
Subject:
RUSALCA mooring recoveries
From:
Jonathan Whitefield <jwhitefield@alaska.edu>
Date:
8/29/2012 12:54 PM
To:
Rebecca Woodgate <woodgate@apl.washington.edu>, Tom Weingartner <tjweingartner@alaska.edu>
CC:
Aleksey Ostrovskiy <aao7777@gmail.com>, Vladimir Bakhmutov <bakhmutov@list.ru>, Kathy Crane <kathy.crane@noaa.gov>

Hi Tom and Rebecca

You'll be pleased to know that the mooring recoveries went well. We
had fairly bad weather in the Strait, with 6-8ft seas during the first
recovery! However, we managed to recover everything successfully in a
~12 hour period. I took notes while downloading data with Vladimir,
and have included them below. I have also attached the agreement that
was signed as we handed the data over to Vladimir for it to be
inspected. The data should be returned to us within a couple of
months.

A1-3:
First attempts to communicate with the release were successful,
although the deck unit only transmitted intermittently. The release
code was sent and confirmed several times, but the mooring did not
surface. Dragged for the mooring and managed to shake it free.
Data downloaded from RCM9 from 20100731 2200 until 20111011 1454 (15.5
months worth). SBE37 was still logging, and a STOP command had to be
sent. Data downloaded from SBE37 from 20100803 1200 until 20120824
2145 (over 2 years!). The SBE37 had a large amount of growth all over
the instrument, but I did not really get a good look at the quality of
the data or the conductivity cell.

A1-1:
Deck box refused to turn on and, on inspection by Marshall, started
smoking! Recovery by trawling at approximate position. Loss of tension
during recovery thought to have been mooring slipping off the line,
but 37" float seen on surface. Broke the recovery pole, but still able
to grapple it. Chain to weight from release very corroded, and that
was what broke during trawling, so all instruments and releases on
board. No ISCAT (obviously), but data downloaded from 20100804 0004
until 20111226 1904 (16.75 months - i.e. survived winter of 2010).
ADCP had low battery, and several files were created at the end of
battery life. Data available from ADCP from 20100801 0300 until
20120718, with four drop outs of around 1 hour, with the exception of
one one 20120515 1400 that did not restart until 20120715 1943. SBE37
was still logging, and a STOP command had to be sent. Data downloaded
from SBE37 available from 20100803 1200 until 20120825 0230 (over 2
years!). Again, the SBE37 had a large amount of growth all over the
instrument, but I did not really get a good look at the quality of the
data or the conductivity cell.

A1-2:
Deck box now fixed (10kHz relay removed) so used to communicate with
releases. Command sent, and mooring releaseed no problems. Deck crew
able to find another pole, and mooring recovered easily. Data
available from RCM9 from 20100731 2200 until 20111125 1105 (15.75
months), but DSU not at zero once downloaded. Re-downloaded data to
confirm that all data was in fact downloaded. At beginning of second
download, display showed 5:6445 (the : means +100000 words). On
completion of download, display showed approximately 7:6000, i.e.
GREATER than the start. In addition, while the DSU remained hooked up
to the reader after download, the word display kept decreasing as if
data was being read, but the program was idle and no data was being
downloaded. On disconnect, the display returned to the original value
of 5:6445. The second file of downloaded data was identical to the
first. I don't know whether this behaviour is consistent for use of a
2990e (extended DSU) as I've only used the standard capacity ones. The
SBE16+ showed low battery on recovery, so external power used to
download data. Data available from SBE16+ from 20100803 1600 until
20110703 0000 (only 11 months of data). SBE26+ bottom pressure gauge
also showing low battery, and external power was used. Data downloaded
very quickly, and when the *.hex file was run through the ConvertHex
program in SeaSoftWaves, it only returned data from 20100801 0030
until 20100920 1800 (1.5 months)... Reason for this is unknown. ISUS
data retrieved by Mike. Data available from 20100803 until 20120825 (2
years of data, but quality not checked).

The two PCMCIA cards from the ADCP, the CF cards from the ISUS and the
data logger, and the two DSUs were given to Vladimir and will be
returned to us. One DSU is empty, but everything else has the original
data left on them. Data from the other instruments (i.e the SBE
equipment) had the memory erased on the ship.

Hope these notes are of some help to you!

-- Jonathan Whitefield, M.Sc. Ph.D. Student, Physical Oceanography 110 O'Neill Building, P.O. Box 757220 University of Alaska Fairbanks Fairbanks, AK 99775-7220 Phone: (907) 474-5184 Fax: (907) 474-5863


