NASA Earth Observatory: New Studies Examine Climate/Vegetation Links

Two new spaceborne Earth-observing instruments will help scientists better understand how global forests and ecosystems are affected by changes in climate and land use change. 

This image of the Amazon rainforest is from a 2010 global map of the height of the world's forests based on multiple satellite datasets. 

Image courtesy NASA Earth Observatory.

NASA has selected proposals for two new instruments, including one from NASA's Jet Propulsion Laboratory, Pasadena, California, that will observe changes in global vegetation from the International Space Station.

UMD will develop the Global Ecosystem Dynamics Investigation Lidar (GEDI) for up to $94 million while JPL will build the ECOsystem Spaceborne Thermal Radiometer Experiment (ECOSTRESS) on Space Station for as much as $30 million, NASA said Wednesday.

The sensors will give scientists new ways to see how forests and ecosystems are affected by changes in climate or in land use.

A high-resolution, multiple-wavelength imaging spectrometer from JPL will study the effectiveness of water use by vegetation.

This instrument will be completed in 2018 and will not cost more than $30 million. A laser-based system from the University of Maryland, College Park, will observe the structure of forest canopy. This instrument will be completed in 2019 and will not cost more than $94 million.

John Grunsfeld

"We are excited to expand the use of the International Space Station to make critical Earth observations that will help scientists understand the diversity of forests and vegetation and their response to a changing climate," said John Grunsfeld, associate administrator of NASA's Science Mission Directorate in Washington.

"These innovative Earth Venture Instruments will join a growing suite of NASA Earth-observing sensors to be deployed to the station starting this year."

The instruments were competitively selected from 20 proposals submitted to NASA's Earth Venture Instrument program.

Part of the Earth System Science Pathfinder program (ESSP), Earth Venture investigations are small, targeted science investigations that complement NASA's larger research missions.

The National Research Council recommended in 2007 that NASA undertake this type of regularly solicited, quick-turnaround project. The program's first selection was awarded in 2010.

Simon Hook of JPL is the principal investigator for the ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS).

This project will use a high-resolution thermal infrared radiometer to measure plant evapotranspiration, the loss of water from growing leaves and evaporation from the soil.

These data will reveal how ecosystems change with climate and provide a critical link between the water cycle and effectiveness of plant growth, both natural and agricultural.

The ECOSTRESS team has extensive experience in development and analysis of thermal infrared spectroscopic images of Earth's surface.

ESA's Herschel space observatory links Jupiter's water to comet impact

Credit: Shoemaker-Levy 9 impact site G

ESA's Herschel space observatory has solved a long-standing mystery as to the origin of water in the upper atmosphere of Jupiter, finding conclusive evidence that it was delivered by the dramatic impact of comet Shoemaker-Levy 9 in July 1994.

During the spectacular week-long collision, a string of 21 comet fragments pounded into the southern hemisphere of Jupiter, leaving dark scars in the planet's atmosphere that persisted for several weeks.

The remarkable event was the first direct observation of an extraterrestrial collision in the Solar System. It was followed worldwide by amateur and professional astronomers with many ground-based telescopes and the NASA/ESA Hubble Space Telescope.



ESA's Infrared Space Observatory was launched in 1995 and was the first to detect and study water in Jupiter's upper atmosphere. It was widely speculated that comet Shoemaker-Levy 9 may have been the origin of this water, but direct proof was missing.

Scientists were able to exclude an internal source, such as water rising from deeper within the planet's atmosphere, because it is not possible for water vapour to pass through the 'cold trap' that separates the stratosphere from the visible cloud deck in the troposphere below.

Thus the water in Jupiter's stratosphere must have been delivered from outside. But determining its origin had to wait more than 15 years, until Herschel used its sensitive infrared eyes to map the vertical and horizontal distribution of water's chemical signature.

Water in Jupiter’s atmosphere.

Herschel's observations found that there was 2–3 times more water in the southern hemisphere of Jupiter than in the northern hemisphere, with most of it concentrated around the sites of the 1994 comet impact.

Additionally, it is only found at high altitudes.

"Only Herschel was able to provide the sensitive spectral imaging needed to find the missing link between Jupiter's water and the 1994 impact of comet Shoemaker-Levy 9," says Thibault Cavalié of the Laboratoire d'Astrophysique de Bordeaux, lead author of the paper published in Astronomy and Astrophysics.

"According to our models, as much as 95% of the water in the stratosphere is due to the comet impact."

This shows an abundance of water in Jupiter's stratosphere. 

The north-south asymmetry is clearly observed. 

The green and red areas correspond to the highest abundances. 

Credit: Astronomy & Astrophysics, Cavalié et al. 2013, A&A, 553, A21 

Another possible source of water would be a steady rain of small interplanetary dust particles onto Jupiter.

But, in this case, the water should be uniformly distributed across the whole planet and should have filtered down to lower altitudes.

Also, one of Jupiter's icy moons could deliver water to the planet via a giant vapour torus, as Herschel has seen from Saturn's moon Enceladus, but this too has been ruled out.

None of Jupiter's large moons is in the right place to deliver water to the locations observed.

Finally, the scientists were able to rule out any significant contributions from recent small impacts spotted by amateur astronomers in 2009 and 2010, along with local variations in the temperature of Jupiter's atmosphere. Shoemaker-Levy 9 is the only likely culprit.

Frozen jet stream links Pakistan floods, Russian fires

Raging wildfires in western Russia have reportedly doubled average daily death rates in Moscow. Diluvial rains over northern Pakistan are surging south – the UN reports that 6 million have been affected by the resulting floods.

It now seems that these two apparently disconnected events have a common cause. They are linked to the heatwave that killed more than 60 in Japan, and the end of the warm spell in western Europe. The unusual weather in the US and Canada last month also has a similar cause.

According to meteorologists monitoring the atmosphere above the northern hemisphere, unusual holding patterns in the jet stream are to blame. As a result, weather systems sat still. Temperatures rocketed and rainfall reached extremes.

Renowned for its influence on European and Asian weather, the jet stream flows between 7 and 12 kilometres above ground. In its basic form it is a current of fast-moving air that bobs north and south as it rushes around the globe from west to east. Its wave-like shape is caused by Rossby waves – powerful spinning wind currents that push the jet stream alternately north and south like a giant game of pinball.

In recent weeks, meteorologists have noticed a change in the jet stream's normal pattern. Its waves normally shift east, dragging weather systems along with it. But in mid-July they ground to a halt, says Mike Blackburn of the University of Reading, UK (see diagram). There was a similar pattern over the US in late June.

Stationary patterns in the jet stream are called "blocking events". They are the consequence of strong Rossby waves, which push westward against the flow of the jet stream. They are normally overpowered by the jet stream's eastward flow, but they can match it if they get strong enough. When this happens, the jet stream's meanders hold steady, says Blackburn, creating the perfect conditions for extreme weather.

A static jet stream freezes in place the weather systems that sit inside the peaks and troughs of its meanders. Warm air to the south of the jet stream gets sucked north into the "peaks". The "troughs" on the other hand, draw in cold, low-pressure air from the north. Normally, these systems are constantly on the move – but not during a blocking event.

Tattooing linked to higher risk of hepatitis C: UBC study — Science Blog

Young women, prison inmates and individuals with multiple tattoos that cover large parts of their bodies are at higher risk of contracting hepatitis C and other blood-borne diseases, according to a University of British Columbia study.

The researchers reviewed and analysed 124 studies from 30 countries, including Canada, Iran, Italy, Brazil and the United States, and found the incidence of hepatitis C after tattooing is directly linked with the number of tattoos an individual receives. The findings are published in the current issue of the International Journal of Infectious Diseases.

Tattoos have become increasingly popular in recent years. In the U.S., an estimated 36 per cent of people under 30 have tattoos. In Canada, approximately eight per cent of high school students have at least one tattoo and 21 per cent of those who don’t have one want one. During tattooing, the skin is punctured 80 to 150 times a second in order to inject color pigments.

“Since tattoo instruments come in contact with blood and bodily fluids, infections may be transmitted if instruments are used on more than one person without being sterilized or without proper hygiene techniques,” says lead author Dr. Siavash Jafari, a Community Medicine Resident in the UBC School of Population and Public Health (SPPH).

“Furthermore, tattoo dyes are not kept in sterile containers and may play a carrier role in transmitting infections,” says Jafari. “Clients and the general public need to be educated on the risks associated with tattooing, and tattoo artists need to discuss harms with clients.”

Other risks of tattooing identified by the study include allergic reactions, HIV, hepatitis B, bacterial or fungal infections, and other risks associated with tattoo removal.

The researchers are calling for infection-control guidelines for tattoo artists and clients, and enforcement of these guidelines through inspections, reporting of adverse events and record-keeping. They also recommend prevention programs that focus on youth — the population who are most likely to get tattoos — and prisoners — who face a higher prevalence of hepatitis C — to lower the spread of hepatitis infection. In Canada, 12 to 25 per cent of hepatitis C infections among prisoners are associated with tattooed individuals, compared to six per cent of the general population.

The chemical ingredients in tattoo dyes can include house paint, ink from computer printers, or industrial carbon. Toxic contents of some tattoo inks may be entering the kidney, lungs and lympth nodes through the circulatory system. The study also revealed a new trend among youth to get tattooed with glow-in-the-dark ink, the risks of which are not yet known.