NASA plans to launch a new satellite this month that will measure elevation changes on Earth with unprecedented detail. Once in the air, it will track shifts in the height of polar ice, mountain glaciers and even forest cover around the planet.

Two ÌìÃÀÓ°ÊÓ´«Ã½ polar scientists are advising the mission scheduled to launch Sept. 15 from California’s Vandenberg Air Force Base. UW researchers provided expertise in two areas of intense interest for long-term tracking: massive glaciers covering Antarctica and Greenland, and sea surface height in the Arctic and other oceans.

“ICESat-2 is designed to answer a simple glaciology question very, very well: It will tell us where, and how fast, the ice sheets are thickening and thinning,” said , a glaciologist at the UW’s Applied Physics Laboratory. “When these data start coming in we will immediately get a big-picture map of how Antarctica and Greenland have changed over the past decade.”

Smith is a member of the science definition team and the lead author of the document that describes the data that ICESat-2 will provide for ice that covers land.

“My specific role is to work out how to turn the raw data that NASA generates — which track the location of individual photons — into the answer we want to give the scientific community, which is how high the ice sheet surface is at a particular point,” Smith said.

The instrument, whose full name is the Ice, Cloud, and Land Elevation Satellite, succeeds the original ICESat-1 satellite that operated from 2003 to 2009. Since then NASA has been running annual flights to collect data over a few important parts of Antarctica and Greenland during the gap. The new satellite will provide nonstop, higher-resolution data for the Earth sciences community starting this October, one month after it launches.

“For me, the most exciting aspect of ICESat-2 is its extremely fine resolution,” said , a polar oceanographer and former leader of the North Pole Environmental Observatory. The new satellite uses six laser beams to get readings every 2-3 feet, each one focused over a 30-foot patch of the surface. For comparison, Morison said, today’s instruments measure surface elevation by averaging over many hundreds of feet to miles between each data point. The new instrument’s orbit is designed to collect more data over the poles, and it can detect very small elevation changes over long timescales.

Morison is a physical oceanographer on the science definition team, and lead author the document that describes ICESat-2 data for the open oceans.

“For the oceans, ICESat-2 will yield fine-scale measurements that are important to coastal oceanography, revealing smaller features in the open ocean and even down to the characteristics of larger surface waves,” Morison said. “ICESat-2 will also help measure sea-level change, particularly at high latitudes where the most established radar altimeters don’t go, and it will give us higher-resolution measurements of the sea surface slopes that drive changing ocean circulation.”

The two UW researchers were members of a 12-person that consulted on the project over the years leading up to the launch. They also are among the hundreds of scientists who anticipate using the data in their research.

“ICESat-2 observations will make it possible to study glaciers that are too remote for aircraft to reach, and it will make it possible to detect small changes over large areas, which were difficult to see clearly with older data,” Smith said. “There are a lot of places in Antarctica where we assume that not much is happening, but we don’t have great evidence one way or another. My guess is that when we look carefully, there will be a lot to see.”

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For more information, contact Smith at besmith@uw.edu or 206-616-9176 and Morison at jhm2@uw.edu or 206-543-1394. More ICESat-2 multimedia is .

They will be available in Seattle until Thursday, Sept. 13, when they will travel to California for Saturday’s anticipated launch.

‘Hurricane hunter’ measures polar vortex

A long-planned mission researchers had feared could be finally left in late October. , a research meteorologist at the Joint Institute for the Study of the Atmosphere and Ocean, returned from 2 1/2 weeks in Alaska as part of a trip to measure how less ice and more open water in the Arctic Ocean might influence storm paths.

The partnership between the UW and the National Oceanic and Atmospheric Administration used NOAA’s “hurricane hunter” aircraft to and see how heat radiating off the surface could destabilize the polar vortex, a huge weather feature that can affect storms throughout the Northern Hemisphere.

“When the polar vortex is strong, it’s very stable,” Bond said. “It’s like a Frisbee spinning fast – it’s stable and the cold air that develops in the Arctic is kind of bottled up.”

When the polar vortex is weaker, however, wobbles can send cold air shooting south. That’s when places like New York City, Washington, D.C., Northern Europe and Eastern Asia get hit with snowstorms and wintry weather.

Some scientists have suggested that an ice-free Arctic Ocean could destabilize the polar vortex. The mission collected data to help test this controversial theory, Bond said.

The measurements meant flying just 200 feet above the surface, and it often felt closer than that, Bond said. The specialized aircraft was equipped with more instruments than most weather stations to collect detailed measurements of heat and air turbulence.

In coming months, Bond and his colleagues will analyze the data and compare the observations with output from weather forecasting and climate models. They hope to understand whether the extra heat from the open water is enough to destabilize the polar vortex. Also of interest is how well weather-forecasting and ice models can predict conditions in the Chuchki Sea northwest of Alaska, an area now being explored for its oil.

The 16-day federal shutdown delayed the mission, but unseasonably warm weather meant the team was taking measurements at the right time to capture the fall freeze-up, Bond said.

“We were just fortunate, and it actually worked out pretty well,” he said.

Measuring summer glacier melt

Also this month, UW researchers helped the National Aeronautics and Space Administration create laser maps of melting Greenland glaciers. , a geophysicist with the UW Applied Physics Laboratory, helped design flight paths for the 16-day that ended Saturday (Nov. 16).

Scientists hope to better understand glaciers, the wild card in terms of climate change and rising sea levels. A NASA research aircraft used lasers to make an elevation-change map for important parts of the Greenland ice sheet.

Smith will compare the new data with similar measurements taken last spring to calculate how much the surface melted during the summer. This first-ever fall measurement will provide a baseline estimate of summer melt, in preparation for year-round laser monitoring of glaciers set to begin in 2016.

“Jakobshavn Glacier is the most exciting glacier in Greenland right now because it’s losing tremendous amounts of mass into the ocean,” Smith said. Flight paths included measurements right at the foot of the glacier, where ice is lost both to melting and to icebergs calving, and higher up on the ice sheet in colder conditions.

The government shutdown delayed the flight and some snow had already accumulated on the glacier. Another consequence was the temperatures – flights conducted by NASA scientists were very cold, Smith said.

UW–Coast Guard monitoring flights

Also under way this month is the last installment this year in a series of flights in which UW Applied Physics Laboratory on flights out of Kodiak, Alaska to drop oceanographic probes into cracks in the sea ice and deploys buoys in tough-to-reach Northern waters.

, an oceanographer at the Applied Physics Lab, leaves Tuesday (Nov. 19) for his first such flight in three months. This will be the latest in the year that the 40-year veteran of Arctic research has ever been out on the ice.

“With the limited daylight, finding open water for our sensor drops will be challenging,” Morison said.

The ocean current and temperature observations help UW researchers, the National Snow and Ice Data Center and others to monitor and understand changing Arctic conditions.

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For more information, contact Bond at 206-526-6459 or nab3met@uw.edu; Smith at 206-616-9176 or bsmith@apl.washington.edu and Morison at 206-543-1394 or morison@apl.washington.edu.

Pictures of the NOAA trip:

NOAA news release: “”ÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌýÌý

NASA news release: ““

“Every summer when the sun melts the surface the water has to go someplace, so it accumulates in these ponds,” said , a polar scientist at the UW Applied Physics Laboratory and principal investigator since 2000 of the . “This doesn’t look particularly extreme.”

After media coverage in , and the U.K.’s , Morison returned from overseas travel late last week to a pile of media inquiries. Over the weekend the team posted an on the project website.

One of the issues in interpreting the image, researchers said, is that the camera uses a fisheye lens.

“The picture is slightly distorted,” said Axel Schweiger, who heads the Applied Physics Laboratory’s Polar Science Center. “In the background you see what looks like mountains, and that’s where the scale problem comes in – those are actually ridges where the ice was pushed together.”

Researchers estimate the melt pond in the picture was just over 2 feet deep and a few hundred feet wide, which is not unusual to find on an Arctic ice floe in late July.

In the midst of all the concern, the pool drained late July 27. This is the normal cycle for a meltwater pond that forms from snow and ice — it eventually drains through cracks or holes in the ice it has pooled on.

The now-infamous buoy was first plunked into floating ice in April, at the beginning of the melt season, about 25 miles from the North Pole. Morison drilled a hole about three football fields away for a second camera, which is pointing in a different direction and shows a more typical scene. Since then the ice floe holding both cameras has drifted about 375 miles south.

The U.S. National Science Foundation has funded an observatory since 2000 that makes yearly observations at fixed locations and installs 10 to 15 drifting buoys.

The buoys record weather, ice, and ocean data, and the webcams transmit images via satellite every 6 hours. Images show the ice, buoys and yardsticks placed in the snow to track the surface conditions throughout the summer melt season. Maybe the instruments will survive the summer without getting crushed by shifting ice to record data for another year. Maybe they will fall in the water and eventually wash ashore. Researchers place the buoys to try to maximize their useful lifetime.

While researchers say the so-called lake at the North Pole is not out of the ordinary, there is a lot of meltwater that could affect the sea ice in coming weeks, in the closely watched lead-up to the September ice minimum.

Last summer the sea-ice hit a record low in extent since measurements began in 1979. This year the melting started a bit later than usual, Schweiger said, but picked up in the last couple of weeks. Late summer is usually the strongest period of shrinking because the ice is already thin.

“Whether we’re going to see another record or not is still up in the air,” Schweiger said.

He flew over the ice last month in a to drop instruments that measure oceanic and atmospheric conditions and ice motion.

Morison was last on the ice in April when he deployed the buoys. His forecast for this summer, based on years of experience, is included on a compiled by the National Atmospheric and Oceanic Administration’s Seattle office.

Morison will not change his June estimate that this summer will come close to, but not pass, the 2012 record, but he is having his doubts. Looking at the photos from the recent flyover shows more melt along the Alaskan coast, and his experience suggests that ice is fragile.

“I think it’s going to be pretty close to last year,” Morison said. “Up in the Canada Basin the ice looks like Swiss cheese, with lots of holes. Even though the ice extent is pretty good, our thinking is that if there’s a big storm event we’re going to see a rapid breakup of that ice and it’s going to disappear pretty quickly.”

The UW team manages another sea-ice tracking tool. The U.S. National Snow and Ice Data Center publishes daily images and calculations of , while the UW group combines those satellite images and other data to tabulate . For many people, the UW’s monthly updates are a go-to source for getting the latest numbers on sea ice.

And while the North Pole lake news stories don’t exactly hold water, UW researchers say that it at least shows public interest and concern.

“While the hoopla about Santa’s swimming pool was off the mark,” Morison said, “it is the long-term observational record from these buoys that provides the perspective needed to understand what really is going on.”

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For more information, contact Morison at 206-543-1394 or morison@apl.washington.edu and Schweiger at 206-543-1312 or axel@apl.washington.edu.