Posts Tagged "black carbon"

Roundup: Remote Sensing, Black Carbon, and Skiing

Posted by on Dec 19, 2016 in All Posts, Featured Posts, Roundup | 0 comments

Roundup: Remote Sensing, Black Carbon, and Skiing

Spread the News:ShareRoundup: Glacier Surface Motion, Black Carbon & Skiing   Remote Sensing Measures Glacier Surface Motion From ISPRS Journal of Photogrammetry and Remote Sensing: “For monitoring of glacier surface motion in pole and alpine areas, radar remote sensing is becoming a popular technology accounting for its specific advantages of being independent of weather conditions and sunlight… Synthetic aperture radar (SAR) imaging is a complementary information source which has the advantage of providing images all year long, with no limitations in terms of weather condition and imaging time. It can reliably collect data with a pre-defined temporal interval over long periods of time with a ground resolution meeting the demands of glacier monitoring. Additionally, active SAR sensors observe both the amplitude and phase information of the backscattered signal from the ground target.” Read more about remote sensing in alpine areas here.   Effects of Black Carbon on the Tibetan Plateau From Advancements in Climate Change Research: “The Tibetan Plateau (TP), which has an abundance of snow and ice cover, is referred to as the water tower of Asia. Melting snow/ice makes a large contribution to regional hydrological resources and has direct impacts on local society and economic development. Recent studies have found that light-absorbing impurities, which may accelerate snow/ice melting, are considered as a key factor in cryospheric changes. However, there have been few assessments of the radiative effects of light-absorbing impurities on snow/ice cover over the Tibetan Plateau. Flanner et al. (2007) coupled a snow radiative model with a global climate model (GCM) and estimated the anthropogenic radiative forcing by the deposition of black carbon in snow averaged 1.5 W m−2 over the Tibetan Plateau.” Learn more about this study here.   Skiing Across World’s Glaciers To Raise Awareness From National Geographic: “Børge Ousland, now 54, teamed up with French adventurer Vincent Colliard, 30, for the Alpina Ice Legacy project. Over 10 years, the duo plans to ski across the world’s 20 largest glaciers in an effort to raise awareness about climate change. They crossed Alaska’s Stikine Glacier on their second expedition in May 2015, and in May 2016 they tackled the project’s third glacier, the St. Elias-Wrangell Mountains Range Ice Field. After 19 days and 267 miles in the field, [National Geographic] caught up with Ousland and Colliard in Alaska to talk suffering, partnership, and coming home alive.” Read more from the interview here.   Spread the...

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Wildfires Melt Glaciers From a Distance

Posted by on Sep 1, 2016 in All Posts, Featured Posts, News, Science | 0 comments

Wildfires Melt Glaciers From a Distance

Spread the News:ShareScientists have begun to trace a link between climate change, an increased number of wildfires and glacier melting.  Particles emitted by wildfires and then deposited on glaciers are thought to darken the ice’s surface, and may lead to more rapid melting. Natalie Kehrwald, a geologist from the United States Geological Survey (USGS), is currently studying the levels of wildfire particles deposited on the Juneau Icefield in Alaska. Kehrwald and her fellow USGS geologist, Shad O’Neel,  who is tracking the retreat of glaciers in the Juneau Icefield, are working together to document the contributions of wildfires to glacier melting. “In the past two to three years there have been huge wildfires [in Alaska]… I am trying to see if there are aerosols being deposited on the Juneau ice field and if they are accelerating the melting,”  said Kehrwald in an interview with GlacierHub. According to multiple sources, including the University of Alaska Fairbanks and the non-profit research and news organization Climate Central, rising Arctic temperatures are creating longer and more severe wildfire seasons, with larger and more frequent fires.  Kehrwald proposes that an increase in wildfires has led to a greater volume of aerosols, a mixture of carbon and other particles, deposited onto glaciers.  There may be a minor feedback as well. Since glaciers act as large mirrors and keep the planet cooler by reflecting solar energy back into space, the loss of glaciers could also accelerate the rise in temperaturse. In early August, Kehrwald and O’Neel led a team of student researchers from the Juneau Icefield Training Program into the field, where they gathered ice cores.  They will later analyze these cores for wildfire indicators in a lab.   “We take samples from the highest, flattest parts of the glacier in specific locations that are impacted by air masses.  We drill down 7-9 meters, which date back about two to three years,” said Kehrwald, summarizing their trip. The carbon deposits from wildfires can be grouped into a larger category called black carbon, which have been linked to rapid glacier melting.  Black carbon refers to carbon released from both biomass burning and fossil fuel emissions.  In order to determine whether the carbon on the Juneau Icefield is from wildfires, Kehrwald will look for a specific molecular marker in the ice.   “It is a sugar called levoglucosan and it is only produced if you burn cellulose at a temperature of about 250 degrees Celsius,” said Kehrwald.  “So if you see high concentrations of that molecule you know the origin is biomass burning, which is generally wildfires but could be a big compilation of household fires.” Although the Alaskan wildfires occur predominantly in the boreal forest located in a drier region far north of the Juneau Icefield, smoke from wildfires have been known to travel great distances.  The phenomena of darkening glaciers due to particles from wildfires was well documented last year when large wildfires in British Columbia deposited particles on glaciers across the North American Arctic and as far as Greenland. According to the University of Alaska Fairbanks, three of the top ten largest Alaskan wildfires since 1940 occurred in the last decade.  In 2015, Alaskan wildfires burned over 5 million acres of land.  Alaska’s burnt acreage represented five-sixths of the national total land consumed by wildfires in that year, according to The Washington Post.  The acreage of wildfire burned land in 2015 is second only to the approximately 6.5 million acres burned in 2004. A 2015 report, The Age of Alaskan Wildfires, produced by non-profit group Climate Central stated that large Arctic wildfires are no longer rare.   “We found the number...

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Roundup: Antarctica and Greenland in peril, black carbon

Posted by on Jul 25, 2016 in All Posts, Featured Posts, Roundup, Science, Uncategorized | 0 comments

Roundup: Antarctica and Greenland in peril, black carbon

Spread the News:ShareNinety percent of the western Antarctic Peninsula’s glaciers are retreating From Carbon Brief: “These rivers of ice ooze their way down through the Peninsula’s rocky mountain range and into the ocean, powered by gravity and their own weight. But of the 674 glaciers on the Peninsula’s western side, almost 90% are retreating. This happens when their ice melts faster than new snowfall can replenish it. “The Antarctic Peninsula is one of the fastest warming regions on Earth. Temperatures have risen by more than 3C over the past 50 years. The warming atmosphere has caused some remarkable changes to the eastern side of the Peninsula. The Larsen ice shelf, a floating sheet of ice formed from glaciers spilling out onto the cold ocean, has lost two of its four sections in recent decades.” Learn more about the Antarctic Peninsula’s glaciers and effects on the ocean here.   Greenland lost a mind-blowing 1 trillion tons of ice in under four years From Washington Post: “It’s the latest story in a long series of increasingly worrisome studies on ice loss in Greenland. Research already suggests that the ice sheet has lost at least 9 trillion tons of ice in the past century and that the rate of loss has increased over time. Climate scientists are keeping a close eye on the region because of its potentially huge contributions to future sea-level rise (around 20 feet if the whole thing were to melt) — not to mention the damage it’s already done. Ice loss from Greenland may have contributed as much as a full inch of sea-level rise in the last 100 years and up to 10 percent of all the sea-level rise that’s been documented since the 1990s. “Overall, the ice loss was particularly prevalent in the southwest, but the scientists noted that there were also losses observed in the cooler, northern parts of the ice sheet. Notably, the researchers also found that a solid 12 percent of all the ice loss came from just a handful of glaciers composing less than 1 percent of the ice sheet’s total area.” Read more here.   Understanding black carbon impact on glaciers From International Centre for Integrated Mountain Development (ICIMOD): “In April 2016 and team of glaciologists and experts from the International Centre for Integrated Mountain Development’s (ICIMOD) and partner organisations — Department of Hydrology and Meteorology, Utrecht University, Kathmandu University (KU),Tribhuvan University (TU), Norwegian Water Resources and Energy Directorate (NVI) went to Langtang for a field visit. “‘The elevation of Yala Glacier is higher compared to those in Pakistan. Gulkin Glacier, in Pakistan, starts from 2700 to 4000 m, so there was almost no snow on the glacier in this season. Only towards the top of the glacier at around 4000m AMSL snow was present. The rest of the glacier was mostly debris’, Chaman said. Sachin Glacier, at 3200- 4000m AMSL, is different to Yala and Gulkin, and samples collected from this glacier represent semi-aged or aged-snow. ‘There was fresh snow on the night of collection so the samples were very fresh’  Chaman said of Langtang. He expects to see large variability in black carbon concentrations in the samples, contributing to effect of elevation, geographical location, glacier type, age and fresh samples.” Learn more here.   Spread the...

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The Question of Black Carbon

Posted by on Oct 15, 2015 in All Posts, Featured Posts, Science | 0 comments

The Question of Black Carbon

Spread the News:ShareBlack carbon has only recently emerged as a known major contributor to climate change, especially for the Arctic. Formed by the incomplete combustion of fossil fuels, biofuels, and biomass, black carbon absorbs light more strongly than any other particulate matter, especially when deposited onto glaciers and snow cover. Here, it lowers their reflectivity, thereby absorbing atmospheric heat and resulting in earlier spring melt and higher temperatures. New research, published in Atmospheric Chemistry and Physics, is attempting to address research gaps in this new but significant climate agent by quantifying and analyzing black carbon concentration and deposition in Svalbard, the major archipelago north of Norway. The study, focusing on black carbon on the Holtedahlfonna glacier in Svalbard between 1700 and 2004, found significant rises in black carbon concentration from the 1970s until 2004 , with unprecedented levels in the 1990s.  Importantly, the study concludes that the increase in black carbon concentration “cannot be simply explained by changes in the snow accumulation rate at the glacier,” or simply by glacial melt and shrinkage in Svalbard. This indicates that black carbon was instead deposited in increasing quantities during this time period. The study raises some puzzling differences between black carbon concentrations and deposition in Svalbard and between previous data from other Arctic regions. While Svalbard’s black carbon values increased rapidly from a low point in 1970 until 2004, reaching a high in the 1990s, black carbon analyzed in Greenland ice cores indicated generally decreasing atmospheric black carbon concentrations since 1989 in the Arctic. This difference is likely at least partly explained by differences in the specific methodologies used in the studies, such as the operational definition of black carbon that determined which size particles were included in the study. The Svalbard study collected its data by filtering the inner part of a 125 m deep ice core from the Holtedahlfonna glacier through a quartz fiber filter. The filtrate was analyzed using a thermal-optical method, while previous comparable studies used an SP2 (Single Particle Soot Photometer) method. The different methodologies used between studies makes it hard to assess the validity of the studies’ findings. Indeed, previous studies on black carbon on Himalayan and European ice cores have repeatedly shown different and contracting trends when measured with different analytical methods, even when studies examined the same glaciers. This indicates a significant need for more and improved research on black carbon research in the Arctic. Black carbon concentrations, as the study reveals, are immensely complicated and depend on a variety of factors, such as air concentration of black carbon, the amount of precipitation, local wind drift patterns post-deposition, sublimation, and melt. Black carbon concentration can also be affected by sudden changes in snow and ice accumulation, or seasonal melt. These factors make it difficult for scientists to collect faithful data of black carbon concentration over time. However, black carbon data in the Arctic is incredibly important: in the Arctic, black carbon is a more important warming agent than greenhouse gases. Its levels are intensely impacted from local and regional emission sources near Svalbard, such as forest and wild fires and flaring at gas wells in Russia, impacts that are difficult to accurately quantify, the researcher state. While this study sheds light on recent trends of black carbon levels in Svalbard, it raises some key questions about the particle’s measurement, suggesting a need for further development of accurate black carbon measurement techniques and for further research on the role black carbon plays in Arctic warming. Spread the...

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Roundup: Snowmaking Guns, Antarctic Ice, and Black Carbon

Posted by on Jun 22, 2015 in All Posts, Featured Posts, News, Roundup, Science | 0 comments

Roundup: Snowmaking Guns, Antarctic Ice, and Black Carbon

Spread the News:ShareSki Resort’s New Snowmaking Guns  Describing a major ski resort in British Columbia, Canada: “De Jong says that after commercial operations end in July, four snowmaking guns and other infrastructure will be installed. It is expected to be used beginning in October. ‘If the pilot project is conclusive, this unique project will become a significant addition to Whistler Blackcomb’s list of adaptations to ensure long-term resilience against climate change,’ he said.” Read here for more info. Sudden and Rapid Ice Loss Discovered in Antarctica “Several massive glaciers in the southern Antarctic Peninsula suddenly started to crumble in 2009, a new study reports today (May 21) in the journal Science. ‘Out of the blue, it’s become the second most important contributor to sea level rise in Antarctica,’ said lead study author Bert Wouters, a remote sensing expert and Marie Curie Fellow at the University of Bristol in the United Kingdom.” Read here for more info. Study uses ice cores to estimate biomass burnings’ contributions to black carbon “We analyzed refractory black carbon (rBC) in an ice core spanning 1875–2000 AD from Mt. Muztagh Ata, the Eastern Pamirs [of western China], using a Single Particle Soot Photometer (SP2)…. Mean rBC concentrations increased four-fold since the mid-1970s and reached maximum values at end of the 1980s. The observed decrease of the rBC concentrations during the 1990s was likely driven by the economic recession of former USSR countries in Central Asia. Levoglucosan concentrations showed a similar temporal trend to rBC concentrations, exhibiting a large increase around 1980 AD followed by a decrease in the 1990s that was likely due to a decrease in energy-related biomass combustion. The time evolution of levoglucosan/rBC ratios indicated stronger emissions from open fires during the 1940s–1950s, while the increase in rBC during the 1980s–1990s was caused from an increase in energy-related combustion of biomass and fossil fuels.” Read here for more info. Spread the...

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