Ocean eddies help jump-start plankton blooms that spread across hundreds of square miles
On this July 4th week, U.S. beachgoers are thronging their way to seaside resorts and parks to celebrate with holiday fireworks. But across the horizon and miles out to sea toward the north, the Atlantic Ocean’s own spring and summer ritual unfolds. It entails the blooming of countless microscopic plants, or phytoplankton.
In what’s known as the North Atlantic Bloom, an immense number of phytoplankton burst into existence, first “greening,” then “whitening” the sea as one or more species take the place of others.
What turns on this huge bloom, what starts these ocean fireworks? Is it the Sun’s warmth? (more…)
It’s shaping up to be a fiery summer across the United States. According to the National Interagency Fire Center, as of July 3, 45 large active wildfires are currently burning in 15 states. Combined, these fires have scorched nearly three-quarters of a million acres. Since January 1, wildfires have burned nearly 2.2 million acres across the country, including devastating blazes in Colorado and New Mexico. We asked JPL Climatologist Bill Patzert to discuss the recent wildfire outbreak and whether climate change is playing a role.
Q: The U.S. wildfire season is off to an active start. What factors have contributed to the recent rash of blazes?
Patzert: Across the West, out-of-control wildfires this summer have left a heartbreaking path of destruction. The primary condition that triggered these fires was an unusually dry and warm La Nina winter and spring. These conditions primed the Western U.S. for an incendiary summer. The arrival of a persistent, scorching high-pressure system over the Western and Central U.S. just exacerbated already dangerous conditions, which reached a tipping point when strong, gusty winds sent these fires rampaging across the landscape. From New Mexico to Colorado and many other states, out-of-control wildfires are still burning through forests, grasslands and destroying neighborhoods. (more…)
UCLA life scientists have discovered new laws that determine the construction of leaf vein systems as leaves grow and evolve. These easy-to-apply mathematical rules can now be used to better predict the climates of the past using the fossil record.
The research, published May 15 in the journal Nature Communications, has a range of fundamental implications for global ecology and allows researchers to estimate original leaf sizes from just a fragment of a leaf. This will improve scientists’ prediction and interpretation of climate in the deep past from leaf fossils.
Leaf veins are of tremendous importance in a plant’s life, providing the nutrients and water that leaves need to conduct photosynthesis and supporting them in capturing sunlight. Leaf size is also of great importance for plants’ adaptation to their environment, with smaller leaves being found in drier, sunnier places. (more…)
The fragile and rapidly changing Arctic region is home to large reservoirs of methane, a potent greenhouse gas. As Earth’s climate warms, the methane, frozen in reservoirs stored in Arctic tundra soils or marine sediments, is vulnerable to being released into the atmosphere, where it can add to global warming. Now a multi-institutional study by Eric Kort of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., has uncovered a surprising and potentially important new source of Arctic methane: the ocean itself.(more…)
In the face of mass deforestation of the Amazon, we could learn from its earliest inhabitants who managed their farmland sustainably.
Research from an international team of archaeologists and paleoecologists, published in the journal Proceedings of the National Academy of Sciences, shows for the first time that indigenous people, living in the savannas around the Amazonian forest, farmed without using fire.
Led by the University of Exeter, the research could provide insights into the sustainable use and conservation of these globally-important ecosystems, which are being rapidly destroyed. Pressure on the Amazonian savannas today is intense, with the land being rapidly transformed for industrial agriculture and cattle ranching.
By analysing records of pollen, charcoal and other plant remains like phytoliths spanning more than 2,000 years, the team has created the first detailed picture of land use in the Amazonian savannas in French Guiana. This gives a unique perspective on the land before and after the first Europeans arrived in 1492. (more…)
A new study led by the University of Massachusetts Amherst and involving the University of Colorado Boulder proposes a simple new mechanism to explain the source of carbon that fed a series of extreme warming events on Earth about 50 million years ago called the Paleocene-Eocene Thermal Maximum, or PETM, as well as a sequence of similar, smaller warming events afterward.
“The standard hypothesis has been that the source of carbon was in the ocean in the form of frozen methane gas in ocean-floor sediments,” said lead study author Rob DeConto of the University of Massachusetts Amherst. “We are instead ascribing the carbon source to the continents in polar latitudes where permafrost can store massive amounts of carbon that can be released as CO2 when the permafrost thaws.” (more…)
Glaciers play a vital role in Earth’s climate system, and it’s critical to understand what contributes to their fluctuation.
Increased global temperatures are frequently viewed as the cause of glacial melt, but a new study of Patagonia’s Gualas Glacier highlights the role of precipitation in the glacier’s fluctuation. The study, conducted by Sébastien Bertrand of the Woods Hole Oceanographic Institution (WHOI) and his colleagues, reconstructs a 5,400 year-record of the region’s glacial environment and climate, comparing past temperature and rainfall data with sediment records of glacier fluctuations and the historical observations of early Spanish explorers. (more…)
Mesquite trees and woody shrubs are better adapted than grasslands to a Southwestern climate predicted to shift toward higher temperatures and greater variability in rainfall, UA ecologists have discovered.
As the desert Southwest becomes hotter and drier, semi-arid grasslands are slowly being replaced by a landscape dominated by mesquite trees, such as Prosopis velutina, and other woody shrubs, a team of University of Arizona researchers has found.
In a “leaf-to-landscape” approach, the team combined physiological experiments on individual plants and measurements across entire ecosystems to quantify how well grasslands, compared to mesquite trees and woody shrubs, cope with heat and water stress across seasonal precipitation periods. (more…)
