Roundup

Roundup: New Islands, New Bacteria, and New Maps

Posted by on Feb 6, 2017 in All Posts, Featured Posts, News, Roundup | 0 comments

Roundup: New Islands, New Bacteria, and New Maps

Spread the News:ShareNew Islands, Bacteria, and Maps Retreating Coronation Glacier Forms New Deltaic Island From American Geophysical Union: “In 1989 Coronation Glacier (Nunavut, Canada) terminates where the main outlet stream has created a pair of small deltaic islands on the northern side of the fjord. In 2016 a new deltaic island has formed near the southern edge of the margin, indicating a shift in the position of the main river outlet emanating from below the glacier, this is also marked by a large plume. The island formed is larger than those observed in 1989 or 1998. The size of the island gives it potential to survive, based on satellite imagery. A visit to the island would be needed to shed light on its potential for enduring. Retreat from 1989 to 2016 has been 1100 meters on the northern side of the fjord and 500 meters on the south side of the fjord. The average retreat of 800 meters in 27 years is over 30 meters/year, much faster than the 1880-1988 period.” Read more about Coronation Glacier here.   Microbial Subglacial Communities in Greenland From Microbial Ecology: “The Watson River drains a portion of the southwest Greenland ice sheet, transporting microbial communities from subglacial environments to a delta at the head of Søndre Strømfjord. This study investigates the potential activity and community shifts of glacial microbiota deposited and buried under layers of sediments within the river delta. A long-term (12-month) incubation experiment was established using Watson River delta sediment under anaerobic conditions, with and without carbon dioxide/hydrogen enrichment. The results highlight the need for further investigations into the fate of subglacial microbiota within downstream environments.” Learn more about subglacial microbial communities here.   Improving Glacier Bed Topography Mapping From Oceanography: “Melting of the Greenland Ice Sheet has the potential to raise sea level by 7.36 meters and is already contributing to global sea level rise at a rate higher than 1 milimeter/year. Computer models are our best tools to make projections of the mass balance of Greenland over the next centuries, but these models rely on bed topography data that remain poorly constrained near glacier termini. We combine here for the first time mass conservation glacier bed mapping and newly collected bathymetry data from NASA’s Oceans Melting Greenland (OMG) to evaluate and improve descriptions of bed topography under grounded ice near glacier termini, where it matters most for improving the reliability of ice sheet models.” Read more about NASA’s Oceans Melting Greenland data here.   Spread the...

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Roundup: Carbon Sinks, Serpentine Syndrome and Migration Dynamics

Posted by on Jan 30, 2017 in Adaptation, All Posts, Communities, Featured Posts, Roundup, Science | 0 comments

Roundup: Carbon Sinks, Serpentine Syndrome and Migration Dynamics

Spread the News:ShareRoundup: Carbon, Serpentine, and Migration   Dwindling Glaciers Lead to Potential Carbon Sinks From PLOS ONE: “Current glacier retreat makes vast mountain ranges available for vegetation establishment and growth. As a result, carbon (C) is accumulated in the soil, in a negative feedback to climate change. Little is known about the effective C budget of these new ecosystems and how the presence of different vegetation communities influences CO2 fluxes. On the Matsch glacier forefield (Alps, Italy) we measured over two growing seasons the Net Ecosystem Exchange (NEE) of a typical grassland, dominated by the C3 Festuca halleri All., and a community dominated by the CAM rosettes Sempervivum montanum L… The two communities showed contrasting GEE but similar Reco patterns, and as a result they were significantly different in NEE during the period measured. The grassland acted as a C sink, with a total cumulated value of -46.4±35.5 g C m-2 NEE, while the plots dominated by the CAM rosettes acted as a source, with 31.9±22.4 g C m-2. In spite of the different NEE, soil analysis did not reveal significant differences in carbon accumulation of the two plant communities, suggesting that processes often neglected, like lateral flows and winter respiration, can have a similar relevance as NEE in the determination of the Net Ecosystem Carbon Balance.” Learn more about the colonization of a deglaciated moraine here.   Vegetation and the Serpentine Syndrome From Plant and Soil: “Initial stages of pedogenesis (soil formation) are particularly slow on serpentinite (a dark, typically greenish metamorphic rock that weathers to form soil). This implies a slow accumulation of available nutrients and leaching of phytotoxic (poisonous to plants) elements. Thus, a particularly slow plant primary succession should be observed on serpentinitic proglacial areas. The observation of soil-vegetation relationships in such environments should give important information on the development of the serpentine syndrome (a phrase to explain plant survival on serpentine)… Plant-soil relationships have been statistically analysed, comparing morainic environments on pure serpentinite and serpentinite with small sialic inclusions in the North-western Italian Alps….Pure serpentinite supported strikingly different plant communities in comparison with the sites where the serpentinitic till was enriched by small quantities of sialic rocks.” Find out more about the serpentine syndrome here.   Climate Changes Landscape of South American Communities From Global Migration Issues: “Mountain regions are among the most vulnerable areas with regard to global environmental changes. In the Bolivian Andes, for example, environmental risks, such as those related to climate change, are numerous and often closely intertwined with social risks. Rural households are therefore characterized by high mobility, which is a traditional strategy of risk management. Nowadays, most rural households are involved in multi-residency or circular migratory movements at a regional, national, and international scale. Taking the case of two rural areas close to the city of La Paz, we analyzed migration patterns and drivers behind migrant household decisions in the Bolivian Andes… Our results underline that migration is a traditional peasant household strategy to increase income and manage livelihood risks under rising economic pressures, scarcity of land, insufficient local off-farm work opportunities, and low agricultural productivity… Our results suggest that environmental factors do not drive migration independently, but are rather combined with socio-economic factors.” Read more about migration dynamics here. Spread the...

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Roundup: Rock Glaciers, Ice Tongues and Flood Warnings

Posted by on Jan 23, 2017 in All Posts, Featured Posts, News, Roundup, Science | 0 comments

Roundup: Rock Glaciers, Ice Tongues and Flood Warnings

Spread the News:ShareRoundup: Rock Glaciers, Floating Glaciers, and Flood Warnings Ecology of Active Rock Glaciers From Boreas: “Active rock glaciers are periglacial landforms (areas that lie adjacent to a glacier or ice sheet that freeze and thaw) consisting of coarse debris with interstitial ice (ice formed in the narrow space between rocks and sediment) or ice-core. Recent studies showed that such landforms are able to support plant and arthropod life and could act as warm-stage refugia for cold-adapted species due to their microclimate features and thermal inertia. However, integrated research comparing active rock glaciers with surrounding landforms to outline their ecological peculiarities is still scarce… Our data show remarkable differences between stable slopes and unstable landforms as a whole, while few differences occur between active scree slopes and active rock glaciers: such landforms show similar soil features but different ground surface temperatures (lower on active rock glaciers) and different occurrence of cold-adapted species (more frequent/abundant on active rock glaciers)… The role of active rock glaciers as potential warm-stage refugia for cold-adapted species is supported by our data; however, at least in the European Alps, their role in this may be less important than that of debris-covered glaciers, which are able to host cold-adapted species even below the climatic tree line.” Read more about the role of active rock glaciers as potential warm-stage refugia here:   Fluid-Ice Structure Interaction of the Drygalski Ice Tongue From UTAS: “The Drygalski Ice Tongue (DIT) is the largest floating glacier in Antarctica, extending approximately 120km into McMurdo Sound, and exhibits a significant influence upon the prevailing northward current, as the ice draft (measurement of ice thickness below the waterline) of the majority of the DIT is greater than the depth of the observed well-mixed surface layer. This influence is difficult to characterize using conventional methods such as in-situ LADCP (Lowered Acoustic Doppler Current Profiler) measurements, vertically collected profiles or long-term moorings as these are generally relatively spatially sparse datasets. In order to better relate measurements across the entire region of influence of the DIT region, a set of Computational Fluid Dynamics simulations (uses numerical analysis to analyze fluid flows) were conducted using a generalized topography of a mid-span transect of the DIT… Numerical modeling of environmental flows around ice structures advances the knowledge of the fluid dynamics of the system in not only the region surrounding the DIT but also provides a clearer insight into fluid-ice structure interactions and heat flux in the system. This may lead to a better understanding of the long-term fate of floating glaciers.” Learn more about fluid-ice structure interactions here:   Flood Early Warning Systems (EWSs) in Bhutan From ICIMOD: “Bhutan experiences frequent hydrometeorological disasters. In terms of relative exposure to flood risk as a percentage of population, Bhutan ranks fourth highest in the Asia-Pacific region, with 1.7% of its total population exposed to flood risk. It is likely that climate change will increase the frequency and severity of flood disasters in Bhutan. Inequalities in society are often amplified at the times of disaster and people living in poverty, especially women, the elderly, and children, are particularly vulnerable to flood hazards. Timely and reliable flood forecasting and early warnings that consider the needs of both women and men can contribute to saving lives and property. Early warning systems (EWSs) that are people-centered, accurate, timely, and understandable to communities at risk and that recommend the appropriate action to be taken by vulnerable communities can save people more effectively. To improve the understanding of existing early warning systems (EWSs) in the region and their effectiveness, ICIMOD has conducted an assessment of...

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Roundup: Siberia, Serpentine and Seasonal Cycling

Posted by on Jan 16, 2017 in All Posts, Featured Posts, Roundup | 0 comments

Roundup: Siberia, Serpentine and Seasonal Cycling

Spread the News:ShareRoundup: Siberian Glaciers, Vegetation Succession and Sea Ice   Glaciers in Siberia During the Last Glacial Maximum From Palaeogeography, Palaeoclimatology, Palaeoecology: “It is generally assumed that during the global Last Glacial Maximum (gLGM, 18–24 ka BP) dry climatic conditions in NE Russia inhibited the growth of large ice caps and restricted glaciers to mountain ranges. However, recent evidence has been found to suggest that glacial summers in NE Russia were as warm as at present while glaciers were more extensive than today… We hypothesize that precipitation must have been relatively high in order to compensate for the high summer temperatures… Using a degree-day-modelling (DDM) approach, [we] find that precipitation during the gLGM was likely comparable to, or even exceeded, the modern average… Results imply that summer temperature, rather than aridity, limited glacier extent in the southern Pacific Sector of NE Russia during the gLGM.” Read more about the study here.     Plant Communities in the Italian Alps From Plant and Soil: “Initial stages of pedogenesis (soil formation) are particularly slow on serpentinite… Thus, a particularly slow plant primary succession should be observed on serpentinitic proglacial (in front of glaciers) areas..Ssoil-vegetation relationships in such environments should give important information on the development of the “serpentine syndrome” .Pure serpentinite supported strikingly different plant communities in comparison with the sites where the serpentinitic till was enriched by small quantities of sialic (rich in silica and aluminum) rocks. While on the former materials almost no change in plant species composition was observed in 190 years, four different species associations were developed with time on the other. Plant cover and biodiversity were much lower on pure serpentinite as well.” Read more about “serpentine syndrome” here.     Carbon Cycling and Sea Ice in Ryder Bay From Deep Sea Research Part II: Topical Studies in Oceanography: “The carbon cycle in seasonally sea-ice covered waters remains poorly understood due to both a lack of observational data and the complexity of the system… We observe a strong, asymmetric seasonal cycle in the carbonate system, driven by physical processes and primary production. In summer, melting glacial ice and sea ice and a reduction in mixing with deeper water reduce the concentration of dissolved organic carbon (DIC) in surface waters… In winter, mixing with deeper, carbon-rich water and net heterotrophy increase surface DIC concentrations… The variability observed in this study demonstrates that changes in mixing and sea-ice cover significantly affect carbon cycling in this dynamic environment.” Read more about carbon cycling in West Antarctica here.   Spread the...

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Roundup: Sediments, Swamps and Sea Levels

Posted by on Jan 9, 2017 in All Posts, Featured Posts, Roundup | 0 comments

Roundup: Sediments, Swamps and Sea Levels

Spread the News:ShareRoundup: High Arctic, Peru, and Global Seas   Suspended Sediment in a High-Arctic River From Science of The Total Environment: “Quantifying fluxes [the action of flowing] of water, sediment and dissolved compounds through Arctic rivers is important for linking the glacial, terrestrial and marine ecosystems and to quantify the impact of a warming climate… This study uses a 8-years data set (2005–2012) of daily measurements from the high-Artic Zackenberg River in Northeast Greenland to estimate annual suspended sediment fluxes based on four commonly used methods: M1) is the discharge weighted mean and uses direct measurements, while M2-M4) are one uncorrected and two bias-corrected rating curves extrapolating a continuous concentration trace from measured values.”   Read more about suspended sediment fluxes here:     Glacier Recession in Cordillera Blanca From Applied Geography: “Receding mountain glaciers affect the hydrology of downslope ecosystems with consequences for drinking water, agriculture, and hydropower production. Here we combined land cover derived from satellite imagery and other environmental data from the northern Peruvian Andes into a first differencing regression model to assess wetland hydrologic connectivity… The results indicate that there were two primary spatial driving forces of wetland change in Peru’s Cordillera Blanca from 1987 to 1995: 1) loss in glacier area was associated with increased wetland area, controlling for other factors; while 2) an increase in mean annual stream discharge in the previous 12 months increased wetland area.”   Learn more about the study here:     Observation-Based Estimates of Glacier Mass Change From Surveys in Geophysics: “Glaciers have strongly contributed to sea-level rise during the past century and will continue to be an important part of the sea-level budget during the twenty-first century. Here, we review the progress in estimating global glacier mass change from in situ measurements of mass and length changes, remote sensing methods, and mass balance modeling driven by climate observations. For the period before the onset of satellite observations, different strategies to overcome the uncertainty associated with monitoring only a small sample of the world’s glaciers have been developed. These methods now yield estimates generally reconcilable with each other within their respective uncertainty margins. Whereas this is also the case for the recent decades, the greatly increased number of estimates obtained from remote sensing reveals that gravimetry-based methods typically arrive at lower mass loss estimates than the other methods. We suggest that strategies for better interconnecting the different methods are needed to ensure progress and to increase the temporal and spatial detail of reliable glacier mass change estimates.”   Read more about global sea-level rise here:   Spread the...

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Roundup: Peruvian Climate, Tibetan Lakes, and Greenland’s Glaciers

Posted by on Jan 2, 2017 in All Posts, Featured Posts, Roundup | 0 comments

Roundup: Peruvian Climate, Tibetan Lakes, and Greenland’s Glaciers

Spread the News:ShareRoundup: Peru, Tibet and Greenland   Project to Improve Climate Services in Peru From Climate Services: “CLIMANDES is a pilot twinning project between the National Weather Services of Peru and Switzerland (SENAMHI and MeteoSwiss), developed within the Global Framework for Climate Services of the World Meteorological Organization (WMO). Split in two modules, CLIMANDES aims at improving education in meteorology and climatology in support of the WMO Regional Training Center in Peru, and introducing user-tailored climate services in two pilot regions in the Peruvian Andes… The efforts accomplished within CLIMANDES improved the quality of the climate services provided by SENAMHI.” Read more about CLIMANDES here.   Monitoring Lake Levels on the Tibetan Plateau From Journal of Hydrology: “Lakes on the Tibetan Plateau (TP) are of great interest due to their value as water resources but also as an important indicator of climate change. However, in situ data in this region are extremely scarce and only a few lakes have gauge measurements… In this study, Cryosat-2 SARIn mode data over the period 2010–2015 are used to investigate recent lake level variations… Lakes in the northern part of the TP experienced pronounced rising (avg. 0.37 ± 0.10 m/yr), while lakes in southern part were steady or decreasing even in glaciated basins with high precipitation… These results demonstrate that lakes on the TP are still rapidly changing under climate change, especially in northern part of the TP, but the driving factors are variable and more research is needed.” Learn more about climate change on the Tibetan Plateau here.   Data Portal to Study Greenland’s Ice Sheet From Eos: “A new web-based data portal gives scientists access to more than 40 years of satellite imagery, providing seasonal to long-term insights into outflows from Greenland’s ice sheet… This portal harnesses more than 37,000 images from Landsat archives, dating back to the early 1970s, to track changes in outlet glaciers over time… Through analyzing data from this portal, we can see in great detail how several outlet glaciers are speeding up their treks to the sea. What’s more, any user can access the data to conduct their own studies of glacier behavior at Greenland’s coasts through time.” Read more about Greenland’s retreating glaciers here: Spread the...

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