Readme for CTD data Nov.30, 2005 by Yuji Kashino Sea-Bird Electronics CTD (SBE9/11) and a winch (Tsurumi Seiki Co. Ltd.) with a 10.6mm armored cable was used during the cruises. The CTD casts were usually carried out from sea surface to 1,000m depth at descent rates of 1 m/s to 1.5 m/s and a sampling rate of 24 Hz. On each cast, we stopped a CTD fish at around 10 m depth until the CTD pump could be activated in order to remove air bubbles in the T-C sensor of the CTD. Two temperature sensors, two conductivity sensors, and one dissolved oxygen sensor were installed in the CTD. We usually processed the data from primary temperature and conductivity sensors. The sensor calibrations were performed before and after cruises. Temperature and conductivity sensors were calibrated by the manufacturer (Sea-Bird Electronics Inc.), and pressure sensors by technicians of Nippon Marine Enterprise Co Ltd. or Marine Works Japan Ltd. The calibration results suggested that sensor drifts were less than the accuracy required for this project (temperature, 0.01K; salinity, 0.01PSU; pressure, 1dbar). Therefore, we do not correct sensor drift. We just removed large noise and created a 1 dbar-averaged data set. We also checked conductivity sensor performance using Autosal during the cruises. Although the dissolved oxygen sensor had been calibrated annually by the manufacturer, its data had large errors. We think that we may be able to use CTD DO data if we correct it using DO values from adequately sampled water. Therefore, we do not correct CTD DO values and just flag the non-calibrated data as questionable. Data format is almost the same as that defined in the WOCE Hydrographic Programme (WHP) considering data processing as follows: 1st line: Expedition designation (country code(49), ship code(XK), cruise/leg designation), line name and date(month/day/year). format(9x,a10,12x,a5,6x,3i2) 2nd line: Station number and the number of records. format(7x,i3,12x,i5) 3rd line: date(day/month/year), time(hour/minute) and location(latitude/longitude, N/S: North/South, E/W: East/West). format(i2,1x,a3,1x,i4,1x,i2,1x,i2,2x,i2,1x,f5.2,1x,a1,1x,i3,1x,f5.1,1x,a1) 4th line: Headers for data columns. 5th line: Units headers for data columns. Pressure:deci-bar, Temperature: degree (ITS-90), Salinity: Practical Salinity Unit, Dissolved oxygen: Milli-liter/liter 6th line: Separation 7th line-End of file: Data lines (pressure, in-situ temperature, salinity and dissolved oxygen). Pressure interval is one deci-bar.Numbers of observation are -9. Data flag are always as follows: Pressure: 2 (acceptable measurement) Temperature: 2 Salinity 2: Oxygen: 3 (questionable measurement) format(f8.1,2f8.3,f8.2) Following is a sample FORTRAN program. --------------------------------------------------------------------- c c Sample program c character expocode*10,lineid*5,NS*1,EW*2,cmonth*3,dummy*48 dimension p(5000),t(5000),s(5000),o(5000) c open(10,file='F:\TOCS\Ky0111\CTD\K0111001.CTD',status='old') c read(10,101) expocode,lineid,imo,idy,iyr 101 format(9x,a10,12x,a5,6x,3i2) write(6,201) expocode,lineid,imo,idy,iyr 201 format('EXPOCODE='a10,1x,'Line id='a5,1x,'Date=',i2,'/',i2,'/',i2) c read(10,102) istnnbr,irec 102 format(7x,i3,12x,i5) write(6,202) istnnbr,irec 202 format('Stn No.=',i3,1x,'No of records=',i5) c read(10,103) idy,cmon,iyr,ihr,imi,ilat,flat,NS,ilon,flon,EW 103 format(i2,1x,a3,1x,i4,1x,i2,1x,i2,2x,i2,1x,f5.2,1x,a1,1x,i3, @ 1x,f5.1,1x,a1) write(6,203) idy,cmon,iyr,ihr,imi,ilat,flat,NS,ilon,flon,EW 203 format('Date=',i2,'/',a3,'/',i4,1x,'Time='i2,':',i2,1x, @ 'Lat= ',i3,'-',f5.2,a1,1x,'Lon= ',i3,'-',f5.2,a1) c read(10,'(a)') dummy read(10,'(a)') dummy read(10,'(a)') dummy c do 10 n=1,irec read(10,104) p(n),t(n),s(n),o(n) 104 format(f8.1,2f8.3,f8.2) if( n.eq.1 .or. n.eq.irec ) then write(6,204) p(n),t(n),s(n),o(n) 204 format('P=',f8.1,1x,'T=',f8.3,1x,'S=',f8.3,1x,'O=',f8.2) endif 10 continue close(10) stop end