Scientific Reports
Scientific Reports
X-Sender: thayward@coast.ucsd.edu
Date: Wed, 22 Jul 1998 09:02:44 -0700
To: jives@ucsd.edu, amantyla@ucsd.edu, jmcginnis@ucsd.edu, shipsked@ucsd.edu,
mmullin@ucsd.edu
From: Thomas Hayward <thayward@ucsd.edu>
Subject: New Horizon cruise report
Cc: thayward@ucsd.edu
Cruise Report: CalCOFI cruise 9807NH, RV New Horizon, Mon Jul. 20, 1998.
A brief review for those who may not be familiar with CalCOFI. The California
Cooperative Oceanic Fisheries Investigations are a partnership among the
Marine Life Research Group Of SIO, the National Marine Fisheries Service,
and the California Department of Fish of Game. At the center of these
investigations are the CalCOFI cruises, a shipboard monitoring program
which makes seasonal measurements of the physical, chemical and biological
characteristics of the California Current. After almost 50 years of work,
CalCOFI has the most complete ocean time series in the world, and the data
set continues to grow.
We are now working stn 48 of the 85 stations scheduled for this trip. This is
just off Santa Rosa Island, working shoreward on line 83 of the CalCOFI grid.
A quick look at our CTD data indicates that temperatures at 10 m are
much closer to the 30 year mean than they have been over recent months,
though generally still a bit warmer. An exception to this are the inshore
So. Cal. Bight stations on line 93, which are markedly cooler than the mean.
Temperatures at 100 m continue to be higher than the mean. This difference is
about 1 deg. C. within the So. Cal. Bight, and commonly 3-4 degrees further
offshore.
Working conditions have been typical. Winds are routinely 15 to 20 kts., and
our cruise track was designed years ago to assure that we would always be
steaming in the trough of the predominant swell.
Our bird and mammal observer, David Hyrenbach, has provided the following
report on his sightings: "Inshore, overall seabird abundance has increased
>from that observed during Spring. Sooty and Pink-footed shearwaters were
the most abundant species, with hundreds of rafting and feeding birds sighted
along line 87 out to San Nicholas Island. We also encountered countless
sea lions and several blue and fin whales in the vicinity of station 87.50.
Offshore, Cook's petrels and Leach's storm-petrels were the dominant species,
though overall seabird density remains low. Thus far, the highlight of the
cruise is the unusual sighting of red-billed (stn 90.53) and red-tailed
(stn 83.80) tropicbirds. These are central Pacific species, and their
presence in the CALCOFI region is probably related to the anomalous
hydrographic conditions. The crew caught a mahi-mahi north of station
93.120; another welcome by-product of this ENSO event."
My thanks to Captain John Manion and the officers and crew of the New Horizon.
Their help and dedication to seeing that we can accomplish our work
efficiently
and safely is greatly appreciated. Coming aboard the New Horizon for a cruise
seems much like going to visit old friends. It is always a pleasure.
Ed Renger
A note added from shore: The circulation pattern is typical of the
long-term mean with the addition of a strong anticyclonic eddy in the
coastal waters offshore of San Diego on Line 93. There is strong
equatorward flow of low-salinity water and the upper layers in core of the
low-salinity jet of the California Current are anomalously cool.
Thermocline waters below remain anomalously warm. Strong el Niño conditions
still prevail, although they have moderated to some extent. These are
evident as a much warmer and deeper thermocline than normal, especially in
the waters offshore of the core of the California Current where temperature
anomalies in the depth zone from 100 to 200 m range from 3-5 degrees C.
(Tom Hayward and Arnold Mantyla).
___________________________________________
Thomas L. Hayward (thayward@ucsd.edu)
Marine Life Research Group
Scripps Institution of Oceanography
Phone (619) 534-4479 FAX (619) 534-6500
___________________________________________
This cruise is being funded by a grant from the University of California.
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