Date: Mon, 10 Nov 97 11:49:45 PST
X-Sender: capt@murex
Mime-Version: 1.0
To: shipsked@ucsd.edu, seaweed@mpl.ucsd.edu, mfshop@mpl.ucsd.edu,
knox@sio.ucsd.edu
From: Thomas Althouse
Subject: RG Sproul El Nino study cruises
For Info.
Tom
>X-Sender: restech@sdsioa.ucsd.edu (Unverified)
>Date: Fri, 7 Nov 1997 13:18:37 -0700
>To: Capt@mpl.ucsd.edu
>From: restech@sdsioa.ucsd.edu (Resident Technicians of SIO)
>Subject: RG Sproul El Nino study cruises
>Cc: thayward@ucsd.edu
>
> On Nov 6th a precruise meeting was held to discuss the upcoming RG Sproul
>El Nino cruises. Following is this office's perception of those cruises
>and our recommendations.
>
> Science Operations
> Station work
> 1. Ctd/Rosette (24 place, 10 liter btls) casts to 500 meters
> 2. Salinity, Chlorophyll and Dissolved O2 samples from rosette
> 3. Vertical net tows to 70 meters
>
> Underway work
> 1. Manta (surface towed net)
> 2. Bongo Plankton net, oblique tows to 200 meters
> 3. Uncontaminated seawater samples - continous to main lab
> 4. ADCP (side mounted) continuous measurements
>
> Loadout
> 1. MLRG Van forward portside main deck
> 2. Salinity and Dissolved O2 set up main lab
> 3. Chorophyll and zooplankton preservation set up in MLRG van.
> 4. CTD set up in 01 level van.
>
> Personnel
> 3 MLRG
> 1 Fisheries "type"
> 2(?) Resident Technicians
> ?# Volunteers
>
> RECOMMENDATIONS: Full complement of scientists, 12, for minimum
> of 5 people/12 hour watch for deployment and recoveries.
>
> Science needs
> 1. Uncontaminated SeaH20, if ship's anchorchain locker unc.seaH20
> is not ambient temperature a lab pump to an attached hose on
> ADCP can be run through the wet lab.
> 2. Minimum of 3 hand held radios for deck ops.
> 3. Accurate winch readouts for over the side work. ie Bongo
>oblique tows, deployed at 50 meter/min to 300 meter wire out,
>towed for 30
> secs, retreived at 20 m/min. Tow done at a 45 deg wire angle. If
>wire
> angle is off +or- 5 deg tow must be redone.
>
> Potential problems
> 1. 0 degree wire angle needed for CTD's
> 2. Constant wire angle for oblique tows
> As per phone patch with Capt. Zimm 07 Nov 98. "No bow thruster
> use, i.e. ineffective in 3' swells and/or 12+ kt winds. Minimum
> speed, light wind 1.2- 1.5 kts, no wind 1.7 kts"
>
> RECOMMENDATIONS
> To avoid propwash Bongo and Manta tows to be done off portside.
> Setup with Northernline winch (has T&L readout) with 1/4" hydrowire.
> Winch is placed just aft of wet lab with wire leading to:
> 1. forward outboard tending crane (in crutch) with hydroblock
> or 2. SGG airgun davit mounted on deck with forward wire stay,
> this setup is preferable as it frees up the crane and does
>not
> require a crane operator for operations.
> One recognizable fault with this layout is the wire leading across
> the deck.
>
> Alternative setup: Trawl winch is turned 90 deg to port with 1/4"
> hydrowire drum. Wire is fairled to 1.or 2. above.
> Positive- No main deck winch is needed.
> Negative- Additional work to set up winch, one less winch to do the
> work, i.e. vertical tows will need to be done over portside.
>
>
> Rough weather alternatives to 24 place rosette:
> 1. 12 btl rosette with seacat profiler.
> 2. Seacat profiler on either cable.
>
> Future objectives: CTD deployment and recovery off portside.
>
>
> \
> \ \ Resident Marine Technician Group
> \ \/ Shipboard Technical Support
> \/\ Scripps Institution of Oceanography
> \ Voice: 619 534-1632 Fax: 619 534-1635
> \
>