Jesse Enloe and Shawn R. Smith
World Ocean Circulation Experiment (WOCE)
Surface Meteorological Data Assembly Center
Center for Ocean Atmospheric Prediction Studies
Florida State University
May 13, 1999
Report WOCEMET 99-02
Version 1.0
Introduction:
This report summarizes the quality of surface meteorological data collected by the research vessel Akademik Shuleykin (identifier: UBNZ) automated weather system (AWS) on one WOCE cruise beginning 22 February 1992 and ending on 30 April 1992. The data were provided to the Florida State University Data Assembly Center (DAC) in electronic format by S. Gulev and were converted to standard DAC netCDF format. The data were then processed using an automated screening program, which adds quality control flags to the data, highlighting potential problems. Finally, the Data Quality Evaluator (DQE) reviewed the data and current flags, whereby flags were added, removed, or modified according to the judgement of the DQE and other DAC personnel. Details of the WOCE quality control procedures can be found in Smith et al. (1996). The data quality control report summarizes the flags for the Akademik Shuleykin AWS surface meteorological data, including those added by both the preprocessor and the DQE.
Statistical Information:
The Akademik Shuleykin AWS data are expected
to include observations taken hourly. Values for the following variables
were collected:
Time | (TIME) |
Latitude | (LAT) |
Longitude | (LON) |
Platform Course | (PL_CRS) |
Platform Speed | (PL_SPD) |
Earth Relative Wind Direction | (DIR) |
Earth Relative Wind Speed | (SPD) |
Atmospheric Pressure | (P) |
Temperature | (T) |
Sea Temperature | (TS) |
Dewpoint Temperature | (TD) |
Relative Humidity | (RH) |
Atmospheric Radiation | (RAD) |
Details of the cruise are listed in Table 1 and include
cruise dates, number of records, number of values, number of flags, and
total percentage of data flagged. A total of 14,378 values are evaluated
with 465 flags added by both the preprocessor and the DQE resulting in
a total of 3.23% of the values being flagged.
Table 1: Statistical Cruise Information
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Summary:
The AWS data from the Akademic Shuleykin proves to be of very good
quality. Six F flags were assessed to the latitude and longitude at values
that indicated unrealistic platform velocity (>15m/s) determined by platform
position data. The pressure data showed a drop in pressure of approximately
20 mb in an hour's time, followed immediately by a rise in pressure of
approximately 20 mb, also in an hour's time. This value was flagged a spike
by the DQE as it had no other meteorological data supporting such an occurrence.
A spike was also assessed to the dewpoint temperature as the data indicated
an increase and decrease of approximately 15 degrees Celsius inside of
two hours, also with no supporting meteorological evidence. The sea temperature
was flagged 220 times with the B flag and it should be noted that these
values were anomalously low given the climatology for this region. The
bounds flag was left on to indicate where the sea surface temperatures
fell below freezing. Also worthy of mention are the R flags which indicate
values that were interpolated by the data provider. These interpolated
values were found to be of good quality. The distribution of these flags
assessed by the preprocessor and the DQE is detailed in Table 2.
Table 2: Number of Flags and Percentage Flagged for Each Variable
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TIME LAT LON PL_CRS PL_SPD DIR SPD P T TS TD RH RAD |
4 220 10
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37
37
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6 6
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10 10 17 17 10 10 49
10 10 |
1
1
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0 6 6 10 10 17 17 11 51 269 48 10 10 |
0.00 0.54 0.54 0.90 0.90 1.54 1.54 0.99 4.61 24.32 4.34 0.90 0.90 |
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References:
Smith, S.R., C. Harvey, and Legler, D.M., 1996: Handbook of Quality Control Procedures
and Methods for Surface Meteorology Data. WOCE Report No. 141/96, Report WOCEMET
96-1, Center for Ocean-Atmospheric Prediction Studies, Florida State University,