Background for Light Vessel/ Light Station Oceanographic Observations
East Coast of the United States
U.S. Coast Guard Reports
1. "To establish a program of observations to detect changes in
oceanic circulation."
2. "To analyze climate and weather records to determine the cause
of such changes."
Activities undertaken by WHOI in support of the program were
1. "To maintain oceanographic posts at lightships/light stations
from Portland to Frying Pan Shoals."
2. "To analyze and report the data in relation to climatic and other
oceanographic data."
3. "To study the non-tidal drift at the surface and bottom on the
continental shelf off the east coast of the United States."
4. "To cooperate -with a number of agencies interested in the waters
of the shelf. ..."
In early 1970 the direct use of these LV'S and LTSTA'S in the study
of nontidal drift ended while the release of drift bottles was phased out.
Considerable drift bottle data were collected and have been presented elsewhere
(Bumpus, 1969a and Bumpus and Lauzier, 1965).
The U.S. Fish and Wildlife Service published temperature and salinity data
from 1956-1965. The U.S. Coast Guard published data from 1966-1970.
On 1 January 1971 the U.S. Coast Guard Oceanographic Unit (CGOU) assumed
responsibility for this continuing program of salinity and temperature
observations.
Data Collection and Processing
The data collected once daily, included temperatures taken at depth by
mechanical bathythermograph (BT), surface reference temperature and surface
water salinity sample obtained by thermometer bucket and weather recorded
at time of observation. Bottom water salinity samples were obtained twice
weekly by Nansen bottle.
The Coast Guard handled all logistics for LOSAMP in 1971. The data were analyzed and processed at the Coast Guard Oceanographic Unit.
Salinity samples were analyzed on inductive salinometers, and salinity values were determined by computer at CGOU. The mechanical bathythermograph traces were read with handheld grids. The BT temperatures at selected depths were corrected by the following procedures:
Separate corrections were computed within any BT-month when obvious shifts in BT calibration occurred.