ESA CryoSat-2 and Jason-1 Satellites detect 'thousands' of new ocean-bottom mountains

ESA CryoSat-2 and NASA's Jason-1 satellites capture new gravity data.

ESA's CryoSat-2 and NASA's Jason-1 satellites capture new gravity data gives us our clearest view yet of the shape of the ocean floor

It is not every day you can announce the discovery of thousands of new mountains on Earth, but that is what a US-European research team has done.

What is more, these peaks are all at least 1.5km high.

ESA's CryoSat-2 Earth Observation satellite.

Credit: ESA

The reason they have gone unrecognised until now is because they are at the bottom of the ocean.

Prof Dave Sandwell (UCSD) and colleagues used Cryosat-2 and Jason-1 radar satellites to discern the mountains' presence under water and report their findings in Science Magazine.

"In the previous radar dataset we could see everything taller than 2km, and there were 5,000 seamounts," Prof Sandwell told reporters.

"With our new dataset, and we haven't fully done the work yet, I'm guessing we can see things that are 1.5km tall.

"That might not sound like a huge improvement but the number of seamounts goes up exponentially with decreasing size.

"So, we may be able to detect another 25,000 on top of the 5,000 already known," the Scripps Institution of Oceanography researcher explained.

The new detailed map of the sea floor is available here.

Knowing where the seamounts are is important for fisheries management and conservation, because it is around these topographic highs that wildlife tends to congregate.

The roughness of the seafloor is important also as it steers currents and promotes mixing, behaviours that are critical to understanding how the oceans transport heat and influence the climate.

But our knowledge of the seafloor is poor; witness the problems they have had searching for the missing Malaysia Airlines jet MH370, which is believed to have crashed west of Australia.

Seeing fracture zones tells scientists about the movement of the continents
The problem is that saltwater is opaque to all the standard techniques that are used to map mountains on land.

Ship-borne echosounders can gather very high-resolution information by bouncing sound off bottom structures, but less than 10% of the global oceans have been properly surveyed in this way because of the effort it involves.

ESA Cryosat-2 finds sharp rise in Antarctica ice loss

Three years of observations from ESA’s CryoSat-2 satellite show that the Antarctic ice sheet is now losing 159 billion tonnes of ice each year – twice as much as when it was last surveyed.

The polar ice sheets are a major contributor to the rise in global sea levels, and these newly measured losses from Antarctica alone are enough to raise global sea levels by 0.45 mm each year.

These latest findings by a team of scientists from the UK’s Centre for Polar Observation and Modelling show that the pattern of imbalance continues to be dominated by glaciers thinning in the Amundsen Sea sector of West Antarctica.

Between 2010 and 2013, West Antarctica, East Antarctica and the Antarctic Peninsula lost 134, 3 and 23 billion tonnes of ice each year, respectively.

The average rate of ice thinning in West Antarctica has increased compared to previous measurements, and this area’s yearly loss is now one third more than measured over the five years before CryoSat’s launch.

Launched in 2010, CryoSat-2 carries a radar altimeter that can measure the surface height variation of ice in fine detail, allowing scientists to record changes in its volume with unprecedented accuracy.

CryoSat-2 surveys almost all – 96% – of the Antarctic continent, reaching to within 215 km of the South Pole. In addition, it has increased coverage over coastal regions, where today’s ice losses are concentrated.

Andrew Shepherd

“Thanks to its novel instrument design and to its near-polar orbit, CryoSat-2 allows us to survey coastal and high-latitude regions of Antarctica that were beyond the capability of past altimeter missions, and it seems that these regions are crucial for determining the overall imbalance,” said Prof. Andrew Shepherd from the University of Leeds, UK, who led the study.

In particular, newly mapped areas by CryoSat-2 in West Antarctica have now brought altimeter observations closer to estimates based on other approaches.

“We find that ice losses continue to be most pronounced along the fast-flowing ice streams of the Amundsen Sea sector, with thinning rates of 4-8 m per year near to the grounding lines, where the ice streams lift up off the land and begin to float out over the ocean, of the Pine Island, Thwaites and Smith Glaciers,” said Dr Malcolm McMillan from the University of Leeds, UK, and lead author of the study.

Malcolm McMillan

This area has long been identified as the most vulnerable to changes in climate.

Recent assessments say its glaciers may have passed a point of irreversible retreat.

“Although we are fortunate to now have, in CryoSat-2, a routine capability to monitor the polar ice sheets, the increased thinning we have detected in West Antarctica is a worrying development,” said Prof. Shepherd.

“It adds concrete evidence that dramatic changes are under way in this part of our planet. The challenge is to use this evidence to test and improve the predictive skill of climate models.”

The findings were published in Geophysical Research Letters.

ESA: CryoSat goes to sea

CryoSat was launched in 2010 to measure sea-ice thickness in the Arctic, but data from the Earth-observing satellite have also been exploited for other studies. High-resolution mapping of the topography of the ocean floor is now being added to the ice mission’s repertoire.

The main objective of the polar-orbiting CryoSat is to measure the thickness of polar sea ice and monitor changes in the ice sheets that blanket Greenland and Antarctica.

But the satellite’s radar altimeter is not only able to detect tiny variations in the height of the ice but it can also measure sea level.

The topography of the ocean surface mimics the rises and dips of the ocean floor due to the gravitational pull. Areas of greater mass, such as underwater mountains, have a stronger pull, attracting more water and producing a minor increase in ocean-surface height.

Therefore, instruments that measure sea-surface height incidentally map the ocean floor in previously uncharted areas.

There have been several recent global gravity missions, such as ESA’s GOCE satellite, that provide extraordinarily accurate measurements of gravity at the spatial resolution of hundreds of kilometres.

But CryoSat’s radar altimeter can sense the gravity field at the ocean surface, so that seafloor characteristics at scales of 5–10 km are revealed. This is the first altimeter in 15 years to map the global marine gravity field at such a high spatial resolution.

Recent studies at the Scripps Institution of Oceanography in San Diego, USA, found that the range precision of CryoSat is at least 1.4 times better than the US's Geosat or ESA's ERS-1.

They estimate that this improved range precision combined with three or more years of ocean mapping will result in global seafloor topography – bathymetry – that is 2–4 times more accurate than measurements currently available.

“We know more about the surfaces of Venus and Mars than we do about the bathymetry of deep oceans,” said David Sandwell from the Scripps Institution of Oceanography in the US.

“This new mapping from CryoSat will revolutionise our understanding of ocean floor tectonics and reveal, perhaps, 10 000 previously uncharted undersea volcanoes.”

Most satellite radar altimeters such as the one on the joint CNES/NASA/Eumetsat/NOAA Jason-2 follow repeated ground-tracks every 10 days to monitor the changes in ocean topography associated with ocean currents and tides.

CryoSat’s 369-day repeat cycle provides a dense mapping of the global ocean surface at a track spacing of over 4 km. Three to four years of data from CryoSat can be averaged to reduce the ‘noise’ due to currents and tides and better chart the permanent topography related to marine gravity.

ESA's Latest CryoSat results revealed

After nearly a year and a half of operations, CryoSat has yielded its first seasonal variation map of Arctic sea-ice thickness. 

Results from ESA's ice mission were presented at the Royal Society in London. In June 2011, the first map of Arctic sea-ice thickness was unveiled, using CryoSat data acquired between January and February of that year.

Now, the complete 2010-11 winter season data have been processed to produce a seasonal variation map of sea-ice thickness.

This is the first map of its kind generated using data from a radar altimeter at such a high resolution compared to previous satellite measurements.

CryoSat's altimeter makes precise measurements of its height above the ice by measuring the time interval between the transmission and reception of very short radar pulses.

Readings over the Arctic from October 2010 to March 2011 were processed to map the seasonal formation of floating ice.

ESA and NASA have been collaborating to perform carefully coordinated flights directly under CryoSat's orbit over the Arctic, gathering data to ensure the accuracy of the satellite measurements.

This first validated CryoSat dataset demonstrates the full potential of this innovative ice mission.

Owing to the high rate of change in the Arctic Ocean, this has a special relevance for climate change research.

Other significant results from this collaborative European mission will be presented and discussed, with perspectives from UK industrial and scientific communities.

This event is being jointly organised by ESA and the UK Space Agency as part of the wider celebration of the 50th anniversary of the UK in space.

The map, along with a full digital elevation model of Greenland and other scientific results from the collaborative European mission, were presented at the Royal Society in London.

The event was jointly organised by ESA and the UK Space Agency as part of the wider celebration of the 50th anniversary of the UK in space.

"Within the 50th anniversary celebrations of space activities in the UK, we have seen how the UK has been able to contribute to and lead in the many aspects of ESA's CryoSat mission," said David Williams, Chief Executive of the UK Space Agency.

Director of ESA's Earth Observation Programmes, Volker Liebig, outlined the dramatic effects that climate change has had on the Arctic, and how satellites have been monitoring sea-ice for over 30 years.

"In the coming years, the Arctic will become a very important geo-political region," said Prof. Liebig.

"15 to 20 per cent of the world's oil and gas reserves are expected there, and we will find shorter shipping routes as the ice melts. Satellites will play and ever-important role in the sustainable management of this sensitive region."

Link to ESA Portal Cryosat-2 and animation of Results Summary

Every year, the Arctic Ocean experiences the seasonal formation and then melting of vast amounts of floating ice. Over the past decade, satellites have seen an acceleration in the rate of overall sea ice loss.

Radars on satellites such as ESA's CryoSat can acquire high-resolution images through clouds and darkness. This is particularly useful when observing the inaccessible Arctic, which is prone to long periods of bad weather and extended darkness.

In the coming years, CryoSat data will map precise changes in sea-ice thickness year to year, furthering our understanding of the effects that climate change has on the Arctic.

ESA's SMOS mission is providing complementary information on sea-ice cover and the thickness of thin ice.

ESA and NASA join forces to measure Arctic sea ice

Credits: NASA/M. Studinger

A view of Arctic sea ice from NASA’s P-3 aircraft as it joins ESA to validate measurements of the ice taken from space by CryoSat. 

On 2 April, ESA and NASA planes flew together across the Arctic Ocean, exactly under CryoSat orbiting 700 km above.

Credits: ESA/DTU Space/R. Saldo/M. Davidson

The animation shows the flight tracks of the ESA and NASA aircraft during joint operations on 2 April 2012 over the Arctic Ocean. The blue line represents the ESA Twin-Otter aircraft, the green shows the track of the NASA P-3 plane and the red line shows CryoSat’s path as it orbits 700 km above. The background images, assembled by the Technical University of Denmark, come from ESA’s Advanced Synthetic Aperture Radar on Envisat.

Marking another remarkable collaborative effort, ESA and NASA met up over the Arctic Ocean this week to perform some carefully coordinated flights directly under CryoSat orbiting above.

The data gathered help ensure the accuracy of ESA’s ice mission.

The aim of this large-scale campaign was to record sea-ice thickness and conditions of the ice exactly along the line traced by ESA’s CryoSat satellite orbiting high above. A range of sensors installed on the different aircraft was used to gather complementary information.

These airborne instruments included simple cameras to get a visual record of the sea ice, laser scanners to clearly map the height of the ice, an ice-thickness sensor called EM-Bird along with ESA’s sophisticated radar altimeter called ASIRAS and NASA’s snow and Ku-band radars, which mimic CryoSat’s measurements but at a higher resolution.

In orbit for two years, CryoSat carries the first radar altimeter of its kind to monitor changes in the thickness of ice.

As with any Earth observation mission, it is important to validate the readings acquired from space. This involves comparing the satellite data with measurements taken in situ, usually on the ground and from the air.

The teams of scientists from Europe, US and Canada expect that by pooling flight time and the results they will get a much-improved accuracy of global ice-thickness trends measured by CryoSat and NASA’s IceSat.

This will, in turn, lead to a better understanding of the impact of climate change on the Arctic environment.

ESA CryoSat breaks the ice with ocean currents

Click on the image to visit ESA Portal and view the animation.

Animation of the intensity of ocean surface currents as predicted by MyOcean’s global ocean model (1/12°) after assimilation of altimetry data. 

In addition to major currents such as the Gulf Stream, the turbulence driving the ocean circulation is visible. 

The blue-to-white colour scale represents surface currents in metres per second.

Credits: MyOcean/Mercator-Ocean

Ocean measurements from ESA’s CryoSat mission are being exploited by the French space agency CNES to provide global ocean observation products in near-real time. Understanding sea-surface currents is important for marine industries and protecting ocean environments.

As it orbits from pole to pole, CryoSat’s main objective is to measure the thickness of polar sea ice and monitor changes in the ice sheets that blanket Greenland and Antarctica. But the satellite also features an innovative radar altimeter that not only detects tiny variations in the height of the ice, but can also measure sea level and the height of the waves.

Starting today , CryoSat ocean measurements are being processed by CNES and distributed to the oceanography community. These products will be assimilated using models from the MyOcean project in near-real time to enhance sea surface products and to improve the quality of the model forecasts.

ESA CryoSat ice satellite rides new waves

Estimate of wind speed over oceans using data from ESA’s CryoSat mission from 17 November – 13 December. The product was generated by NOAA using CryoSat’s fast delivery mode radar echoes.

Credits: NOAA – E. Leuliette

ESA's ice mission CryoSat in orbit. CryoSat is Europe's first mission dedicated to monitoring ice. 

By measuring the changes in the thickness of ice, both marine ice floating in the oceans and the vast ice sheets on land, the CryoSat mission will lead to a better understanding of how Earth's ice fields are responding to climate change.

Credits: ESA - AOES Medialab

ESA’s CryoSat mission has been gathering detailed information on the thickness of Earth’s ice since its launch in 2010. Through international collaboration, this state-of-the-art mission is soon to be used to monitor conditions at sea for marine forecasting.

CryoSat was built to measure tiny variations in the thickness of Earth’s ice. As a result, the mission is providing scientists with the data they need to help improve our understanding of the relationship between ice, climate and sea level.

As CryoSat orbits from pole to pole, it passes over vast expanses of ocean. So while the mission was designed specifically for ice monitoring, it can also serve to help improve the safety of marine traffic.

Sea level off the southeast coast of Australia on 15 December 2011 by combining CryoSat data with Envisat, Jason 1 and Jason 2.

Credits: CSIRO - D. Griffen

The satellite carries Europe’s first radar altimeter specialised for the purpose of detecting tiny variations in the height of the ice – but it can also be used to measure sea level and the height of the waves.

The instrument sends out short radar pulses and measures the time it takes for the signals to travel from the satellite to the ground and back. This information provides the height of the surface below.

The advantage of yielding this kind of information from CryoSat is also down to the advanced performance of its main SIRAL instrument.

When data from CryoSat are merged with other altimeter data such as that from the Envisat and Jason satellites, the combined estimation of wave height and wind speed is greatly improved.

In addition, thanks to its drifting orbit, CryoSat allows a high number of crossovers with other altimeter missions. This provides a set of measurements that have not been available before.

ESA CryoSat rocking and rolling - video

Since its launch in April 2010, CryoSat-2 has been collecting data to improve our understanding of the relationship between ice and climate.

To ensure the precision of the measurements, an operation is underway to roll the spacecraft by ±0.4 degrees to test the radar altimeter in measuring the topography of ice margins. This animation is not to scale.

Credits: ESA, M. Pinol (ESTEC)

ESA CryoSat - New ice thickness map of the Arctic unveiled

The first map of sea-ice thickness from ESA’s CryoSat mission was revealed today at the Paris Air and Space Show.

This new information is set to change our understanding of the complex relationship between ice and climate.

From an altitude of just over 700 km and reaching unprecedented latitudes of 88º, CryoSat has spent the last seven months delivering precise measurements to study changes in the thickness of Earth’s ice.

Satellites have already shown that the extent of sea ice in the Arctic is diminishing. In fact, spring 2011 is the third lowest extent recorded by satellite.

However, to understand fully how climate change is affecting the fragile polar regions, there is a need to determine exactly how the thickness of the ice is changing.

To answer this question, a group of scientists together with Prof. Duncan Wingham from University College London proposed the CryoSat mission to ESA in 1998. The loss of the original CryoSat satellite in 2005 as a result of a launch failure has unfortunately made this a longer than normal wait.

Nevertheless, the launch of the replacement satellite in April 2010 has resulted in these first maps of ice thickness.

They clearly demonstrate that CryoSat is a mission of excellence and will greatly advance polar science.

The results were presented at the Le Bourget air and space show by Volker Liebig, ESA's Director of Earth Observation Programmes, Duncan Wingham and René Forsberg from the National Space Institute at the Technical University of Denmark.

ESA - CryoSat - New ice thickness map of the Arctic unveiled

See also the ESA Paris video of Cryosat Presentation here

ESA Cryosat video - Paris Air & Space Show

ESA - Paris Air & Space Show - Live from Paris Air & Space Show today today: CryoSat

Ihe ESA pavilion at the Paris Air & Space show, ESA’s CryoSat - Europe’s first satellite dedicated to the study of ice.

Results from measurements performed during the first year of the mission will be presented. Streaming starts at 12:00 CEST.

See the ESA Paris Presentation  on Cryosat here

ESA Cryosat-2 Handover to Mission Controller

CryoSat-2 is Europe's first mission dedicated to monitoring Earth's ice fields.

The satellite carries a sophisticated radar altimeter that can measure the thickness of sea ice down to centimetres and also monitor changes in ice sheets, particularly around the edges where icebergs are calved from the vast ice sheets that cover Greenland and Antarctica.

This milestone is not only achievement for the CryoSat mission, but also for ESA's programme for Earth observation. After the GOCE gravity mission and the SMOS water mission, CryoSat is the third Earth Explorer mission to begin operational life in orbit.

Looking to the future, a host of missions, including the Swarm magnetic field Earth Explorer and the family of Sentinel satellites for the Global Monitoring for Environment and Security programme are in various stages of development and will be launched over the next few years.

These satellite missions will significantly contribute to advancing our understanding of how Earth works as a system and provide much-needed information to assess how climate change is affecting our environment.

ESA Cryosat-2 Launch: Invitation for Press Witnesses

Credits: ESA - AOES Medialab

CryoSat's 'roof' is formed from solar panels rigidly fixed to the satellite body, designed to provide adequate power under all orbital conditions for this non-Sun synchronous satellite.

Lift-off is scheduled for 15:57 CEST (13:57 UTC) on Thursday 8 April 2010. The launch operator is Kosmotras. Representatives of the press are invited to watch the event live from ESA's European Space Operations Centre (ESOC) in Darmstadt, Germany.

This new launch date has been confirmed by International Space Company Kosmotras following the implementation and validation of a change in the DNEPR launcher’s flight software.

Monitoring variations in the thickness of marine ice floating in the polar oceans and changes in the vast ice sheets that overlie Greenland and Antarctica, ESA’s ice mission CryoSat deploys the most sophisticated satellite ever to study the Earth's ice fields.

CryoSat-2 will be placed into orbit 700 km above the Earth by a Russian Dnepr rocket launched from the Baikonur Cosmodrome in Kazakhstan.

Press representatives are invited to watch the launch live from ESA’s ESOC establishment in Darmstadt. A European Press Centre will be open from 12:30 to 17:30 and ESA is hosting a launch event from 14:00 to 16:30.

Live televised transmission of the launch will provide pictures from Baikonur and from Mission Control at ESOC for broadcasters. Further details of the TV transmission can be found at http://television.esa.int/. ESA senior management and programme specialists will be on hand to give explanations and interviews.

Media representatives wishing to follow events from Darmstadt or watch the launch live from another ESA establishment should fill in the accreditation form (link) and fax it back to one of the numbers provided.

ESA Cryosat-2 Polar Ice Observation

The campaign activities, which include further testing on the main instrument antenna – the Synthetic Aperture Radar (SAR)/Interferometric Radar Altimeter (SIRAL) and the Doppler Orbit and Radio Positioning Integration by Satellite (DORIS), which provides the satellite with accurate time and positioning data, have continued on schedule.

Once the final phase of testing had been completed, permission was given to fuel the satellite and encapsulate it with the upper stage of the Dnepr rocket.

CryoSat-2 is now sealed with the upper stage – the 'space head module' – of the rocket and next week will make its way to the launch pad where it will be integrated onto the rest of the launcher in the silo

ESA Cryosat-2 being loaded into Dnepr launcher

Credits: ESA/W. Simpson

Final look at ESA’s CryoSat-2 satellite as it disappears from view within the Dnepr 'space head module' on 10 February.



Credits: ESA/P. Carril

CryoSat-2 will be taken into orbit on a Dnepr launch vehicle. Unusually, the upper stage flies backwards before releasing the satellite, ensuring the most accurate orbit injection.

As preparations for the launch of ESA's ice mission on 25 February continue on schedule, an important milestone has just been reached with the team at the Baikonur Cosmodrome saying farewell to CryoSat-2 as it was encapsulated in the rocket's 'space head module'.

This milestone is the culmination of over three weeks of work testing the satellite at the launch site in Kazakhstan. Now, sealing CryoSat-2 from view, the protective fairing will not be released until just over 16 minutes after launch, when the satellite is injected into orbit.

Dnepr separation
The CryoSat mission is dedicated to precise monitoring of the variations in the thickness of ice. The mission will provide detailed data on changes in the thickness of both ice floating in the polar oceans and the vast ice sheets that cover Greenland and Antarctica. With the effects of a changing climate fast becoming apparent, particularly in the polar regions, this information is urgently needed to further our understanding of the complex interactions between ice and climate.

Since it was shipped to the Baikonur Cosmodrome in January, the CryoSat-2 satellite has been undergoing an intense series of tests to ensure it is ready for launch. Although this particular launch campaign has not all been plain sailing, the preparations remain on schedule and launch is still set for 25 February at 14:57 CET (13:57 UT).

ESA: CryoSat-2 Satellite Prepared for Launch

Following the safe arrival of the CryoSat-2 satellite at the launch site in Baikonur a week ago, the launch campaign team has been busy unpacking the satellite and the containers of support equipment.


Initial inspections show the satellite to be in good shape.

Marking the official start of the launch campaign, CryoSat-2 arrived at the Yubileiniy airfield at the launch site on 13 January. The first task was to unload the satellite container and support equipment from the Antonov aircraft, which had carried the cargo from Munich in Germany.

Fortunately, the weather was kind; sunny, around –12°C and a slight breeze, which helped with the job of unloading and transporting the precious cargo by lorry to the integration facilities.

The following day was spent unpacking and setting up the ground support equipment. This equipment includes a lifting beam and the multipurpose trolley, which is used to support the satellite while it is being tested. Once the equipment was set up the satellite could be unpacked and installed on the trolley – an important milestone in the launch campaign.

Read the full article on the ESA site ....