preliminary report
may 18, 1995
A. Cruise Narrative
A.1 Highlights
A.1.a WOCE designation PR21
A.1.b EXPOCODE 21OR266/2
A.1.c Chief Scientist: Cho-Teng Liu
Institute of Oceanography
National Taiwan University
Taipei POB 23-13
Taiwan, ROC 10764
e-mail: Ctliu@ccms.ntu.edu.tu
A.1.d Ship Name: R/V Ocean Researcher I
A.1.e Ports of call: Leg 1: Kaohsiung to Manila
Leg 2: Manila to Kaohsiung
A.1.f Cruise Dates: Leg 1: 1990/12/16-21, southbound
Leg 2: 1990/12/26-30, northbound
A.2 Cruise Summary
A.2.a Geographic boundaries
A.2.b Total number of stations occupied
There was no water sample collected
11 CTD stations
A.2.c Floats and drifters deployed
None
A.2.d Moorings deployed or recovered
None
A.3 List of Principal Investigators
Table 1: List of Prinicipal Investigators
Name Responsibility Institution*
-------------------------------------------------------------------
LIU, Cho-Teng Calibration, processing and NTU
interpretation of CTD data
PAI, Su-Cheng collection, analysis and NTU
interpretation of water
sample data
CHEN, Chen-Tung Arthur developing skills for NSYSU
collecting C-14 samples for
one-time survey
JACINTO, Gil Interpretation of chemistry UP
data, jointly with S-C PAI
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*See Table 2 for list of Institutions
Table 2: List of Institutions
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Abbreviation Institutions
----------------------------------------------------------------------
NTU National Taiwan University
Taipei, Taiwan, ROC 10764
NSYSU National Sun Yat-sen University
Kaohsiung, Taiwan, ROC
UP University of the Philippines
Quezon City, RP
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A.4 Scientific Programme and Methods
This cruise was carried out jointly by oceanographers from the Republic
of China in Taiwan and from the Republic of the Philippines. After a simple
ceremony for the start of Sino-Filipino Cooperative WOCE Program, R/V Ocean
Researcher 1 left Kaohsiung Harbor at the noon of December 16, 1990. The
southbound cruise along PR21 was under heavy seas. The sections of T & S show
lots of interleaving water masses and the T & S structures of Kuroshio were
smeared. During the return trip two weeks later, the weather improved slightly
but it was not good enough for collecting water samples. So, there is no water
sample data from Leg-2 and the Leg-2 CTD data were corrected by the water
sample data collected during Leg-1.
A.5 Major Problems
None
A.6 Other Incidents of Note
A.7 List of Cruise Participants
Table 3: List of Cruise Participants
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Name Responsiblity Institution*
------------------------------------------------------------------------------
LIU, Cho-Teng chief scientist NTU
PAI, Su-Cheng chief chemist NTU
GONG, Gwo-Ching nitrate analysis, chemical hydrography NTU
data processing NTU
LIN, Sheng-Fon CTD data processing NTU
YANG, Chung-Cheng silicate analysis NTU
JENG, Kwung-Lung phosphate analysis NTU
KUO, Ting-Yu dissolved oxygen analysis NTU
JACINTO, Gil Quality check on chemical data UP
WANG, Shu-lun pH analysis N
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*See Table 2 for list of Institutions
C. Hydrographic Measurements
The pressure, temperature (T) and salinity (S) were derived from the
CTD data according to the methods described in the SBE-9 CTD manual. The CTD
Digiquartz pressure transducer was calibrated in 1987. The CTD temperature and
conductivity sensor were calibrated on 1991/01/24 through Sea Bird Electronics
Inc.. Assuming that the drift of temperature sensor is linear with time, we
found that temperature data have bias 0.0006 oC. The conductivity and salinity
data were corrected by the following procedure:
(1) use the Guildline Salinometer to measure the salinity of water samples
collected during Leg-1;
(2) use the corrected CTD temperature data and the measured salinity from
step (1) to derive the in situ conductivity of each sample;
(3) use polynomial fit to derive the bias of CTD's conductivity; the bias of
CTD conductivity was found to be negligible;
(4) calculate the salinity with no correction on conductivity data.
All the data presented in this report are derived from the T and S data which
have been corrected by the above procedure.
Comparing the T-S data of St. 118 to those of St. 36 & 37 of INDOPAC
Expedition, we found that the temperature is 0.04C higher at St. 118 than
those at St. 36 & 37. Same for the salinity data which is 0.002 psu higher at
St. 118. In the T-S diagram the salinity minimum of NPIW (North Pacific
Intermediate Water) is less apparent for water closer to shore.
Since St. 118 is on the shelf side of Kuroshio as compared to St. 36 & 37,
the result of above comparison is reasonable.
D. Acknowledgements
E. References
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
G. Data Quality Evaulation
Several data files are associated with this report. They are the or266.sum,
(no hydro data at the present time), or266.csl and *.wct files. The
or266.sum file contains a summary of the location, time, type of parameters
sampled, and other pertient information regarding each hydrographic station.
The *.wct files are the ctd data for each station. The *.wct files are zipped
into one file called or266wct.zip. The or266.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 or266.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.