Tracking Hurricane Irene?


As Hurricane Irene strengthens and threatens the East Coast, it seems a particularly apt time to dust off this 2007 video that explains how hot towers – immensely tall cumulonimbus clouds at the center of tropical cyclones – play a key role in strengthening storms. In 2004, researchers at Goddard Space Flight Center found that a tropical cyclone with a hot tower in its eyewall (the part of a storm the most damaging winds and rain occur) was twice as likely to intensify within the next six hours than a cyclone that lacked a tower. NASA satellites did, as detailed here, observe hot towers in Irene before forecasters elevated the storm to hurricane status.

Tracking Irene? Here are some useful links:

The National Hurricane Center
NASA’s Hurricane Resource Page
The Earth Observatory’s Irene Page
The Tropical Rainfall Measuring Mission (TRMM) Page
@NASAHurricane

Text by Adam Voiland. Image from the Earth Observatory.

Piloting Through Hurricane Earl

NASA scientists are deep into a two-month airborne hurricane research campaign known as GRIP (Genesis and Rapid Intensification Processes). GRIP is designed to put multiple aircraft, outfitted with scientific instruments, above a hurricane at the same time, allowing scientists to observe these destructive storms for longer periods than ever before. GRIP is breaking new ground by flying the unmanned Global Hawk at 60,000 feet above the surface, the first time NASA has used this drone in a hurricane field campaign.

But the NASA’s DC-8 and WB-57 planes get to a hurricane the old-fashioned way — with pilots in the cockpit. Dryden Flight Research Center DC-8 pilot Dick Ewers spoke to the media in Ft. Lauderdale, Fla., last week about what it takes and what it’s like to fly into the heart of a storm that your average pilot would try to avoid entirely. What On Earth was on hand to get some of his thoughts.

What should a first-time rider expect on a DC-8 flight through a hurricane?

It’s pretty bumpy at times, but most of the time it’s a lot of clouds. Then, as we get closer, we’ll go into some bumps and turbulence. As we break out into the eye, hopefully we’ll be able to see the sky above and all the way down to the water below. That’s very nice. All the sudden you’re out of the car wash and you’re looking down and can see what’s happening below. Normally it’s about 10 to 15 minutes of excitement per hour.

What’s the strongest Earl was when you flew through it?

At our level it was about 100 mph, but the worst part is down below. We’re above where it’s very intense. And when you’re flying in an airplane and through an airmass, and the airmass is moving at 100 mph, you don’t really notice that. But what you do notice is when you come out, the winds drops off and the airplane rises and falls based on what’s happening around it. So the plane isn’t able to be very level at times.

What’s your strategy to make sure the plane rides smoothly?

Most of the time it’s very solid. It’s bumpy but it isn’t weaving back and forth.

Even in 100 mph winds?

Oh, yeah. It goes right through it.

Is there a level of risk involved?

My job is to take the risk out of it. My job is to make sure what I do is safe and doesn’t put the scientists or the instruments at risk. My whole mission is to make sure that plane is back here tonight. Where the risk and danger is, I will take precautions and go around it and do something to avoid something where danger is involved.

How many flights did you make through Earl?

This will be the fourth and final flight. We thought it was declining yesterday, but it’s stronger this morning, so we’re going back out.

How was the view of the eye?

There are rare storms that are very crystal clear. This one had a lot of strataform in there, so there were clouds around and some clouds above us, so it wasn’t a pristine, clear blue eye. But you were able to see daylight above us and the water below us. I want to say it was 20 to 25 miles wide inside. You wouldn’t want to be in a boat down there.

— Patrick Lynch, NASA’s Earth Science News Team

Images taken by Patrick Lynch during the Sept. 2 GRIP media day in Ft. Lauderdale, Fla.

Flying high with NASA's Joanne Simpson

Joanne Simpson, the first woman to earn a PhD in meteorology, didn’t just break into a field where women weren’t welcome. She broke the door down and accumulated a list of scientific achievements that’s rare for any scientist, regardless of gender.

Early in her career, she made the key insight that narrow cumulonimbus clouds–she called them “hot towers” — are the engines that drive tropical circulation and help sustain the eyes of hurricanes. Later, she became one of the first scientists to develop a cloud model, an advance that ultimately sparked a whole new branch of meteorology. She spent decades with NASA, helping to lead the Tropical Rainfall Measurement Mission, a satellite that’s led to key insights about how hurricanes start and how dust affects precipitation. And she was a key proponent for the upcoming Global Precipitation Measurement (GPM), the follow up satellite to TRMM.

No stranger to controversy, she stirred up a scientific furor when she sought to test the validity of her cloud model by experimenting with cloud seeding. Even well into her eighties, Simpson didn’t shy from vigorous debate about the scientific basis of global warming.

In March, at the age of 86, Simpson passed away in Washington, D.C. In a recent interview with the Discovery Channel, a producer asked her what was the most fascinating thing about studying the atmosphere. “In my case, it’s the clouds,” she said without hesitation. “There are some beautiful ones out there right now,” she said while gesturing toward the window.

In tribute to Simpson’s efforts to understand clouds, we’ve chosen four of our favorite cloud images from a series of images that Simpson donated to the NOAA Photo Library and likely took. The photographs were taken from NASA’s DC-8 during the TOGA-COARE project in the 1990s.

Joanne Simpson Portrait Information: Illustration by Martin Mueller of NRC and NASA GSFC via NASA’s Earth Observatory.


Puffy fair weather cumulus clouds and hints of reefs are visible below the right wing of NASA’s DC-8. Credit: NOAA Photo Library/Dr. Joanne Simpson Collection


A towering example of a showering anvil cloud roils over the Pacific Ocean. Credit: NOAA Photo Library/Dr. Joanne Simpson Collection


Dusk falls over the Pacific Ocean with a large cumulonimbus cloud in the distance. Credit: NOAA Photo Library/Dr. Joanne Simpson Collection

— Adam Voiland, NASA’s Earth Science News Team