Posts tagged temperature
As the planet warms faster, more species will be increasingly at risk
Apr 21st
The acceleration of change means that the species inhabiting each zone have less time to adapt to the climatic changes, said lead author Irina Mahlstein, a CIRES scientist who works at NOAA’s Earth System Research Laboratory in Boulder, Colo. “The warmer the climate gets, the faster the climate zones are shifting. This could make it harder for plants and animals to adjust.”
The study is the first to look at the accelerating pace of the shifting of climate zones, which are areas of the Earth defined by annual and seasonal cycles of temperature and precipitation, as well as temperature and precipitation thresholds of plant species. Over 30 different climate zones are found on Earth; examples include the equatorial monsoonal zone, the polar tundra zone and cold arid desert zone.
“A shift in the climate zone is probably a better measure of ‘reality’ for living systems, more so than changing temperature by a degree or precipitation by a centimeter,” said Mahlstein.
The scientists used climate model simulations and a well-known ecosystem classification scheme to look at the shifts between climate zones over a two-century period, 1900 to 2098. The team found that for an initial 3.6 degrees Fahrenheit of warming, about 5 percent of Earth’s land area shifts to a new climate zone.
The models show that the pace of change quickens for the next 3.6 F of warming as an additional 10 percent of the land area shifts to a new climate zone. The paper was published online in the journal Nature Climate Change on April 21.
Certain regions of the globe, such as northern middle and high latitudes, will undergo more changes than other regions, such as the tropics, the scientists found. In the tropics, mountainous regions will experience bigger changes than low-altitude areas.
In the coming century, the findings suggest that frost climates — the coldest climate zone of the planet — will largely decrease. In general, dry regions in different areas of the globe will increase, and a large fraction of land area will change from cool summers to hot summers, according to the study.
The scientists also investigated whether temperature or precipitation had a greater impact on how much of the land area changed zones. “We found that temperature is the main factor, at least through the end of this century,” said Mahlstein.
John Daniel at the NOAA Earth System Research Laboratory and Susan Solomon at the Massachusetts Institute of Technology co-authored the study.
-CU press release
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NASA sends CU Boulder big bucks for space weather mission
Apr 15th
The University of Colorado Boulder will receive roughly $36 million from NASA to build and operate a space instrument for a mission led by the University of Central Florida that will study Earth’s upper atmosphere to learn more about the disruptive effects of space weather.
The mission, known as the Global-scale Observations of the Limb and Disk, or GOLD, involves imaging Earth’s upper atmosphere from a geostationary orbit some 22,000 miles above the planet. The mission is expected to have a direct impact on the understanding of space weather like geomagnetic storms that alter the temperature and composition of Earth’s atmosphere, which can disrupt communication and navigation satellites, affecting everything from automobile GPS and cell phone coverage to television programming.
The GOLD mission, which is being led by research scientist Richard Eastes of the University of Central Florida, will launch aboard a commercial communications satellite as a “hosted” payload. Such payloads, which are secondary to the satellite’s main objective, represent the most cost-effective way to reach geostationary orbit, said CU-Boulder aerospace engineer Mark Lankton of the Laboratory for Atmospheric and Space Physics, the GOLD project manager.
“LASP is extremely pleased to be working on this mission with Richard Eastes at the University of Central Florida, who we have been collaborating with for seven years,” said Lankton. “This mission is one of the first to involve a science instrument being launched on a communication satellite, which is a terrific idea and exactly the right way to run a quality mission on a smaller budget.”
The LASP instrument, known as an imaging spectrograph, weighs roughly 60 pounds and is about 2 feet long and about 1 foot tall and 1 foot wide – roughly the size of a microwave oven. It will launch aboard a commercial satellite built by SES Government Solutions in McLean, Va. The LASP instrument will be gathering data on Earth’s upper atmosphere in the far ultraviolet portion of the electromagnetic spectrum.
“GOLD’s imaging represents a new paradigm for observing the boundary between Earth and space,” said Bill McClintock, the deputy principal investigator on the CU-Boulder spectrograph and a senior research scientist at LASP. “It will revolutionize our understanding of how the sun and the space environment affect our upper atmosphere.”
A geosynchronous orbit is an orbit that completes one revolution in the same amount of time it takes for the Earth to rotate once on its polar axis. “We will be able to view almost a complete hemisphere of the Earth, almost all the time, with this orbit,” said Lankton.
The mission scientists will be looking for the effects of space weather on the upper atmosphere — the ionosphere and thermosphere located roughly 50 miles to 350 miles above Earth – caused by the sun and Earth’s lower atmosphere, said Lankton. “The giant driver is the sun, including geomagnetic storms that can cause bright auroras and the disruption of satellite communications,” he said.
Lankton said the science team also will investigate the effects that atmospheric waves and tides from Earth’s lower atmosphere have on the thermosphere-ionosphere system. The mission will make use of other instruments gathering data on the sun, including LASP’s $42 million Extreme Ultraviolet Variability Experiment flying on NASA’s Solar Dynamics Observatory.
Roughly 40 LASP researchers will be working on the GOLD mission when it is at full strength, including five to 10 students, split about evenly between undergraduates and graduates, said Lankton. Other participants in the GOLD mission include the National Center for Atmospheric Research in Boulder, the University of California, Berkeley, Computational Physics Inc. of Springfield, Va., and the National Oceanic and Atmospheric Administration.
The GOLD mission is part of NASA’s new Heliospheric Explorer Program designed to provide space observations to study Earth’s ionosphere and thermosphere. The mission is slated for launch in 2017. NASA Explorer missions of opportunity, such as GOLD, are capped at $55 million each.
by CU media relations
CU study: 66 million years ago, an asteroid turned Earth into a crispy critter
Mar 27th
A new look at conditions after a Manhattan-sized asteroid slammed into a region of Mexico in the dinosaur days indicates the event could have triggered a global firestorm that would have burned every twig, bush and tree on Earth and led to the extinction of 80 percent of all Earth’s species, says a new University of Colorado Boulder study.
Led by Douglas Robertson of the Cooperative Institute for Research in Environmental Sciences, or CIRES, the team used models that show the collision would have vaporized huge amounts of rock that were then blown high above Earth’s atmosphere. The re-entering ejected material would have heated the upper atmosphere enough to glow red for several hours at roughly 2,700 degrees Fahrenheit — about the temperature of an oven broiler element — killing every living thing not sheltered underground or underwater.
The CU-led team developed an alternate explanation for the fact that there is little charcoal found at the Cretaceous-Paleogene, or K-Pg, boundary some 66 million years ago when the asteroid struck Earth and the cataclysmic fires are believed to have occurred. The CU researchers found that similar studies had corrected their data for changing sedimentation rates. When the charcoal data were corrected for the same changing sedimentation rates they show an excess of charcoal, not a deficiency, Robertson said.
“Our data show the conditions back then are consistent with widespread fires across the planet,” said Robertson, a research scientist at CIRES, which is a joint institute of CU-Boulder and the National Oceanic and Atmospheric Administration. “Those conditions resulted in 100 percent extinction rates for about 80 percent of all life on Earth.”
A paper on the subject was published online this week in the Journal of Geophysical Research-Biogeosciences, a publication of the American Geophysical Union. Co-authors on the study include CIRES Interim Director William Lewis, CU Professor Brian Toon of the atmospheric and oceanic sciences department and the Laboratory for Atmospheric and Space Physics and Peter Sheehan of the Milwaukee Public Museum in Wisconsin.
Geological evidence indicates the asteroid collided with Earth about 66 million years ago and carved the Chicxulub crater in Mexico’s Yucatan Peninsula that is more than 110 miles in diameter. In 2010, experts from 33 institutions worldwide issued a report that concluded the impact at Chicxulub triggered mass extinctions, including dinosaurs, at the K-Pg boundary.
The conditions leading to the global firestorm were set up by the vaporization of rock following the impact, which condensed into sand-grain-sized spheres as they rose above the atmosphere. As the ejected material re-entered Earth’s atmosphere, it dumped enough heat in the upper atmosphere to trigger an infrared “heat pulse” so hot it caused the sky to glow red for several hours, even though part of the radiation was blocked from Earth by the falling material, he said.
But there was enough infrared radiation from the upper atmosphere that reached Earth’s surface to create searing conditions that likely ignited tinder, including dead leaves and pine needles. If a person was on Earth back then, it would have been like sitting in a broiler oven for two or three hours, said Robertson.
The amount of energy created by the infrared radiation the day of the asteroid-Earth collision is mind-boggling, said Robertson. “It’s likely that the total amount of infrared heat was equal to a 1 megaton bomb exploding every four miles over the entire Earth.”
A 1-megaton hydrogen bomb has about the same explosive power as 80 Hiroshima-type nuclear bombs, he said. The asteroid-Earth collision is thought to have generated about 100 million megatons of energy, said Robertson.
Some researchers have suggested that a layer of soot found at the K-Pg boundary layer roughly 66 million years ago was created by the impact itself. But Robertson and his colleagues calculated that the amount of soot was too high to have been created during the massive impact event and was consistent with the amount that would be expected from global fires.
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