Climate Blog and News Recap: 2011 02 05
Looks like my winter lull at work is over. However, I continue to work on the Huybers 2006b review. I didn’t spend much time cruising the blogosphere. If you have a science based blog entry you would like to share, feel free to add it to the comments. In fact, I strongly encourage you to do so. Links to your own work welcome.
Ice Cores Yield Rich History of Climate Change
On Friday, Jan. 28 in Antarctica, a research team investigating the last 100,000 years of Earth’s climate history reached an important milestone completing the main ice core to a depth of 3,331 meters (10,928 feet) at West Antarctic Ice Sheet Divide (WAIS). The project will be completed over the next two years with some additional coring and borehole logging to obtain additional information and samples of the ice for the study of the climate record contained in the core. …
…The WAIS Divide Ice Core Project is specifically investigating the small timing offsets between past changes in the atmospheric concentration of greenhouse gases and changes in temperature. By understanding these timing offsets, the research team can determine the role that changes in ocean circulation had in the release of carbon dioxide from the ocean and how an increase in carbon dioxide in the atmosphere warms the planet…
‘Old’ Information Theory Makes It Easier to Predict Flooding
Many different aspects are involved in predicting high water and floods, such as the type of precipitation, wind, buildings and vegetation. The greater the number of variables included in predictive models, the better the prediction will be. However, the models will inevitably become increasingly more complex. PhD student from Delft Steven Weijs uses basic insight from the information theory (Shannon’s Information Theory) to demonstrate the cohesion between this added complexity, the information from observational data and the uncertainty of predictions. …
…In his research, the Delft PhD student Steven Weijs shows how Shannon’s Information Theory can also be applied to studying high water and flooding. Information theory, first devised in 1948 by Claude Shannon, sees information and uncertainty as numerical quantities, measured in ‘bits’, that correspond with the extent to which the recipient of a message is surprised by that message (‘surprisal’). The level of surprisal depends on how likely the recipient considered the event to be: rain in the Netherlands, for example, is hardly a surprise, but seeing rain in the desert is highly unlikely and surprising and therefore provides more information …
Underwater Ridges Impact Ocean’s Flow of Warm Water; Findings to Improve Climate Models
… An underwater ridge can trap the flow of cold, dense water at the bottom of the ocean. Without the ridge, deepwater can flow freely and speed up the ocean circulation pattern, which generally increases the flow of warm surface water.
Warm water on the ocean’s surface makes the formation of sea ice difficult. With less ice present to reflect the sun, surface water will absorb more sunlight and continue to warm.
U.S. Geological Survey scientists looked back 3 million years, to the mid-Pliocene warm period, and studied the influence of the North Atlantic Ocean’s Greenland-Scotland Ridge on surface water temperature. …
Pakistan Floods Last Summer Could Have Been Predicted, Experts Say
Five days before intense monsoonal deluges unleashed vast floods across Pakistan last July, computer models at a European weather-forecasting center were giving clear indications that the downpours were imminent. Now, a new scientific study that retrospectively examines the raw data from these computer models, has confirmed that, if the information had been processed, forecasters could have predicted extremely accurate rainfall totals 8-10 days beforehand.
The study also finds that the floods themselves could have been predicted if this data, which originated from the European Centre for Medium-Range Weather Forecasting (ECMWF), had been processed and fed into a hydrological model, which takes terrain into account….
Two Severe Amazon Droughts in Five Years Alarms Scientists
New research shows that the 2010 Amazon drought may have been even more devastating to the region’s rainforests than the unusual 2005 drought, which was previously billed as a one-in-100 year event.
Analyses of rainfall across 5.3 million square kilometres of Amazonia during the 2010 dry season, recently published in Science, shows that the drought was more widespread and severe than in 2005. The UK-Brazilian team also calculate that the carbon impact of the 2010 drought may eventually exceed the 5 billion tonnes of CO2 released following the 2005 event, as severe droughts kill rainforest trees. For context, the United States emitted 5.4 billion tonnes of CO2 from fossil fuel use in 2009.
The authors suggest that if extreme droughts like these become more frequent, the days of the Amazon rainforest acting as a natural buffer to man-made carbon emissions may be numbered….
New Drought Record from Long-Lived Mexican Trees May Illuminate Fates of Past Civilizations
A new, detailed record of rainfall fluctuations in ancient Mexico that spans more than twelve centuries promises to improve our understanding of the role drought played in the rise and fall of pre-Hispanic civilizations.
Prior evidence has indicated that droughts could have been key factors in the fates of major cultures in ancient Mexico and Central America (Mesoamerica). But there have been many gaps in the paleoclimate record, such as the exact timing and geographic extension of some seemingly influential dry spells.
The new, 1,238-year-long tree-ring chronology, the longest and most accurate of its kind for Mesoamerica, is the first to reconstruct the climate of pre-colonial Mexico on an annual basis for more than a millennium, pinning down four ancient megadroughts to their exact years….
Rain in Spain Is on the Decline, Research Finds
A study led by the University of Zaragoza (UNIZAR) has studied precipitation trends in Spain’s 10 hydrological basins over the 1946 to 2005 period. The results show that precipitation has declined overall between the months of March and June, reducing the length of the rainy season. The rains are heavier in October in the north west of the country.
Since 1946, the average precipitation falling on Spanish hydrological basins has undergone “notable” changes. The researchers observed a widespread decline in March and June, above all in March (except in the basin of the Segura), with less intense rains in June.
NASA Satellite Captures U.S. ‘Big Chill’
The current winter storm system blasting much of the United States is depicted in this new NASA satellite image from the Atmospheric Infrared Sounder (AIRS) instrument on NASA’s Aqua satellite.
NASA Satellites Capture Data on Monster Winter Storm Affecting 30 U.S. States
One of the largest winter storms since the 1950s is affecting 30 U.S. states today (Feb. 1, 2011) with snow, sleet, freezing rain and rain. NASA satellites have gathering data on the storm that stretches from Texas and the Rockies to the New England states.
Turtle Populations Affected by Climate, Habitat Loss and Overexploitation
he sex of some species of turtles is determined by the temperature of the nest: warm nests produce females, cooler nests, males. And although turtles have been on the planet for about 220 million years, scientists now report that almost half of the turtle species is threatened. Turtle scientists are working to understand how global warming may affect turtle reproduction. To bring attention to this and other issues affecting turtles, researchers and other supporters have designated 2011 as the Year of the Turtle.
How Humans Are Changing the World
Human influence on the landscape, global warming, sea level rise, ocean acidification and biodiversity are highlighted in a new set of studies led by University of Leicester researchers.
New Images Show Cloud Exploding from Sun Ripples Like Clouds on Earth
Physicists, led by a researcher at the University of Warwick, studying new images of clouds of material exploding from the Sun have spotted instabilities forming in that exploding cloud that are similar to those seen in clouds in Earth’s atmosphere.
Surprise Hidden in Titan’s Smog: Cirrus-Like Clouds
… Icky as it may sound, Titan is really the rarest of gems: the only moon in our solar system with an atmosphere worthy of a planet. This atmosphere comes complete with lightning, drizzle and occasionally a big, summer-downpour style of cloud made of methane or ethane — hydrocarbons that are best known for their role in natural gas.
Now, thin, wispy clouds of ice particles, similar to Earth’s cirrus clouds, are being reported by Carrie Anderson and Robert Samuelson at NASA’s Goddard Space Flight Center in Greenbelt, Md. The findings, published February 1 in Icarus, were made using the Composite Infrared Spectrometer (CIRS) on NASA’s Cassini spacecraf …
Northern Mars Landscape Actively Changing
Sand dunes in a vast area of northern Mars long thought to be frozen in time are changing with both sudden and gradual motions, according to research using images from a NASA orbiter. …
… Scientists had considered the dunes to be fairly static, shaped long ago when winds on the planet’s surface were much stronger than those seen today, said HiRISE Deputy Principal Investigator Candice Hansen of the Planetary Science Institute, Tucson, Ariz. Several sets of before-and-after images from HiRISE over a period covering two Martian years — four Earth years — tell a different story.
“The numbers and scale of the changes have been really surprising,” said Hansen. …
NASA Finds Earth-Size Planet Candidates in Habitable Zone, Six Planet System
NASA’s Kepler mission has discovered its first Earth-size planet candidates and its first candidates in the habitable zone, a region where liquid water could exist on a planet’s surface. Five of the potential planets are near Earth-size and orbit in the habitable zone of smaller, cooler stars than our sun. …
…The discoveries are part of several hundred new planet candidates identified in new Kepler mission science data, released on Feb. 1. The findings increase the number of planet candidates identified by Kepler to-date to 1,235. Of these, 68 are approximately Earth-size; 288 are super-Earth-size; 662 are Neptune-size; 165 are the size of Jupiter and 19 are larger than Jupiter.
Of the 54 new planet candidates found in the habitable zone, five are near Earth-sized. The remaining 49 habitable zone candidates range from super-Earth size — up to twice the size of Earth — to larger than Jupiter. …
Kepler Finds Evidence of Habitable Earth-Size Planets in Milky Way
“We went from zero to 68 Earth-sized planet candidates and zero to 54 candidates in the habitable zone — a region where liquid water could exist on a planet’s surface. Some candidates could even have moons with liquid water,” said William Borucki of NASA’s Ames Research Center, Moffett Field, Calif., and the Kepler Mission’s science principal investigator. “Five of the planetary candidates are both near Earth-size and orbit in the habitable zone of their parent stars.”
Planet candidates require follow-up observations to verify they are actual planets.
NASA’s Kepler Spacecraft Discovers Extraordinary New Planetary System
… “The five inner planets are all closer to their star than any planet is to our sun and the sixth planet is still fairly close,” said Lissauer.
If placed in our solar system, Kepler-11g would orbit between Mercury and Venus, and the other five planets would orbit between Mercury and our sun. The orbits of the five inner planets in the Kepler-11 planetary system are much closer together than any of the planets in our solar system. The inner five exoplanets have orbital periods between 10 and 47 days around the dwarf star, while Kepler-11g has a period of 118 days.
“By measuring the sizes and masses of the five inner planets, we have determined they are among the smallest confirmed exoplanets, or planets beyond our solar system,” said Lissauer. “These planets are mixtures of rock and gases, possibly including water. The rocky material accounts for most of the planets’ mass, while the gas takes up most of their volume.”…