Filename = m99_IOP_readme.txt (written: 18th Jan, 2000)

MOCE-5 cruise, SIMBIOS (NASA) sponsored.
RV Melville, 1st - 21st October 1999.

Dr. J.R.V. Zaneveld
(541) 737-3571
zaneveld@oce.orst.edu

Dr. W.S. Pegau
(541) 737-5229
spegau@oce.orst.edu

Mr. A.H. Barnard
(541) 737-4635
abarnard@oce.orst.edu

Optical Oceanography
104 Ocean. Admin. Bldg.
College of Oceanic & Atmospheric Sciences
Oregon State University
Corvallis  OR  97331

	This document provides a description of the IOP 
(Inherent Optical Property) data collected on the research 
ship R/V Melville during the MOCE-5 (MODIS validation) cruise 
by the Optical Oceanography group at Oregon State University, 
College of Oceanic and Atmospheric Sciences.  The IOP data 
collected by the OSU group was made using the SlowDROP optical
package and via an ac-9 placed inline with the ships intake 
system.  See the file m99_IOP_log.txt for the collection times
and locations of the profiler data, and m99_cruise_report.htm
and m99_cals.txt for further details on processing.  A total 
of forty-eight profiles were made using the SlowDROP platform 
and submitted to SeaBASS.
	
	Photos were taken every day and at most stations in 
order to help keep a record of sea and sky conditions.  A jpeg
file is referenced in the comments section in the header 
information as appropriate.

	A description of the filenaming conventions are in 
m99_cals.txt.

	Various other researchers were involved in this 
cruise, making apparent optical property and biogeochemical 
measurements.  See file m99_cruise_report.htm. 

	The Slow Descent Rate Optical Platform (SlowDROP) was 
used to obtain high vertical resolution measurements of 
optical and physical parameters.  Mounted on the platform were
two WET Labs ac-9 meters, HydroScat6, SeaBird 25 CTD, WETLabs 
WetStar fluorometer, and WETLabs C-Star transmissometer.  A 
WET Labs SMODAPS unit was used to archive the data from the 
instruments with a time stamp that allowed the various 
instruments to be merged based on time.  The filter set used 
in each of the ac9s was 412, 440, 488, 510, 532, 555, 650, 
676, and 715 nm.  The ac-9's were normally calibrated every 
day using water produced by a Barnstead Nanopure water system.  

	Post processing included temperature and salinity 
corrections of all the absorption and attenuation data and 
scattering correction of the total absorption data.  Details 
of the calibrations and processing of the ac9 data can be 
found in the file m99_cals.txt.  HydroScat data was processed 
using the manufacturers software and the calibration file 
(Hs990317 26mar99-corrected.ini).  The data from the SeaBird 
25 CTD (SN 2511494-0146) was processed using the calibration 
file modis_p242.con or modis_p128.con and elements of the 
Seasoft software (DOS version 4.218) in the following order:  
Datcnv, wfilter on pressure (wpress.cfg), wfilter on 
temperature (wtgauss.cfg), wfilter on conductivity 
(wcgauss.cfg), derive (salinity and density) and asciiout. 

The variables submitted are:

Press	= 	Pressure (dbar)
Wt	=	Water temperature during profile (degrees C)
Sal	=	Salinity (PSU)
Density = 	Sigma-t (kg/m^3)
stimf	=	Stimulated chlorophyll fluorescence (volts)
trans	=	Light transmission (volts)
ays 	= 	dissolved absorption @ 412, 440, 488, 510, 
		532, 555, 650 nm
atp	=	particulate absorption @ 412,440,488,510,532,
		555,650,676 nm
aT	=	total absorption including water (POPE and 
		FRY,1998) @ 412,440,488,510,532,555,650,676 nm
bac	=	beam attenuation without water (POPE & Fry, 
		1998 and Morel & Prieur, 1974) @ 412,440,488,
		510,532,555,650,676 nm
tac	= 	total beam attenuation including water (POPE 
		& Fry,1998 and Morel & Prieur, 1974) @ 412,
		440,488,510,532,555,650,676 nm
Pscat	=	particulate scattering @ 412,440,488,510,532,
		555,650,676 nm
bb	=	backscatterance @ 442, 488, 532, 555, 620, 
		676 nm

(The units of the optical parameters is 1/m.)  

	The absorption by water (aw) values used in computing 
the totals were taken from Pope and Fry, Applied Optics 
36:8710-8723, 1998.  The scattering by water values used were 
taken from Morel and Prieur (1974).  These values in addition 
to the absorption by water values were used to form the beam 
attenuation water (cw) values and were added to the Total 
beam attenuation values (bac).  They are both given below:

	lambda aw	lambda cw
412	0.004562 	0.009662
440	0.00635		0.01025
488	0.0146		0.0171
510	0.0325 		0.0345
532	0.04444 	0.04614
555	0.0596		0.061
650	0.34		0.34071
676	0.4558		0.45641