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.

• MPL Scott Algorithm Cloud Base Height(CloudBaseMplScott)
• MPL Clothiaux et al. Algorithm Cloud Base Height(CloudBaseMplCloth)
• CloudBasePrecipitation
• base_time
• BLC/VCEIL Clothiaux et al. Algorithm Cloud Base Height(CloudBaseCeilometerCloth)
• MPL Campbell et al. Algorithm Cloud Base Height(CloudBaseMplCamp)
• time_offset
• BLC/VCEIL Standard Algorithm Cloud Base Height(CloudBaseCeilometerStd)

SGP/ARSCL/C1 - ARSCL Cloud Bases and Low-level reflectivities

Prior to February 4, 2000, the ARSCL data set incorporated data from the
Beaufort Laser Ceilometer as one of its inputs.  Because of the BLC's
high spatial resolution, this data was often chosen by ARSCL as the
"CloudBaseBestEstimate" for boundary layer clouds. It was subsequently
determined that the BLC cloud base was biased, with the BLC reporting
cloud base heights that are 122 meters too high.

The bias error will be corrected when the entire ARSCL data set is
reprocessed as part of release_4.  (The release version number is included
the the netCDF global comments).   This reprocessing will also include a
small correction the the MMCR near-field reflectivities.  This correction
is less than 1 dB except for hydrometers within 200 meters of the surface.

Thanks to Roger Marchand for helping bracket this problem.

• BLC/VCEIL Clothiaux et al. Algorithm Cloud Base Height(CloudBaseCeilometerCloth)
• BLC/VCEIL Standard Algorithm Cloud Base Height(CloudBaseCeilometerStd)

TWP/ARSCL/C2 - Reprocess: ARSCL CloudBasePrecipitation field incorrect

The CloudBasePrecipitation field is incorrect and has no physical meaning.  An ARSCL 
processing error occurred when the smet60s data stream format changed, causing the wrong data 
field to be used to supply precipitation measurements to the ARSCL VAP.	The error caused 
no significant degradation in other ARSCL fields, since manual quality control corrected 
any related errors.

• CloudBasePrecipitation

TWP/ARSCL/C1  - Reprocess: ARSCL CloudBasePrecipitation field incorrect

The CloudBasePrecipitation field is incorrect and has no physical meaning.  An ARSCL 
processing error occurred when the smet60s data stream format changed, causing the wrong data 
field to be used to supply precipitation measurements to the ARSCL VAP.  The error caused 
no significant degradation in other ARSCL fields, since manual quality control corrected 
any related errors.

• CloudBasePrecipitation

TWP/ARSCL/C3 - Reprocess: ARSCL CloudBasePrecipitation field incorrect

The CloudBasePrecipitation field is incorrect and has no physical meaning.  An ARSCL 
processing error occurred when the smet60s data stream format changed, causing the wrong data 
field to be used to supply precipitation measurements to the ARSCL VAP.  The error caused 
no significant degradation in other ARSCL fields, since manual quality control corrected 
any related errors.

• CloudBasePrecipitation

TWP/ARSCL/C2 - Reprocess: ARSCL CloudBasePrecipitation field incorrect

The CloudBasePrecipitation field is incorrect and has no physical meaning. 
An ARSCL processing error occurred when the smet60s data stream format
changed, causing the wrong data field to be used to supply precipitation
measurements to the ARSCL VAP.  The error caused no significant
degradation in other ARSCL fields, since manual quality control corrected
any related errors.

• CloudBasePrecipitation

SGP/ARSCL/C1 - Ceilometer not used during processing

The ceilometer was not used during processing due to a ceilometer data format change that 
ARSCL did not handle properly.  As a result, cloud boundaries in the lowest several 
kilometers may be less accurate than usual, as they are based solely on the micropulse lidar 
and millimeter cloud radar.

• BLC/VCEIL Clothiaux et al. Algorithm Cloud Base Height(CloudBaseCeilometerCloth)
• BLC/VCEIL Standard Algorithm Cloud Base Height(CloudBaseCeilometerStd)