HYDROGAPHIC DATA ---------------------------------------------------------- 1. Dates and Areas CRUISE NAME; DATES ; AREA NH92-2 ; August 7, 1992 - October 5, 1992 ; A section from 48N to 15S along 175E NH93-1 ; April 13, 1993 - June 11, 1993 ; A section from 48N to equator along 175E NH93-2 ; August 7, 1993 - October 5, 1993 ; A section from 48N to 15S along 175E NH94-1 ; April 13, 1994 - June 11, 1994 ; A section from 48N to 15S along 175E NH94-2 ; August 8, 1994 - October 6, 1994 ; A range from 48N to 3S between 171E and 177E NH95-1 ; April 14, 1995 - June 12, 1995 ; A range from 35N to 36S between 143E and 163E NH95-2 ; August 7, 1995 - October 5, 1995 ; A range from 48N to 23N between 150E and 175E ---------------------------------------------------------- 2. Ship: R/V Hakurei ---------------------------------------------------------- 3. Methods for Sampling and Analysis (1) Sampling Surface samples were obtained using a polyethylene bucket under dead slow condition. Shallow samples ( between 0m and 300 m depth ), Middle samples ( between 300m and 3000 m depth ) and Deep samples ( between 3000 m and near the bottom ) were obtained using twelve 12-liter Niskin bottles attached to CTD/RMS (CTD: Sea Bird electricsCTD system SBE-911, RMS: General Oceanics Rosette Multi-Bottle Array System1015-12) when the wire was rewinded. However, samples below 300 m depth of the cruise NH92-2 were obtained using 12-liter Niskin bottles with reversing thermometers. (2) Measurements and Analysis a. Ship position Ship position was determined using GPS (Global Positioning System) or NNSS(Navy Navigator Satellite System). b. Water depth Water depth was determined using PDR (Precision Depth Recorder) and uncorrected. c. Meteorological parameters Air temperature, barometer, wind direction and wind speed was measured automatically using sensors installed on the upper deck of the vessel every 10 minutes. Those data were recorded at the start time of the sampling. Weather and sea condition were determined by visual observations based on the Beaufort scale. d. Sampling depth and water temperature Depth and temperature were determined from the CTD record just before firing the RMS. However, depth and temperature below 300 m of the cruise NH92-2 were determined using reversing thermometers equipped with Niskin bottles. e. Salinity Salinity was measured on shipboard following a double conductivity comparison method using Guildline Autosal Salinometer model 8400A. f. Dissolved oxygen Dissolved oxygen was measured on shipboard following the electric potentiometric titration method using Ag/AgCl combined electrode Rodiometer Model VIT90 ABU91, but on the cruise NH9202, following the modified Winkler method using a manual bullet. g. Phosphate Phosphate was measured on shipboard following the molybdate-ascorbic acid method using a spectrophotometer Hitachi Model U-1000. h. Silicate Silicate was measured on shipboard following the molybdate-stannic method using a continuous flow analytical system Alpkem Model RFA-300. All the silicate levels were adjusted to the SiO2. i. Nitrite Nitrite was measured on shipboard following the sulfanilamide-diazotizing method using a continuous flow analytical system Alpkem Model RFA-300. j. Nitrate and Nitrite Nitrate and Nitrite were measured on shipboard following the sulfanilamide-diazotizing method with a copper coated cadmium tube using a continuous flow analytical system Alpkem Model RFA-300. k. Total alkalinity Alkalinity was measured on shipboard following the electric potentiometric titration method with HCl using Ag/AgCl combined electrode Rodiometer Model VIT90 ABU91. l. pH pH was measured on shipboard following the electric potentiometric method using a closed-jacketed glass and a Ag/AgCl combined electrode Rodiometer Model ION85. Both NBS (National Breau of Standards) and SWS (Seawater Scale) were used. m. Total carbonate content Total carbonate content was measured on shipboard following the phosphate-helium purging method using a gaschromatograph with TCD Shimazu Model GC-14A. n. Chlorophyll-a One liter of seawater sample was sequentially filtered by 10-, 3- and 1-um Nuclepore filters and Whatman GF/F filter. Chlorophyll-a on each filter was measured by fluorometrically using Turner Designs Fluorometer Model 10-005R after extraction with dimethylformamide. Total concentration of chlorophyll-a was obtained by summing the values of four different filters. o. POC, PON 6-7 liter of seawater was filtered by a 25mm GF/F filter, which was convasted before the filtration for 4 hr. with 450C, and the filter was preserved in a freezer. POC and PON were measured with Perkin-Elmer PE2400CHN, AD-6.