Title:  METADATA FOR MANTA FRAME PROFILE DATA SETS 
COLUMBIA RIVER LMER PROJECT

Contact:David Jay
	Center for Coastal and Land Margin Research
	Oregon Graduate Institute of Oceanography
	PO Box 91000 
	Portland, OR  97291-1000
	USA
	email: djay@ese.ogi.edu

Principle Investigators (Institution) and research area: 
	Antonio Baptista (Oregon Graduate Inst. of Oceanography), hydrodynamics;
	David Jay (Oregon Graduate Inst. of Oceanography), geophysics;

Preliminary manta-frame (CTD, AC-3, OBS) data sets are located on this website, and
"post-processed" data sets and plots are later made available at:

	http://www.ccalmr.ogi.edu/~orton/lmer-cretm/

When visiting that site, be sure to consult the README.TXT file for guidance.  To get 
the PASSWORD for the post-processed data server, email Philip Orton at: orton@ccalmr.ogi.edu.    

The post-processed data sets are different in that they have had additional quality control, 
are converted into matrix form, are referenced to depth AND height above the bed, have had 
OBS data converted to suspended particulate matter (SPM), and have had depth adjusted for 
atmospheric pressure offset (see below).  Plots are available with data referenced to height 
above the bed.

DATA DESCRIPTION:  Pump cast sampling, and associated CTD/AC-3/OBS casts took place during one 
28-35 day cruise per year in 1990, 1991, 1992, 1995, and 1996; two-week "seasonal" cruises in 
May, July, and October 1997, and February 1998; and two-week comparison cruises on the Columbia 
River and the Fraser River in British Columbia, Canada, in June and July 1999.  CTD data was also 
collected from a roving vessel during 
these cruises.  For these data, please link to the webpage 
given above.

General hydrographic profiles indicate the nature of physical, biological, and particle 
stratification in the water column.  From these data, PIs determined depths to sample during pump
casts.  In addition, profiles of hydrographic and biophysical parameters may be used to explore 
potential links between or among these parameters and to verify instrument accuracy.  Location 
and vertical extent of water column phenomena (e.g. ETMs) 
can be determined on a scale of 0.2 m.

METHODOLOGY:   Measurements were conducted from an anchored vessel.  A Seabird (1990-1992) SBE 
9/11 or Ocean Sensors (1995-1996) model OS-200 CTD equipped with a CT cell, OBS sensor, and a 
WetLabs AC-3 chlorophyll absorption-attenuation sensor were deployed for vertical profiles 
approximately every 30 minutes.  More frequent casts were conducted during "high intensity" 
sampling (e.g E or F series, see below).  Data were averaged into 0.2 m bins and referenced 
from the surface (i.e. not de-tided).

Data files are listed by series designation, i.e. each series file contains profiles from all 
casts during that series.

VARIABLES:
	Code		cast-specific code number (see below)
	Date		Date in MM/DD/YY format
	Time		Time of day (Pacific Standard Time)
	Salinity	salinity
	Temp		temperature in degrees Celcius
	Depth		depth in meters
	Density		density (sigma-T)
	OBS		optical backscattering (see below)
	Fluor		chlorophyll a (mg/m^3) determined by AC-3 (1992 only)
	AC3chla		chlorophyll a (mg/m^3) determined by AC-3 (see below)
	Atten		beam attenuation (1/m)	
	Transmiss	transmissivity (% pure water)

Explanation of Code:
	Format of code is:  YYBSENN

				YY	first two digits indicate year
				B	letter(s) indicates boundary location or tidal series as 
					follows: U=upstream (beyond salt wedge), D=downstream 
					(below estuarine turbidity maximum), N=neap tide, S=spring
					tide, SN=spring-neap transition, E= ebb, F=flood, L=long 
					time series, YB=Young's Bay, CB=Cathlamet Bay, P=Pitt River 
					(Fraser only), T=Transect (Fraser only)
				S	number of sample series at that location/tidal stage
				E	event number (sequence) within that series (an 'E' or 'F' 
					may follow this number indicating and ebb or flood tide sampling
				NN	two (or three) digits indicate CTD cast number that corresponds 
					to the pump cast
				*	an asterisk after the code indicates CTD data taken from the downcast
					immediately prior to the pump cast

OTHER NOTES:
*** OBS units (FTU, formazine turbidity units) are linearly related to suspended particulate 
material as measured in mg/L.

***  The AC-3 unit was used beginning in 1995; data sets since then will have a column for  
this variable. The voltage reading from the AC-3 is transformed into a chlorophyll a value using 
the factory calibration coefficients.  The voltage signal is proportional to chlorophyll 
absorption after light passage through a series of filters contained within the AC-3 unit.

*** In 1995 and 1996, there was a malfunction in the AC-3 unit on the CTD.  This resulted in no
chlorophyll or transmissometer readings.  Furthermore, temperature readings were affected at low 
salinities (< 1.0) and may be inaccurate by as much as +/- 0.2 degrees C.  It is unknown if/when 
these data can be reconstructed.  No chlorophyll sensor was employed in 1990 and 1991.	

*** Atmospheric pressure offsets:  Before post-processing, up to a 50cm offset may exist in the 
depth data.  The CTD pressure offset varies slightly from cruise to cruise, and is typically less 
than 50cm.  Superimposed on this relatively constant offset, the effect of ordinary atmospheric 
pressure fluctuations is small, and varies from -10cm to 10cm (except perhaps in strong low 
pressure systems.)

File format: tab-delineated ASCII with header line; maximum number of records = 5351; number of 
data columns = 11