Charles Darwin Multimet Data Quality Control Report
Cruises: AR_12_/01
              AR_12_/02


Daniel M. Gilmore and Shawn Smith



World Ocean Circulation Experiment(WOCE)


Surface Meteorological Data Assembly Center
Center for Ocean Atmospheric Prediction Studies
The Florida State University

August 28, 1996

Report WOCEMET 96-10

Version 1.0


Introduction:

The data referenced in this report were collected from the research vessel Charles Darwin (call sign: GDLS; data provider: British Oceanographic Data Center/R. Pollard) Multimet automated data collection system from 2 different cruises. The data were recieved in electronic format and converted to a standard FSU format. Then they were preprocessed using an automated data checking program. Next a visual inspection was completed by a Data Quality Evaluator who reviewed, modified and added appropriate quality control (QC) flags to the data. Details of the WOCE QC can be found in Smith et al (1996). The data quality control report summarizes the flags for the Charles Darwin data, including those added by both the preprocessor and the analyst.


Statistical Information:

The data from the Charles Darwin were expected to include observations every minute from 2 cruises. The start and end dates, the number of observations, and the number and percentage of non-Z flags for each cruise is given in table 1. Time (TIME), latitude (LAT), longitude (LON), earth relative wind direction

Table 1: List of dates and number of records and flags for each of the cruises

CTCDatesNumber of RecordsNumber of ValuesNumber of FlagsPercentage Flagged
AR_12_/0104/25/91-05/15/9129,669356,0283,4150.96
AR_12_/0205/18/91-06/08/9130,662367,9447000.19


(DIR), earth relative wind speed (SPD), sea temperature (TS), air temperature (T), wet-bulb temperature (TW), longwave atmospheric radiation (RAD), shortwave atmospheric radiation (RAD2), and photosynthetically active radiation (RAD3) were quality controlled. A total of 663,641 values were checked and 4115 flags were added resulting in 0.62 percent of the data being flagged. The distribution, including percentages flagged for each variable sorted by type is detailed in table 2.

Table 2: Percentage of Flags Assigned by Flag Type and Variable

VariableData out of BoundsErroneous DataCaution /Suspect DataLand ErrorQSpikeTotal Number of FlagsPercentage of Variables Flagged
TIME      00.00
LAT   46  460.08
LON   46  460.08
DIR  29  7360.06
SPD  29  1201490.25
TS      00.00
T      00.00
Tw      00.00
RAD35543322   33805.60
RAD2    25242870.48
RAD3 171    1710.28
Totals:3522533809225213141150.62
Percentage of Flags Used0.010.030.510.010.040.020.62 



Summary:

A: Summary of significant problems

The only major problem with the data is that on 04/27/91, 04/28/91, and 04/29/91 RAD shows no indication of a diurnal wave pattern one would expect with longwave radiation. However, there is no indication of malfunction or any other problems that could account for the data pattern. Consequently, a total of 3258 "K" flags were added to RAD over the 3 day period.



Figure 1(Typical Day)


Figure 2(Suspect Data)

B: Other cautionary flags: