RINEHART COASTAL Historical Lightship Ocean and Atmospheric Observations RESEARCH CENTER

Resurrecting a WHOI Legacy WOODS HOLE OCEANOGRAPHIC INSTITUTION Kathryn L. Elder, Christopher D. Weidman, Steven J. Lentz

20 wind speed Background (m/s) 0 The U.S. Government maintained manned lightships and light stations along the U.S. East Coast for about 100 years from the early 10 1870s until the early 1970s. In addition to their primary mission as crucial aids to navigation, lightship personnel regularly recorded sea wave surface conditions and other meteorological information. Of special significance were the highly detailed meteorological and hydro- 5 height (m) graphic records produced between 1956 and 1972 when the Woods Hole Oceanographic Institution conducted a Government contracted 0 oceanographic program at selected Coast Guard light vessels and offshore light stations. This program was collectively called LOSAMP or, the Light Vessel/ Light Station Oceanographic Sampling Program. During this period, government personnel at roughly 12 localities 30 bottom salinity (the number varied depending on the specific years) collected meteorological data every 6 hours. Daily ocean temperatures were taken 20 salinity surface salinity at depth by mechanical bathythermograph (MBT), and surface reference temperature and salinity obtained by thermometer bucket. Bottom water salinity samples were obtained twice weekly by Nansen bottle and read onshore with inductive salinometers. 20 temp (ûC) This 17 year period of intense effort to collect oceanographic data from the lightship posts was largely motivated and supervised by 10 0m two distinguished Woods Hole Oceanographic Institution scientists, Dean Bumpus and Joseph Chase. Hydrographic data in the form 0 5m of bathythermograph slides were forwarded to Woods Hole where they were processed and published in a series of U.S. Government 10m Reports all with WHOI contribution numbers. Records of air temperature, weather, wind, and cloud conditions logged by hand onto -10 15m U.S. Weather Service Observation sheets, were studied elsewhere and eventually archived at the National Climatic Data Center in -20 20m Asheville, . The usefulness of these data has been severely limited by the fact that they exist in paper form only. Our goal -30 25m 30m was to make all the subsurface records digitally accessible to the WHOI and oceanographic community and as much of the meteorologi- -40 cal data as resources allow. Combined hydrographic and atmospheric lightship records for the period from 1956 to 1972 form a unique -50 and detailed data set. Such a time-series can offer a tremendous asset to oceanographers for looking at long-term oceanic and meteoro- 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 logical variability and the relationship between atmospheric forcing and the oceanic response on daily to inter-annual time scales.

80ûW 76ûW 72ûW 68ûW 64ûW 60ûW A peak in maritime cyclone frequency (tropical storms and 80ûW 76ûW 72ûW 68ûW 64ûW 60ûW Portrait of a June Storm Event: Wind speed, Portland Light Station Weekly-averaged Seasonal cycles of 30 44ûN 44ûN nor’easters) occurred in the Atlantic in the early 1960’s (Hayden, 44ûN 44ûN wave height and subsurface water tempera- 0 m Sub-surface Water Temperature C)

1981, Davis et al, 1992). On Jan. 15, 1961 Texas Tower 4 collapsed o 9 m USCG LIGHTSHIP/STATION LOCALITIES 42ûN 42ûN 42ûN 42ûN tures (0, 5, 10, 15, 20 and 25 meters) plotted for 20 Storm Track of into the sea during one of these raging storms resulting in the 15 m Timeseries weekly averages of temperature data are plotted here for all years Storm Track 30 m 40ûN 40ûN 40ûN 40ûN Ambrose Channel Light Station, June of 1968. 80W 76W 72W 68W tragic death of 28 men. 46 m within the period of observation at the following localities. , of a Nor’easter, 10 38ûN 38ûN 38ûN 38ûN A more unusual event was a late-season that tracked up the eastern Of the six tropical storms that began during the month of ( temperature

10-27 Sept., 1961 36ûN 36ûN 27-30 June, 1968 36ûN 36ûN September of 1961, hurricane Esther is most clearly evident in seaboard from June 27-30, 1968, when stratification was still develop- 0 Locality Latitude Longitude Period of Subsurface Temp. Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ing. As this storm passed Ambrose, wind speeds exceeded 20 m/s (40 observation Intervals (m) 34ûN 34ûN both the sub-surface and meteorological records from Ambrose 34ûN 34ûN Mt. Desert 44N Light Station. knots) and wave heights reached 5 meters. Prior to this event the Lightship 32ûN 32ûN 32ûN 32ûN 30 Portland 43 31.6 N 70 5.5 W Jan 1956 - Dec 1971 0, 9, 15, 30, 46 Rock temperature difference within the water column was about 8 degrees C. 0 m

Portland 30 30ûN 30ûN 25 30ûN 30ûN C)

# Name Dates Wind Press Cat o 9 m 80ûW 76ûW 72ûW 68ûW 64ûW 60ûW 80ûW 76ûW 72ûW 68ûW 64ûW 60ûW During the storm, the temperatures of the water column became Nantucket Shoals 40 30 N 69 28 W Jan 1956 - Dec 1971 0, 9, 15, 30, 46, 60 2 Hurricane BETSY 2-12 SEP 120 945 4 20 15 m vertically uniform for a brief period. This does not appear to be due to 30 m Ambrose Channel 40 26.9 N 73 48.8 W Dec 1955 - Dec 1971 0, 5, 10, 15, 20 25 20 3 3-16 SEP 150 931 5 vertical mixing, since the surface waters did not cool very much. Rather, 46 m 10 4 6-16 SEP 105 970 3 60 m Five Fathom Bank 38 47.3 N 74 34.6 W Jan 1956 - Dec 1971 0, 9, 15, 24 20 the deeper water temperatures rose to surface levels suggesting that the 15 ( temperature 5 Hurricane ESTHER 10-27 SEP 125 927 4 near shore region was temporarily filled with warmer surface waters. Diamond Shoal 35 9.21 N 75 17.9 W Jan 1955 - Oct 1966 0, 9, 15, 30, 46, 53 42N 0 15 6 Tropical Storm #6 12-15 SEP 35 - - This is also consistent with the subsequent recovery of the thermal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Frying Pan Shoals 33 29 N 77 35.5 W Jan 1958 - Dec 1971 0, 9, 15, 20 Woods Hole 7 Hurricane FRANCES 30 SEP-10 OCT 110 948 3 10 stratification over the next few weeks. 10 Ambrose Channel Lightship Buzzards Bay 30 wind speed (m/s)

wind speed (m/s) From the Colorado State Hurricane Database. Winds in knots, 5 0 m The seasonal cycles from these lightships show a similar pattern for most of 5 pressure in millibars, category is based on Saffir-Simpson scale. C) Nantucket o 5 m Ambrose 20 10 m the U.S. East Coast. In winter, water temperatures are cold and thermal 0 0 15 m 23 28 3 8 13 18 23 28 2 7 12 17 22 27 stratification is weak. Temperatures and stratification increase during the 40N 12 17 22 27 1 6 11 16 21 26 1 6 11 16 20 m 10 Barnegat Aug Sep Oct Portrait of Esther: Wind speed, wave May June July spring reaching maximums in August, then a cooling and breakdown of

Measuring Water Temperature and Depth ( temperature stratification occurs in the fall. 12 height and subsurface water tempera- 6 with a Bathythermograph 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Water temperatures at Portland Lightship () are approximately 10 Five Fathom Bank tures (0, 5, 10, 15, 20 and 25 meters) A Bathythermograph or BT is an instrument for obtaining a record degrees C colder than temperatures at Frying Pan Shoals (S. Carolina) 10 plotted for Ambrose Channel Light Sta- 5 Five Fathom Bank Light Station of the temperature of sea water at moderate depths. The BT is 30 throughout the year. 8 tion, September of 1961. 4 0 m Winter Quarter 38N lowered into the sea and retrieved by means of a wire rope. The C) o 8 m thermal element of the BT, corresponding to the mercury column in 20 6 Hurricane Esther tracked up the eastern seaboard as a force 4 to 3 15 m a glass thermometer, consists of about 45 to 50 feet of fine copper 22 m force 3 hurricane (wind speeds 100-120 knots) from September Chesapeake tubing filled with xylene. As the xylene expands or contracts with 10 4 20 - 22, then was downgraded to a tropical storm as it made a 2 temperature ( temperature wave height (m) wave wave height (m) wave the changing water temperature, the pressure inside the tubing clockwise loop southeast of for four more days 2 1 increases and decreases. This pressure change is transmitted to a 0 Do It Yourself Kits for before continuing northward on the 26th. As Esther passed Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 36N Bourdon tube, a hollow brass coil spring which carries a stylus at its Lightships 0 about 200 km east of Ambrose Lightship on September 21st, 0 12 17 22 27 1 6 11 16 21 26 1 6 11 16 23 28 3 8 13 18 23 28 2 7 12 17 22 27 free end. The stylus records, on a coated glass slide, the movements Diamond Shoals Light Station wind speeds there exceeded 25 m/s (50 knots) and wave 30 of the Bourdon tube as it expands or contracts with changes of Work in Progress Diamond Shoals Dean F. Bumpus is pictured here on Aug Sep Oct heights were over 10 meters. May June July C) temperature. The slide is held rigidly by the depth element o To date, all LOSAMP data, over 71,000 subsurface MBT and salinity the Woods Hole dock posing with one 20 25 Prior to Esther, the temperature difference throughout the 20 0 m of fifteen do-it-yourself kits that were assembly which is on the end of a coil spring enclosed in a copper records from 15 localities, have been digitized as part of this project. water column was over 10 degrees C. In response to the strong 9 m 34N distributed to Coast Guardsmen on bellows or sylphon. 15 m Our focus has now shifted to the more difficult digitization of hand- winds and large waves generated by the passing of Esther, 10 30 m board lightships in 1955. The kits were 46 m written meteorological records archived at the National Climatic and

20 Water pressure, which increases with depth, compresses the ( temperature C) 15 Frying Pan Shoals 53 m o thermal stratification of the water column was completely Data Center (NCDC). By collaborating with NCDC, we have been able carefully fitted with an array of sylphon as the BT sinks. 0 broken down and subsequently remained weak. While Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec to retrieve several periods of meteorological records from several scientific instruments, chief among This pulls the slide toward 15 Hurricane Esther is an extreme example, these sorts of storm 10 Lightship localities in coded digital form. Furthermore, we have them the bathythermograph displayed the nose of the BT, at right Frying Pan Shoals Light Station events are typically responsible for the fall breakdown of contracted an outside company to perform the digitization of selected here by Dean Bumpus. Also, neatly angles to the direction in 30 32N stratification in the Mid-Atlantic Bight. periods to expand what records we already have. Our web page, at C)

fitted into a slot, was a Nansen bottle temperature ( 10 temperature (ûC) which the stylus moves;

5 o http://dana.nosams.whoi.edu/, is currently limited to WHOI access, to obtain water samples at any desired thus, the trace scratched 20 0 m and indexes all of the data and related meta-data products resulting depth using “messengers” which slid on the coated surface of 9 m 5 0 10 from this project. We hope to complete the digitization of meteorologi- down the wire to close the bottle cap. 12 17 22 27 1 6 11 16 21 26 1 6 11 16 23 28 3 8 13 18 23 28 2 7 12 17 22 27 the glass slide is a 15 m 20 m cal records for at least several more localities with support from the A brass bucket with an accurate thermometer, a large hand-winch and boom to lower and Aug Sep Oct May June July combined record of depth ( temperature 30N 0 Rinehart Coastal Research Center. hoist the instruments and blank forms completed the kit. 1961 1968 and temperature. Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 80W 76W 72W 68W