Boothbay Harbor Environmental Data

Available Data

Weather and sea condition data have been collected from our station in Boothbay Harbor (BBH) continuously since 1989. To access these data, go to the Data Reporting, Graphing, and Download Tool, care of the Gulf of Maine Ocean Observing System (GoMoos) server.

The Boothbay Harbor Sea Water Temperature Record, extending over more than a century, constitutes one of the longest running, continuous series of sea temperature observations for any point on the North American Atlantic Coast. Observations began in March 1905 and have continued, with minimal interruption, to the present day.

Annual and current monthly summaries of BBH Environmental Data and the monthly means of BBH sea water temperature can be obtained by contacting Mark Lazzari.

2007 summaries are available here. Most are PDF files, and may require Adobe Acrobat or Adobe Reader software (download here free) to view or print. Please contact Mark Lazzari if you require an alternate format.

Station History

In 1905, the U.S. Bureau of Commercial Fisheries began the Environmental Monitoring Program at the fish hatchery in Boothbay Harbor. Air and sea surface temperatures were recorded three times daily from 1905 until 1949, when instruments were installed and data were recorded continuously on strip charts. Environmental observations were expanded in the 1960's to include other physical oceanographic and meteorological variables in addition to temperature. In 1973, the program was transferred to the Maine Department of Marine Resources and computerized data collection, processing, and storage began in 1986. New sensors for air temperature, sea surface and bottom temperature, relative humidity, and tide height as well as new datalogger hardware and software were installed in 1996. Currently, observations of air temperature, barometric pressure, precipitation, sea surface and bottom temperature, solar radiation, relative humidity, tide height, wind speed and wind direction are recorded at hourly, and daily intervals. Monthly and yearly summaries of the first six observations listed above are distributed to various U.S., Canadian, and state governmental agencies, academic institutions, aquaculture companies, and environmental consulting firms. Sea surface temperature data are reported daily to the U.S. Naval Air Station in Brunswick and a variety of data are provided on request to the public, news media, and university and government researchers.

Station Description

The Environmental Monitoring Program is operated by the Maine Department of Marine Resources with the goal of maintaining a continuous source of high-quality physical environmental data for the Maine coast. The station is located at the Department's Fisheries Laboratory in West Boothbay Harbor, Maine (43°50'40" N, 69°38'30" W). All of the station's sensors are deployed at or near the laboratory pier in a sheltered cove on the west side of Boothbay Harbor. The main harbor is very sheltered and the cove is more so. Wave heights during a severe storm may reach three or four feet in the main harbor but rarely reach even two feet in the cove. Mean tide range has been calculated by the National Ocean Service at 8.8 feet and the spring tide range is given as 10.1 feet. While the harbor typically remains open throughout the year, the cove often develops a thin layer of ice which would extend from shore to shore if it weren't broken up by the passage of various small vessels. Freshwater influences within the harbor consist of a few small streams which provide drainage for the immediate area. Two larger rivers, the Sheepscot to the southwest and the Damariscotta to the northeast, are nearby.

Sea surface and bottom temperature sensors are located at fixed levels: -5.5 feet MLW (relative to mean low water) and -25 feet MLW, respectively. Air temperature and relative humidity sensors are mounted on the dock in a down-looking radiation shield. Precipitation is measured by a heated, shielded, tipping bucket gauge installed at the northernmost end of the pier The wind speed/direction and the solar radiation sensors are tower mounted 30 feet above the ground at approximately 30 feet above sea level. However, both the eastern and western horizons are obscured slightly by terrain and trees.

Statistics Reported

Several statistics are calculated for the monthly and annual summaries. Mean values for periods of one month and one year are calculated from daily means. Extreme values reported in the annual summary (i.e. highest, lowest) are instantaneous extremes observed to the nearest minute but reported in summary form only to the day of occurrence. The average daily maximum reported in the annual summary is the mean of all daily maximums for the given month. This is contrasted with the maximum daily average reported in the monthly summaries which is simply the greatest daily mean for a given month. A corresponding contrast can be drawn between the average daily minimum and the minimum daily average.

Narrative Summary of 2007

The daily mean sea surface temperature (SST) for 2007 showed about average water temperatures for the year compared to those recorded in Boothbay Harbor since the 1950s. SST was only well above normal in January and again in July, and also was generally warmer than normal from May through summer in comparison with the 30-year (1977–2006) average observations for the same days. However, SST was below average in February and from October through December. Overall, SST exceeded the high values for the station established back in the 1950s only on a few days in January. The sea bottom temperature (SBT) record was similar in trend to SST, but was lower and less variable than the sea surface temperatures. Average air temperatures for 2007 were above normal levels in January, and again in August, September and October. Air temperatures were about average or slightly cooler than the 30-year average during the remainder of the year.

Precipitation was well above average for the year (118% of normal), with more than two inches of rainfall falling within a single 24-hour period being recorded during three months of the year (March, April, and October). Over eight inches of rain fell in April, and about six inches fell in March and October. Precipitation was generally sparse during February. Solar radiation was normal for the year but below normal from October into November. Wind speeds were generally higher than normal from January through March and in November. Barometric pressure, relative humidity, wind direction and tidal height, all remained within their normal levels of variation in 2007.

The Campbell Scientific Instruments environmental sensors and data logging equipment continue to collect high-quality physical environmental data for the Environmental Monitoring Project in Boothbay Harbor.

DEPT. OF MARINE RESOURCES