Seeing how rain falls from top to bottom and how heavy the rain falls throughout parts of a tropical cyclone is very important to hurricane forecasters. NASA has sped up the process of getting this data within three hours, and making it appear in 3-D. The new process now gives information quickly enough for forecasters to use.

Scientists at NASA have developed a way to process radar data from NASA and the Japan Aerospace Exploration Agency’s (JAXA) Tropical Rainfall Measuring Mission (TRMM) satellite that can help with forecasting changes in a hurricane�s intensity.

What is important is that the vertical rain structure data used to take a longer time to process, said Jeffrey Halverson, Meteorologist and TRMM Education and Outreach Scientist. With hurricane forecasts, events change quickly, and meteorologists need data as fast as possible. This new process gives them data within three hours from the time the satellite has flown over a tropical cyclone.

TRMM is a unique satellite that is able to estimate rainfall measurements from space, and rainfall is a key ingredient in hurricanes. For example, heaviest concentrations of rainfall for example are found around the eye or center of the hurricane. Scientists can tell, based on if the rain is getting stronger or weaker, whether or not the hurricane is strengthening or weakening.

In 2004, research confirmed that when larger towering clouds reach a certain height surrounding the hurricane’s open eye, in what is called the eye-wall, they can be associated with a strengthening storm. TRMM can identify these hot towers of piled up clouds and cam help make forecasts more accurate.

Because the TRMM satellite covers the tropical areas of the entire globe, the Precipitation Radar (PR) instrument takes snapshots of storms as it passes by. Every time it passes over a named tropical cyclone anywhere in the world, the PR will send data to create these 3-D snapshots of the storms.

The hurricane snapshot will show forecasters information on how heavy the rain is falling from different parts of the storm, such as the in eye-wall versus the outer rainbands, for example. It also gives a 3-D look at the cloud heights and hot towers inside the storm. Higher hot towers around the eye usually indicate a strengthening storm.

The snapshot also gives valuable information about how the storm is put together. For example, when scientists studying a snapshot see that the body of the hurricane may be tilted inward to the hot towers, it could give clues as to whether a wind shear, or a sudden change in direction of winds near the top of the storm, may impact the storm’s strength. Normally, when a hurricane runs into a strong wind shear, it weakens.

Forecasters and the general public can access the data and look into the eye of a storm by going to the TRMM website.

Original press release: NASA Offers a Real Time 3D Look at the Inside of Hurricanes (NASA Earth Observatory)

Scientists from across Europe convened at the Barrax test site near Albacete, Spain, to join the chase for an elusive signal emitted by vegetation, which may just hold the key to mapping photosynthesis at a global scale from space.

Currently, the approach to monitoring vegetation from space is based on images that record sunlight reflected from the Earth’s surface. Using this technique, optical satellite images generally contain information on how much vegetation is on the surface. For example, whether a field is bare, partly covered or completely covered with crops - and about potential photosynthetic activity of the vegetation cover. To understand more about photosynthetic activity occurring in plants at the very moment the observations take place, it would be better to measure solar induced fluorescence, which is directly related to actual photosynthetic activity.

Solar induced fluorescence occurs when part of the energy absorbed by chlorophyll in vegetation is re-emitted at longer wavelengths as fluorescence. This would provide a direct measurement of the vegetation’s ability to absorb atmospheric carbon dioxide, which, if mapped at global scales, would lead to greatly improving our understanding of the carbon cycle and climate change.

However, measuring fluorescence from space is challenging. The signal is very weak compared to reflected sunlight, and special instrumentation and techniques are required. In addition, little is known about the characteristics of the fluorescence signal over natural vegetation. While it is routinely used in laboratories to study photosynthetic activity, measuring fluorescence levels outside has never been done on a large scale, or at least until now.

Indeed, the first SENT2FLEX (Sentinel-2 Fluorescence Experiment) campaign, which took place 30 May to 4 June 30, 2005 provided a historical first; the first dedicated airborne fluorescence measurements. It represented the accumulation of a long preparation phase and extensive collaboration between research organizations. It first started with ESA supporting the development of a dedicated airborne fluorescence measuring instrument called AIRFLEX. The instrument was developed under an ESA contract by the LURE Photosynthesis and Remote Sensing team in Paris, France led by Dr. Ismael Moya. The German Space Agency (DLR) flight department based in Oberpfaffenhofen, Germany was responsible for both the integration of the AIRFLEX instrument into a Cessna Caravan plane, the chosen host for the instruments, and for the execution of the flights.

Efforts to prepare for the SENT2FLEX campaign this last month were especially intense. Three airborne instruments installed in two planes had to be organized. In addition to the AIRFLEX instrument in the DLR Caravan plane, two additional imagining sensors, the CASI-1500 from ITRES Research (Canada) and AHS from the Spanish National Institute for Aerospace Technology (INTA), were also installed in the INTA CASA 200 plane. Last but not least, teams had to be equipped and organized on the ground. These teams collected independent information at ground level at the same time as the aircrafts flew over the test site. Typically, soil and vegetation characteristics, their reflectance properties and atmospheric properties were measured at a number of locations.

It was with some relief that, after all these preparations, the first successful acquisitions were made in the air and on the ground on 30 May 2005. Even more exciting was the report from the AIRFLEX team the next day stating that the fluorescence signal could be identified and was providing information about different land cover types in the test site.

“For the first time we can look at how the fluorescence signal over vegetation varies from one field to the next and take a hard look at what it is telling us about the vegetation in each field”, said an enthusiastic Ismael Moya from LURE. “After all the work developing the instrument and preparing the campaign this is extremely rewarding.”

Jose Moreno, from the University of Valencia, Spain added, “We are now convinced we can measure the weak fluorescence signal so the next step is to make use of the fluorescence signal at the relevant spatial scales. In fact, fluorescence alone already provides quite significant information about plant photosynthesis, but to map CO2 assimilation at global scale, the fluorescence information must be assimilated in dynamic models of vegetation together with other data sources. The SENT2FLEX dataset provides all the elements to understand fluorescence signal variations and practical usage of such innovative measurements mapping photosynthesis.”

In total, three days of data were collected. Additional measurements are planned for this July when the condition of the vegetation will be quite different. Overall, these campaigns will lead to a unique dataset, one that documents the elusive fluorescence signal over different land cover types and under various conditions. Perhaps the signal has lost some of its elusiveness? In any case, a major step to help define novel ways of measuring photosynthesis from space has just been taken.

Original press release: A new sensor developed by ESA could lead to a better understanding of the carbon cycle (ESA)

Understanding how tropospheric or near-surface-level ozone is produced, distributed and transported from city to city, region to region and continent to continent is an important step toward improving the complex mathematical computer models used to forecast air pollution as we do for weather. Such models can be used to provide alerts days in advance so that people sensitive to pollutants can modify planned outdoor activities to minimize their exposure.

The troposphere is where we all live, work, play and breathe! It’s the region of the atmosphere where our weather occurs and it extends from the Earth’s surface to roughly the cruising altitude of a passenger jet-about 40,000 feet. In some cases air pollutants have natural causes such as lightning induced wildfires that can emit large plumes of particulates into the troposphere. Fossil fuel burning in industrial areas and vehicular traffic in metropolitan areas are also major pollutant sources. Complex chemical interactions and atmospheric processes can transport these pollutants across thousands of miles.

To improve our ability to track the transport of pollutants from their various sources to populated cities and towns around the globe, NASA technologists are exploring an innovative technology called the ’sensor web’. This interconnected ‘web of sensors’ coordinates observations by spacecraft, airborne instruments and ground-based data-collecting stations. Instead of operating independently, these sensors collect data as a collaborative group, sharing information about an event as it unfolds over time. The sensor web system is able to react by making new, targeted measurements as a volcanic ash plume is transported to air traffic routes, or when smoke of a wildfire is carried aloft, then dispersed over large metropolitan areas. The sensor web has the potential to improve the response time of our observing systems by reconfiguring their sensors to react to variable or short-lived events and then transmit that information to decision makers so that appropriate alerts can be issued to those people living in the impacted areas.

To test the value and benefit of using dynamic sensor web measurement techniques and adaptive observing strategies, NASA technologists have formulated experiments involving two NASA Earth observing satellites that fly in formation high above Earth. These consist of Aqua and the recently launched Aura, along with sophisticated atmospheric chemistry models that can forecast the global distribution and concentration of one particular pollutant; carbon monoxide (CO).

“The sensor web behaves as a search-and-rescue team,” said Principal Investigator Stephen Talabac, lead technologist with the Science Data Systems Branch at NASA’s Goddard Space Flight Center, Greenbelt, Md. “Each sensor collects data as part of a team of cooperating sensors. It is able to respond to the needs of the team members. The sensors on one satellite react to data and information sent to it from other sensors on other satellites that have different but complementary capabilities. The sensors then change their observing strategy accordingly, to target and then collect data for a particular event.” Talabac offered the analogy of a search-and-rescue team whereby the unique skills of firefighters, police officers, and paramedics are brought together to form and then implement a plan to find and rescue a person in need of help.

Computer forecast models can also help decide where the sensors should make observations. If a model forecasts high concentrations of CO, the sensor web’s instruments can be commanded to make targeted observations of those locations. The actual sensor measurements can then be fed back into the computer model to improve the accuracy of the forecast. Talabac’s team hopes to illustrate how such a model-driven sensor web could be used to enhance current measurement techniques, and bring to bear multiple complementary instruments to respond to rapidly changing environmental conditions.

“These simulations fall into the category of ‘proof of concept,’ to assess the feasibility of what is also planned for the next generation observing systems to enable real, full-fledged sensor web measurements,” explained Talabac. “We hope to demonstrate that such an approach, or ‘targeted intelligent data collection techniques,’ can bring about more efficient use of our Earth observation satellites and their sensors.”

In September 2005, Talabac’s team will use an atmospheric chemistry computer model to predict global CO distribution. The team will also make measurements using Aura’s Tropospheric Emission Spectrometer (TES), at key locations to improve the model prediction. In the future the team hopes to be able to use their prototype software to recommend regions where the TES instrument could be commanded to look and make real measurements at key locations predicted by the model.

“Our goal here is improve our ability to monitor and assess the Earth’s environment,” Talabac added. “With the sensor web, policy and decision makers will have access to the most useful and timely information available to help maintain a high quality of life and to potentially save lives.”

Original press release: Sensor Web Simulation Investigates Technique To Improve Prediction Of Pollution Across The Globe (NASA Earth Observatory)

Cuts in emissions of the greenhouse gas carbon dioxide are the only way to stem the rising levels of acidity in our oceans and prevent potentially damaging consequences for marine life warns a new report published by the Royal Society today (Thursday 30 June 2005).

According to the report, Ocean acidification due to increasing atmospheric carbon dioxide, excess carbon dioxide in the atmosphere, from man’s burning of fossil fuels, has already increased the acidity of the world’s oceans to a level that is irreversible in our life times. This is because the oceans act as a sponge, taking up carbon dioxide from the atmosphere which dissolves and forms an acid in the seawater.

Professor John Raven, chair of the Royal Society working group on ocean acidification said: “Along with climate change, the rising acidity of our oceans is yet another reason for us to be concerned about the carbon dioxide we are pumping into the atmosphere. Our world leaders meeting at next week’s G8 summit must commit to taking decisive and significant action to cut carbon dioxide emissions. Failure to do so may mean that there is no place in the oceans of the future for many of the species and ecosystems that we know today.”

Sea creatures such as corals, shell fish, sea urchins and star fish are likely to suffer the most because higher levels of acidity makes it difficult for them to form and maintain their hard calcium carbonate skeletons and shells. For example, even under the ‘low’ predictions for future carbon dioxide emissions into the atmosphere, the combined effects of climate change and ocean acidification mean that corals could be rare on tropical and subtropical reefs, such as the Great Barrier Reef, by 2050. This will have major ramifications for hundreds of thousands of other species that dwell in the reefs as well as for the people that depend upon them, both for food and to help to protect coastal areas from, for example, tsunamis.

The report says that changes in ocean chemistry, caused by ocean acidification, means that we can predict that some creatures in the Antarctic Ocean will be among the first to be affected. For example, some types of plankton a major source of food for fish and other animals may be unable to make their calcium carbonate shells by 2100. This may have significant consequences for entire food webs in the region, although the overall impact of this is unclear.

Higher concentrations of carbon dioxide may also make it harder for some larger marine animals to obtain oxygen from seawater. For example, squid are particularly sensitive because they move by jet propulsion this is very energy-demanding and requires a good supply of oxygen.

Professor Raven said: “Basic chemistry leaves us in little doubt that our burning of fossil fuels is changing the acidity of our oceans. And the rate change we are seeing to the ocean’s chemistry is a hundred times faster than has happened for millions of years. We just do not know whether marine life which is already under threat from climate change can adapt to these changes.”

By absorbing carbon dioxide the oceans actually help stave off climate change. In the past 200 years the oceans have absorbed about half of the carbon dioxide produced by humans, primarily through the burning of fossil fuels. They are currently taking up one tonne of this carbon dioxide for each person on the planet every year.

However, the report warns that rising levels of acidity in the ocean may mean that the ability of the oceans to mop up carbon dioxide from the atmosphere will be reduced. This is because the chemistry of the surface waters of the ocean means that as carbon dioxide is added, its ability to take up more is decreased. Furthermore, any rise in ocean temperatures, due to climate change, could reduce the ability of the surface waters to take up carbon dioxide from the atmosphere.

Professor Raven said: “The oceans play a vital role in the earth’s climate and other natural systems which are all interconnected. By blindly meddling with one part of this complex mechanism, we run the risk of unwittingly triggering far reaching effects.”

The report looks at various ways of tackling rising acidity such as adding limestone to the oceans to make them more alkaline. However, it found that the only practical way to minimise the risk to the oceans and marine life is to reduce emissions of carbon dioxide into the atmosphere.

The report point out that there is still much uncertainty around the impacts of ocean acidification and recommends that a major international effort be launched into this relatively new area of research.

1. Calculations indicate that the oceans uptake of carbon dioxide has led to a reduction of the pH (the scale of acidity whereby a reduction in pH indicates a rise in acidity) of surface seawater of 0.1 units. If the global emissions of carbon dioxide from human activities continue to rise on current trends then the average pH is projected to fall by up to 0.5 units by 2100. Surface oceans currently have an average pH of 8.2.

2. The report recommends that if the risk of irreversible damage arising from ocean acidification is to be avoided, particularly in the Southern Ocean, the cumulative future emissions of carbon dioxide from human activities to the atmosphere must be considerably less than 900 Giga tonnes of Carbon by 2100.

Original press release: Cuts in carbon dioxide emissions vital to stem rising acidity of oceans (Royal Society)

Cleaner-burning coal technologies are urgently needed to minimise greenhouse gas emissions from the inevitable ongoing use of fossil fuels in the coming decades, Lord Oxburgh of Liverpool, outgoing chairman of Shell, will say in a talk at the Royal Society today (Wednesday 29 June 2005).

Lord Oxburgh will point out that human civilisation has developed rapidly in a climate that has been exceptionally stable over eight thousands years, but one that we are now destabilising with emissions from the use of fossil fuels. He believes that bringing greenhouse gases under control is a massive task and that there is no quick or simple answer, both because the developed world has an enormous infrastructure geared to the availability of cheap fuel and because world population and energy demand are growing rapidly.

Lord Oxburgh will say: “We have to economise, be more efficient and move away from fossil fuels. Renewable energy sources such as wind, wave and solar have a role to play, but will not really come into their own until we have a way of storing their energy. New enzyme technology makes agricultural by-products, such as straw, a cost-effective and low carbon dioxide source of vehicle fuels, opening the way to co-production of fuel and food. Urban waste is another largely untapped energy source.

“It is, however, inevitable that fossil fuels will be widely used for many decades, particularly coal in developing countries. No energy policy is complete that does not take account of this. It is urgent that techniques for burning coal cleanly be matured.”

Lord Oxburgh will say: “Time is pressing and we have to make a start on greenhouse gas control now with the technologies we have today new approaches will undoubtedly emerge and can be fed in as they develop over the next 25 years. Research developments in energy storage, carbon capture and efficient use of energy will be particularly important.”

Original press release: Cleaner-burning coal technologies urgently needed to tackle climate change says Lord Oxburgh (Royal Society)

How sunny is it outside right now, not just locally but all across Europe and Africa? Answering this question is at the heart of many weather-related business activities: solar power and the wider energy sector, architecture and construction, tourism, even health care.

Today accurate and continent-wide scale measurements of ground radiances are provided every 15 minutes by ESA’s Meteosat Second Generation satellite.

Integrating this information with the business practices of solar energy managers is the objective of the ENVISOLAR project (Environmental Information Services for Solar Energy Industries), funded by ESA within the framework of the Earth Observation Market Development Programme (EOMD).

Solar energy has switched from a green aspiration to a solid business. The solar market in photovoltaics, the direct conversion of sunlight to electricity, has an annual turnover of 600 million euros in Germany and 1000 million euros in the rest of Europe. The latter figure is predicted to increase to 2500 million euros by this decade’s end. Furthermore, thousands of megawatt of renewable energy potential are also available in Africa, Asia and Central America as shown by the Solar & Wind Energy Resource Assessment (SWERA) project of the UN Environment Programme (UNEP).

There are two kinds of solar energy establishments: solar thermal plants which concentrate heat from the Sun, and photovoltaic plants that convert sunlight into electricity.

In both cases precise, long-term irradiance data is needed for choosing plant locations and estimates of likely energy yield for prospective investors. Then once a plant is built, managers need data updated in near real-time to check the facility is working optimally, and energy output tallies with available sunshine.

“Today our audits form the basis of huge investments in the range of 50 million euros for single projects,” explains Gerd Heilscher from Meteocontrol, a company auditing photovoltaic systems and involved in ENVISOLAR. “Besides the layout, solar radiation is the most important issue. But unfortunately only a few high-quality ground-based measurements are available at this time.”

Within the wider energy market, such information is also valuable for forecasting electricity load; irradiance is the other major environmental influence on demand besides temperature.

How best to measure sunlight? Ground radiance is quite complex to quantify as it is influenced by much more than simply a site’s distance from the equator. Variations in cloud cover, humidity, aerosols and ozone in the air determine the amount of incoming solar radiation actually reaching the ground. Local topography is also important and there are large regional differences; in Europe the southern side of the Alps receives twice the annual radiance of northern slopes.

Measuring from below using in-situ data is technically demanding, expensive on an ongoing basis and limited in coverage; there are only around 200 solar-energy-measuring stations to cover all of Europe and Africa in the official networks affiliated to the World Meteorological Organisation (WMO).

Measuring from above using satellites provides a wide-area, objective and cost-effective solution. Research by MeteoSwiss has shown that satellites are even more accurate than ground measurements once the distance to the next ground station is greater than about 30 kilometres.

Today, ENVISOLAR partners are developing and marketing a variety of solar services based on satellite radiance data. These services benefit from the latest scientific results and state-of-the-art algorithms developed by a EU Research&Development project called Heliosat-3.

ENVISOLAR services based on these data products comprise solar plant yield estimates, plant fault detection and performance checking, energy forecasting for energy utilities, and time series services including maps and statistics of irradiance, its direct and diffuse components and spectral components such as illumination.

Customers of ENVISOLAR services include SAG Solarstrom AG, a publicly quoted German firm that builds and operates photovoltaic installations, providing entire financial investments in photovoltaics to its customers.

“We need solid information for investment decisions, especially with regard to future markets like Spain,” said Uwe Ilgeman, CEO of SAG Solarstrom AG. “The sampling and spatial resolution of ground-based data is too coarse; for example in Spain there are only 30 sites available at the moment.”

High-resolution radiance data from the Solar Energy Mining (Solemi) service operated by the German Aerospace Centre (DLR) - leader of ENVISOLAR - have contributed to the quantification of the renewable energy potential within 14 developing countries, in the framework of the SWERA project of UNEP. Results of SWERA suggest the potential is far greater than has previously been supposed.

“These countries need greatly expanded energy services to help them in the fight against poverty and to power sustainable development,” said Klaus Toepfer, Executive Director of UNEP. “SWERA offers them the technical and policy assistance to capture the potential that renewable energy can offer.”

A wide range of users besides climate scientists can benefit from EO-based solar services, in particular farmers, architects interested in knowing locally appropriate window sizes, and even PVC manufacturing companies. One of these, Deceuninck, used the ENVISOLAR Solar service (SoDa) to study how the ultraviolet in sunshine degrades PVC building parts, so that their warranties could be tailored to local conditions.

Medical researchers are using sunshine maps to investigate links between sunlight and health. The International Agency of Research on Cancer (IARC), an institute of the World Health Organisation (WHO) is probing the relationship between ultraviolet radiation exposure and skin cancer.

And scientists at the UK’s University of Southampton and the Royal London Hospital have also used the data to study whether lack of vitamin D ’supplied through sunlight’ in pregnant women contributes to osteoporosis or ‘brittle bone syndrome’ in later life.

Another EOMD project called HappySun Mobile is also applying satellite-based sunlight data to public health care. With exposure to sunlight being the leading cause of melanomas and other skin cancers, this one-year project will set up a means of generating automatic warnings about safe sunbathing times based on measured ultraviolet levels, and deliver them to sunbathers via text messaging.

Original press release: Sunshine Mapping from Space Means Brighter Solar Energy Future (ESA)