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Express map delivery from space

Copyright ESA

Meeting the environmental needs of an ever-expanding Europe requires consistent and regularly updated information on its land cover and use. As part of ESA’s GlobCorine project, a pan-European land cover and use map for 2009 is now available online.

The map, based on ESA’s Envisat MERIS data from 1 January to 31 December 2009, is the first of its kind to be produced in such a short time – nine months as opposed to years. GlobCorine shows how an automated service can generate and regularly update such maps, which are essential for environmental agencies.

The map, providing a resolution of 300 m, was delivered to the European Environmental Agency (EEA), the project’s main user, in October.

“The novelty of this map is that we can finally have relevant, timely global land cover information compatible with the time series of European Corine land cover data for decision-making,” EEA’s Chris Steenmans, Head of Programme, Shared Environmental Information System, said at the final GlobCorine meeting held at ESA’s Earth observation centre (ESRIN) in Frascati, Italy, last week.

“If you want to bring the environment into the context of economic and social development, then the speed of environmental information delivery needs [...]

Watching solar activity muddle Earth’s magnetic field

watching-solar-activity-muddle-earths-magnetic-field

Copyright ESA

<- Effect of extreme solar activity on Earth’s magnetosphere

Scientists have found that extreme solar activity drastically compresses the magnetosphere and modifies the composition of ions in near-Earth space. They are now looking to model how these changes affect orbiting satellites, including the GPS system.

The results were obtained from coordinated in-situ measurements performed by ESA’s four Cluster satellites along with the two Chinese/ESA Double Star satellites.

Under normal solar conditions, GPS satellites orbit within the magnetosphere—the protective magnetic bubble carved out by Earth’s magnetic field. But when solar activity increases, the picture changes significantly: compressed and particles become energized, exposing satellites to higher doses of radiation that can perturb signal reception.

“Looking at such a large-scale physical phenomena with a single satellite is akin to predicting the impact of a tsunami with a single buoy.”

Such increased solar activity affects all satellites, not only the GPS system. This is why monitoring and forecasting its impact on near-Earth space is becoming increasingly critical to safeguarding daily life on Earth. One way to do this is by studying the physics of near-Earth space and observing the impact of such activity in time.

During two extreme solar explosions, or [...]

Arctic sea ice thinning at record rate

arctic-sea-ice-thinning-at-record-rate

Copyright ESA

The thickness of sea ice in large parts of the Arctic declined by as much as 19% last winter compared to the previous five winters, according to data from ESA’s Envisat satellite.

Using Envisat radar altimeter data, scientists from the Centre for Polar Observation and Modelling at University College London (UCL) measured sea ice thickness over the Arctic from 2002 to 2008 and found that it had been fairly constant until the record loss of ice in the summer of 2007.

Unusually warm weather conditions were present over the Arctic in 2007, which some scientists have said explain that summer ice loss. However, this summer reached the second-lowest extent ever recorded with cooler weather conditions present.

Dr Katharine Giles of UCL, who led the study, said: “This summer’s low ice extent doesn’t seem to have been driven by warm weather, so the question is, was last winter’s thinning behind it?”

Arctic sea ice extent in September 2007 and September 2008 The research, reported in Geophysical Research Letters, showed that last winter the average thickness of sea ice over the whole Arctic fell by 26 cm (10%) compared with the average thickness of the previous five winters, but sea [...]

Chilean volcano captured blasting ash

chilean-volcano-captured-blasting-ash

Copyright ESA

Chile’s Chaiten Volcano is shown spewing ash and smoke (centre left of image) into the air for hundreds of km over Argentina’s Patagonia Plateau in this Envisat image acquired on 5 May 2008.

The 1000 m-high volcano had been dormant for thousands of years before erupting on 2 May, causing the evacuation of thousands. Chaiten Volcano is located in southern Chile 10 km northeast of the town of Chaiten on the Gulf of Corcovado.

Envisat’s Medium Resolution Imaging Spectrometer (MERIS) instrument processed this image at a resolution of 1200 m.

Satellite data can be used to detect the slight signs of change that may foretell an eruption. Once an eruption begins, optical and radar instruments can capture the lava flows, mudslides, ground fissures and earthquakes.

Atmospheric sensors onboard satellites can also identify the gases and aerosols released by the eruption, as well as quantify their wider environmental impact.

To boost the use of Earth Observation (EO) data at volcanic observatories, ESA has started to monitor volcanoes worldwide within the Agency’s Data User Element programme.

The Globvolcano project, started in early 2007, will define, implement and validate information services to support volcanological observatories in their daily work by integration [...]

Cluster makes a shocking discovery

cluster-makes-a-shocking-discovery

Copyright ESA

ESA’s Cluster was in the right place and time to make a shocking discovery. The four spacecraft encountered a shock wave that kept breaking and reforming – predicted only in theory.

On 24 January 2001, Cluster’s spacecraft observed shock reformation in the Earth’s magnetosphere, predicted only in theory, over 20 years ago. Cluster provided the first opportunity ever to observe such an event, the details of which have been published in a paper on 9 March this year.

The shock wave that sits above the Earth’s surface is a natural phenomenon. It is located on the side facing the Sun, at approximately one quarter of the distance to the Moon, and is caused by the flow of electrically charged particles from the Sun.

This flow of electrically charged particles known as solar wind is emitted in a gusty manner by the Sun. When it collides with the Earth’s magnetic field, it is abruptly slowed down and this causes a barrier of electrified gas, called the bow shock, to build up. It behaves in the same way as water being pushed out of the way by the front of a ship.

On 24 January 2001, the four Cluster spacecraft [...]