"During the late 1970s, Indonesian Borneo changed from being highly fire-resistant to highly fire-prone during drought years, marking the period when one of the world's great tropical forests became one of the world's largest sources of pollution," says Field, a PhD student of atmospheric physics.
"Ultimately, this abrupt transition can be attributed to rapid increases in deforestation and population growth. The resulting occurrences of haze currently rank among the world's worst air pollution episodes, and are a singularly large source of greenhouse gas emissions."
Sumatra has suffered from large fires at least since the 1960s, but Indonesian Borneo seems to have been resistant to large fires – even in dry years – until population density and deforestation increased substantially and land use changed from small-scale subsistence agriculture to large-scale industrial agriculture and agro-forestry.
"We've had a good understanding of fire events since the mid 1990s, but little before this due to the absence of fire data from satellites," says Field, who collaborated with Guido van der Werf of VU University Amsterdam and Sam Shen of San Diego State University. "However, one of the major impacts of large-scale fires is a reduction in visibility due to the smoke produced. Visibility is recorded several times a day at airports in the region, and these records proved to be an excellent indicator of severe fire activity. We were able to piece together visibility observations back to the 1960s, and hence develop a longer term record of the fires."
Having a long-term record of the fires allowed the scientists to better understand their causes. "Using weather records, we were able to estimate the specific rainfall level below which large fires have occurred in the previous two decades. In turn, we found that the rainfall over Indonesia was influenced equally by the Indian Ocean Dipole and the El Niño Southern Oscillation phenomena. Hopefully, this information can be used to better anticipate and prevent future haze disasters in Indonesia."
Field says that there is a direct link between the increased prevalence of severe fires and haze disasters and the man-made change in land use. "The visibility record also showed, quite strikingly, the impact of human settlement on a previously pristine tropical forest. This should give pause to further agro-forestry expansion in Indonesia, particularly for oil palm as a source of biofuel."
Sean Bettam | EurekAlert!
In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
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25.09.2017 | Trade Fair News
25.09.2017 | Physics and Astronomy