Whaling Through Wind and Weather

As the sun rises once more on the final day in Provincetown, the Morgan’s third whale-watching trip seems as promising as the last two. At Stellwagen Bank, however, the humpbacks, fins, and minkes are nowhere to be seen. Though they understand that the whales may have simply followed their prey elsewhere, the voyagers likely feel a similar frustration to that experienced by whalers in the absence of their elusive prey. Still, while today’s logbook will not contain any marine mammal sightings, the hourly entries will nonetheless hold a more important observation, one that sailors never failed to make: the characteristics of the prevailing wind.

Voyagers using anemometer

The 38th Voyagers used a handheld anemometer to calculate the direction of the prevailing wind. Source: Mystic Seaport

One of many measurements that the voyagers frequently take throughout the voyage, it is easy to forget how crucial this information can be. Still, no matter how brief the entry, every historic whaling expedition recorded hourly wind speed and direction. During the 38th Voyage, wind speed will be measured using a handheld anemometer. This device is a common weather station instrument, used by meteorologists to study weather patterns. Like a tiny wind turbine, the stronger the wind, the faster the fan spins.  The anemometer then counts the number of rotations over a certain amount of time to calculate wind speed.

This tool has changed little since its invention in the 15th century. Italian architect Leon Battista Alberti invented the first mechanical anemometer around 1450, though in following centuries numerous other people developed their own versions. The whalers often simply measured the wind through their sails. In fact, the sail plans in a ship’s logbook are a valuable source for determining the type of winds that a ship encountered during a voyage. For example, with a fast wind, sailors would need to set fewer sails. Captains would also adjust their course based on prevailing wind patterns in order to safely take advantage of the speed that the wind would provide. Even more so than the presence of whales, this subtle factor contributed heavily to the success of a whaling expedition in a variety of ways. A change in wind direction could indicate a change in weather patterns, such as an approaching storm or cyclone. More importantly, global wind patterns drive circulation of surface currents. Since whaling vessels were powered by sail, ship captains needed to possess knowledge of winds and currents to reach their destinations as quickly and safely as possible.

Maury Map

As in the nineteenth century, the direction and speed of the wind continues to be a critical measurement in most logbooks. Source: Lisa Gilbert

The significance of this information is reflected in the observations of wind and sea conditions kept in the logbook of most sailing voyages. With his endeavor to encourage citizen science in the 1820s, Lieutenant Matthew Fontaine Maury compiled these data into a comprehensive map that would depict the predictability of global winds and currents. Since then, scientists have developed more technical ways of tracing surface currents and their driving winds, one of which is being tested during the 38th Voyage by voyager Michael Whitney.

Drifter tracks

GPS-tracked surface drifters provide a larger-scale view of wind patterns in New England waters. Source: University of Connecticut, Avery Point

In the absence of whales on this third day-trip to Stellwagen Bank, today is a perfect opportunity to release two GPS-tracked surface drifters for Whitney’s project. An associate professor of marine sciences at the University of Connecticut, Avery Point, Whitney merged his historic approach to weather with the power of the internet. Before visiting Stellwagen Bank himself during the first day-trip on July 11, Whitney merged his historic approach to weather with the power of the internet. An associate professor of marine sciences at the University of Connecticut, Avery Point, he created an electronic database and map from the information in the journal kept by Joseph F. Edward, who sailed on the Morgan’s 1918-1919 Atlantic expedition from New Bedford. With every available chance along the voyage track, the voyagers release his drifters, which will flow along the same currents sailed by Edwards and the Morgan’s 20th century crew. The drifters report their positions every two hours for several weeks, and their paths can be traced on the Northeast Fisheries Science Center drifter program website. Ultimately, like Maury, Whitney will use this science to allow the general public to view climate and weather trends over the past century, through new technology inspired by the simple observations written in a logbook.