed minimum(wind2_spd_min)
• Vapor pressure mean(vappress_mean)
• Battery Voltage(internal_voltage)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• Wind #1 speed minimum(wind1_spd_min)
• Temperature minimum(temp_min)
• Barometric Pressure(atmos_pressure)
• Wind #2 speed standard deviation(wind2_spd_sd)
• Vapor pressure standard deviation(vappress_sd)
• lat(lat)
• Precipitation maximum(precip_max)
• External voltage(external_voltage)
• Precipitation standard deviation(precip_sd)
• Mean Relative Humidity(relh_mean)
• Mean Air Temperature or Hardware Error(temp_mean)
• Temperature maximum(temp_max)
• lon(lon)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Bit data. See details.(bit_data)
• Time offset of tweaks from base_time(time_offset)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #2 speed maximum(wind2_spd_max)
• GPS raw data filename(filename)
• Std Dev of Air Temperature(temp_sd)
• Dummy altitude for Zeb(alt)
• Relative humidity minimum(relh_min)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Relative humidity maximum(relh_max)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• 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)
• Relative humidity minimum(relh_min)
• Dummy altitude for Zeb(alt)
• precipitation minimum(precip_min)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Wind #1 speed maximum(wind1_spd_max)
• Battery Voltage(internal_voltage)
• Std Dev of Air Temperature(temp_sd)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• base time(base_time)
• Wind #1 speed minimum(wind1_spd_min)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Mean Air Temperature or Hardware Error(temp_mean)
• Precipitation maximum(precip_max)
• Wind #2 speed maximum(wind2_spd_max)
• Wind #2 direction standard deviation(wind2_dir_sd)
• External voltage(external_voltage)
• Barometric Pressure(atmos_pressure)
• Wind #1 direction standard deviation(wind1_dir_sd)
• Wind #2 speed minimum(wind2_spd_min)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• lat(lat)
• Mean Relative Humidity(relh_mean)
• Temperature maximum(temp_max)
• GPS raw data filename(filename)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Vapor pressure standard deviation(vappress_sd)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Wind #2 speed standard deviation(wind2_spd_sd)
• lon(lon)
• Precipitation mean(precip_mean)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Logger panel temperature(logger_temp)
• Relative humidity maximum(relh_max)
• Wind #1 speed standard deviation(wind1_spd_sd)
• Time offset of tweaks from base_time(time_offset)
• Bit data. See details.(bit_data)
• Vapor pressure mean(vappress_mean)
• Temperature minimum(temp_min)

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.

• Dummy altitude for Zeb(alt)

• Dummy altitude for Zeb(alt)

• Dummy altitude for Zeb(alt)

• Dummy altitude for Zeb(alt)

• Dummy altitude for Zeb(alt)

TWP/MET/C3 - WIND DIRECTION SENSOR #2 MISALIGNED

Wind direction sensor #2 was misaligned and off by 15 degrees.

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

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

TWP/SMET/C1 - Reprocess: Wind Speed #2 incorrect

Wind Speed #2 sensor 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.

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

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

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

Data in these data streams should be reports 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.

• Vapor pressure mean(vappress_mean)
• External voltage(external_voltage)
• Temperature minimum(temp_min)
• Precipitation standard deviation(precip_sd)
• base time(base_time)
• Precipitation mean(precip_mean)
• Barometric Pressure(atmos_pressure)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #2 speed maximum(wind2_spd_max)
• Wind #2 speed standard deviation(wind2_spd_sd)
• Wind #1 speed minimum(wind1_spd_min)
• lat(lat)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Dummy altitude for Zeb(alt)
• Logger panel temperature(logger_temp)
• Std Dev of Air Temperature(temp_sd)
• Vapor pressure standard deviation(vappress_sd)
• Relative humidity maximum(relh_max)
• Mean Air Temperature or Hardware Error(temp_mean)
• lon(lon)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• Mean Relative Humidity(relh_mean)
• Time offset of tweaks from base_time(time_offset)
• Relative humidity minimum(relh_min)
• Wind #2 direction standard deviation(wind2_dir_sd)
• Bit data. See details.(bit_data)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Wind #1 speed standard deviation(wind1_spd_sd)
• Wind #2 speed minimum(wind2_spd_min)
• Battery Voltage(internal_voltage)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Temperature maximum(temp_max)
• precipitation minimum(precip_min)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Wind #1 speed maximum(wind1_spd_max)
• Precipitation maximum(precip_max)
• Wind #1 direction standard deviation(wind1_dir_sd)
• Wind #2 speed maximum gust(wind2_spd_max_gust)

• Time offset of tweaks from base_time(time_offset)
• Precipitation maximum(precip_max)
• Battery Voltage(internal_voltage)
• Wind #1 speed minimum(wind1_spd_min)
• Wind #2 speed maximum(wind2_spd_max)
• Wind #1 direction standard deviation(wind1_dir_sd)
• Wind #2 speed minimum(wind2_spd_min)
• Wind #1 speed maximum(wind1_spd_max)
• Mean Air Temperature or Hardware Error(temp_mean)
• Temperature maximum(temp_max)
• Barometric Pressure(atmos_pressure)
• Relative humidity maximum(relh_max)
• Mean Relative Humidity(relh_mean)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #1 speed standard deviation(wind1_spd_sd)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• Relative humidity minimum(relh_min)
• Bit data. See details.(bit_data)
• Temperature minimum(temp_min)
• Dummy altitude for Zeb(alt)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Precipitation standard deviation(precip_sd)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• lon(lon)
• Wind #2 direction standard deviation(wind2_dir_sd)
• Wind #2 speed standard deviation(wind2_spd_sd)
• External voltage(external_voltage)
• lat(lat)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Logger panel temperature(logger_temp)
• precipitation minimum(precip_min)
• Vapor pressure mean(vappress_mean)
• Vapor pressure standard deviation(vappress_sd)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Precipitation mean(precip_mean)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• base time(base_time)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Std Dev of Air Temperature(temp_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 mean(precip_mean)
• Precipitation maximum(precip_max)
• Precipitation standard deviation(precip_sd)
• precipitation minimum(precip_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 - 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 standard deviation(precip_sd)
• precipitation minimum(precip_min)
• Precipitation mean(precip_mean)
• Precipitation maximum(precip_max)

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.

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

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.

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

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.

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

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

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.

• Barometric 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.

• Barometric 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(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(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(base_time)