prelininary data report may 18, 1995 A . Cruise Narrative A.1 Highlights A.1.a WOCE Designation PR19 A.1.b EXPOCODE 49TU9210/4 A.1.c Chief Scientist Yoshisuke Tomiyama, NMO A.1.d Ship R/V Chofu Maru A.1.e Port of Call Nagasaki to Nagasaki A.1.f Cruise Dates November 8 to November 19, 1992 A.2 Cruise Summary A.2.a Geographic boundaries A.2.b Total number of stations occupied A.2.c Floats and drifters deployed A.2.d Moorings deployed or recovered A.3 List of Principal Investigators Table 1. Principal Investigators for All Measurements ------------------------------------------------------- Name Responsibility Affiliation ------------------------------------------------------- T. Tomiyama CTD,S NMO K. Kimura O2,Nutrients NMO ------------------------------------------------------- A.4 Scientific Programme and Methods Observations of PR18 were carried out as a part of the R/V Chofu Maru Cruise NC9210 Leg 1. The ship sailed from Nagasaki at 0600 UTC on 5 October 1992. By 1738 UTC on 8 October, the ship was at the first station of a section PR18. At the station PN-d', the Raytheon acoustic fathometer system broke down. After this incident, the bottom depths were the estimated value from the navigation chart or a bottom depth which is observed in the last time cruise. The observations of PR18 finished at 1711 UTC on 10 October. Water sampling on the cruise included mesurements of salinity both by CTD and water bottle samples, CTD temperature, bottle sample oxygen determination, and nutrients (nitrates, nitrites, and phosphates). A.5 Major Problems and Goals not Achieved A.6 Other Incidents of Note A.7 List of Cruise Participants Table 2. Cruise Participants --------------------------------------------------------------- Name Responsibility Affiliation --------------------------------------------------------------- Y. Tomiyama Chief Scientist, NMO CTD,S,O2 E. Moriyama CTD Hardware NMO T. Hinata CTD Software NMO T. Tashiro Watch Stander NMO T. Shiga S NMO T. Shimizu O2,Nutrients NMO J. Jifuku O2,Nutrients NMO S. Saito CTD Software NMO S. Shiraishi CTD Software NMO H. Fukushima Maritime Meteorology NMO ---------------------------------------------------------------- B. Underway Measurements B.1 navigation and bathymetry B.2 Acoustic Doppler Current Profiler (ADCP) B.3 Thermosalinograph and underway dissolved oxygen, fluorometer, etc. B.4 XBT and XCTD B.5 Meteorological observations B.6 Atmospheric chemistry C. Hydrographic Measurements 2. CTD The NBIS Mark III B CTD (1600 dbar sensor without oxygen sensor) mounted on the 12 x 1.7 Liter General Oceanics rosette multisampler frame was used for all of the vertical CTD work. The performance of the CTD was good throughout the cruise, but The multisampler was no good in leg one, because there were some mis-firings and double-tripping of the water sampling bottles. So, the rossete commander unit replaced by sub one, but this problem was not settled. Eventually this problem was caused by slippage between the stepping motor and the tripping mechanism. The CTD re- cast was carried out at the station of PN-8 and PN-7 for double tripping. At the station of PN-6, one of the Niskin bottles was broken, therefore, that repleced by another one. The CTD full sampling was started from this cruise. The details of the data collection and data processing methods are described in "CTD Full Sampling and Data Processing Method Used at Nagasaki Marine Observatory". These method were based on Millard and Yang ( 1992 ). The results of the laboratory calibration for the temperature and pressure are shown in Table 3. These calibration constants were used from this cruise. Table 3. CTD calibration constants at laboratory -------------------------------------------------------------- Temperature; linear fit Time Bias Slope Pre -Cruise 26 Sep. 1992 0.0042191 0.9999142 Pressure increasing (0-1600 dbar range); linear fit Time Bias Slope Pre -Cruise 28 Sep. 1992 -0.175173 0.9992790 Pressure decreasing (0-1600 dbar range); linear fit Time Bias Slope Pre -Cruise 28 Sep. 1992 -1.4067743 0.9999869 --------------------------------------------------------------- The conductivity scaling factor given in Table 4 is derived from a linear fit of CTD data to water sample data and were used for the final data load. The salinity determination of the water samples was with the Guildline AUTOSAL 8400A. Standard Seawarter batch of P114 was used to standardize the AUTOSAL. The precision of the salinity determination of the water samples was 0.0003 PSS derived from the standard deviation of the fifteen water samples collected from the same bottle. Table 4. The conductivity scaling factor; linear fit --------------------------------------------------------- Station No. Bias Slope -------------------------------------------------------- PN-1 - PN-9 0.008894 0.999761 --------------------------------------------------------- A temperature time lag was decided the CTD time constant dicision program, time lag was 0.288 seconds. The ITS-90 scale was used for the temperature and potential temperature. 3. Oxygen measurements The determination of dissolved oxygen was done by the modified version of the Winkler method described in "Kaiyou kansoku shishin (Manual of Oceanographic Observation)" published by the Oceanographical Society of Japan (1970). The reagent blank was not subtracted. The results of the estimation of precision are shown in Table 5. No estimation of accuracy has been made. Table 5. The precision of oxygen analises by three analysts -------------------------------------------------------------- Sample Number Average One sigma precision umol/l umol/l % -------------------------------------------------------------- Analyst A 10 210.6 0.36 0.18 Analyst B 9 210.7 0.18 0.09 Analyst C 10 209.7 0.28 0.13 --------------------------------------------------------------- 4. Nutrient analyses The nutrients analyses were done by the Technicon Auto Analyzer II described in "Kaiyou kansoku shishin (Manual of Oceanographic Observation)" published by the Oceanographical Society of Japan (1970). Sampling for nutrients followed that for dissolved oxygen on average 10-20 minutes after the casts were on deck. Samples were drawn into 10 cm3 glass, narrow mouth, screw-capped bottles. Then they were immediately introduced on the sampler tray of the Technicon Auto Analyzer II for the analysis and generally the analyses were begun within one hour after the casts were on deck. If the delays were anticipated to be more than one hour, the samples were refrigerated. Samples were refrigerated and stored up to one hour on stations PN-9,PN-8,PN-7,PN-5,PN-4' and PN-3. The precisions of the onboard Nitrate and Nitrite analyses estimated from the standard deviation of the five samples from the same working standard solution on each analysis are shown in Table 6. The precision of the onboard Phosphate analysis estimated from the standard deviation of the four samples from the same working standard solutions are also shown in Table 5. The concentrations of the working standard of nitrate, nitrite and phosphate were 40 umol/l, 2 umol/l and 3 umol/l, respectively. No estimation of accuracy have been made. Table 6. The median and the range ( in the parentheses ) of the precision of the onboard nutrients analyses. ------------------------------------------------------------------- Nitrate Nitrite Phosphate unit:% ------------------------------------------------------------------- 0.287 1.457 0.824 (0.040-2.875) (0.063-10.560) (0.106-2.947) ------------------------------------------------------------------- The concentrations in umol/kg of oxygen, nitrate, nitrite and phosphate were converted from the concentrations in umol/l using the density calculated from the room temperature and salinity of the water samples. The laboratory temperature for each station are given in Table 7 Table 7. Laboratory temperature for each station.*********** ------------------------------------------------------------- Station Temp. Station Temp. Station Temp. ------------------------------------------------------------ PN-9 26.8 PN-8 26.8 PN-7 29.5 PN-6 29.5 PN-5 24.8 PN-4' 27.8 PN-4 27.8 PN-3' 25.8 PN-3 26.2 PN-2 24.8 PN-1 24. ------------------------------------------------------------ 5. Notes for the --.SUM,--.SEA and --.CTD files The first 2 characters of the file name of --.SUM, --.SEA and --.CTD files are NC for R/V Chofu Maru of Nagasaki Marine Observatory. These characters are followed by the last two digits of year, the month and character R (R for PR18) or character S (S for PR19) for the --.SUM and --.SEA files. In addition, the leg of the cruise is appended in the file name of --.SEA files. For the -- .CTD files The characters NC are followed by the unique station number and the cast number given in the Comments. The file names of the --.SUM and --.SEA for this cruise are as follows; NC9210R.SUM, NC9210R1.SEA 5.1 --.SUM Since some of the water depth of the cast were not recorded, we leave the column of them blank. Since the surface water samplings were by a stainless steel water bucket, "Number of bottles" includes this bucket sampling. The unique station numbers given by the Japan Meteorological Agency with the cast numbers, which are used as the --.CTD files name, are given in the "Comments". 5.2 --.SEA We leave "the sample number (SAMPNO)" blank because the sample numbers are different among the salinity, oxygen and nutrients on our assignments. Since the surface water samplings were by a stainless steel water bucket, we leave the column of "The Bottle Number (BTLNBR)" at the surface layer blank. All water sample quality flags for the oxygen during this cruise were "3" because the precision did not exceed the WOCE standard of 0.1% and no estimation of accuracy has been made. 5.3 --.CTD The detail of the number of samles averaged at the pressure level, NUMBER, is described in "CTD Full Sampling and Data Processing Method Used at Nagasaki Marine Observatory". 6. GPS For examine the accuracy of the position data of the GPS systems, standard deviations were caluculated in after cruise. The position data were good throughout the cruise. The results are shown in Table 8. Table 8. Standard deviation of position data -------------------------------------------------------- Date Port Standard deviation Latitude Longitude -------------------------------------------------------- Oct. 22 Nagasaki 19.6m 26.4m -------------------------------------------------------- D. Acknowledgements E References Oceanographical Society of Japan, 1970: Kaiyou kansoku shishin (Manual of Oceanographic Observation). Ed. by the Japan Meteoro- logical Agency. (in Japanese) Aoyama,M, S.Saito, T.Kobuchi and S.Shiraishi, 1993: CTD full Sampling and Data Processing Method Used at Nagasaki Marine Observatory. (Draft) Unesco, 1983. International Oceanographic tables. Unesco Technical Papers in Marine Science, No. 44. Unesco, 1991. Processing of Oceanographic Station Data, 1991. By JPOTS editorial panel. F. WHPO Summary Several data files are associated with this report. They are the tu92104.sum, tu92104.hyd, tu92104.csl and *.wct files. The tu92104.sum file contains a summary of the location, time, type of parameters sampled, and other pertient information regarding each hydrographic station. The tu92104.hyd file contains the bottle data. The *.wct files are the ctd data for each station. The *.wct files are zipped into one file called tu92104.wct.zip. The tu92104.csl file is a listing of ctd and calculated values at standard levels. The following is a description of how the standard levels and calculated values were derived for the tu92104.csl file: Salinity, Temperature and Pressure: These three values were smoothed from the individual CTD files over the N uniformly increasing pressure levels. using the following binomial filter- t(j) = 0.25ti(j-1) + 0.5ti(j) + 0.25ti(j+1) j=2....N-1 When a pressure level is represented in the *.csl file that is not contained within the ctd values, the value was linearly interpolated to the desired level after applying the binomial filtering. Sigma-theta(SIG-TH:KG/M3), Sigma-2 (SIG-2: KG/M3), and Sigma-4(SIG-4: KG/M3): These values are calculated using the practical salinity scale (PSS-78) and the international equation of state for seawater (EOS-80) as described in the Unesco publication 44 at reference pressures of the surface for SIG-TH; 2000 dbars for Sigma-2; and 4000 dbars for Sigma-4. Gradient Potential Temperature (GRD-PT: C/DB 10-3) is calculated as the least squares slope between two levels, where the standard level is the center of the interval. The interval being the smallest of the two differences between the standard level and the two closest values. The slope is first determined using CTD temperature and then the adiabatic lapse rate is subtracted to obtain the gradient potential temperature. Equations and Fortran routines are described in Unesco publication 44. Gradient Salinity (GRD-S: 1/DB 10-3) is calculated as the least squares slope between two levels, where the standard level is the center of the standard level and the two closes values. Equations and Fortran routines are described in Unesco publication 44. Potential Vorticity (POT-V: 1/ms 10-11) is calculated as the vertical component ignoring contributions due to relative vorticity, i.e. pv=fN2/g, where f is the coriolius parameter, N is the bouyancy frequency (data expressed as radius/sec), and g is the local acceleration of gravity. Bouyancy Frequency (B-V: cph) is calculated using the adiabatic leveling method, Fofonoff (1985) and Millard, Owens and Fofonoff (1990). Equations and Fortran routines are described in Unesco publication 44. Potential Energy (PE: J/M2: 10-5) and Dynamic Height (DYN-HT: M) are calculated by integrating from 0 to the level of interest. Equations and Fortran routines are described in Unesco publication, Processing of Oceanographic station data. Neutral Density (GAMMA-N: KG/M3) is calculated with the program GAMMA-N (Jackett and McDougall) version 1.3 Nov. 94. G. Data Quality Evulation