Notes from the Field

Aerosol Measurements in Hurricane Cristobal

September 3rd, 2014 by Luke Ziemba

After a lengthy waiting period, we have successfully deployed our instrumentation to make aerosol measurements inside a tropical storm/hurricane.

As of our last post, instrumentation was mounted aboard the NOAA hurricane hunter aircraft but we were awaiting installation of an inlet.  This is not a trivial task, as any structure mounted to the exterior of an airplane requires a fair amount of hardware fabrication and engineering review in order to ensure flight safety.  After a doubler plate was manufactured (at the interface between the aircraft and the inlet), we were cleared to make measurements.  Below is a picture of our inlet on the plane (directly forward of the american flag).

NOAA WP-3D Kermit

NOAA WP-3D Kermit, with aerosol inlet

 

With the inlet installed, we were able to fly a brief test-flight near Tampa, FL, and three flights into CRISTOBAL last week.  These flights were back-to-back-to-back (1 every 24-hours) with 2am takeoffs, sampling the storm at 3km altitude during its transition from depression to tropical storm (8/24), as a tropical storm (8/25), and as a weak category-1 hurricane (8/26).  GOES-IR images below show the storm’s minimal organization as it slowly moved North from Hispaniola.

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Tropical-Depression (3) – 8/24

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Tropical Storm Cristobal – 8/25

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Hurricane Cristobal – 8/26

 

Below are a few pictures from the flights.  Since there was only moderate convection, turbulence on the aircraft generally wasn’t too uncomfortable.  Our 2-am take-off time allowed a very pleasant sunrise about halfway through each flight.  We could even see a rainbow in the storm vicinity, an unexpected sight while inside a hurricane!

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In the NE quadrant of Hurricane Cristobal. Low level clouds with lots of cirrus outflow

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Rainbow during Hurricane Cristobal Flight

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Typical view from the Hurricane Hunter aircraft, rain.

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Sunrise flying into Tropical Storm Cristobal

If able to sample more organized storms, we hope to observe new particle formation inside the hurricane eye, a potential mechanism for intensifying the storm.  Additionally, we aim to assess how hurricanes can redistribute biological particles that could act as efficient seeds for ice clouds at higher altitudes.

No storms are on the immediate horizon, but it is looking like a deployment to St. Croix is going to happen in the last half of September.

Thanks for reading.  Luke

Hurricane Hunter Integration Begins!

July 14th, 2014 by Luke Ziemba

Welcome to the LARGE (Langley Aerosol Research Group Experiment) blog.  We are a group of scientists at NASA Langley Research Center in Hampton, VA who study the chemical, optical, and microphysical properties of atmospheric aerosols and their effects on climate and air quality.  We are involved in many exciting experiments with vastly different objectives and applications, but this blog will begin by focusing on a project this summer/fall to assess the distribution and impacts of aerosols on hurricanes.

 

This project is just starting but the hurricane season is already underway with the passage of Hurricane Arthur, which made landfall on the Outer Banks of North Carolina on July 4, 2014.  Our work began the following week with installation of our instrumentation aboard the NOAA WP-3D aircraft known as “Kermit” (the other operational WP-3D aircraft is called “Miss Piggy”).  Operating scientific instrumentation aboard airplanes requires a lot of planning and adherence to strict guidelines to ensure flight safety and collection of high-quality data.  Since we make measurements in-situ (by bringing ambient air inside the aircraft cabin), our goal is to design a system that routes aerosols into the cabin and to our instruments without losing particles along the way.  This involves a complex web of tubing, fittings, and cabling shown below.

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Front-view of the LARGE rack onboard the NOAA WP-3D aircraft.

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Back-view of LARGE plumbing.

 

We still have work to do to complete our instrument integration, especially to install an aerosol inlet on the aircraft.  This will be completed soon and we will be poised to participate in the next hurricane flights!  Check back later for more details about our instrumentation, science objectives, and pictures from inside the next Atlantic hurricane…

More information on our research can be found at the links below:

LARGE:  http://science.larc.nasa.gov/large/

NOAA P-3 aircraft at the Aircraft Operations Center: http://www.aoc.noaa.gov/aircraft_lockheed.htm

Hurricanes, make way for Knorr!

September 7th, 2012 by Maria-Jose Viñas

By Eric Lindstrom

Cloudy skies over the Atlantic, with Hurricane Leslie in the distance.

We knew when we left Woods Hole yesterday that we had two hurricanes (Leslie and Michael) standing between us and our study site, far southeast of Woods Hole in the mid-Atlantic. How Captain Adam of the Knorr chooses to deal with this over the next days is a study in weather and ocean forecasting – and calculated risks. We considered at least three options: delay departure until the coast is clear, make a significant departure to the cruise track (sail far south, then east), or leave on time but travel quickly to the east and then south to miss the worst of the hurricane weather.

The last option is what we are doing. We abandoned plans to do test stations and do science training for a few days so we can make hast to the east, to the east side of Leslie’s track. Then we can make our way south and around Michael. Tom Farrar and Fred Bingham of the SPURS science team have provided the bridge with Gulf Stream analyses that we hope will help us take best advantage of ocean currents in our race eastward. We could easily have found ourselves in an eddy that would hinder our progress, and no one wants that with bad weather coming toward us! It was a fabulous start to the voyage to have the crew of the Knorr and the SPURS team working so closely on the strategy to both keep us safe and on schedule.

The Knorr's new track to avoid Hurricane Leslie.

It’s worth mentioning too that satellite data and the shore-based team play a crucial role in our cruise planning. Zhinjin Li and Michelle Gierach at the NASA Jet Propulsion Lab have been feeding us the latest satellite images from the Atlantic so we can better understand the wind, waves, and currents in our path. We rely on these contributions because it is difficult to surf the web from sea – we have Internet access, but it can be quite slow.

Today we feel the enormous forces of the tropical storms on the western Atlantic. There is a good swell running – speaking clearly of some strong wind at a distance. Some aboard are feeling seasick, but the mess is still full of hearty eaters and smiling faces!

SPURS scientist Fred Bingham goes through safety training.

One of the things you notice in these conditions are all the items that can shake, rattle, squeak, groan, or otherwise move and make noise. I have been up and down in my cabin a number of times during the night to silence rattling cupboard doors, toppling books, sliding glasses – it’s almost an endless battle. At sea you don’t just put something down – you secure something, wedge something, pad something, or it becomes something broken, lost, dangerous or just plain noisy! Sometimes one even has to wedge oneself in a place and just stop moving around! All of us have greater appreciation than most for the stability of land and the silence that stability brings. When things are shipshape, all is secure and in its place. We are living shipshape today.