Data from satellite sensors show that during the Northern Hemisphere’s growing season, the Midwest region of the United States boasts more photosynthetic activity than any other spot on Earth, according to NASA and university scientists.
Healthy plants convert light to energy via photosynthesis, but chlorophyll also emits a fraction of absorbed light as a fluorescent glow that is invisible to the naked eye. The magnitude of the glow is an excellent indicator of the amount of photosynthesis, or gross productivity, of plants in a given region. (more…)
Call it a bird’s eye view of migration. Scientists are taking a fresh look at animal movement with a big data approach that combines GPS tracking data with satellite weather and terrain information.
The new Environmental-Data Automated Track Annotation (Env-DATA) system, featured in the journal Movement Ecology, can handle millions of data points and serve a hundred scientists simultaneously, said co-founder Dr. Roland Kays, a zoologist with North Carolina State University and the North Carolina Museum of Natural Sciences. (more…)
A solar tsunami observed by NASA’s Solar Dynamics Observatory (SDO) and the Japanese Hinode spacecraft has been used to provide the first accurate estimates of the Sun’s magnetic field.
Solar tsunamis are produced by enormous explosions in the Sun’s atmosphere called coronal mass ejections (CMEs). As the CME travels out into space, the tsunami travels across the Sun at speeds of up to 1000 kilometres per second.
Similar to tsunamis on Earth, the shape of solar tsunamis is changed by the environment through which they move. Just as sound travels faster in water than in air, solar tsunamis have a higher speed in regions of stronger magnetic field. This unique feature allowed the team, led by researchers from UCL’s Mullard Space Science Laboratory, to measure the Sun’s magnetic field. The results are outlined in a paper soon to be published in the journal Solar Physics. (more…)
Researchers working with data from NASA’s Cassini spacecraft have discovered one way the bubble of charged particles around Saturn — known as the magnetosphere — changes with the planet’s seasons. The finding provides an important clue for solving a riddle about the planet’s naturally occurring radio signal. The results might also help scientists better understand variations in Earth’s magnetosphere and Van Allen radiation belts, which affect a variety of activities at Earth, ranging from space flight safety to satellite and cell phone communications.
The paper, just published in the Journal of Geophysical Research, is led by Tim Kennelly, an undergraduate physics and astronomy major at the University of Iowa, Iowa City, who is working with Cassini’s radio and plasma wave science team. (more…)
Sea-surface height data from NASA’s Jason-2 satellite show that the equatorial Pacific Ocean is still locked in what some call a neutral, or ‘La Nada’ state. This condition follows two years of strong, cool-water La Nina events.
PASADENA, Calif. – An area of the Amazon rainforest twice the size of California continues to suffer from the effects of a megadrought that began in 2005, finds a new NASA-led study. These results, together with observed recurrences of droughts every few years and associated damage to the forests in southern and western Amazonia in the past decade, suggest these rainforests may be showing the first signs of potential large-scale degradation due to climate change.
An international research team led by Sassan Saatchi of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., analyzed more than a decade of satellite microwave radar data collected between 2000 and 2009 over Amazonia. The observations included measurements of rainfall from NASA’s Tropical Rainfall Measuring Mission and measurements of the moisture content and structure of the forest canopy (top layer) from the Seawinds scatterometer on NASA’s QuikScat spacecraft. (more…)
AMHERST, Mass. – Though it seems like an oxymoron, Arctic hurricanes happen, complete with a central “eye,” extreme low barometric pressure and towering 30-foot waves that can sink small ships and coat metal platforms with thick ice, threatening oil and gas exploration. Now climate scientists at the University of Massachusetts Amherst and in England report the first conclusive evidence that Arctic hurricanes, also known as polar lows, play a significant role in driving ocean water circulation and climate.
Results point to potentially cooler conditions in Europe and North America in the 21st century than other models predict. (more…)
A device designed by engineers at the Georgia Tech Research Institute (GTRI) is part of the Hurricane Imaging Radiometer (HIRAD), an experimental airborne system developed by the Earth Science Office at the NASA Marshall Space Flight Center in Alabama.
Known as an analog beam-former, the GTRI device is part of the radiometer, which is being tested by NASA on a Global Hawk unmanned aerial vehicle. The radiometer measures microwave radiation emitted by the sea foam that is produced when high winds blow across ocean waves. By measuring the electromagnetic radiation, scientists can remotely assess surface wind speeds at multiple locations within the hurricanes. (more…)
