scholarly journals Estimation of permafrost thawing rates in a sub-arctic catchment using recession flow analysis

2009 ◽  
Vol 6 (1) ◽  
pp. 63-83 ◽  
Author(s):  
S. W. Lyon ◽  
G. Destouni ◽  
R. Giesler ◽  
C. Humborg ◽  
M. Mörth ◽  
...  
Keyword(s):  
Average Rate ◽  
Flow Analysis ◽  
Local Scale ◽  
Northern Sweden ◽  
The Past ◽  
Direct Observations ◽  
Flow Pathways ◽  
Thawing Rate ◽  
Permafrost Thawing

Abstract. Permafrost thawing is likely to change the flow pathways taken by water as it moves through arctic and sub-arctic landscapes. The location and distribution of these pathways directly influence the carbon and other biogeochemical cycling in northern latitude catchments. Direct observations of permafrost depth are difficult to perform at scales larger than a local scale. Using recession flow analysis, it may be possible to detect and estimate the rate of permafrost thawing based on a long-term streamflow record. We demonstrate the application of this approach to the sub-arctic Abiskojokken catchment in northern Sweden. Based on recession flow analysis, we estimate that permafrost in this catchment may be thawing at an average rate of about 0.9 cm/yr during the past 90 years. This estimated thawing rate is consistent with direct observations of permafrost thawing rates, ranging from 0.7 to 1.3 cm/yr over the past 30 years in the region.

scholarly journals Estimation of permafrost thawing rates in a sub-arctic catchment using recession flow analysis

2009 ◽  
Vol 13 (5) ◽  
pp. 595-604 ◽  
Author(s):  
S. W. Lyon ◽  
G. Destouni ◽  
R. Giesler ◽  
C. Humborg ◽  
M. Mörth ◽  
...  
Keyword(s):  
Average Rate ◽  
Flow Analysis ◽  
The Arctic ◽  
Northern Sweden ◽  
The Past ◽  
Direct Observations ◽  
Flow Pathways ◽  
Thawing Rate ◽  
Permafrost Thawing

Abstract. Permafrost thawing is likely to change the flow pathways taken by water as it moves through arctic and sub-arctic landscapes. The location and distribution of these pathways directly influence the carbon and other biogeochemical cycling in northern latitude catchments. While permafrost thawing due to climate change has been observed in the arctic and sub-arctic, direct observations of permafrost depth are difficult to perform at scales larger than a local scale. Using recession flow analysis, it may be possible to detect and estimate the rate of permafrost thawing based on a long-term streamflow record. We demonstrate the application of this approach to the sub-arctic Abiskojokken catchment in northern Sweden. Based on recession flow analysis, we estimate that permafrost in this catchment may be thawing at an average rate of about 0.9 cm/yr during the past 90 years. This estimated thawing rate is consistent with direct observations of permafrost thawing rates, ranging from 0.7 to 1.3 cm/yr over the past 30 years in the region.

scholarly journals Hurricanes as a Major Driver of Coastal Erosion in the Mississippi River Delta: A Multi-Decadal Analysis of Shoreline Retreat Rates at Bay Champagne, Louisiana (USA)

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1480 ◽  
Author(s):  
Marianne Dietz ◽  
Kam-biu Liu ◽  
Thomas Bianchette
Keyword(s):  
Mississippi River ◽  
Average Rate ◽  
Landsat Imagery ◽  
Mississippi River Delta ◽  
Coastal Lake ◽  
Shoreline Retreat ◽  
The Past ◽  
Coastal Features ◽  
Mexico Coast

The Louisiana shoreline is rapidly retreating as a result of factors such as sea-level rise and land subsidence. The northern Gulf of Mexico coast is also a hotspot for hurricane landfalls, and several major storms have impacted this region in the past few decades. A section of the Louisiana (USA) coast that has one of the highest rates of shoreline retreat in North America is the Caminada-Moreau headland, located south of New Orleans. Bay Champagne is a coastal lake within the headland that provides a unique opportunity to investigate shoreline retreat and the coastal effects of hurricanes. In order to examine the influence of hurricanes on the rate of shoreline retreat, 35 years (1983–2018) of Landsat imagery was analyzed. During that period of time, the shoreline has retreated 292 m. The overall rate of shoreline retreat, prior to a beach re-nourishment project completed in 2014, was over 12 m per year. A period of high hurricane frequency (1998–2013) corresponds to an increased average shoreline retreat rate of >21 m per year. Coastal features created by multiple hurricanes that have impacted this site have persisted for several years. Bay Champagne has lost 48% of its surface area over the last 35 years as a result of long-term shoreline retreat. If shoreline retreat continues at the average rate, it is expected that Bay Champagne will disappear completely within the next 40 years.

Comparing streamflow analysis and remote sensing observations to assess climate change impact on permafrost degradation

2020 ◽  
Author(s):  
flore sergeant ◽  
rene therrien ◽  
ludovic oudin ◽  
anne jost ◽  
françois anctil
Keyword(s):  
Climate Change ◽  
Remote Sensing ◽  
Satellite Images ◽  
Ground Subsidence ◽  
Permafrost Degradation ◽  
Analysis Method ◽  
Temporal And Spatial ◽  
Thawing Rate ◽  
Permafrost Thawing

<p><strong>ABSTRACT</strong></p><p>Due to polar amplification of climate change, high latitudes are warming up twice as fast as the rest of the world. This warming leads to permafrost thawing, which induces greenhouse gases release, ground subsidence, and modifies surface and subsurface hydrologic regimes. Ground subsidence in turn affects local infrastructure stability. In this context and to better manage future infrastructures and water resources of northern regions, it is crucial to be able to evaluate the thawing rate of permafrost.</p><p>In many Arctic zones, the frequency of environmental disturbances caused by permafrost thawing increases so rapidly that maintaining an accurate inventory of the state of permafrost at a regional scale represents a great challenge. Moreover, depending on the study area and the permafrost ice content, the thawing rate can vary from millimetres to decimeters per year. Another current challenge is the limited availability of temporal and spatial data on permafrost thawing rates.</p><p>To address the above challenges, two indirect methods are used: (1) Arctic river streamflow analysis method and (2) Ground settlement analysis method via satellite image observation. Both methods use free-access data that have an exceptionally large temporal and spatial coverage capacity for such a poorly instrumented region. The first method analyses the recession events’ behavior of Arctic streams and relates those behaviors to changes in catchment-scale depth to permafrost that influences storage-discharge dynamics. This work differs from previous hydrological system analysis in northern systems in that it looks at long-term trends (>10 years) in recession intercept to assess permafrost dynamics, while other studies looked at recession characteristics within a season to assess active-layer dynamics. The second method analyses satellite images of the Arctic ground and associates surface elevation change to long-term permafrost degradation due to climate change.</p><p>Both methods have already been tested through multiple local investigations and gave promising results. The recession flow analysis method has been applied to Yukon river basin, northern Sweden basins and Lena basin in Siberia, while the remote sensing analysis method has been tested on Baffin Island, Herschel Island in Canada, North Slope of Alaska and the Tibetan Plateau. However, no comparative study and no large-scale application have been conducted so far. Extending the analysis to hundreds of Arctic basins and comparing the resulting permafrost-thawing rate values from both methods constitute the innovative aspect of this project.</p><p> </p><p>KEY WORDS: climate change, permafrost thawing, storage-discharge dynamics, ground subsidence, satellite images</p>

scholarly journals Quasi ~500-year Cycle Signals in Solar Activity

2018 ◽  
Vol 7 (1) ◽  
pp. 131
Author(s):  
Lihua Ma ◽  
Zhiqiang Yin ◽  
Yanben Han
Keyword(s):  
Solar Activity ◽  
Power Spectrum ◽  
Wavelet Power Spectrum ◽  
Geomagnetic Variations ◽  
The Past ◽  
Direct Observations ◽  
Periodic Signals ◽  
Activity Series

Direct observations of solar activity are available for the past four century, so some proxies reflecting solar activity such as 14C, 10Be and geomagnetic variations are used to reconstruct solar activity in the past. In this present paper, the authors use rectified wavelet power transform and time-averaged wavelet power spectrum to investigate long-term fluctuations of the reconstructed solar activity series. Results show obvious a quasi ~500-year cycle exists in the past solar activity. Three reconstructed solar activity series from 14C variations confirm the periodic signals.

scholarly journals Long-term changes in lower tropospheric baseline ozone concentrations at northern mid-latitudes

2012 ◽  
Vol 12 (23) ◽  
pp. 11485-11504 ◽  
Author(s):  
D. D. Parrish ◽  
K. S. Law ◽  
J. Staehelin ◽  
R. Derwent ◽  
O. R. Cooper ◽  
...  
Keyword(s):  
Average Rate ◽  
Data Sets ◽  
Full Time ◽  
Model Calculations ◽  
The Past ◽  
Rate Of Increase ◽  
Varying Length ◽  
Consistent Picture ◽  
Autumn And Winter

Abstract. Changes in baseline (here understood as representative of continental to hemispheric scales) tropospheric O3 concentrations that have occurred at northern mid-latitudes over the past six decades are quantified from available measurement records with the goal of providing benchmarks to which retrospective model calculations of the global O3 distribution can be compared. Eleven data sets (ten ground-based and one airborne) including six European (beginning in the 1950's and before), three North American (beginning in 1984) and two Asian (beginning in 1991) are analyzed. When the full time periods of the data records are considered a consistent picture emerges; O3 has increased at all sites in all seasons at approximately 1% yr−1 relative to the site's 2000 yr mixing ratio in each season. For perspective, this rate of increase sustained from 1950 to 2000 corresponds to an approximate doubling. There is little if any evidence for statistically significant differences in average rates of increase among the sites, regardless of varying length of data records. At most sites (most definitively at the European sites) the rate of increase has slowed over the last decade (possibly longer), to the extent that at present O3 is decreasing at some sites in some seasons, particularly in summer. The average rate of increase before 2000 shows significant seasonal differences (1.08 ± 0.09, 0.89 ± 0.10, 0.85 ± 0.11 and 1.21 ± 0.12% yr−1 in spring, summer, autumn and winter, respectively, over North America and Europe).

Enabling Community Well-being Self-Monitoring in the Context of Mining: The Naskapi Nation of Kawawachikamach

2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Robert Klinck ◽  
Ben Bradshaw ◽  
Ruby Sandy ◽  
Silas Nabinacaboo ◽  
Mannie Mameanskum ◽  
...  
Keyword(s):  
Indigenous Peoples ◽  
Well Being ◽  
Aboriginal Community ◽  
Self Monitoring ◽  
Community Engaged Research ◽  
The Past ◽  
Mineral Development ◽  
Iron Deposits ◽  
Term Monitoring

The Naskapi Nation of Kawawachikamach is an Aboriginal community located in northern Quebec near the Labrador Border. Given the region’s rich iron deposits, the Naskapi Nation has considerable experience with major mineral development, first in the 1950s to the 1980s, and again in the past decade as companies implement plans for further extraction. This has raised concerns regarding a range of environmental and socio-economic impacts that may be caused by renewed development. These concerns have led to an interest among the Naskapi to develop a means to track community well-being over time using indicators of their own design. Exemplifying community-engaged research, this paper describes the beginning development of such a tool in fall 2012—the creation of a baseline of community well-being against which mining-induced change can be identified. Its development owes much to the remarkable and sustained contribution of many key members of the Naskapi Nation. If on-going surveying is completed based on the chosen indicators, the Nation will be better positioned to recognize shifts in its well-being and to communicate these shifts to its partners. In addition, long-term monitoring will allow the Naskapi Nation to contribute to more universal understanding of the impacts of mining for Indigenous peoples.

Courting the Youth Vote in 2008: The Obama Effect

2009 ◽  
Vol 5 ◽  
Author(s):  
Lindsey C Bohl
Keyword(s):  
Presidential Elections ◽  
Voter Registration ◽  
The Internet ◽  
The Past ◽  
Several Variables ◽  
High Turnout ◽  
Short And Long Term ◽  
Use Of The Internet ◽  
Youth Vote

This paper examines a few of the numerous factors that may have led to increased youth turnout in 2008 Election. First, theories of voter behavior and turnout are related to courting the youth vote. Several variables that are perceived to affect youth turnout such as party polarization, perceived candidate difference, voter registration, effective campaigning and mobilization, and use of the Internet, are examined. Over the past 40 years, presidential elections have failed to engage the majority of young citizens (ages 18-29) to the point that they became inclined to participate. This trend began to reverse starting in 2000 Election and the youth turnout reached its peak in 2008. While both short and long-term factors played a significant role in recent elections, high turnout among youth voters in 2008 can be largely attributed to the Obama candidacy and campaign, which mobilized young citizens in unprecedented ways.

TINJAUAN STUDI KELAYAKAN USAHA BADAN USAHA MILIK DESA (NAGARI) KAMANG HILIA SEJAHTERA KENAGARIAN KAMANG HILIA, KECAMATAN KAMANG MAGEK, KABUPATEN AGAM, PROVINSI SUMATERA BARAT

2018 ◽  
Vol 3 (2) ◽  
pp. 160
Author(s):  
Halkadri Fitra ◽  
Salma Taqwa ◽  
Charoline Cheisviyanny ◽  
Abel Tasman ◽  
Nurzi Sebrina
Keyword(s):  
Cash Flow ◽  
Net Present Value ◽  
Average Rate ◽  
Flow Analysis ◽  
Payback Period ◽  
Rate Of Return ◽  
Internal Rate Of Return ◽  
Present Value ◽  
Internal Rate

Penelitian ini bertujuan untuk melihat kelayakan aspek keuangan usaha grosir sembako Badan Usaha Milik Desa (Nagari) Kamang Hilia Sejahtera di Kenagarian Kamang Hilia Kecamatan Kamang Magek Kabupaten Agam Provinsi Sumatera Barat yang dilakukan pada tahun 2018. Penelitian bersifat deskriptif kuantitatif dengan menggunakan metode cash flow analysis, payback period, net present value, profitability index, internal rate of return, dan average rate of return. Hasil penelitian menunjukkan bahwa nilai net cash flow Badan Usaha Milik Desa (Nagari) Kamang Hilia Sejahtera adalah positif yaitu Rp.21.774.000, nilai payback period adalah 1,15 tahun, nilai net present value positif sebesar Rp.10.680.034,47, nilai profitability index adalah positif 1,37, sedangkan nilai internal rate of return adalah 46,7% dan nilai average rate of return adalah 57,23%. Berdasarkan standar penilaian maka semua metode yang digunakan memberikan kesimpulan bahwa usaha grosir sembako milik Badan Usaha Milik Desa (Nagari) Kamang Hilia Sejahtera dalam kategori layak untuk dilaksanakan.

Impact of FII’s and FDI’s on Indian Stock Market

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Dr. Kamlesh Kumar Shukla
Keyword(s):  
Stock Market ◽  
Financial Markets ◽  
Global Economy ◽  
Short Term ◽  
Earnings Growth ◽  
The Past ◽  
Bull Market ◽  
Indian Stock Market

FIIs are companies registered outside India. In the past four years there has been more than $41 trillion worth of FII funds invested in India. This has been one of the major reasons on the bull market witnessing unprecedented growth with the BSE Sensex rising 221% in absolute terms in this span. The present downfall of the market too is influenced as these FIIs are taking out some of their invested money. Though there is a lot of value in this market and fundamentally there is a lot of upside in it. For long-term value investors, there’s little because for worry but short term traders are adversely getting affected by the role of FIIs are playing at the present. Investors should not panic and should remain invested in sectors where underlying earnings growth has little to do with financial markets or global economy.

Chinese Medicine Protein and Peptide in Gene and Cell Therapy

2019 ◽  
Vol 20 (3) ◽  
pp. 251-264 ◽  
Author(s):  
Yinlu Feng ◽  
Zifei Yin ◽  
Daniel Zhang ◽  
Arun Srivastava ◽  
Chen Ling
Keyword(s):  
Chinese Medicine ◽  
Cell Therapy ◽  
Future Research ◽  
The Past ◽  
Promising Strategy ◽  
Wide Range ◽  
New Directions ◽  
Gene And Cell Therapy ◽  
Proteins And Peptides

The success of gene and cell therapy in clinic during the past two decades as well as our expanding ability to manipulate these biomaterials are leading to new therapeutic options for a wide range of inherited and acquired diseases. Combining conventional therapies with this emerging field is a promising strategy to treat those previously-thought untreatable diseases. Traditional Chinese medicine (TCM) has evolved for thousands of years in China and still plays an important role in human health. As part of the active ingredients of TCM, proteins and peptides have attracted long-term enthusiasm of researchers. More recently, they have been utilized in gene and cell therapy, resulting in promising novel strategies to treat both cancer and non-cancer diseases. This manuscript presents a critical review on this field, accompanied with perspectives on the challenges and new directions for future research in this emerging frontier.

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