ESA Sentinel-1A: Preparation for radar vision

This ‘interferogram’ shows Petermann Glacier grinding towards the sea along the northwestern coast of Greenland. 

Two Radarsat-2 TOPS images acquired 24 days apart were used to generate it. 

Radarsat-2 was programmed specially by MDA to work in an experimental imaging mode called Terrain Observation by Progressive Scans (TOPS) in azimuth to match the way ESA’s Sentinel-1 will image Earth. 

Credit: ESA/MDA

Sentinel-1A, Europe's first satellite for Copernicus, is almost ready for launch on 3 April. Meanwhile, ESA is showing how its advanced radar will map ice, monitor subsidence and much more.

Marking a new era in Earth observation focusing on operational applications, Sentinel-1A is set to deliver timely imagery for numerous Copernicus services.

Carrying an advanced radar, it will scan Earth's surface no matter what the weather and regardless of whether it is day or night.

In crisis situations, it will be used for rapid response to disasters such as floods and earthquakes. Its radar will routinely monitor shipping zones, map sea ice and provide information on winds and waves for marine traffic, track changes in the way land is being used, and monitor subsidence.

It will also track how glaciers move, as shown in the image above of Petermann Glacier in northwest Greenland.

So that users are fully prepared for the images Sentinel-1A delivers, Canada's Radarsat-2 was recently programmed by MacDonald, Dettweiler & Associates to scan Earth's surface using the same novel 'interferometric' wide-swath mode technique as Sentinel-1.

Consequently, a suite of images was acquired over various sites.



Carrying an advanced radar, Sentinel-1A can image Earth’s surface no matter what the weather and regardless of whether it is day or night. 

This makes it an ideal mission for monitoring the polar regions, which are shrouded in darkness for months at a time. 

As well as providing information on changing ice cover and glacial flows, Sentinel-1 will provide imagery of sea-ice for maritime navigation in polar waters. 

Sentinel-1A will also be used to track changes in the way land is used and to monitor ground movement. 

Moreover, this new mission is designed specifically for fast response to aid emergencies and disasters such as flooding and earthquakes. 

Sentinel-1A, the first in the family of satellites for Europe’s environmental monitoring Copernicus programme, marks a new era in Earth observation, focusing on operational missions to support users for decades to come. 

Credit: ESA/ATG medialab

As the most realistic Sentinel-1A-like images to date, they show the performance and suitability of the new mission for classifying different types of sea ice, detecting ships and monitoring oil platforms.

They also included image pairs to show changes in glaciers such as Petermann, and a 'stack' of 11 images to map surface subsidence in Mexico City.

The image of Petermann Glacier was derived from two images taken 24 days apart. It shows some stationary and slowly moving features, as well as some large areas of much faster-moving ice.

The pattern's fringes are widely spaced in the stationary areas and closer together in the centre of the glacier where the ice is moving much faster.

The wealth of data available through ESA's Earth observation campaign data website is helping to pave the way for users to get the maximum out of the upcoming mission.

The Sentinel-1mission comprises two identical satellites for optimal global coverage and data delivery.

Sentinel-1B will join Sentinel-1A in orbit next year.

NASA IceBridge: 2014 Arctic campaign starts with two surveys of sea ice north of Greenland

This is a moon shot over northeast Greenland while descending into the survey area north of the Fram Strait. 

Credit: NASA/Michael Studinger

NASA's Operation IceBridge started the 2014 Arctic campaign with two surveys of sea ice north of Greenland.

The two flights follow similar surveys flow in previous years and continue the mission's goals of collecting data on changing sea ice in the Arctic.

Following the Mar. 10 transit flight from NASA's Wallops Flight Facility in Virginia to Thule Air Base, Greenland, the IceBridge team continued preparing for the weeks of work ahead.

On Mar. 11 the team unpacked cargo and set up ground-based GPS stations that are used to ensure IceBridge's instruments are accurate.

The next morning, Mar. 12, researchers, pilots and flight crew boarded the P-3 and took off for the first science flight of the campaign, a mission called Sea Ice – Nansen Gap.


This survey was a variation of flights over the Fram Strait flown in previous years that sampled ice farther north and east than in the past.

Researchers used the mission's laser and radar instruments to collect data on sea ice elevation and snow depth and collected ice thickness and elevation data while flying high over the Greenland Ice Sheet.

While studying the ice below, the team was treated to interesting sights in the sky during this flight.

Shortly after takeoff the moon made an appearance on the horizon, giving those aboard the aircraft a good photo opportunity.

In addition the team got to see the sun setting twice – once on the eastern end of the survey line and again when returning to Thule Air Base.

At this time of year days are short at high latitudes, making this sort of thing common.

SECOND SURVEY
On Mar. 13, the IceBridge team carried out their second survey of the campaign, a flight plan known as Sea Ice – Zigzag East.

On this flight the P-3 headed north-northeast out of Thule, roughly following the coast of Greenland along the Nares Strait—a narrow body of water separating Greenland and Canada's Ellesmere Island.

Then researchers headed along an alternating north and south pattern to measure how sea ice thickness changes closer to the North Pole, something known as ice gradient.

On this flight, researchers collected data on thick, multi-year ice near the coast and thinner ice farther north.

With two successful surveys and nearly three weeks left before the mission moves south to Kangerlussuaq, IceBridge is off to a successful start.

Over the next several days the mission plans to collect even more sea ice data, including a cross-basin survey of the Arctic Ocean and several flights based out of Fairbanks, Alaska, over the Beaufort and Chukchi seas.

Greenland Aurora Borealis Dragon's head

A dragon's head appears on the horizon as the Northern Lights (Aurora Borealis) dance across the night sky making magical shapes . 

The mythical creature formed in swathes of green light as particles bombard the Earth's atmosphere above the Arctic. 

Picture: Juan Carlos Casado/Barcroft

NASA IceBridge Flight Over Baffin Island

NASA IceBridge closed out the fourth week of its Arctic campaign with a flight over the striking landscape of eastern Greenland's Geikie Peninsula and a survey of a Canadian ice cap before taking two days off over the weekend. 

Soon the mission will return to Thule to finish up Arctic flights for 2013.

The morning of April 12, 2013 saw the P-3B take off for a flight to the west, across the Davis Strait to Canada's Baffin Island, the largest island in Canada and home to an ice formation known as the Penny Ice Cap.

This mission was a repeat of airborne surveys by the ATM and radar teams flown in 1995, 2000 and 2005, and added new survey lines along ICESat ground tracks.

Previous airborne surveys showed the ice cap thinning and glaciers retreating in the area and the April 12 mission aimed at measuring several glaciers in the area to see how much the Penny Ice Cap has melted in recent years.

The image captures ice covered fjord on Baffin Island with Davis Strait in the background.

Image Credit: NASA /Michael Studinger

Michael Studinger

NASA Icebridge Mission: P-3B Starts the Day

On March 21, 2013, the P-3B waits outside the hangar at Thule Air Base with the Greenland Ice sheet in the background.

IceBridge, a six-year NASA mission, is the largest airborne survey of Earth's polar ice ever flown. 

It will yield an unprecedented three-dimensional view of Arctic and Antarctic ice sheets, ice shelves and sea ice. 

These flights will provide a yearly, multi-instrument look at the behaviour of the rapidly changing features of the Greenland and Antarctic ice.

Data collected during IceBridge will help scientists bridge the gap in polar observations between NASA's Ice, Cloud and Land Elevation Satellite (ICESat) -- in orbit since 2003 -- and ICESat-2, planned for early 2016. 

ICESat stopped collecting science data in 2009, making IceBridge critical for ensuring a continuous series of observations.

IceBridge will use airborne instruments to map Arctic and Antarctic areas once a year. IceBridge flights are conducted in March-May over Greenland and in October-November over Antarctica. Other smaller airborne surveys around the world are also part of the IceBridge campaign.

Image Credit: NASA/Goddard/Michael Studinger

NASA MODIS Image: Sea Ice Off Eastern Greenland

The MODIS instrument on NASA's Aqua satellite captured this visible image of Sea Ice off eastern Greenland on October 16, 2012.

Image Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team

Terra (formerly known as EOS/AM-1) is a joint Earth observing mission within NASA's ESE (Earth Science Enterprise) program between the United States, Japan, and Canada. 

The US provided the spacecraft, the launch, and three instruments developed by NASA (CERES, MISR, MODIS). 

Japan provided ASTER and Canada MOPITT. 

The Terra spacecraft is considered the flagship of NASA's EOS (Earth Observing Satellite) program. In February 1999, the EOS/AM-1 satellite was renamed by NASA to “Terra”.

2012 Greenland Ice Melt Strongest On Record, More to Come

New data shows that melting of the vast ice sheet that covers more than three-quarters of Greenland is the strongest ever seen -- and there are still four weeks to go in the melting season.

Marco Tedesco, a researcher at the City College of New York, says the melting that scientists have observed in 2012 has already outstripped the melt in 2010. The melting season typically lasts from June to early September.

"With more yet to come in August, this year's overall melting will fall way above the old records," Tedesco said in a statement Monday.

"That's a goliath year, the greatest melt since satellite recording began in 1979."

This latest observation has not yet been published in a peer-reviewed journal, but Tedesco and his colleagues have a forthcoming paper looking at models projecting gains and losses to the ice sheet throughout the rest of this century.

NASA announced in July that its Earth Observation satellites (Modis, Aqua, Terra) had found that about 97 percent of the ice sheet's 660,000 square-mile surface had undergone melting.

This latest data from Tedesco and his colleagues jives with that finding. They used data from microwave satellite sensors in order to calculate the cumulative melting index, which gauges the "strength" of the melting season.

The index is generated by multiplying the number of days the ice sheet has melted by the total area of the ice sheet that has melted.

Rutgers University in Greenland

Åsa Rennermalm, a Rutgers University Hydrologist and researcher unaffiliated with the current project, studies the streams and rivers both on the ice sheet and those that are fed by meltwater.

She says the residents of Kangerlussauq, a town near her research site, confirm that this season's melt is the biggest they remember.

Kangerlussauq, which contains Greenland's major airport, was directly impacted by the higher melt on July 11, when a major bridge was destroyed by rising river, fed by melt-water.

"It was pretty dramatic," Rennermalm said.

Byrd Polar Research centre

Tedesco's colleague Jason Box, a researcher at Ohio State University's Byrd Polar Research Center, says there's a positive feedback mechanism at play in the ice sheet's melting; as the surface melts, it gets darker, which absorbs more heat from the sun.

In a downward spiraling action, the melted surfaces absorb more heat and this encourages further melting.

NASA Earth Observation Satellites reveal sudden Greenland ice melt

Image Credit: Reuters

Greenland's massive ice sheet has melted this month over an unusually large area, Nasa has said.

Scientists said the "unprecedented" melting took place over a larger area than has been detected in three decades of satellite observation.

Melting even occurred at Greenland's coldest and highest place, Summit station.

The thawed ice area jumped from 40% of the ice sheet to 97% in just four days from 8 July.

Although about half of Greenland's ice sheet normally melts over the summer months, the speed and scale of this year's melting surprised scientists, who described the phenomenon as "extraordinary".

Nasa said that nearly the entire ice cover of Greenland, from its thin, low-lying coastal edges to its centre, which is 3km (two miles) thick, experienced some degree of melting at its surface.

"When we see melt in places that we haven't seen before, at least in a long period of time, it makes you sit up and ask what's happening," Nasa chief scientist Waleed Abdalati said.

"It's a big signal, the meaning of which we're going to sort out for years to come."

He said that, because this Greenland-wide melting has happened before, Nasa is not yet able to determine whether this is a natural but rare event, or if it has been sparked by man-made global warming.

Scientists said they believed that much of Greenland's ice was already freezing again.

Until now, the most extensive melting seen by satellites in the past three decades was about 55% of the area.

Ice last melted at Summit station in 1889, ice core records show.

The news comes just days after Nasa satellite imagery revealed that a massive iceberg, twice the size of Manhattan, had broken off a glacier in Greenland.

"This event, combined with other natural but uncommon phenomena, such as the large calving event last week on Petermann Glacier, are part of a complex story," said Nasa's Tom Wagner.

NASA - Petermann Glacier, Greenland

The Petermann Glacier grinds and slides toward the sea along the northwestern coast of Greenland, terminating in a giant floating ice tongue.

Like other glaciers that end in the ocean, Petermann periodically calves icebergs.

A massive iceberg, or ice island, broke off of the Petermann Glacier in 2010. Now, nearly two years later, another chunk of ice has broken free.

The Moderate Resolution Imaging Spectroradiometer, or MODIS, on NASA’s Aqua satellite observed the new iceberg calving and drifting downstream on July 16–17, 2012. Because Aqua is a polar-orbiting satellite, it makes multiple passes over the polar regions each day.

Image Credit: NASA

'Gravity is climate' - 10 years of climate research satellites GRACE

The uneven distribution of mass on and within the planet causes, due the resulting variability of gravity, the earth to have an irregular shape, which deviates significantly from sphericity. 

Known as the "Potsdam Gravity Potato, the geoid has achieved global notoriety but this potato shape is equally subject to temporal changes.

For the first time, the melting of glaciers in Greenland could now be measured with high accuracy from space.

Just in time for the tenth anniversary of the twin satellites GRACE (Gravity Recovery and Climate Experiment) a sharp image has surface, which also renders the spatial distribution of the glacial melt more precisely.

The Greenland ice shield had to cope with up to 240 gigatons of mass loss between 2002 and 2011. This corresponds to a sea level rise of about 0.7 mm per year.

These statements were made possible by the high-precision measurements of the GRACE mission, whose data records result in a hitherto unequaled accurate picture of the earth's gravity. One of Newton's laws states that the gravity of an object depends directly on its mass.

"When the mass of the Greenland ice sheet changes, so does the gravity there," explains Dr. Frank Flechtner from the GFZ German Research Centre for Geosciences.

"The GRACE gravity field measurements therefore give us information on mass changes, including climate-related ones."

But there's more. The uneven distribution of mass on and within the planet causes, due the resulting variability of gravity, the earth to have an irregular shape, which deviates significantly from sphericity.

Known as the "Potsdam Gravity Potato," the geoid has achieved global notoriety. But this potato shape is equally subject to temporal changes.

During the last Ice Age, a mile-thick ice sheet covered North America and Scandinavia. Since the ice melted, the crust, now liberated from its load, continues to rise to this day.

This causes material flow in the earth's interior, in the mantle, to replenish. With GRACE, this glacial-isostatic adjustment can for the first time be accurately detected globally as a change in the geoid height: the ice ages continue to have an effect, which is especially evident in North America and Scandinavia.

NASA ER-2 to Check Out MABEL Laser Altimeter

NASA's ER-2 Earth Resources aircraft No. 806 will be flying high-altitude missions over Greenland this spring to validate the accuracy of the newly developed Multiple Altimeter Beam Experiment Lidar. (NASA / Tony Landis)

A NASA ER-2 Earth Resources aircraft based at NASA's Dryden Aircraft Operations Facility in Palmdale, Calif., will be flying a number of high-altitude missions over five weeks this spring to validate the accuracy of a new laser altimeter.


The high-flying ER-2 is scheduled to depart Palmdale on March 22 for a deployment base in Keflavik, Iceland, to test Goddard's Multiple Altimeter Beam Experiment Lidar, or MABEL, that simulates a similar instrument planned for NASA's IceSat-2 environmental satellite scheduled for launch in 2016.

Although not directly connected to the Spring 2012 Operation IceBridge Arctic polar ice survey, the ER-2 flights will be conducted concurrently with many of the same flight tracks being flown by IceBridge mission aircraft.

Operation IceBridge, conducted in the Arctic in March and April and the Antarctic during October and November, is the largest survey of Earth's polar ice ever flown. Although not participating in the Arctic study this spring, NASA's DC-8 flying science laboratory, also based in Palmdale, participates annually in the Antarctic study and has participated in the Arctic study in past years.

Learn more about the 2012 Operation IceBridge Arctic campaign at: http://www.nasa.gov/mission_pages/

NASA Aqua MODIS Image: Clouds over Southern Greenland

Spectacular cloud streets surrounded southern Greenland in late winter, 2012.

The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite captured this true-colour image on March 6, 2012.

Cloud streets are bands of cumulus clouds that form parallel to the low-level wind direction when conditions are right.

They form by convection, a process in which warm air rises and cold air sinks.

When the sun shines, moist air at the ground level begins to rise. As it rises, it cools and when moist air cools to a critical temperature water condenses onto tiny particles suspended in the atmosphere and clouds are formed.

Cloud streets form in the planetary boundary layer, within the lower one to three kilometers of the atmosphere, and can form over water or land.

Although beautiful when seen from below, when patterns stretch across hundreds of kilometers the view is best from above.

Aqua, as well as Terra, from their orbits at 705 kilometers above sea level, offer especially stunning looks at cloud patterns.

ESA CryoSat: Greenland, the Netherlands and maldives look for answers on ice

ESA’s Earth Explorer CryoSat mission is dedicated to precise monitoring of changes in the thickness of marine ice floating in the polar oceans and variations in the thickness of the vast ice sheets that blanket Greenland and Antarctica.

Credits: ESA/AOES Medialab

As the impact of climate change is felt in the Arctic, ESA’s CryoSat ice mission is highlighted as a source of vital information at an exhibition in the Netherlands.

The exhibition, called Roots2Share, opened on 13 October at the museum of culture and science, Museon, in The Hague.

The aim of the exhibition is to highlight the cultural relationship between Greenland and the Netherlands and their interests in understanding more about the Arctic and how changing ice cover will affect both countries.

ESA's ice mission
Around 100 students were present at the opening to learn more about Greenland and how ice is central to the way of life in the Arctic.

The reduction of ice cover around Greenland may offer new opportunities for navigation and the exploitation of natural resources. At the same time, ice melting from the vast ice sheet that blankets the country is likely have serious consequences for low-lying lands such as the Netherlands and the Maldives.

One of the most important issues is to understand exactly how the ice is changing and what impacts this may bring to all.

By measuring variations in the thickness of the ice floating the in polar oceans and lying on land, CryoSat is collecting essential information to help answer these pressing questions.

Playing an active role in field of water management, Prince Willem-Alexander stated how important it is that CryoSat is providing detailed information on ice so that effective strategies to adapt to climate change can be adopted.

Read more on CryoSat at ESA Portal

NASA Goddard Blog: Operation Ice Bridge

Operation IceBridge Off to a Successful Start in Greenland

Credit: Michael Studinger
The IceBridge crew fly down Petermann Glacier in northern Greenland with NASA's DC-8 aircraft.