The Karakoram Predicament

2020 ◽  
Author(s):  
Bibhasvata Dasgupta ◽  
Prasanta Sanyal
Keyword(s):  
Accumulation Rate ◽  
Vertical Mixing ◽  
Winter Rainfall ◽  
Snow Cover Area ◽  
Local Factors ◽  
Input Surface ◽  
Increasing Trend ◽  
Wet Snow ◽  
Accumulation Index ◽  
State Nature

<p>The anomalous behaviour of Karakoram Glaciers (Hewitt, 2005) in the backdrop of a warming planet has been a decade long debate baffling climatologists worldwide. While a lot of effort has been given to understand this behaviour, very little has been explored with respect to the factors that favour glaciation rates. A fundamental approach to glacial mass budget calculation involves a simplistic assessment of accumulation and melt. Analysis of meteorological datasets over the last 40 years yields conflicting scenarios. On one hand, we have observed a significant negative trend in winter rainfall and snowfall amount coupled with increasing surface temperatures and vertical mixing of atmospheric vapour. On the other hand, parameters that reflect the bulk of a cryospheric reservoir such as snow depth, dry snow/wet snow percentages show stable to increasing trend. Between lower moisture input and potential ablation rates, the steady-state nature of Karakoram glaciers have emulated optimism in the works of climatologists worldwide. In this study, we have tried to formulate an ‘accumulation index’ as a function of moisture input, surface temperature and atmospheric vertical circulation. Precipitation trends are negative yet periodic which suffices a positive accumulation rate. At the same time, local factors such as debris field and wet snow cover area help preserve the accumulated bulk of a given winter through the upcoming warm summers. However, in a potentially warming planet, accumulation rates aren't proportional to ambient temperature. Studies show that the mass balance turns sharply negative at temperatures above -10 °C due to accelerated ablation which overcompensates accumulation. This makes the Karakoram phenomenon a function of global meteorology rather than local factors i.e. debris cover, vorticity, etc. Therefore, we suggest that the Karakoram Glaciers aren’t behaving anomalously, but lagging in phase with central and eastern Himalayan glaciated regions.</p>

scholarly journals Model calculations of the age of firn air across the Antarctic continent

2004 ◽  
Vol 4 (5) ◽  
pp. 1365-1380 ◽  
Author(s):  
K. A. Kaspers ◽  
R. S. W. van de Wal ◽  
M. R. van den Broeke ◽  
J. Schwander ◽  
N. P. M. van Lipzig ◽  
...  
Keyword(s):  
Climate Model ◽  
Accumulation Rate ◽  
Methyl Chloride ◽  
Trace Gas ◽  
Model Calculations ◽  
Antarctic Plateau ◽  
Input Surface ◽  
Antarctic Continent ◽  
High Level ◽  
Air Diffusion

Abstract. The age of firn air in Antarctica at pore close-off depth is only known for a few specific sites where firn air has been sampled for analyses. We present a model that calculates the age of firn air at pore close-off depth for the entire Antarctic continent. The model basically uses four meteorological parameters as input (surface temperature, pressure, accumulation rate and wind speed). Using parameterisations for surface snow density, pore close-off density and tortuosity, in combination with a density-depth model and data of a regional atmospheric climate model, distribution of pore close-off depth for the entire Antarctic continent is determined. The deepest pore close-off depth was found for the East Antarctic Plateau near 72° E, 82° S, at 150±15 m (2σ). A firn air diffusion model was applied to calculate the age of CO2 at pore close-off depth. The results predict that the oldest firn gas (CO2 age) is located between Dome Fuji, Dome Argos and Vostok at 43° E, 78° S being 148±23 (1σ or 38 for 2σ) years old. At this location an atmospheric trace gas record should be obtained. In this study we show that methyl chloride could be recorded with a predicted length of 125 years as an example for trace gas records at this location. The longest record currently available from firn air is derived at South Pole, being 80 years. Sensitivity tests reveal that the locations with old firn air (East Antarctic Plateau) have an estimated uncertainty (2σ) for the modelled CO2 age at pore close-off depth of 30% and of about 40% for locations with younger firn air (CO2 age typically 40 years). Comparing the modelled age of CO2 at pore close-off depth with directly determined ages at seven sites yielded a correlation coefficient of 0.90 and a slope close to 1, suggesting a high level of confidence for the modelled results in spite of considerable remaining uncertainties.

scholarly journals Rainfall trend analysis and its future projection over Gangetic West Bengal (GWB) region of India during post-monsoon and winter season

2016 ◽  
Vol 8 (3) ◽  
pp. 1152-1156 ◽  
Author(s):  
Pramiti Kumar Chakraborty ◽  
Lalu Das
Keyword(s):  
Trend Analysis ◽  
West Bengal ◽  
Winter Season ◽  
Policy Formulation ◽  
Rainfall Data ◽  
Future Projection ◽  
Short Term ◽  
Winter Rainfall ◽  
Post Monsoon ◽  
Increasing Trend

Studying the variability of rainfall and its future projection during post-monsoon and winter season is important for providing the information to the farmers regarding crop planning. For evaluating rainfall scenario, long (1901-2005) and short term (1961-2005 and 1991-2005) rainfall data of nine selected IMD stations of South Bengalwas collected and subdivided into 30 year period up to 1990 and a 15 year period from 1991 to 2005. The data were subjected to trend analysis and available GCM data were compared with the observed rainfall data. The postmonsoon and winter rainfall changes during 1901-2005 were positive (except Krishnangar, -47.67 mm) and negative (except Alipore and Berhampur) respectively. During 1991-2005 all the stations recorded a positive change during post-monsoon, while reverse was true for winter. Among the different GCMs, INGV-ECHM4 estimated the postmonsoon rainfall at the best, whereas winter rainfall successfully estimated by MIROC-Hi. Future projection of both post-monsoon and winter rainfall over the region showed an increasing trend. This will help in policy formulation for water management in agriculture.

Estimation of wet snow cover area with SAR imagery in the basin of Tupungato River, Mendoza, Argentina

2018 ◽  
Author(s):  
Sofia A. Teverovsky ◽  
Ignacio G. Pascual ◽  
Claudia Notarnicola ◽  
Graciela Salinas de Salmuni
Keyword(s):  
Snow Cover ◽  
Snow Cover Area ◽  
Wet Snow ◽  
Sar Imagery

scholarly journals Spectral reflectance behavior of different boreal snow types

2019 ◽  
Vol 65 (254) ◽  
pp. 926-939 ◽  
Author(s):  
Henna-Reetta Hannula ◽  
Jouni Pulliainen
Keyword(s):  
Spectral Reflectance ◽  
Near Infrared ◽  
Forest Litter ◽  
Snow Cover Area ◽  
Near Surface ◽  
Mapping Algorithms ◽  
Wet Snow ◽  
Natural Snow ◽  
Incoming Light ◽  
Snow Samples

AbstractSpectral reflectance of natural snow samples representing various stratigraphies was investigated in a controlled dark laboratory environment. Mean and Std dev. of band specific reflectance values were determined for several satellite sensor bands utilized in remote sensing of snow. The reflectance values for dry, moist, wet and wet and littered snow for different instruments varied between 0.63–0.97 in the visible and near-infrared bands at an incoming light zenith angle of θ = 55°. The results indicate that in MODIS band 4 (545–565 nm), essential to snow mapping, the reflectance of snow drops by 9% when dry snow changes to wet snow and by a further 10% when typical forest litter inclusions exist on the wet snow surface. A separate investigation of individual snow types revealed that they can be grouped either as dry or wet snow based on their spectral behavior. However, some snow types were located between these two distinct groups, such as snow with near-surface melt-freeze crusts, and could not be clearly distinguished. The reflectance statistics collected and analyzed here can be directly used to refine accuracy characterization and parametrization of snow mapping algorithms, such as the SCAmod method, used for the mapping of snow cover area.

scholarly journals Onset, intensification, and decline of phytoplankton blooms in the Southern Ocean

2015 ◽  
Vol 72 (6) ◽  
pp. 1971-1984 ◽  
Author(s):  
Joan Llort ◽  
Marina Lévy ◽  
Jean-Baptiste Sallée ◽  
Alessandro Tagliabue
Keyword(s):  
Southern Ocean ◽  
Temporal Dynamics ◽  
Accumulation Rate ◽  
Vertical Mixing ◽  
Biomass Accumulation ◽  
Detection Methods ◽  
Biogeochemical Model ◽  
Iron Availability ◽  
Top Down ◽  
Bottom Up

Abstract The seasonal cycle of phytoplankton biomass in the Southern Ocean (SO) is characterized by a period of rapid accumulation, known as bloom, that is typical of high-latitude regions. Recent studies have illustrated how spatial and temporal dynamics of blooms in the SO are more complex than in other oceans. This complexity is likely related to differences in vertical mixing and the iron availability. In this work, we examine the sensitivity of bloom dynamics to changes in vertical mixing and iron availability using a biogeochemical model. Under idealized physical forcing, we produce seasonal cycles of phytoplankton for an ensemble of SO scenarios and we describe the bloom dynamics in terms of the net biomass accumulation rate. Based on this metric, we define three crucial bloom phases: the onset, the climax, and the apex. For the ensemble of modelled blooms, onsets always occur in winter and can be either bottom-up (increase in productivity) or top-down (decrease in grazing) controlled. Climaxes are mostly found in spring and their magnitudes are bottom-up controlled. Apexes are always found in late spring and strongly top-down controlled. Our results show that while a “strict” onset definition is consistent with a winter onset, the surface spring bloom is associated with the climax of the integrated bloom. Furthermore, we demonstrate that onset phase can be distinguished from climax phase using appropriate bloom detection methods based on surface satellite-based products. The ensemble of these results suggests that Sverdrup's blooming conditions are not indicative of the bloom onset but of the climax. We conclude that the recent bloom onset debate may partly be due to a confusion between what is defined here as the bloom onset and the climax, and that the SO observed complexity is due to the factors that control the climax.

scholarly journals Measuring the Level of Environmental Performance on Coastal Environment before and during the COVID-19 Pandemic: A Case Study from Cyprus

2021 ◽  
Vol 13 (5) ◽  
pp. 2485
Author(s):  
Pantelitsa Loizia ◽  
Irene Voukkali ◽  
Georgia Chatziparaskeva ◽  
Jose Navarro-Pedreño ◽  
Antonis A. Zorpas
Keyword(s):  
Environmental Performance ◽  
Accumulation Rate ◽  
Management Strategies ◽  
Coastal Environment ◽  
Coastal Areas ◽  
Coastal Zones ◽  
Accumulation Index ◽  
Plastic Containers ◽  
Waste Accumulation

Tourism activities are considered, among others, the backbone of the local economies. However, tourism activities lead to adverse environmental impacts, especially in coastal zones. Coastal areas are considered and recognized as of strategic importance due to the fact that several activities take place, from leisure to business. At the same time, coastal areas are under pressure from tourist activities, and the waste generated is a very serious issue. Therefore, there are limited studies related to the environmental dimensions of the COVID-19 pandemic in the coastal environment. This paper provides answers to the hypothesis that the pandemic lockdown scenario would improve environmental performance due to reduced usage and, therefore, waste, taking into account specific key performance indicators (KPIs) as these KPIs are used to evaluate the performance of an area. The results showed that the study area improved, as did the selected KPIs, i.e., clean coast index (CCI), waste accumulation rate (WAR), and waste accumulation index (WAI). Additionally, according to the final results, the concentration of micro-, meso- and macroplastics on the beach reduced, and the main issues remained the solutions on cigarette butts, straws, and other plastic containers. Furthermore, the final results are considered very useful to local authorities, stakeholders, consultants, policymakers, and any other competent authorities, to reschedule their waste management strategies, to improve waste infrastructures and their level of services (LOS), as well as, to suggest frequent awareness-raising activities to their visitors on how to protect the coastal environment, taking into account a pandemic scenario, as well as, the policy alternative impacts on EU coastal zones 2000–2050.

scholarly journals Urban strategies evaluation for waste management in coastal areas in the framework of area metabolism

2021 ◽  
pp. 0734242X2097277
Author(s):  
Irene Voukkali ◽  
Pantelisa Loizia ◽  
Jose Navarro Pedreño ◽  
Antonis A. Zorpas
Keyword(s):  
Waste Management ◽  
Accumulation Rate ◽  
Compositional Analysis ◽  
Total Surface Area ◽  
Management Plan ◽  
Coastal Areas ◽  
The European Union ◽  
Coastal Regions ◽  
Accumulation Index ◽  
Administrative Units

Europe is considered one of the most attractive and safe prevalent tourist destinations in the entire world. Approximately half (47.4%) of European tourist visits occurred in coastal regions, defined “on the basis of and consist of local administrative units or municipalities that border the sea, or have at least half of their total surface area within a distance of 10 km from the sea.” Destinations such as Malta, Greece, Cyprus, Spain and Croatia presented with an increased level of tourist accommodation establishments, as well as, the overall flow of tourism in the European Union is mostly concentrated on Mediterranean coastal regions (as nine out 10 tourists, in 2015, spent their holidays at coastal areas). This paper, is dealing with the assessment of a tourist area and how the concept of urban metabolism has been affected by touristic activities. Moreover, this research using several key performance indicators such as waste compositional analysis, the clean coast index, the accumulation rate, and accumulation index, etc., tries to measure the level of environmental performance, and furthermore, to assess the existing infrastructures and the waste management plan, that are being implemented. The results are very useful, for any policy-maker, as well as competent authorities and/or tourist organizations which are dealing with tourist activities and aim to propose or re-schedule any waste strategy targeting the goals of United Nations Sustainable Development Goals, European Green Deal, and the new circular economy strategy.

scholarly journals Model calculations of the age of firn air across the Antarctic continent

2004 ◽  
Vol 4 (2) ◽  
pp. 1817-1853 ◽  
Author(s):  
K. A. Kaspers ◽  
R. S. W. van de Wal ◽  
M. R. van de Broeke ◽  
J. Schwander ◽  
N. P. M. van Lipzig ◽  
...  
Keyword(s):  
Climate Model ◽  
Accumulation Rate ◽  
Methyl Chloride ◽  
Trace Gas ◽  
Model Calculations ◽  
Antarctic Plateau ◽  
Input Surface ◽  
Antarctic Continent ◽  
High Level ◽  
Air Diffusion

Abstract. The age of firn air in Antarctica at pore close-off depth is only known for a few specific sites where firn air has been sampled for analyses. We present a model that calculates the age of firn air at pore close-off depth for the entire Antarctic continent. The model basically uses four meteorological parameters as input (surface temperature, pressure, accumulation rate and wind speed). Using parameterisations for surface snow density, pore close-off density and tortuosity, in combination with a density-depth model and data of a regional atmospheric climate model, distribution of pore close-off depth for the entire Antarctic continent is determined. The deepest pore close-off depth was found for the East Antarctic Plateau near 72° E, 82° S, at 150±15 m (2σ). A firn air diffusion model was applied to calculate the age of CO2 at pore close-off depth. The results predict that the oldest firn gas (CO2 age) is located between Dome Fuji, Dome Argos and Vostok at 43° E, 78° S being 148±23 (1σ or 38 for 2σ) years old. At this location an atmospheric trace gas record should be obtained. In this study we show that methyl chloride could be recorded with a predicted length of 125 years as an example for trace gas records at this location. The longest record currently available from firn air is derived at South Pole, being 80 years. Sensitivity tests reveal that the locations with old firn air (East Antarctic Plateau) have an estimated uncertainty (2σ) for the modelled CO2 age at pore close-off depth of 30% and of about 40% for locations with younger firn air (CO2 age typically 40 years). Comparing the modelled age of CO2 at pore close-off depth with directly determined ages at seven sites yielded a correlation coefficient of 0.90 and a slope close to 1, suggesting a high level of confidence for the modelled results in spite of considerable remaining uncertainties.

Trends in Periprosthetic Knee Infection and Associated Costs: A Population-Based Study Using National Data

2020 ◽  
Author(s):  
Robert Brochin ◽  
Jashvant Poeran ◽  
Khushdeep S. Vig ◽  
Aakash Keswani ◽  
Nicole Zubizarreta ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Length Of Stay ◽  
Knee Arthroplasty ◽  
Trend Test ◽  
Strong Impact ◽  
Hospitalization Costs ◽  
Teaching Status ◽  
Increasing Trend ◽  
Total Knee ◽  
Increasing Trends

AbstractGiven increasing demand for primary knee arthroplasties, revision surgery is also expected to increase, with periprosthetic joint infection (PJI) a main driver of costs. Recent data on national trends is lacking. We aimed to assess trends in PJI in total knee arthroplasty revisions and hospitalization costs. From the National Inpatient Sample (2003–2016), we extracted data on total knee arthroplasty revisions (n = 782,449). We assessed trends in PJI prevalence and (inflation-adjusted) hospitalization costs (total as well as per-day costs) for all revisions and stratified by hospital teaching status (rural/urban by teaching status), hospital bed size (≤299, 300–499, and ≥500 beds), and hospital region (Northeast, Midwest, South, and West). The Cochran–Armitage trend test (PJI prevalence) and linear regression determined significance of trends. PJI prevalence overall was 25.5% (n = 199,818) with a minor increasing trend: 25.3% (n = 7,828) in 2003 to 28.9% (n = 19,275) in 2016; p < 0.0001. Median total hospitalization costs for PJI decreased slightly ($23,247 in 2003–$20,273 in 2016; p < 0.0001) while median per-day costs slightly increased ($3,452 in 2003–$3,727 in 2016; p < 0.0001), likely as a function of decreasing length of stay. With small differences between hospitals, the lowest and highest PJI prevalences were seen in small (≤299 beds; 22.9%) and urban teaching hospitals (27.3%), respectively. In stratification analyses, an increasing trend in PJI prevalence was particularly seen in larger (≥500 beds) hospitals (24.4% in 2003–30.7% in 2016; p < 0.0001), while a decreasing trend was seen in small-sized hospitals. Overall, PJI in knee arthroplasty revisions appears to be slightly increasing. Moreover, increasing trends in large hospitals and decreasing trends in small-sized hospitals suggest a shift in patients from small to large volume hospitals. Decreasing trends in total costs, alongside increasing trends in per-day costs, suggest a strong impact of length of stay trends and a more efficient approach to PJI over the years (in terms of shorter length of stay).

Study on Causes of Female Infertility at National Ayurveda Teaching Hospital, Borella, Sri Lanka: A Survey Based Study

2017 ◽  
Vol 3 (1) ◽  
pp. 249-252
Author(s):  
Farzana MUZN ◽  
Arshiya Sultana
Keyword(s):  
Sri Lanka ◽  
Teaching Hospital ◽  
Married Women ◽  
Female Infertility ◽  
Policy Makers ◽  
Complex Disorder ◽  
Anovulatory Cycle ◽  
Common Causes ◽  
Increasing Trend ◽  
One Year

Background: Infertility is defined as the inability to conceive after at least one year of unprotected intercourse. It is a complex disorder with significant medical, psychosocial, and economic problems. In about one third of couples are infertile. Approximately 167 million married women aged 15-49 years in developing countries were infertility. The present study aimed to determine the most common causes of female infertility in patients who visiting the National Ayuvedic Teaching Hospital, Borella, Sri Lanka. Methods: In this study 635 infertile (primary and secondary) women were selected to determine the causes of infertility. The subjects were selected from the gynecology clinic, between the periods of February 2015 to March 2016. The data were gathered using a questionnaire; and after that proper statistical method was applied to analyze the data. Results: From the results age between 28-37 years (37.16%) are more prevalent to infertility and the causes of infertility are mainly due to anovulatory cycle (31.18%) and menstrual irregularities (19.21%). BMI also one of the significant cause for infertility. Conclusion: Therefore, identifying the risk factors and proper treatment on time along with policy makers providing facilities to resolve the infertility could possible diverse this alarming increasing trend of infertility.

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