Notes from the Field

MABEL readied to snap photos from above

July 15th, 2014 by Kate Ramsayer

Clouds blanketed much of MABEL’s potential flight routes over the Alaskan Arctic or southern glaciers on Monday, so the ER-2 aircraft stayed in the hangar at Fort Wainwright in Fairbanks, Alaska.

But the MABEL team was busy. They took advantage of a day on the ground by improving the instrument’s new camera. The goal is to take more images like the one below, to help scientists interpret the data from the airborne lidar instrument.

As the ER-2 aircraft traveled from Palmdale, California, to Fairbanks, Alaska, the camera on MABEL took this shot of wind turbines near Bakersfield, California. (Credit: NASA)

It’s the first week of the summer 2014 campaign for MABEL, or the Multiple Altimeter Beam Experimental Lidar, the ICESat-2 satellite’s airborne test instrument. MABEL measures the height of Earth below using lasers and photon-counting devices. This year, the team is using a new camera system to take snapshots of the land, ice and water in parallel with MABEL’s measurements.

The MABEL instrument is nestled snug in the nose cone of the high-altitude ER-2, which has a circular window in the base where the laser and the camera view the ground. To get access to MABEL and the camera, the crew propped up the nose and wheeled it away from the aircraft.

The ER-2 crew rolls the aircraft’s nose — containing MABEL — away from its body, so engineers could work on the instrument. (Credit: Kate Ramsayer/NASA)

The team then carefully slid the instrument out onto a cart, so that MABEL’s on-site engineer and programmer – Eugenia DeMarco and Dan Reed – could work on the camera and ensure the connections were sound.

MABEL engineer Eugenia DeMarco and programmer Dan Reed work on improving the new camera system for the instrument. (Credit: Kate Ramsayer/NASA)

When the camera was set to document the terrain from 65,000 feet, the team slid MABEL back to its spot and wheeled the aircraft’s nose back to the rest of its body. They connected the instrument to the plane’s electronics, sealed the plane back up, and are ready to go whenever the weather cooperates.

Luis Rios, with NASA’s ER-2 crew, checks the connections between the MABEL instrument and the aircraft. (Credit: Kate Ramsayer/NASA)

NASA’s Alaska Forest Survey Kicks Off

July 14th, 2014 by Kathryn Hansen

From early July through mid-August 2014, scientist Doug Morton of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, will be flying low over the treetops of interior Alaska. The purpose? First-of-a-kind look at the state’s forests with a portable, airborne imaging system called G-LiHT to map the composition, structure and function of the ecosystem.

From http://earthobservatory.nasa.gov/IOTD/view.php?id=81416

According to Morton, key components of the fieldwork include:

“First, we are partnering with the U.S. Forest Service, as directed by the recently-passed Farm Bill, to incorporate remote sensing technology into forest monitoring efforts. Our pilot study will be the first inventory of forests in interior Alaska; a standard ground inventory (as in the lower 48) has always been too costly or logistically challenging to implement.

Second, we will study post-fire recovery, with plans to sample more than 80 percent of all fires in the Tanana region since 1950. Fire is the major agent of change in interior Alaska, and understanding the patterns of forest recovery is essential to gauge the vulnerability/resilience of forests to future climate change.

Third, we will benchmark conditions (topography/permafrost, forest cover, forest composition) across a large portion of the Arctic-Boreal Vulnerability Experiment (ABoVE) science domain.”

Follow Morton through the summer as, Internet connection permitting, he sends updates and photos from the field.

MABEL: Welcome to Fairbanks!

July 14th, 2014 by Kate Ramsayer

Very few people get to fly 65,000 feet above Alaska’s glaciers. And even fewer get to fly over ones they share a name with. But on Friday, as pilot Denis Steele flew NASA’s ER-2 aircraft from Palmdale, California, to Fairbanks, Alaska, he snapped a picture of the scenery below – including Steele Glacier in the southwestern corner of Canada’s Yukon territory.

From NASA's ER-2 aircraft, pilot Denis Steele saw glaciers in southern Alaska and Canada -- including the Steele Glacier, in the center of the image, and the Donjek Glacier (lower right). (Credit: Denis Steele)

From NASA’s ER-2 aircraft, pilot Denis Steele saw glaciers in southern Alaska and Canada — including the Steele Glacier, the horizontal feature in the center of the image, and the Donjek Glacier (lower right). (Credit: Denis Steele)

Steele and the ER-2 team, along with NASA scientists, engineers and others, are here in Fairbanks to fly a laser altimeter – MABEL, or Multiple Altimeter Beam Experimental Lidar – over melting summer sea ice, glaciers and more. It’s a campaign to see what these polar regions will look like with data from ICESat-2, once the satellite launches and starts collecting data about the height of Earth below. Gathering information now allows scientists to get a head start in developing the computer programs scientists will need to analyze ICESat-2’s raw data.

MABEL and other lidar instruments are flying on the ER-2, which provides a high-altitude perspective. In the next three weeks, the plan is to cover melting sea ice, glaciers, vegetation, lakes, and more.

Steele wasn’t the only one looking out of the plane windows on flights north. Kelly Brunt, a research scientist at NASA’s Goddard Space Flight Center, spotted a wildfire in Eastern Washington. The fire, burning in steep terrain, resembled an erupting volcano.

A wildfire burns in Washington, just east of the Cascades. (Credit: Kelly Brunt)

Over the weekend, the team settled into Fairbanks and a hangar at the U.S. Army’s Fort Wainwright, downloading data from the transit flight and ensuring the instruments are ready to fly when the weather allows. Cloudy skies over key sites means the ER-2 won’t fly today (Monday), but the team will check the weather tonight and see if it clears enough to fly the first science flight on Tuesday.

Want to follow MABEL and the ER-2? Check back here, and also check NASA’s flight tracker: http://airbornescience.nasa.gov/tracker/

Yep, we’re in Alaska! A moose along a road east of Fairbanks. I’ll call her Mabel. (Credit: Kate Ramsayer)

Societal Benefits of Ocean Color

May 10th, 2014 by Aimee Neeley

My apologies for the gap between blog posts. My day job has been pretty busy. And even though the NASA folks have already arrived safely to Tahiti as of May 5, 2014, I thought it was fitting to have one last blog post. We have talked a lot about ocean biogeochemical sampling, ocean chemistry, and ocean color radiometry. It is also important to touch on the societal benefits that ocean color radiometry can provide.

In 2007, the International Ocean-Colour Coordinating Group or IOCCG published a report and an additional brochure entitled: “Why Ocean Colour? The Societal Benefits of Ocean-Colour Technology” and “Why Ocean Colour.” I will not go into all of the information detailed in each document here (though feel free to follow the links below at your leisure.)

IOCCG reports

A number of critical uses for ocean color are of particular importance in today’s society. For instance, detection of high algal biomass can indicate the location of potential fishing zone. Fish that eat algae or fish that eat fish that eat algae (did you get all of that?) will be en masse in these blooms. Inter-annual variation in timing and extent of phytoplankton blooms can also affect the survival of larval fish. Satellite imagery can be used to monitor this variation. Moreover, satellite derived sea surface temperature (SST) and wave height information can help aquaculture developers plan where to establish new fish farms. Satellite imagery can be used to detect and monitor blooms of harmful algae, algae (phytoplankton) that ether produce toxins or can clog the gills of fish and invertebrates because of high biomass.

Harmful Algae Bloom in Lake Erie
http://oceanservice.noaa.gov/hazards/hab/

Satellite ocean color imagery is also very important for monitoring delicate ecosystems, particularly in global coastal environments. For example, the European Space Agency (ESA) has developed a program called CoastWatch that helps scientists harness the power of satellite imagery for monitoring water quality in shipping channels and coastal environments. The Medium Resolution Imaging Spectrometer (MERIS) on the Envisat platform (similar to NASA’s MODIS instruments) can be used to monitor sediment deposition onto coral reefs, which can smother the corals. The imagery can also be used to monitor water quality in shipping channels after dredging. Dredging can increase suspended sediments and negatively affect water quality.

MERIS image: sediments flowing onto reef http://www.esa.int/Our_Activities/Observing_the_Earth/ESA_s_sharp_eyes_on_coastal_waters

MERIS image: sediments flowing onto the Great Barrier reef in Australia
http://www.esa.int/Our_Activities/Observing_the_Earth/ESA_s_sharp_eyes_on_coastal_waters

Let’s consider a recent ecological disaster: the Deepwater Horizon oil spill. The Deepwater Horizon oil spill has been called the ‘worst oil spill in U.S. history’. The oil spill resulted from an oil platform explosion that occurred on April 20, 2010, and leaked an estimated 4.9 million barrels of oil by the time it was capped on July 15, 2010. This type of disaster can have long-term impacts on coastal wildlife and fisheries. Immediately following the spill, fishing areas around the Gulf Coast were closed to prevent human exposure to dangerous chemicals, polycyclic aromatic hydrocarbons, found in the oil. These chemicals are known to cause cancer. The fisheries were deemed safe and reopened on April 19, 2011.

Oil in the marshes of the Mississippi Delta
http://ocean.si.edu/gulf-oil-spill

Dolphins swimming through the oil patches from the Deepwater Horizon spill
http://ocean.si.edu/gulf-oil-spill

Satellite ocean color imagery can be used to locate and monitor oil spills of this magnitude. Although this type of imagery is complex, the technology is a great asset. The video below, developed by video producers here at NASA Goddard, shows a timeline of NASA MODIS satellite images. Such imagery allowed scientists to follow the track of the oil slicks. These images can help us prepare for the impact of these disasters when we know where it is headed next. You can find satellite images of the oil spill here.

Satellite image of oil slick in the Gulf of Mexico following the sinking of the Deepwater Horizon platform
http://www.nasa.gov/multimedia/imagegallery/image_feature_1649.html

We have truly enjoyed sharing our experiences with all the blog readers. I hope we can do this again very soon. Until next time, make sure you check out all of the NASA field campaigns here at the Earth Observatory website.

http://www.ioccg.org/reports/report7.pdf

http://www.ioccg.org/reports/WOC_brochure.pdf

http://www.esa.int/Our_Activities/Observing_the_Earth/ESA_s_sharp_eyes_on_coastal_waters

http://www.esa.int/Our_Activities/Observing_the_Earth/New_ESA_project_supports_aquaculture

http://ocean.si.edu/gulf-oil-spill

http://www.nasa.gov/topics/earth/features/oil-spill-video.html

http://www.nasa.gov/topics/earth/features/oilspill/index.html

http://oceanservice.noaa.gov/hazards/hab/

The Pacific or “Peaceful” Ocean

April 24th, 2014 by Aimee Neeley

The global ocean is made up of five major ocean basins: the Pacific, Atlantic, Indian, Southern and Arctic Ocean. The Pacific Ocean is the largest of these basins as well as the deepest. Its expanse runs 155 million square miles and contains “more than half of the free water on earth.” Not only is it the largest and deepest ocean basin, but it is also the oldest, comprised of rocks that have been dated to be 200 million years old. You may have heard the term “Ring of Fire” associated with the Pacific Ocean. This name stems from the fact that the Pacific Ocean is prone to earthquakes and formation of submarine volcanoes along its extensive ridge and trench systems.

Ring of Fire
http://oceanexplorer.noaa.gov/explorations/05fire/background/volcanism/media/tectonics_world_map.html

The Pacific Ocean gained its name in the 16^th century from the Portuguese navigator Ferdinand Magellan. Magellan and his crew set sail from Spain in 1519 in search of the Spice Islands located to the northeast of Indonesia. The Spice Islands were the largest producers in the world of spices such as nutmeg, cloves, and pepper. They navigated through the Atlantic Ocean and around the tip of South America after which they came across an unfamiliar ocean. He called this ocean ‘pacific’ which means peaceful. Unbeknownst to them, they still had a long journey to the Spice Islands. You can learn more about the voyage of Magellan and his crew here.

Magellan’s Voyage
http://news.bbc.co.uk/2/hi/science/nature/6170346.stm

OK, back to science! The CLIVAR P16S field campaign has entered the waters of the South Pacific known as a subtropical gyre. Gyre means “circular or spiral motion.” In the ocean, wind generated surface currents travel in a circular direction, either clockwise or counterclockwise, forming a large, circular body of water. The circular direction of the currents is caused by the Coriolis Force acting to deflect motion to the right in the Northern Hemisphere and to the left in the Southern Hemisphere due to the Earth’s rotation. The South Pacific gyre is located in the Southern Hemisphere, so winds and water are deflected to the left. Because of the deflection to the left, the gyre circulates in the counterclockwise direction, forcing water to pile up in the center of the gyre. In the last post, “An Appreciation for True-Color Satellite Imagery” we discussed how microscopic plants, or phytoplankton, require nutrients to grow. Blooms (large cell numbers) of phytoplankton cannot grow in these gyres because the water that piles up within the center of circulation is nutrient deficient.

Global Ocean Circulation
http://oceanmotion.org/html/background/wind-driven-surface.htm

We can use the information about the color of the light being absorbed and reflected by the ocean to deduce the concentration of phytoplankton biomass using the proxy Chlorophyll a. Chlorophyll a is a pigment that both land plants and phytoplankton use to convert light to sugars in their chloroplast. Chlorophyll a absorbs strongly in the blue color of light. So when there is a lot of Chlorophyll a, then the light reflected back includes very little blue light. When there is very little or no Chlorophyll a, then a lot of blue light is reflected back. The figure below is an ocean color image based on the information I just described. The blue color represents little to no Chlorophyll a (or phytoplankton) present while the bright colors of yellow green and red represent increasing concentration of Chlorophyll a or phytoplankton biomass.

SeaWiFS Ocean Color image, Pacific Ocean
http://oceancolor.gsfc.nasa.gov/cgi/image_archive.cgi?c=CHLOROPHYLL

Please bear in mind that this explanation is very simplistic. You can learn more about how ocean color works here.

See the image below for the current cruise track of CLIVAR P16S. They are almost in Tahiti. Just a couple more weeks…

Cruise Track, CLIVAR-P16S

ACKNOWLEDGEMENTS: NASA’s Ocean Ecology Laboratory Field Support Group is participating in the US Repeat Hydrography, P16S field campaign under the auspices of the International Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP). The US Climate Variability and Predictability Program (CLIVAR), NOAA and the NSF sponsor this campaign.