TITLE: INDOEX: Maldives KCO Meteorology Surface Observations Daily Means (Lobert) Contact/Author: J.M. Lobert Center for Clouds, Chemistry and Climate Scripps Institution of Oceanography University of California, San Diego 9500 Gilman Drive La Jolla, CA 92093-0221 USA Email: jlobert@ucsd.edu; j.lobert@bigfoot.com Telephone: +1 858 822 0297 Fax: +1 858 534 4922 URL: http://www-indoex.ucsd.edu/observatory/ http://www-c4.ucsd.edu/ OR V. Ramanathan Center for Clouds, Chemistry and Climate Scripps Institution of Oceanography University of California, San Diego 9500 Gilman Drive La Jolla, CA 92093-0221 USA Email: ram@fiji.ucsd.edu Telephone: +1 858 534 8815 Fax: +1 858 822 1632 URL: http://www-indoex.ucsd.edu/observatory/ http://www-c4.ucsd.edu/ 1.0 DATA SET OVERVIEW: The data set contains daily means for meteorological data (wind speed, wind direction, barometric pressure, air temperature, relative humidity and rainfall) collected at the Kaashidhoo Climate Observatory (KCO) during the INDOEX IFP January to March 1999. Data coverage is (inclusive) 01 January 1999 to 31 March 1999. KCO is located at 4.9664 degrees N and 73.4657 degrees E, the instruments were mounted about 14 m above sea level (mean elevation of the site is about 0.5-1.0 m) on the top of the observation tower, except for the rain gauge, which was mounted on top of the roof of the observatory, about 6 m above sea level. KCO local time is UT + 5 hours. For website info, see authors. 2.0 INSTRUMENT DESCRIPTION: A standard suite of meteorological instruments was used: Handar sonic anemometer, model 425A; R.M. Young model 61201 pressure sensor, model 41002 temperature/RH sensor, model 52202 tipping bucket rain gauge. Calibration of the instruments was carried out at R.M. Young and Handar before and after the INDOEX campaign. For a more detailed description of these instruments and associated data, see Lobert et al. (2001) or contact the authors. 3.0 DATA COLLECTION AND PROCESSING: Instruments ran continuously and data were collected as 10-second means (cumulative for rain). Data were then averaged into daily means (the number and statistics of 10-second data points per average point depends on the individual instrument's performance and was not included in these datasets). Higher resolution data (10 second, raw data means) are available upon request from the authors. Data between February 1998 and February 2000 are also available upon request. Wind direction was averaged using the polar coordinates of the raw data signal (a simple mean would give erroneous results when averaging data around northerly directions). Wind speed was not considered, as the provided means are short time intervals. For longer-term intervals or air mass movement studies, the wind speed needs to be considered when averaging wind direction. 4.0 DATA FORMAT: All files are in plain, tab-delimited ASCII text. Headers as they appear in the file: DateTimeSpread DOY1999 WndSpd WndDir Pressure AirTmp RelHum Rain decimal decimal m/s degrees hPa degC % mm/hour 36161.02083 1.02083 6.7 37.4 1008.6 27.5 83.7 0.1 Header explanation: "DateTimeSpread" is the Date and Time (Universal time) in spreadsheet format, noon of 01 January is 36161.5. "DOY1999" is the decimal day of year 1999, noon of 01 January is 1.5 WndSpd is the wind speed in meters per second WndDir is the wind direction in degrees (0=360=north) Pressure is the barometric pressure in hPa = mbar AirTmp is the ambient, dry air temperature in degrees Celsius RelHum is the relative humidity in percent Rain is the cumulative rain precipitation in millimeters per time interval (10 minutes, hour, day) Missing data values were replaced with the string "NAN" meaning "not a number" 5.0 DATA REMARKS: Except for smaller data gaps due to instrument or computer malfunctions, the following significant gaps exist: No wind data are available between 13. January and 28. January 1999 due to a malfunction of the wind sensor cable. No pressure data are available between 03 January and 04 February and after 29. March due to a malfunction of the pressure sensor. Missing data values were replaced with the string "NAN" meaning "not a number" 6.0 REFERENCES: 1) J.M. Lobert, V. Ramanathan, J. Prospero, A. Majeed, Kaashidhoo Climate Observatory (KCO): A new site for observing long-term changes in the tropical Indian Ocean, in preparation for JGR, INDOEX special issue (2001).