A new slot has been identified for the second Meteosat Second Generation (MSG) satellite which is now due to be launched towards the end of 2005.

This announcement was made by Arianespace last week, following findings concerning the Ariane 5 GS vehicle which affected the launch date foreseen for early autumn 2005.

The MSG-2 satellite was already shipped to Kourou, French Guiana on 21 June and is being kept in storage after extensive testing confirmed the functionality of the platform and instruments after transport.

Detailed analyses were also successfully concluded to verify that MSG-2’s sensitive instruments, like the Spinning Enhanced Visible and Infrared Imager (SEVIRI) and the Geostationary Earth Radiation Budget (GERB), would not be damaged during the launch.

Given the new slot the launch campaign is scheduled to resume no earlier than 10 October.

For almost 30 years ESA has been building Europe’s orbital weather satellites: the Meteosat series of geostationary spacecraft, the first of which was launched in 1977. The success of the early Meteosats led to the creation of the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) in 1986.

ESA and EUMETSAT worked together on the later satellites in the series, designed to deliver continuous weather images to European forecasters on an operational basis.

This cooperation between the two international organisations continues now the original satellites are gradually being replaced by a new, second generation of Meteosats.

The first of these (MSG-1, now known as Meteosat-8) was launched in August 2002 and declared operational in January 2004. With the launch of MSG-2, continuity of service will be ensured further into the future.

European forecasters and researchers are already benefiting from the advanced data and images provided by Meteosat-8. The image data generated by its 12 spectral channels provide 20 times the information of previous generation satellites.

Meteosat-8 disseminates improved information and imagery for weather forecasting as well as other applications such as hydrology, agriculture, environmental studies as well as risk prevention and disaster warnings. The data collected are routinely used for the study of weather and climate change.

EUMETSAT is currently operating Meteosat-6, -7 and -8 over Europe and Africa, and Meteosat-5 over the Indian Ocean. The data, product and services from these satellites built by ESA for EUMETSAT make a significant contribution to weather forecasting and to the monitoring of the global climate.

Original press release: MSG-2 now planned for launch towards year’s end (ESA)

Dangling from a handy branch in her technical rock-climbing gear, ecologist Nancy Harris of the State University of New York at Syracuse is demonstrating a new way to study one of the richest and least-understood regions of the tropical rain forest: the treetop canopy.
Says Henry Gholz, director of the the National Science Foundation (NSF)’s Long-Term Ecological Research (LTER) program, not only is the canopy the location of much of the biodiversity in rain forests, “it regulates how much light is available to all other plants in the ecosystem.” But getting there, as researchers have learned after decades of trying, is a challenge. Building a tower in the forest is time-consuming, and provides access to only a few treetops at a time. And bringing in a crane is expensive, not to mention being impractical in rugged terrain.

Thus the appeal of Harris’ rock-climbing method, which gives her access to virtually any tree in a forest, regardless of topography.

Working in Puerto Rico’s Luquillo Forest, one of NSF’s 26 LTER sites, she and her colleagues can rig a tree for climbing in as little as an hour. A giant slingshot is used to shoot a three-ounce fishing weight, attached to a 12-pound-test fishing line, over a branch high in the canopy. Once the line is over the branch, it is replaced first with parachute cord and then with a 12-millimeter-diameter rock-climbing rope that can be climbed using a harness and mechanical ascenders. A separate pulley system is rigged so instruments can be raised or lowered to any height in the canopy by pulling a rope from the ground.

Once she ascends, Harris uses a portable device to measure the photosynthetic rates of both canopy and understory leaves of different tree species. She will later combine these measurements with climate modeling techniques to figure out how the element carbon flows through specific “columns” of the Luquillo Forest. Carbon is important in studies of global climate change.

Other researchers at the Luquillo LTER site are climbing trees to find out how much damage hurricanes wreak on rain forest canopies. To match the damage observed after past hurricanes, scientists have removed specific numbers of tree branches from experimental plots.

Tree canopies are important regulators of local environmental conditions because of their exposure and the resistance they provide to wind damage, said Gholz. “But canopies are also very susceptible to the high winds of strong storms like hurricanes.”

Hurricanes like Hugo regularly strike Puerto Rico, said scientist Nick Brokaw of the University of Puerto Rico, cutting a swath through the forest. “However, in our experimental plots mimicking hurricane conditions, we’re seeing that thousands of new seedlings are sprouting, and thickets of saplings are developing.”

If the forest could regenerate after Hugo, Brokaw believes, it can come back after almost anything.

Original press release: Scientists Climb Trees to Study Environmental Change (NSF)

Heavy rainfall and flooding from Typhoon Matsa killed at least 12 people and caused millions of euros worth of damage in China. In Matsa’s aftermath, unique data from ESA’s ERS-2 spacecraft reveal the interior wind fields powering it at its height.

China’s ninth typhoon this year, Matsa first came ashore at Yuhan County in Zhejiang Province on 6 August, with reported winds up to 250 kilometres per hour. Matsa brought heavy rains and serious damage to several coastal provinces and cities – in Zhejiang alone 13 000 houses were destroyed and farmland inundated.

Since downgraded to a tropical storm, Matsa reached Beijing on the evening of 8 August although failed to bring the torrential rainfall that was initially anticipated by the authorities - poised to evacuate thousands from vulnerable areas on the outskirts of the city.

Due to the support of China’s Remote-Sensing Ground Station (RSGS), located in Beijing and run by the Chinese Academy of Sciences, scientifically unique information about the interior structure of Matsa at its strongest has been made available to worldwide meteorological offices and scientific users. A detailed picture of the wind speed and direction around the centre of the typhoon was acquired from ESA’s ERS-2 on 4 August, when the typhoon was still in the East China Sea.

ERS-2 instruments include a C-band scatterometer which works by sending a high-frequency radar pulse down to the ocean, then analysing the pattern of backscatter reflected back again. Scatterometers are particularly useful in measuring wind speed and direction at the sea surface, by detecting signature scatter from water ripples caused by wind.

ERS-2’s scatterometer is the only instrument of its type capable of peering through rain and bad weather, and is also able to gather data during both day and night. This makes it very useful as a tool to study the structure of typhoons, hurricanes and other strong storms.

Back in 2001 the spacecraft was struck a blow as the last of its pointing gyroscopes failed. However all instruments were still functioning perfectly, so ESA engineers worked with industry to develop a new ‘gyro-less’ working mode to resume data delivery.

Then in June 2003 the onboard Low Bit Rate data recorder failed, used to store non-radar image data when out of touch with ESA ground stations. However, recognising the value of this data, international ground stations responded by working voluntarily to collect and distribute ERS-2 results in near-real time.

The Beijing RSGS joined the effort in May 2005, and with NASA’s McMurdo Ground Station having began participating around the same time, ERS-2 data are being acquired across all seven continents, with all data acquired from this voluntary group effort shared with the wider meteorological and scientific community.

ERS-2’s scatterometer saw service interrupted between 2001 and 2003, due to degradation in the spacecraft’s pointing control, but a new algorithm developed by the Belgian Royal Military Academy (RMA) returned it to operational status. This algorithm has been installed in the various cooperating ground stations.

Today, ERS-2 scatterometer data is employed by users worldwide, including the UK-based European Centre for Medium-Range Weather Forecasts (ECMWF), who routinely assimilate its results into their weather prediction models. ECMWF’s remit includes the study of worldwide storms, so they have assimilated the Matua scatterometer results in their weather analysis for this time.

“The ERS-2 scatterometer data was - besides a few pressure observations - the only surface data available in the vicinity of the typhoon, and therefore valuable,” stated Dr Hans Hersbach of ECMWF. “As a result, the maximum surface wind speed was enhanced from 19.8 metres per second to 21.3 metres per second and the central mean sea-level pressure was deepened by 4.5 millibars. From this analysis, the landfall of Matsu was correctly predicted to be a likely scenario.”

ERS-2 flies on the same orbit but half an hour behind ESA’s ten-instrument Envisat environmental satellite, and so offers researchers a means to validate or supplement Envisat observations. Some ERS-2 instruments – its Synthetic Aperture Radar (SAR), Along Track Scanning Radiometer (ATSR) and its atmospheric Global Ozone Monitoring Experiment (GOME) – have counterparts on Envisat, although its scatterometer is unequalled for the time being.

To ensure continuity of C-band scatterometer coverage into the future, a more advanced scatterometer called ASCAT is payload of the payload for the ESA-built MetOp mission, due to launch in 2006.

Typhoon season

A typhoon is the term for a tropical cyclone that occurs in the northwest Pacific or Indian Oceans west of the International Dateline. It is a large, powerful storm that rotates around a central area of extreme low pressure.

Typhoons arise in warm tropical waters that transfer their heat to the air. The warmed air rises rapidly, in the process creating an area of low pressure at the water surface. Winds begin rushing inwards and upwards around this low-pressure zone. Typhoons can form all-year-round in the waters off China, but the peak season comes between June and December.

Original press release: ERS-2 successfully targets China’s Typhoon Matsa (ESA)

As European cities swelter in the summer heatwave, a new report from WWF, analyzing summer temperature data from 16 EU cities, shows the continent’s capitals warming by sometimes more than 2°C in the last 30 years.

The global conservation organization’s report, Europe feels the heat - Extreme weather and the power sector, shows London is the city where average maximum summer temperature increased the most, up 2°C over the last 30 years, followed by Athens and Lisbon (1.9ºC), Warsaw (1.3ºC), and Berlin (1.2ºC).

Meanwhile, the increase in average summer mean temperature was highest in Madrid – up by a staggering 2.2°C, followed by Luxembourg (2ºC), Stockholm (1.5ºC), and Brussels, Rome, and Vienna (1.2ºC). In the last five years, average summer temperatures in 13 of the 16 cities looked at were at least 1ºC higher than during the first five years of the 1970s.

“Summer temperatures in Europe’s cities are heading for an ‘unbearable’ reading on the thermometer,” said Imogen Zethoven, Director of WWF’s Global PowerSwitch! Campaign. “Scientists estimate that man-made greenhouse gas emissions are doubling the risk of more record-breaking hikes in temperature.”

WWF’s report highlights the likelihood of more frequent and intense heatwaves, droughts and rainstorms as average temperatures increase, the kind of events expected as a result of global warming.

It emphasizes that the power sector has fuelled a major part of this hike in temperatures, being responsible for 37 percent of man-made CO2 emissions from burning fossil fuels, mainly coal.

“To make Europe’s cities liveable in summer we must guarantee the cuts needed in emissions to switch off global warming,” added Zethoven. “EU governments must enforce stricter CO2 limits required under the European Emissions Trading Scheme.”

Original press release: It’s getting hotter in the city (WWF)

When a volcano erupts, it does more than just create an ash cloud that darkens and cools a region for a few days. Instead, the most dramatic effect is actually high above us, where spewed volcanic material is not quickly washed out by rain.

If the volcanic eruption is strong enough it will inject material into the stratosphere, more than 10 miles above the Earth’s surface. Here, tiny particles called aerosols form when the volcano’s sulfur dioxide combines with water vapor. Despite their size, these aerosols work to alter interactions between the atmosphere and sun, affecting climate patterns.

Now, new research funded by NASA and the National Science Foundation, focusing on the eruption of Mount Katmai, Alaska, in June 1912, shows that location is also important, as major volcanic eruptions far north of the equator affect the world’s climate much differently than volcanoes in the tropics.

The Mount Katmai eruption was the one of the largest in the world during the 20th century. It actually refers to the eruption of Katmai and the larger explosion of Novarupta, just west, that spewed tons of sulfur dioxide gas into the atmosphere. Novarupta also released an incredible amount of molten rock (magma) that drained under Katmai causing its summit to collapse, forming a massive crater (caldera). The ash fall from the eruption covered an area of more than 3,000 square miles to a depth of a foot or more, while its ash cloud, carried by winds high in the atmosphere, spread a haze as far away as Africa.

“Studying such events will help us be better prepared for the next major eruption while giving scientists clues on the type of climate shifts and changes to expect,” said Luke Oman, a researcher at Rutgers University’s Department of Environmental Sciences, New Brunswick, N.J., and lead author of the study that appeared in the July 2005 issue of the Journal of Geophysical Research-Atmospheres.

By using one of the most modern General Circulation computer climate Models (GCMs) at NASA’s Goddard Institute for Space Studies (GISS), New York, N.Y., the researchers studied the Mount Katmai volcanic eruption. They made a computer simulation of Katmai’s eruption and an eruption three times as large to study their climate impacts.

Unlike earlier studies on volcanic eruptions in the tropics, this research did not show a change in an important climate pattern called the “Arctic Oscillation” (AO) following the Mount Katmai eruption.

AO is a climate pattern defined by winds circulating counterclockwise around the Arctic at about 55 degrees north latitude (about even with Moscow). The air can spin more slowly and spill cold air down toward the equator into the mid-latitudes, or it can spin faster and keep the cold up north.

“Large tropical volcanic eruptions tend to spread aerosols around the globe, but with high-latitude eruptions like Katmai, they remain north of 30°N latitude, where they are heated less efficiently by outgoing, or longwave radiation,” said Oman. “As a result, the lower stratosphere does not warm enough to influence the AO.”

Eruptions in the tropics, like Mount Pinatubo in 1991, create aerosols that block heat from the sun in the lower atmosphere, or troposphere, cooling temperatures in the subtropics. In turn, the reduced north to south temperature gradient results in a “positive” phase of the AO, with generally warmer winters over the Northern Hemisphere.

“In our research, although the Mount Katmai eruption was found to have some role in the winter climate, including distinct cooling in southern Asia, the most significant climate effect was during the summer when strong cooling over the Northern Hemisphere landmasses caused a decrease in the Asian monsoon circulation,” said Oman.

Normally, northern India experiences large amounts of cloudiness and rain due to the summer monsoon, the seasonal shift in winds that develops out of the temperature contrast between the Indian Ocean and Asia. But, the eruption worked to lessen this gradient, weakening the monsoon, bringing reduced cloudiness, warmer temperatures and less precipitation across northern India west into the Persian Gulf.

“This study not only offers further evidence that the location and intensity of an eruption largely determine the Earth’s overall climatic response, it also helps us see how well our computer models perform,” said co-author Gavin Schmidt of NASA GISS.

To verify our knowledge about the effects of volcanoes, researchers often investigate historic intense eruptions that brought major climate swings, like the Laki, Iceland eruption of 1783 that dimmed and reddened the sun while resulting in a very warm summer in Europe and one of the coldest winters on record for the Northeast United States and Europe in 1783-1784. Using a variety of techniques, including the measurement of acid fallout over polar areas from ice cores and analyzing annual growth rings in trees, researchers can confirm first hand the impact of such ancient eruptions.

Image: A nearly perfect volcanic cone built entirely of loose fragmented material in Mojave National Preserve, California. Eruptions in this volcanic field occurred over the last several million years and in some cases lava flowed on the surface up to six miles from the eruption site. Credit: USGS

Original press release: Volcanic Blast Location Influences Climate Reaction (NASA)

The impact of global warming has become obvious in high latitude regions, including Alaska, Siberia and the Arctic, where melting ice and softening tundra are causing profound changes. But, contrary to popular belief, the most serious impact in the next century likely will be in the tropics, says a group of researchers headed by a University of Washington ecologist.

Scientists have noted warming at higher latitudes that already appears to be causing some flowers to bloom earlier than usual and seems to be altering some wildlife migration and hibernation patterns.

“You see this and you think the higher latitudes are really being hammered by climate change. We are arguing that this might not be true,” said Joshua Tewksbury, a UW assistant professor of biology. “To predict the impact of climate change, we need to know the amount of change and how organisms are able to tolerate that change. Previous research has focused on change alone and ignored tolerance.”

The more dramatic impact could actually be in the moist tropics, despite modeling that indicates temperatures there will warm just 2 or 3 degrees by 2100 compared with 6 degrees or more at higher latitudes, Tewksbury said. That is because organisms in the tropics normally do not experience much temperature variation because there is very little seasonality, so even small temperature shifts can have a much larger impact than similar shifts in regions with more seasonal climates.

“Temperatures in the tropics don’t fluctuate that much, so the relatively small temperature shifts predicted by climate change models will be very large in relation to what organisms are adapted to tolerate,” he said. “It’s only going to be perhaps a 2-degree change, but in many tropical areas organisms have never experienced a 2-degree change.”

By contrast, higher latitudes can have vast temperature fluctuations from hot summers to cold winters, and so plants and animals already are adapted to a wide range of temperatures. For example, it is not unusual for temperatures in Alaska’s interior to reach far below zero in the winter and into the mid-70s during the summer. Flowers that bloom earlier and animals that change their hibernation or migration patterns in response to warming temperatures could be an illustration of the adaptability of life at higher latitudes.

Tewksbury’s group collected studies that examined several closely related populations of plants, animals and insects to determine how the populations tolerated changing temperatures. Then they developed models based on the average between a region’s highest temperature in the warmest month of the year and lowest temperature in the coldest month and programmed the region’s expected temperature changes because of climate warming.

“What we find is that organisms in the tropics have very low tolerance,” he said. “The evidence suggests that the range of temperatures an organism experiences dictates its tolerance to changing climate, or defines the temperature envelope in which it can live.”

Tewksbury will present the findings Friday at the Ecological Society of America’s annual meeting in Montreal. Collaborators include Raymond Huey, a UW biology professor, and UW biology doctoral students David Haak, Paul Martin and Kimberly Sheldon, who is lead author for the work.

Tewksbury noted that while direct estimates of tolerance are not available for all organisms or for all regions of the globe, there is good information on the degree of seasonal temperature fluctuation worldwide. That seasonality, he said, can be used to predict how well organisms will tolerate climate change.

The findings also imply that warming could forever alter life on Earth because the vast majority of species live in the tropics and many could be driven to extinction because of their inability to adapt.

“Evolution only happens if you don’t go extinct. From an evolutionary standpoint, a model of the climate change impact reflects a race between adaptation and extinction,” Tewksbury said.

“Climate models project 6 degree temperature shifts in temperate zones during the next 90 years and 2 to 3 degrees in equatorial climates. That is such a rapid change that longer-lived organisms such as trees will have very little opportunity for adaptation — survival might be a matter of tolerance alone. In contrast, for an insect that has three generations a year the evolution of tolerance might play a larger role.

“It’s kind of a bleak outlook for tropical organisms, and it shows how the lack of seasonal temperature variation can magnify the impact of climate warming.”

Original press release: Warming most evident at high latitudes, but greatest impact will be in tropics (University of Washington)