On August 15, 1951, Robert Simpson flew aboard an instrumented B-29 into the eye of Typhoon Marge. Marge was a large tropical cyclone with maximum sustained winds estimated at 115 mph (185 km/hr) during the flight. Simpson had flown into several Atlantic hurricanes by this time, mostly on what he called ‘piggyback missions’ on Air Force Hurricane Hunter flights. But after meeting with General Thomas Moorman on a trip to Asia the previous year, Simpson was offered a chance to fly into a Pacific typhoon on-board a specially instrumented Air Force B-29 of the 54th Weather Reconnaissance Squadron.
The flight departed from Guam, over 900 miles (1450 km) from the storm. While they were still 700 miles (1130 km) distant, they began to observe the cirrus overcast produced by Marge. The flight’s main mission was to obtain center fixes eight hours apart, but for the time in between fixes, Simpson was allowed to direct the plane’s flight pattern. He spent over three hours orbiting in the eye of the typhoon at altitudes ranging from 600 to 20,000 feet (185 to 6100 meters). He also ranged outside the eye to measure the extent of the system’s ‘warm core.’ He found a peak difference between temperatures inside and outside the eye of 32° F (18° C) over 60 miles.
Simpson wrote an article about the flight and his findings for the Bulletin of the American Meteorological Society. The paper detailed many of the observations and photos he took, and noted the existence of ‘hub’ clouds, a moat at lower levels in the eye, and the ‘coliseum of clouds’ appearance (now known as the ‘stadium effect’) of the eyewall viewed from inside the eye. The paper, published a year after the mission, was seminal in shaping scientific ideas about tropical cyclone structure.
Simpson, R.H. “Exploring the eye of Typhoon Marge”, 1951. Bull. Am. Meteor. Soc. 1952, 33, 286–298.