As the city prepares for the assault of Irene, we're almost exactly 190 years away from the only hurricane in recorded history whose eye passed directly over New York. September 3 marks the 190th anniversary of the Hurricane of 1821, which saw flooding and destruction in the growing metropolis. In less than an hour a thirteen-foot storm surge deluged the city, swallowing everything below Canal Street. The Battery was particularly devastated, docks were destroyed, and ships were swept onto streets. Further uptown, a bridge that connected Harlem to Ward’s Island was washed away and somewhere in Chinatown, the East River likely met the Hudson. "New Yorkers were lucky," writes Bruce Parker in The Power of the Sea: Tsunamis, Storm Surges, Rogue Waves, and Our Quest to Predict Disasters. "The hurricane hit at low tide."
We know blizzards and tornadoes but we don’t know hurricanes, points out Parker, once chief scientist at the National Ocean Service and now with Stevens Institute, in Hoboken. We should. The Mid-Atlantic and southern New England coasts form a wedge with New York in the middle, meaning in a storm, water is funneled here. "It all comes down to the shape of the coastline; we're deep in a corner and hurricanes don't seem to get into New York Harbor very often," says Philip Orton, a Stevens Institute oceanographer. "It's very dangerous when one does, because strong winds push water right into that wedge of New York Harbor and that shape amplifies the storm surge. The fact that we’re deep in that nook becomes our enemy."
The city’s Office of Emergency Management website takes this all pretty seriously. "Due to regional geography, hurricanes in New York City — though infrequent — can do far more damage than hurricanes of similar strength in the southern United States," the site states. "Hurricanes can flatten buildings, topple trees and turn loose objects into deadly projectiles
A major hurricane could push more than 30 feet of storm surge into some parts of New York City." Just a five-foot storm surge would flood low-lying neighborhoods, subways, the PATH train, and parts of the FDR, says Orton. This happened with a Nor'easter in 1992 and with Hurricane Donna in 1960. "We think big hurricanes and we think Donna or Gloria, but these storms were mild stuff compared to 1821," says Orton.
Cores extracted from a Jersey salt marsh reveal that a major hurricane strikes the region about once every 350 years. Another one probably struck sometime between 1278 and 1438. Interestingly, the Hurricane of 1821 is not remembered for the wrath it laid upon an adolescent New York, but for what it taught the world about hurricanes themselves. A saddle-maker turned steamboat captain turned amateur scientist named William Redfield, while walking from Middlebury, Connecticut, to northwestern Massachusetts in the wake of his wife’s obstetrical death, noticed that in Connecticut, "fruit trees, corn, etc. were uniformly prostrated towards the north-west," while in Massachusetts, "fruit trees, corn, etc. were uniformly prostrated towards the south-east." In 1831, Redfield published his results in a scientific paper, calling the Hurricane of 1821 "a great whirlwind." The observation created a storm of its own for proving hurricanes spun, with winds that spiraled in toward a calm center. This uprooted the science of the day, which had been laid a century earlier by Benjamin Franklin.
Franklin had suggested a storm was a moving system of winds that traveled in a direction different from the winds themselves. He explained this with a complex chimney analogy: "Immediately the air in the chimney, being rarified by the fire, rises; the air next to the chimney flows in to supply its place, moving towards the chimney; and, in consequence, the rest of the air successively, quite back to the door." Many academics considered Redfield, the observant saddle-maker, a quack. James Espy, a scientist at Philadelphia’s prestigious Franklin Institute, defended Franklin’s idea. This led to a battle of scientific smarts between Philadelphia and Redfield's hometown, New York City.
The issue was finally resolved in an 1856 paper by a meteorologist named William Ferrel, titled "An essay on the winds and the currents of the ocean." Ferrel said that it was temperature differences across the globe, along with the difference in specific gravities between the atmosphere and the ocean, which created wind and currents and set storms spinning. His prose is still palatable today. "The earth is surrounded on all sides by an exceedingly rare and elastic body, called the atmosphere," says Ferrel. "It is also partially surrounded by the ocean ... "