LRandyB's Tropical Weather Discussion

Tropical Cyclone Structure 2008 TCS-08

By: LRandyB, 10:24 AM GMT on July 31, 2008

Hi folks! Things are pretty quiet right now in the Pacific Ocean. But we're ready to fly to collect data for weather research.

The project is called TCS or Tropical Cyclone Structure. We're looking at atmospheric and oceanic factors that go into the development and structure of tropical systems. We're dropping a large number of sondes into the storms we fly. In addition to the sondes, we are also launching AXBTs (Airborne eXpendable BathyThermograph). These are short lived buoys that fall from the aircraft. As soon as the instrument hits the water, it begins to deploy a line from the bottom of it. The line has instruments on it to read water temperature among other things and send it back to the aircraft. The lines are 1000-2500 feet long depending on the model we launch. Once the line has completely deployed, the instrument shuts off.

AXBTs can give the scientists a thermal profile of the ocean in the uppermost 1000-2500 feet. When we combine this with the sonde data we get information from 10,000 feet above the surface to 2500 feet below the surface of the ocean.

The third instrument we have to launch into the systems here are surface meteorological buoys. These are typical weather buoys that float at the surface and transmit data via satellite to NHC, JTWC, and other agencies who will use the data in conjunction with the sonde and AXBT information. We hope to deploy these buoys ahead of typhoons.

Scientists hope this data will help greatly increase our understanding of the factors, both oceanic and atmospheric, that go into the development and structure of tropical systems.

We flew one test flight this past week. Here are some shots from the flight.

A dropsonde system operator prepares an AXBT for release.

A dropsonde system operator loads an AXBT into the launch tube for release.

A dropsonde system operator releases an AXBT.

Scientists monitor data transmitted back to the aircraft from the buoys.

Updated: 9:57 AM GMT on August 06, 2008


Hurricane Bertha Recon Flight - Saturday July 12, 2008

By: LRandyB, 9:47 PM GMT on July 08, 2008

Hurricane Bertha continues to wear down the NHC forecasters. I was pretty amused by the 11am discussion today that started "AFTER A WEEK OR SO...I AM RUNNING OUT OF THINGS TO SAY ABOUT BERTHA."

We flew a 12.4 hour mission into Hurricane Bertha yesterday (July 11th). Since we were flying from Keesler AFB, in Biloxi, MS and Bertha was out southeast of Bermuda, it took about 5 hours to get there and another 5 to get back. That only left us with a couple of hours of fuel burn time to fly the storm so we made a single Alpha pattern which brought us through the center of the storm twice before returning home.

We found Bertha was not too terribly organized. It appeared to be undergoing an eyewall replacement cycle but it was doing so at a much slower rate than these storms usually do. And storms this weak don't normally exhibit eyewall replacemnt cycles but without a doubt there were two eyewalls when we flew. The inner eyewall that was falling apart was about 16 miles across, the new outer eyewall was about 60 miles cross. Neither was a complete closed eye.

Here are the shots I took of the storm and the crew as we flew it.

Updated: 4:26 AM GMT on July 13, 2008


About LRandyB

I was an AF aviation weather forecaster for 12 years, then 15 years as a dropsonde systems operator with the AF Reserve Hurricane Hunters.

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