preliminary cruise report
may 23, 1995
A.   	Cruise narrative

A.1.a  	WOCE designation:      PR24:A hydrographic section from Mindanao  
                                        SE to Indonesia
      	Additional sections     6N: A hydrographic section from Mindanao  
                                        SE to Palau
                                2N: A hydrographic section from 130 E to  
                                        134 E along 2 N
                                1N: A hydrographic section from 130 E to
                                        135 E along 1 N
                                134E: A hydrographic section from 3 N to
                                        6 14 N along 134 E
A.1.b  	Expedition designation:49XK9207/1: Section 6N
                                49XK9207/2: Sections PR24, 1N, and 2N
                                49XK9207/3: Section 134E
A.1.c  	Chief scientist:       Kei Muneyama
                                Japan Marine Science and Technology Center
                                2-15 Natsushima-cho
                                Yokosuka 237, Japan
                                Telephone: +81-468-66-0970
                                Telefax: +81-468-66-3811
                                Telemail (Omnet): JAMSTEC
	Co-Chief scientist:             John I. Pariwono, BPPT, Indonesia

A.1.d       Ship:                  R/V KAIYO
A.1.e       Ports of call:         Marakal to Marakal Palau via Bitung and
                                        Biak, Indonesia
A.1.f       Cruise dates:          6 October to 29 October 1992

A.2.     Cruise Summary Information
                by T. Kawano (11 August 1994)

A.2.a.       Geographic boundaries: 

The 6N section is extended from 6 N, 134 E  
to 6 N, 126 35 E with station spacing of 60 nm or less.   The PR24 section  
is from 6 N, 126 35 E to 2 21 N, 129 26 E and it can be divided into two  
sections, which are the northeast section and the southwest section. The 2N  
section is from 2 N, 130 E to 2 N, 134 E and the 1N section is from 1 N,  
130 E to 1 N, 135 E. We also made CTD casts along 134 E from 3 N, 134 E to  
6 14 N, 134 E.

The station interval from 6 N, 134 E to 6 N, 128 E was 60 nm and that from  
6 N, 128 E to 6 N, 126-35E was 30 nm. Then the ship went to Bitung,  
Indonesia in order to pick Indonesian scientists and a security officer up  
and we continued the observation from 5 35 N, 126 51 E to 2 N, 130 E, which  
is equivalent to PR24. During the observation of this section, we deployed 2  
moorings at 3 25 N, 127 44 E and 3 03 N, 128 17 E. After we observed section  
2N and 1N, we went to Biak, Indonesia where Indonesian scientists and the  
security officer got off the ship. We made CTD casting with 60 nm interval  
on the way to Palau (from 3 N, 134 E to 6 N, 134 E).

A.2.b       Stations occupied: We occupied 41 CTD stations and launched 63 XBTs.
  

A.2.c       Floats and drifters deployed:  None

A.2.d       Moorings deployed or recovered:  
                by T. Kawano (10 August 1994)

Two moorings consisting of 3 current meters and 6 thermometers were deployed  
between Talaud Island and Morotai Island to determine the seasonal variation  
of the Indonesian Throughflow.

In order to estimate the seasonal change of the Indonesian Throughflow  
between the Talaud Island and the Morotai Island, we deployed 2 moorings,  
which consist of 3 current meters and 6 thermometers. The mooring lines are  
shown in Fig.10.1. The instruments are listed below.

(1) 3 28 N, 127 53 E, Depth 2,237 m
Thermometer:    Sanyo-Sokki, Japan, model MTM1 and MTM2
                        MTM1 S/N 111,112,113,114
                        MTM2 S/N 29,54  
Current meter:  AANDERAA RCM5
                        S/N 8472, 64345, 64365
Acoustic Release:       Nichiyu-Giken, Japan, model L-2
                        S/N 4266-3F

(2) 3 13 N, 128 27 E, Depth 2,340 m
Thermometer:    Sanyo-Sokki, Japan, model MTM1 and MTM2
                        MTM1 S/N 115,116,117,118
                        MTM2 S/N 31, 55  
Current meter:  AANDERAA RCM5
                        S/N 8477, 64355, 81055
Acoustic Releaser:      Nichiyu-Giken, Japan, model L-2
                                S/N 4265-3E
NOTE:
     In spite of our best efforts, we could not recover these moorings  
during our next WOCE cruise executed in Feb. 1994. Details are written in  
the cruise report for PR1S and PR24 dated 28 April 1994.

A.3.     List of Principal Investigators
                by T. Kawano (10 August 1993)

TABLE 1:  List of measured parameters, sampling group responsible for each  
and the Principal Investigator for each.

Parameter               Sampling Group          Principal investigator    
CTD/Rosette             JAMSTEC                 Yuji Kashino and T. Kawano
XBT                     JAMSTEC                 Yuji Kashino and T. Kawano
Salinity                JAMSTEC                 T. Kawano
O2                      STM                     Hidetoshi Watanabe
Mooring                 STM/JAMSTEC             Hidetoshi Watanabe and  
                                                Noboru Takiwaki
A.4.     Scientific Programme and Methods

We made hydrographic observations in the southernmost Philippine Sea in  
order to understand the oceanic structure and current field of this area.  
Our interest is mainly focused on the Indonesian Throughflow and the New  
Guinea Coastal Undercurrent.  

We made XBT measurements just before each CTD cast. When the spacing of the  
CTD stations was more than 60 nm, we made XBT measurements halfway between  
the CTD stations.

A General Oceanics (GO) 12 position rosette water sampler with 5 liter  
Niskin bottles was used, and we planned to make water sample salinity  
measurements. However, our Autosal 8400B did not work well because of  
insufficient maintenance of the instrument. We also measured the dissolved  
oxygen, but the accuracy and precision of our method did not meet with the  
WOCE one-time standards. As a result we did not report these measurements.  
We deployed two moorings between Talaud Island and Morotai Island, however  
we could not recover these moorings during the next WOCE cruise done from 12  
February to 3 March 1994.  

The accuracies of CTD salinity and temperature were estimated only on the  
basis of the sensor calibration done at Seabird Electronics, Inc., and these  
measurements are probably accurate only to 0.01 PSU or less in salinity, and  
0.002 C or more in temperature. As the result of our own calibration of the  
pressure sensor, the accuracy was less than 1 dbar.
Since we do not have enough water sample data for the calibration of CTD  
data, especially temperature and conductivity data, we report uncorrected  
data.  

Results
        by Yuji Kashino (8 August 1994)


The prominent features of salinity distribution are low salinity water  
located between Mindanao Island and Morotai Island (depth: 200-400 dbar) and  
high salinity water in the southern part of the observation area (depth: 100-
300 dbar). The low salinity water (lower than 34.5 PSU) is North Pacific  
Intermediate Water (NPIW), which was also observed during WEPOCS III  
(Bingham and Lukas (1994)). The geostrophic velocity field shows that a part  
of the NPIW observed between Talaud Islands and Morotai Island comes from  
Indonesian seas. The high salinity water (higher than 35.0 PSU) is the  
Tropical Water transported by New Guinea Coastal Under Current trough the  
Vitiaz Strait (Tsuchiya et al., 1989). This water reaches 3 N-4 N on 134 E  
section and near Morotai Island. Near the north edge of this current,  
interleaving is observed.

The geostrophic velocity directions are southeastward between Mindanao  
Island and Talaud Islands and northwestward between Talaud Islands and  
Morotai Island above 500 dbar. Total geostrophic transport between Mindanao  
Island and Morotai Island is 6 Sv toward the Pacific.
We missed the volume transport of Mindanao Current because we did not take  
stations near Mindanao Island.

A.5.     Major Problems and Goals Not Achieved
                by T. Kawano (10 August 1994)

1) Rosette sampler
Our rosette sampler did not work well from Station 1 to Station 3. The  
reason was the power supply did not have enough voltage. We used a power  
transformer after Station 4.

2) Noise during CTD casts
There were two types of noise during the CTD casts. One was a shock-like  
noise and data of pressure, conductivity and temperature became meaningless,  
e.g., 9999.9. This noise occurred near surface (less than 10 m) at a few  
stations. The other type of noise was seen only in pressure data. It was  
spikelike and the data shifted abruptly 1 to 20 dbar and then became a  
normal (reasonable) value. This noise was seen several times at almost every  
station. We could not elucidate the cause of this noise.

3) Dissolved oxygen
We could not estimate the accuracy and precision of our dissolved oxygen  
data.
We did not have enough equipment for an accurate measurement of dissolved  
oxygen. Since we used nominal values of the all volumetric equipment,  
including oxygen bottles, and we did not make a blank determination of  
seawater as well as that of reagent, we guessed that our data did not meet  
with the WOCE one-time standards.  

4) Sample water salinity measurement
Although our Autosal 8400B was set to use with 50 Hz AC, we used the  
instrument with 60 Hz AC. The frequency change caused an unstable reading  
with a range of ±20 digits. It was impossible for us to standardize the  
instrument under those conditions and, consequently, we had to give up on  
accurate measurements. The accuracy and precision of our measurement might  
be within the order of 0.01 PSU.

A.6.     Other Incidents of Note
None noted.

A.7	Cruise Participants

B.       Underway Measurements

B.1	Navigation and Bathymetry
B.2	Acoustic Doppler Current Profiler
B.3	Thermosalinograph and underway dissolved oxygen, fluorometer,etc.

B.4.     Expendable bathythermograph and salinity measurements  
                by Y. Kashino (9 August1994)

We deployed T7-XBTs (to 760 m depth) at 63 stations. Data was acquired  
through the data converter every 50 msec. When this data was saved into the  
floppy disk in our NEC PC-9801F, its sampling rate decreased to several  
times per second.  

The first 10 records of data from the sea surface, and the data below 760 m,  
were neglected. The range of depth reported in XBT file is between 4 m and  
760 m. We report the XBT temperature every 1 m. We didn't calibrate the  
depth values. The temperature values of each record were calculated by the  
cubic spline method.

We employed the following formula to convert duration into depth.  
        Zx = (6.472   0.00216t) t
where Zx is depth and t is time.

B.5.     Meteorological observations  
                by T. Kawano and Y. Kashino (11 August 1994)

The southwesterly monsoon wind was dominant and the weather was mostly sunny  
during the period from 6 October to 23 October 1992. It was usual weather in  
the tropical equator. The observed wind direction, however, changed from  
southwesterly to northerly at the end of October 1992 and the weather became  
cloudy with showers.  

The air temperature showed the diurnal variation, namely high in afternoon  
up to 28 to 31 C low in evening to morning at 27 to 28 C on sunny days.  
During heavy showers the air temperature dropped to 25 to 26 C.
During the observation along section 6N, the wind speed was around 5 m/s and  
the wave height was around 1 meter. The wind speed increased to 10 - 11 m/s  
and the wave height increased to around 2 meters during the stations along  
section PR24 north of 4 N. The southwesterly monsoon wind became weak, 2-8  
m/s, at the stations in the southern part of PR24. As the ship sailed on  
section 1N and 2N, the SSW wind of 3-7 m/s was dominant and the wave height  
was below 1 meter. As the ship headed north along 134 E, the wind direction  
became northerly with velocities of 5-10 m/s, while the wave heights were  
sometimes higher than 2 meters.

C.	Hydrographic measurements

D.	Acknowledgments

E.	References

Unesco, 1983. International Oceanographic tables. Unesco Technical Papers in 
	Marine Science, No. 44.

Unesco, 1991. Processing of Oceanographic Station Data. Unesco memorgraph
	 By JPOTS editorial panel.

F.	WHPO Summary

Several data files are associated with this report.  They are the XK9207.sum, 
XK9207.hyd, XK9207.csl and *.wct files.  The XK9207.sum file contains a 
summary of the location, time, type of parameters sampled, and other pertinent
information regarding each hydrographic station.  The XK9207.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 XK9207wct.zip. The XK9207.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 XK9207.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 buoyancy
frequency (data expressed as radius/sec), and g is the local
acceleration of gravity. 

Buoyancy 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 44.

Neutral Density (GAMMA-N: KG/M3) is calculated with the program GAMMA-N
(Jackett and McDougall) version 1.3 Nov. 94.  

G.	Data Quality Evulations

