NASA Draft Technical Memorandum
Cruise Report Draft Technical Memorandum
Cruise Name: MOCE-5
PI: J. R. V. Zaneveld
College of Oceanic and Atmospheric Sciences
104 Ocean. Admin. Bldg.
Oregon State University
Corvallis OR 97331-5503
Phone: (541) 737-4635
Fax: (541) 737-2064
zaneveld@oce.orst.edu
Contract No.: NAS5-97129
Date: Jan 18th, 2000.
i. SCOPE
This document is intended to provide a detailed description of the purpose, instrumentation, measurements, processing, and data collected in the Gulf of California in October of 1999 by the Optical Oceanography Group at Oregon State University. This document does not contain a discussion of the analyses of this data, but rather is intended to aid researchers in the use of this data. Researchers accessing this data should first read this document.
The primary objective of the Marine Optical Characterization Experiment 5 (MOCE-5) cruise was to provide radiometric characterizations of the water-leaving radiances and atmospheric transmittances and their spatial variability concurrent with SeaWiFS observations. A secondary objective was to validate the SeaWiFS bio-optical derived products and the GOES 9 sea surface temperature estimates using in situ measurements. The chief scientist of the cruise was Dr. Dennis Clark (NOAA/NESDIS), and the scientific crew included researchers from the University of Miami, Moss Landing Marine Laboratories, San Diego State University, NOAA/NESDIS, University of South Florida, CICESE (Mexico), and Oregon State University. For more information on the cruise participants, data collected, and the MOCE program, the reader is referred to:
http://orbit-net.nesdis.noaa.gov/orad/mot/moce
The Optical Oceanography's role in this experiment was to provide vertical information on the inherent optical properties in combination with the physical environment, and to provide technical assistance in the measurement of the inherent optical properties along the ship's track. The Slow Decent Rate Optical Profiling (SlowDROP) system was employed to characterize the vertical structure of the inherent optical properties (see below for a description of the system and the measurements). With the assistance of Dr. Ricardo Letelier (Oregon State University) we were able to integrate an instrument (FRRF) designed to examine the physiological parameters of phytoplankton fluorescence into the SlowDROP system. For information regarding this instrument and the data collected, please contact Dr. Letelier.
This document provides a description of the data collected on the research vessel R/V Melville during the cruise MOCE-5, by the Optical Oceanography group at Oregon State University. Data collected by the OSU group includes high vertical resolution inherent optical property (IOP) and CTD profiles, atmospheric aerosol optical thickness (AOT) measurements and continuous underway surface IOP measurements.
The following two tables list the location, date, time, station number and file name of each profiler data file as they appear in two documents in the SeaBASS archives. Inherent Optical Property/CTD (Table 1) and the Aerosol Optical Thickness (Table 2) are taken from document files m99_IOP_log.txt and m99_mtops_log.txt respectively. See also the complete cruise log in file m99_metalog.htm. The following format was used for file naming : m991006c_003.ext. Where m99 = cruise ID, 10 = month, 06 = day in October, c = cast type (c calibration, v validation, p process), 003 = cast number and ext = file extension. Cast type was dictated by when in the schedule of all cruise operations the SlowDROP profile was performed. Validation casts were the first over-the-side operation for each station and generally took place within four hours before the satellite overpass. Process and calibration casts were slotted into the schedule whenever time and conditions allowed. In these SeaBASS documents, specific casts are referred to by day, type and number for example 06c_003.
The underway surface IOP data is submitted as a single data file (seabass-inline.txt) containing times and locations of the 1 minute averaged inherent optical property data.
Table 1 - Inherent Optical Property/CTD profiles
Lat. (deg N) |
Long. (deg W) |
Date (GMT) |
Time (GMT) |
Station |
Arc File |
32.4463 |
-117.3565 |
10/01/99 |
18:53 |
1 |
m991001v.001 |
32.4628 |
-117.3635 |
10/01/99 |
23:23 |
1 |
m991001p.001 |
29.6946 |
-116.1116 |
10/02/99 |
16:15 |
2 |
m991002v.001 |
29.7063 |
-116.1189 |
10/02/99 |
19:45 |
2 |
m991002p.001 |
27.4173 |
-114.9501 |
10/03/99 |
17:08 |
3 |
m991003v.001 |
26.7954 |
-114.3625 |
10/04/99 |
3:59 |
NA |
m991004c.001 |
25.1645 |
-112.9930 |
10/04/99 |
16:07 |
4 |
m991004v.001 |
22.7959 |
-110.1177 |
10/05/99 |
16:20 |
5 |
m991005v.001 |
22.7833 |
-108.0002 |
10/06/99 |
11:08 |
NA |
m991006c.001 |
22.7948 |
-107.1811 |
10/06/99 |
16:13 |
6 |
m991006v.001 |
22.8624 |
-107.1727 |
10/06/99 |
21:31 |
6 |
m991006p.001 |
22.0382 |
-105.7681 |
10/07/99 |
15:21 |
7 |
m991007v.001 |
22.0609 |
-105.7731 |
10/07/99 |
20:03 |
7 |
m991007p.002 |
21.7941 |
-105.7493 |
10/08/99 |
16:43 |
8 |
m991008v.001 |
21.7938 |
-105.7499 |
10/08/99 |
16:46 |
8 |
m991008v.003 |
21.7935 |
-105.7507 |
10/08/99 |
16:51 |
8 |
m991008v.005 |
21.7933 |
-105.7513 |
10/08/99 |
16:54 |
8 |
m991008v.007 |
21.7932 |
-105.7517 |
10/08/99 |
16:56 |
8 |
m991008v.009 |
21.7930 |
-105.7521 |
10/08/99 |
16:59 |
8 |
m991008v.011 |
21.7928 |
-105.7525 |
10/08/99 |
17:01 |
8 |
m991008v.013 |
21.7925 |
-105.7530 |
10/08/99 |
17:04 |
8 |
m991008v.015 |
21.8166 |
-105.7894 |
10/08/99 |
21:22 |
8 |
m991008p.002 |
24.0815 |
-107.7491 |
10/09/99 |
15:55 |
9 |
m991009v.001 |
24.1037 |
-107.7437 |
10/09/99 |
20:51 |
9 |
m991009p.001 |
22.5081 |
-109.5847 |
10/10/99 |
16:53 |
10 |
m991010v.001 |
25.8080 |
-110.7598 |
10/11/99 |
18:04 |
11 |
m991011v.001 |
26.8558 |
-111.4351 |
10/12/99 |
3:09 |
NA |
m991012c.001 |
28.6505 |
-112.2840 |
10/12/99 |
15:47 |
NA |
m991012v.001 |
28.5812 |
-112.4272 |
10/12/99 |
17:22 |
12 |
m991012v.003 |
28.6492 |
-112.4215 |
10/12/99 |
21:49 |
12 |
m991012p.001 |
28.3882 |
-112.7767 |
10/13/99 |
2:28 |
12 |
m991013p.001 |
28.5751 |
-112.5079 |
10/13/99 |
17:17 |
13 |
m991013v.001 |
28.6319 |
-112.5413 |
10/13/99 |
22:14 |
13 |
m991013p.003 |
28.4574 |
-112.3838 |
10/14/99 |
1:33 |
13 |
m991014p.001 |
28.5037 |
-112.6810 |
10/14/99 |
3:52 |
13 |
m991014p.003 |
28.5790 |
-112.5419 |
10/14/99 |
15:44 |
14 |
m991014v.001 |
28.6256 |
-112.5149 |
10/14/99 |
22:12 |
14 |
m991014p.005 |
28.5982 |
-112.4490 |
10/15/99 |
3:32 |
14 |
m991015p.001 |
28.5836 |
-112.5189 |
10/15/99 |
15:41 |
15 |
m991015v.001 |
28.6159 |
-112.5575 |
10/15/99 |
22:48 |
15 |
m991015p.003 |
25.9056 |
-110.1279 |
10/16/99 |
17:17 |
16 |
m991016v.001 |
25.8636 |
-110.1772 |
10/16/99 |
22:29 |
16 |
m991016v.003 |
22.9664 |
-109.4845 |
10/17/99 |
15:19 |
17 |
m991017v.001 |
22.9621 |
-109.5189 |
10/17/99 |
20:01 |
17 |
m991017p.001 |
24.4427 |
-112.0317 |
10/18/99 |
15:42 |
18 |
m991018v.001 |
27.2108 |
-114.6109 |
10/19/99 |
16:33 |
19 |
m991019v.001 |
27.2674 |
-114.6687 |
10/19/99 |
21:13 |
19 |
m991019p.001 |
30.2924 |
-115.9209 |
10/20/99 |
16:37 |
20 |
m991020v.001 |
30.2919 |
-115.9210 |
10/20/99 |
16:43 |
20 |
m991020v.003 |
30.3223 |
-115.9524 |
10/20/99 |
22:06 |
20 |
m991020p.001 |
Table 2 – Aerosol optical thickness
Lat. (deg N) |
Long. (deg W) |
Date (GMT) |
Time (GMT) |
Station |
File Name |
32.45 |
-117.35 |
10/1/99 |
20:14:08 |
1 |
m99-mt01.nas |
29.70 |
-116.12 |
10/2/99 |
20:56:27 |
2 |
m99-mt02.nas |
27.42 |
-114.95 |
10/3/99 |
17:10:24 |
3 |
m99-mt03a.nas |
27.43 |
-114.97 |
10/3/99 |
19:28:57 |
3 |
m99-mt03b.nas |
25.17 |
-113.00 |
10/4/99 |
16:54:13 |
4 |
m99-mt04.nas |
22.80 |
-110.12 |
10/5/99 |
16:44:46 |
5 |
m99-mt05a.nas |
22.80 |
-110.15 |
10/5/99 |
19:10:02 |
5 |
m99-mt05b.nas |
22.85 |
-107.18 |
10/6/99 |
20:02:41 |
6 |
m99-mt06.nas |
24.08 |
-107.75 |
10/9/99 |
16:33:40 |
9 |
m99-mt09a.nas |
24.10 |
-107.75 |
10/9/99 |
19:38:44 |
9 |
m99-mt09b.nas |
22.52 |
-109.58 |
10/10/99 |
17:21:23 |
10 |
m99-mt10.nas |
22.52 |
-109.58 |
10/12/99 |
16:47:51 |
12 |
m99-mt12.nas* |
28.58 |
-112.52 |
10/13/99 |
17:50:56 |
13 |
m99-mt13a.nas |
28.60 |
-112.53 |
10/13/99 |
19:21:31 |
13 |
m99-mt13b.nas |
28.58 |
-112.55 |
10/14/99 |
16:30:06 |
14 |
m99-mt14a.nas |
28.62 |
-112.55 |
10/14/99 |
19:44:56 |
14 |
m99-mt14b.nas |
28.60 |
-112.58 |
10/15/99 |
19:14:27 |
15 |
m99-mt15.nas |
25.88 |
-110.15 |
10/16/99 |
19:10:11 |
16 |
m99-mt16.nas |
22.97 |
-109.48 |
10/17/99 |
15:57:42 |
17 |
m99-mt17a.nas |
22.97 |
-109.48 |
10/17/99 |
19:33:57 |
17 |
m99-mt17b.nas |
24.45 |
-112.02 |
10/18/99 |
19:16:06 |
18 |
m99-mt18.nas |
27.25 |
-114.65 |
10/19/99 |
19:32:53 |
19 |
m99-mt19.nas |
30.30 |
-115.92 |
10/20/99 |
17:12:40 |
20 |
m99-mt20.nas |
* Incorrect latitude and longitude. Should be: 28.58, -112.43
Simultaneous measurements of various parameters were made using the Slow Descent Rate Optical Platform (SlowDROP), a multi-instrument profiling system designed to measure the inherent optical properties and CTD parameters. The profiling system was deployed using a winch wire, with decent rates typically on the order of 25 - 50 cm/sec, providing sub-meter resolution. A total of forty-eight profiles made using the SlowDROP platform have been submitted to SeaBASS, this data set has been binned to 1 meter resolution.
Twenty-three sets of Aerosol Optical Thickness measurements were taken using a sunphotometer made by Solar Light Company whenever conditions allowed, which was at all but three of the stations.
See below for a list of all the parameters that were measured and have been provided to the SeaBASS system. Each parameter is given as its SeaBASS code if one exists, followed by a further description.
CTD parameters
Inherent Optical Property parameters
Measured by Wet Labs ac-9 meter
Measured by HydroScat -6
There were two ac-9 meters on the SlowDROP platform. The following table shows the instrument configuration for each station. Generally one ac-9 was run unfiltered in order to measure totals ("total" in Table 3). One had 0.2 micron filter(s) attached to the attenuation ("c") and/or absorption ("a") side, to measure the dissolved component ("F"). "-" shows that no measurements were taken.
Table 3 – Ac-9 configuration
| File Name | ac90141 |
ac90196 |
||
a |
c |
a |
c |
|
| m991001v | total |
total |
F |
- |
| m991001p | total |
total |
total |
total |
| m991002v | total |
total |
F |
F |
| m991002p | total |
total |
F |
F |
| m991003v | total |
total |
F |
F |
| m991004c | F |
F |
F |
F |
| m991004v | total |
total |
F |
F |
| m991005v | total |
total |
F |
F |
| m991006c | F |
F |
F |
F |
| m991006v | total |
total |
F |
F |
| m991006p | total |
total |
F |
F |
| m991007v | total |
total |
F |
F |
| m991007p | total |
total |
F |
F |
| m991008v | F |
F |
total |
total |
| m991008p | F |
F |
total |
total |
| m991009v | F |
F |
total |
total |
| m991009p | F |
F |
F |
F |
| m991010v | F |
F |
total |
total |
| m991011v | F |
F |
total |
total |
| m991012c | F |
F |
F |
F |
| m991012v(1) | F |
F |
total |
total |
| m991012v(2) | F |
F |
total |
total |
| m991012p | F |
F |
total |
total |
| m991013p | F |
F |
total |
total |
| m991013v | F |
F |
total |
total |
| m991013p | F |
F |
total |
total |
| m991014p | F |
F |
total |
total |
| m991014p | F |
F |
total |
total |
| m991014v | F |
F |
total |
total |
| m991014p | F |
F |
total |
total |
| m991015p | F |
F |
total |
total |
| m991015v | F |
F |
total |
total |
| m991015p | F |
F |
total |
total |
| m991016v | F |
F |
total |
total |
| m991016v | total |
total |
F |
F |
| m991017v | total |
total |
F |
F |
| m991017p | total |
total |
F |
F |
| m991018v | F |
F |
total |
total |
| m991019v | F |
F |
total |
total |
| m991019p | F |
F |
total |
total |
| m991020v | F |
F |
total |
total |
| m991020p | total |
total |
total |
total |
Table 4 - The absorption and scattering coefficient by water values used in deriving the total fractions of the beam attenuation, absorption and scattering coefficients. The absorption coefficient by water were taken from Pope, R. M. and E. S. Fry (1997), while the scattering coefficient of water values were taken from Morel and Prieur (1974).
| Wavelength (nm) | Absorption Coefficient by water (m-1) |
Scattering coefficient by water (m-1) |
412 |
0.00456 |
0.0051 |
440 |
0.00635 |
0.0039 |
488 |
0.01460 |
0.0025 |
510 |
0.03250 |
0.0020 |
532 |
0.04444 |
0.0017 |
555 |
0.05960 |
0.0014 |
630 |
0.29160 |
0.00078 |
650 |
0.34000 |
0.0007 |
676 |
0.45580 |
0.0006 |
The CTD data was merged with the inherent optical property data using the time record of each instrument. Post processing of the inherent optical property data included temperature and salinity corrections and scattering correction of the unfiltered absorption data. The scatter correction method used was to subtract the a715 data from all wavelengths. See also m99_IOP_readme.txt and m99_cal.txt for further processing details.
References:
Pegau, W.S., D. Gray, and J.R.V. Zaneveld. "Absorption of visible and near-infrared light in water: The dependence on temperature and salinity". Appl. Opt., 36,6035-6046, 1997.
M.L. Twardowski et al. "Quantification of the micro- to finescale in situ chromophoric DOM absorption and total absorption in coastal waters with an ac-9". Journal of Atmos. And Ocean. Tech. Submitted. 1997
Ac-9 protocol available to download at: ftp://wetlabs.com/pub/ac9/AC9PROTU.TXT
Sunphotometer parameters
File m99_mtops.cal contains the calibration numbers for this instrument and see file m99_mtops_log.txt for site locations and times.
In line surface ac9 parameters
Measured by Wet Labs ac-9 meter
This ac-9 data was one minute averaged. SeaBASS file contains "time" (a single string of YYYYDDDHHMM, where DDD is a Julian day), latitude, longitude and all variables shown above.
For more information on these instruments see the manufacturers websites:
Inherent optical properties
The ac-9 meters were field calibrated daily using a clean water standard produced by a Barnstead Nanopure water system. Also, where any two ac-9’s on the package were run similarly (i.e. both measuring totals, or both filtered), these casts were used to make inter- instrument comparisons and assist in the diagnostic process.
In order to provide field calibration offsets applicable to each day of the cruise, the full set of field calibrations was processed in the following manner. For any day that had more than one calibration file, the offsets from each calibration were averaged for each wavelength. For any day(s) without a calibration file, numbers were interpolated. This series of numbers were then smoothed using a 3 point running mean, providing a set of offsets for each day.
Dr. Dennis Clark's ac-9 (ac90123) was used to measure the spectral absorption and beam attenuation properties continuously along the ship's track. Surface water was obtained from the ships intake (located approximately at 5m water depth) and provided a continuous flow of surface water to the ac-9. The meter was placed in a modified freezer to maintain the external temperature of the ac-9 a roughly a constant
temperature. We tried to keep the freezer temperature within 5 degrees of the surface ocean temperature in order to reduce the effects of large thermal gradients on the ac-9. The data was collected through the WET Labs provided WETView software, which averaged the data (6Hz) over 16.7 seconds. The inline ac-9 data was then merged with the 1 minute resolution ships metadata and the ships thermosalinograph data using a nearest neighbor scheme. Data collection began on October 2. However, it took a while to effectively stabilize the inline feed into the ac-9 system so that bubbles were not a problem in the data stream. As is such, the first useable data began on October 5 lasting until October 21.
The meter was calibrated at WET Labs 2 weeks before the start of the cruise (9/16/99), and the device offsets were using in processing the data (ac90123_09-16-99.dev). Field calibrations were performed as described above with the exception that the absorption and attenuation sides were calibrated simultaneously. The calibration offsets used are described in the document m99_cals.txt.
See document m99_cals.txt for details of the calibration processing and for the full sets of applied offsets.
HydroScat-6, SN Hs990317
The HydroScat backscattering data was processed using the manufacturer’s software and the calibration file: Hs990317 26mar99-corrected.ini (submitted).
SeaBird 25 CTD, SN 2511494-0146
Some problems were experienced with the pressure sensor and the extreme heat on deck. Two different sensors were used with the CTD. Hence data was processed using calibration file modis_p242.con or modis_p128.con (one for each pressure sensor) and elements of the manufacturers software (Seasoft 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. All *.cfg and modis*.con files have been submitted to SeaBASS.
Microtops II Sunphotometer, SN 03769
The microtops data was downloaded using Hyperterminal, and reformatted to SeaBASS specifications. No further processing has been applied. The internal calibration data in the file m99_mtops.cal has been submitted to SeaBASS.
All of the data, cruise information, and calibration information pertaining to this cruise have been provided to the SeaBASS system within the contracted period.
We plan to participate in the MOCE-5 data meeting in late February 2000. Further plans also include comparison of the ac-9 determined absorption spectra with the absorption spectra determined from seawater samples collected by the ships CTD and processed with a lab spectrophotometer.
This document provides a detailed description of the purpose and data collected by the Optical Oceanography Group, OSU, from a cruise in the Gulf of California from October 1st to October 21st, 1999 on the R/V Melville. The purpose of this research is to examine the temporal and spatial variability in the biogeochemical properties of the region and to validate various remote sensing algorithms. Profiles of the inherent optical properties were collected as well as the standard CTD parameters. Surface inherent optical properties were continuously measured, using an ac-9 connected to the ships intake system. Sunphotometer aerosol optical thickness measurements were also made. All of this data has been provided to the SeaBASS archive.