What's It Like Inside a Typhoon?
A look at Typhoon Reconnaissance missions.

What is a reconnaissance mission?
How is such a thing accomplished?

I met my former meteorology professor one day to find out. Dr. Tomlinson spent 21 years in the Air Force as a Weather Officer and Senior Staff Meteorologist. What began as a brief interview, became a two-hour discussion, filled with sketches, anecdotes and numerous tangents.

WHAT IS A TYPHOON?
A typhoon is the name for tropical hurricanes located in the Western Pacific or South China Sea. Hurricanes are characterized by low pressure centers and strong, rotating winds (counterclockwise in the northern hemisphere and clockwise in the southern) of more than 65 knots (73 mph). 

Tropical storms are less severe, with wind speeds of 35 knots (38mph) or more, but can often escalate into full-blown typhoons. 

HISTORY
The U.S. Air Force and U.S. Navy began typhoon reconnaissance in the late 1940's. They started out in the old B-29's with the transparent nose. Later missions were made in B-47's, then C-130's. The Navy cut their typhoon reconnaissance in 1971 and the Air Force quit their Pacific missions in 1978. This was primarily due to lack of funding, and advancement of meteorological observations from satellites. The Atlantic branch of the AF weather reconnaissance stayed alive because of public and political interest from the Gulf states and lower eastern coast residents. However, weather reconnaissance today is very different from 25 years ago. With the help of satellites, storm centers can be located and characteristics estimated. Still, nothing is as detailed as the data yielded from a flight into its eye.

 MISSIONS
Dr. Tomlinson flew as Weather Officer with the 54th Weather Rec. Squadron in the Pacific. Their missions took them to Guam, Philippines, Wake Island, Japan, and many islands along the equator where tropical storms are apt to materialize. Quite often they were stationed in Thailand which put them in the then-present Vietnam War. 

Each mission was approximately ten hours. Orders were to fix typhoon eye centers every six hours. That usually meant flying into the center of one at least twice during a mission. The crew consisted of six: Pilot, Co-Pilot, Navigator, Flight Engineer, Weather Officer, and Load Master/Dropsonde Operator. 

Tracking
If no typhoons had been located by other missions, reported from land stations, or had not yet formed, the crew had to scout for them. The prevailing winds near the equator are primarily easterly. Changes in pressure, as created by a warm front, direct the winds into a large, wave-like pattern with ridges and troughs. These are perfect sources for tropical storms, where the low-pressure, fast-moving wind is already flowing in a semicircle.

The search begins by zigzagging along the mainstream winds (much like practicing S-turns, using a highway as your reference) until they encounter a westerly wind. A west wind indicates winds are blowing in a full circle. If any west wind is detected, it means a tropical storm is nearby, or imminent. West winds of greater than 10 knots generally predict a tropical storm will develop within 24 hours.

Penetrating
Once a storm is located, the object is to penetrate the wall cloud and find the eye center. First rule of thumb is to always stay behind a storm. Second, is to maintain 700 millibars of pressure, or 10,000 feet MSL. So how could they tell what their altitude was with barometric pressures fluctuating constantly? Standard altimeters you need to calibrate by setting the ground pressure for reference, wouldn't help a bit. 

The remedy is a radio altimeter that emits radio wave pulses toward the ground and receives the reflected pulses. The time between sending and receiving is measured and used to calculate the absolute altitude: 

altitude = time x speed of light 
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