scholarly journals The Components of the Glacial Runoff of the Tsambagarav Massif from Stable Water Isotope Data

Geosciences ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 297 ◽  
Author(s):  
Dmitry V. Bantcev ◽  
Dmitry A. Ganyushkin ◽  
Kirill V. Chistyakov ◽  
Ilya V. Volkov ◽  
Alexey A. Ekaykin ◽  
...  
Keyword(s):  
Global Climate ◽  
Isotopic Analysis ◽  
Ice Formation ◽  
Northwestern Part ◽  
Glacial Ice ◽  
Main Method ◽  
Total Runoff ◽  
Glacial Runoff ◽  
Isotopic Separation ◽  
Main Components

The aim of this study was to determine the contribution of snow and glacial ice to the river fluxes, and to identify the type of ice formation in the Tsambagarav massif (the northwestern part of Mongolia). The main method for this study was isotopic analysis of water samples. The isotopic separation showed that the shares of the main components in the total runoff differed for different rivers of the massif. Alongside with that, glacial meltwater prevailed in all the investigated fluxes. The share of snow and firn in the meltwater coming from the surface of the large valley glaciers in the middle of the ablation season in 2017 changed by only 10%—from 20% to 30%. Thus, further reduction of glaciation caused by global climate change could significantly affect the water balance of the study area. The isotopic composition of glacial ice proves that its alimentation primarily comes from precipitation during the transitional seasons. Superimposed ice is not the basis for nourishment of the glaciers of the Tsambagarav massif.

scholarly journals Impact of mid-glacial ice sheets on deep ocean circulation and global climate: Role of surface cooling on the AMOC

2020 ◽  
Author(s):  
Sam Sherriff-Tadano ◽  
Ayako Abe-Ouchi ◽  
Akira Oka
Keyword(s):  
North Atlantic ◽  
General Circulation ◽  
Global Climate ◽  
Surface Wind ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Meridional Overturning Circulation ◽  
Strengthening Effect ◽  
Surface Cooling ◽  
Glacial Ice

Abstract. This study explores the effect of southward expansion of mid-glacial ice sheets on the global climate and the Atlantic meridional overturning circulation (AMOC), as well as the processes by which the ice sheets modify the AMOC. For this purpose, simulations of Marine Isotope Stage (MIS) 3 and 5a are performed with an atmosphere-ocean general circulation model. In the MIS3 and MIS5a simulations, the global average temperature decreases by 5.0 °C and 2.2 °C, respectively, compared with the preindustrial climate simulation. The AMOC weakens by 3 % in MIS3, whereas it is enhanced by 16 % in MIS5a, both of which are consistent with a reconstruction. Sensitivity experiments extracting the effect of the expansion of glacial ice sheets from MIS5a to MIS3 show a global cooling of 1.1 °C, contributing to about 40 % of the total surface cooling from MIS5a to MIS3. These experiments also demonstrate that the ice sheet expansion leads to a surface cooling of 2 °C over the Southern Ocean as a result of colder North Atlantic deep water. We find that the southward expansion of the mid-glacial ice sheet exerts a small impact on the AMOC. Partially coupled experiments reveal that the global surface cooling by the glacial ice sheet tends to reduce the AMOC by increasing the sea ice at both poles, and hence compensates for the strengthening effect of the enhanced surface wind over the North Atlantic. Our results show that the total effect of glacial ice sheets on the AMOC is determined by the two competing effects, surface wind and surface cooling. The relative strength of surface wind and surface cooling depends on the ice sheet configuration, and the strength of the surface cooling can be comparable to that of surface wind when changes in the extent of ice sheet are prominent.

scholarly journals Climate Change – Probable Socio-Economic Systems (SES) Implications And Impacts In The Anthropocene Epoch

2015 ◽  
Vol 21 (2) ◽  
pp. 308-317
Author(s):  
Eric Gilder ◽  
Dilip K. Pal
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Little Ice Age ◽  
Global Climate ◽  
Ice Age ◽  
Economic Systems ◽  
Human Populations ◽  
Northwestern Part ◽  
Human Society ◽  
Systems Model

Abstract It is vital for security experts to learn from the historical records of global climate change as to how the human society has been impacted by its consequences in the “new” Anthropocene Epoch. Some of these consequences of global climate change include the perishing of several human settlements in different parts of the globe at different times, e.g., in 1700 B.C., prolonged drought contributed to the demise of Harappan civilization in northwest India. In 1200 B.C., under a similar climatic extremity, the Mycenaean civilization in present-day Greece (as well as the Mill Creek culture of the northwestern part of the present-day US state of Iowa) perished. Why did some societies under such climatic events perish while others survived? Lack of preparedness of one society and its failure to anticipate and adapt to the extreme climatic events might have attributed to their extinction. The authors will also analyze the extinction of one European Norse society in Greenland during the Little Ice Age (about 600 years ago), as compared to the still-surviving Inuit society in the northern segment of Greenland, which faced even harsher climatic conditions during the Little Ice Age than the extinct Norsemen. This is how the adaptability and “expectation of the worst” matter for the survival of a particular community against climatic “black swan” events (Taleb, 2007). Similar impacts in terms of sea-level rise expected by the year 2100 whereby major human populations of many parts of the world are expected to lose their environmental evolutionary “niche” will be discussed. Rising temperature will not only complicate human health issues, but also will it take its toll on the staple food producing agricultural belts in some latitudinal expanse. It will also worsen the living condition of the populace living in areas where climate is marginal. Through the Socio-Economic Systems Model provided by Vadineanu (2001), the authors will next consider the effect of extant policy-making “prisms” responding to climate change (such as the “Club of Rome” versus the “Club for Growth” visions) as concerns the ongoing process of globalization and survival of the nation-state.

scholarly journals Hemispheric sea ice extent dynamics as observed from MSMR

MAUSAM ◽  
2021 ◽  
Vol 60 (3) ◽  
pp. 295-308
Author(s):  
NILAY SHARMA ◽  
M. K. DASH ◽  
P. C. PANDEY ◽  
N. K. VYAS
Keyword(s):  
Sea Ice ◽  
Global Climate ◽  
Ice Cover ◽  
The Arctic ◽  
Ice Formation ◽  
Spatial And Temporal Variation ◽  
Polar Regions ◽  
Sea Ice Extent ◽  
Year 2000 ◽  
Formation Phase

The ice covered regions of the polar seas influence the global climate in several ways. Any perturbation in the polar oceanic cryosphere affects the local weather and the global climate through modulation of the radiative forcing, the bottom water formation and the mass & the momentum transfer between Atmosphere-Cryosphere-Ocean System. The cold, harsh and inhospitable conditions in the polar regions prohibit the collection of extensive in situ data with sufficient spatial and temporal variation. However, satellite remote sensing is an ideal technique for studying the areas like the polar regions with synoptic and repetitive coverage.  This paper discusses the analysis of the data obtained over the polar oceanic regions during the period June 1999 – September 2001 through the use of Multi-channel Scanning Microwave Radiometer (MSMR), onboard India’s first oceanographic satellite Oceansat-1. The MSMR observation shows that all the sectors in the Antarctic behave differently to the melting and formation of the sea ice. Certain peculiar features like the increase in sea ice extent during the melt season of 1999 – 2000 in the Indian Ocean sector, 15 – 20% decrease in the sea ice extent in the western Pacific sector during the ice formation period for the year 2000, melting spell within the formation phase of sea ice in B & A sector in the year 2000 were observed. On the other hand the northern polar sea ice extent is seen to be more dominated by the land characteristics. The ice formation in Kara and the Barent Sea sector is dominated by the ocean currents, where as the ice covered in the Japan and the Okhotsk Sea is dominated by the land processes. The sea ice extent in the Arctic Ocean show fluctuations from July to October and remain almost steady over other months. The global sea ice cover shows a formation phase from March to June and melting phase from November to February. In other months, i.e., from July – October the global sea ice cover is dominated by the hemispheric asymmetry of the ice growth and retreat.

scholarly journals Aufeis in the mountainous areas of the northwestern part of the Selenga River basin

2021 ◽  
Vol 885 (1) ◽  
pp. 012034
Author(s):  
V N Chernykh ◽  
B V Sodnomov ◽  
A A Ayurzhanaev ◽  
B Z Tsydypov ◽  
D B Dabaeva ◽  
...  
Keyword(s):  
River Basin ◽  
Satellite Imagery ◽  
Ice Formation ◽  
Northwestern Part ◽  
Economic Aspects ◽  
Mountainous Areas ◽  
Selenga River Basin ◽  
Selenga River ◽  
Small Watersheds ◽  
Current Location

Abstract The article presents the results of research on aufeis (icings) in the area where their concentration is maximal for the Selenga River basin. Landsat and Sentinel satellite imagery data were used to map the current location of aufeis in the valleys of permanent watercourses of the transboundary Dzhida River basin. It was found out that up to 3.5 thousand small aufeis with the area from 0.005 to 1 km2 are formed in small watersheds of the territory. The total area of aufeis within the considered territory can reach up to 92.1 km2, the aufeis coverage is 0.45%. It is revealed that in the total amount, small aufeis prevail, the area of which lies within 0.01 to 0.1 km2. In addition, ecosystem and economic aspects of the processes of ice formation on the territory of Russia and neighbouring Mongolia are considered.

Observing the disintegration of the Thwaites B30 Iceberg with CryoSat-2 and Satellite Imagery

2021 ◽  
Author(s):  
Anne Braakmann-Folgmann ◽  
Andrew Shepherd ◽  
Andy Ridout
Keyword(s):  
Southern Ocean ◽  
Fresh Water ◽  
Satellite Imagery ◽  
Water Flux ◽  
Ice Formation ◽  
Ice Shelf ◽  
Glacial Ice ◽  
Fresh Water Flux ◽  
Maritime Operations ◽  
Basal Melting

<p>Icebergs account for half of all ice loss from Antarctica and, once released, present a hazard to maritime operations. Their melting leads to a redistribution of cold fresh water around the Southern Ocean which, in turn, influences water circulation, promotes sea ice formation, and fosters primary production.</p><p>To quantify the total volume loss of icebergs both changes in area and in thickness have to be considered. In this study, we combine CryoSat-2 satellite altimetry with MODIS and Sentinel-1 satellite imagery to track changes in the area, freeboard, thickness, and volume of the B30 tabular iceberg between 2012 and 2018. Since it calved the iceberg’s area has decreased from 1500 +/- 60 to 426 +/- 27 km^2 , its mean freeboard has fallen from 49.0 +/- 4.6 to 38.8 +/- 2.2 m, and its mean thickness has reduced from 315 ± 36 to 198 ± 14 m. The combined loss amounts to an 80 +/- 16 % reduction in volume, two thirds (69 ± 14 %) of which is due to fragmentation and the remainder (31 ± 11 %) is due to basal melting.</p><p>The quantification of fresh water released from icebergs will help both the risk assessment of maritime operators and the improvement of ocean models by including a realistic – spatially and temporally variable - fresh water flux from iceberg melting in the Southern Ocean. Icebergs can also be used to study the reaction of glacial ice to warming environmental conditions, which they experience when they drift. These conditions might also become present at the ice shelf front in the future and therefore iceberg studies can inform the prediction of ice shelf response to warmer conditions.</p>

Impact of mid-glacial ice sheets on deep ocean circulation and global climate

2021 ◽  
Author(s):  
Sam Sherriff-Tadano ◽  
Ayako Abe-Ouchi ◽  
Akira Oka
Keyword(s):  
North Atlantic ◽  
Global Climate ◽  
Surface Wind ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Meridional Overturning Circulation ◽  
Strengthening Effect ◽  
Surface Cooling ◽  
Glacial Ice ◽  
Cooling Effects

<p>This study explores the effect of southward expansion of Northern Hemisphere (American) mid-glacial ice sheets on the global climate and the Atlantic Meridional Overturning Circulation (AMOC), as well as the processes by which the ice sheets modify the AMOC. For this purpose, simulations of Marine Isotope Stage (MIS) 3 (36ka) and 5a (80ka) are performed with an atmosphere-ocean general circulation model. In the MIS3 and MIS5a simulations, the global average temperature decreases by 5.0 °C and 2.2 °C, respectively, compared with the preindustrial climate simulation. The AMOC weakens by 3% in MIS3, whereas it strengthens by 16% in MIS5a, both of which are consistent with an estimate based on <sup>231</sup>Pa/<sup>230</sup>Th. Sensitivity experiments extracting the effect of the southward expansion of glacial ice sheets from MIS5a to MIS3 show a global cooling of 1.1 °C, contributing to about 40% of the total surface cooling from MIS5a to MIS3. These experiments also demonstrate that the ice sheet expansion leads to a surface cooling of 2 °C over the Southern Ocean as a result of colder North Atlantic deep water. We find that the southward expansion of the mid-glacial ice sheet exerts a small impact on the AMOC. Partially coupled experiments reveal that the global surface cooling by the glacial ice sheet tends to reduce the AMOC by increasing the sea ice at both poles, and hence compensates for the strengthening effect of the enhanced surface wind over the North Atlantic. Our results show that the total effect of glacial ice sheets on the AMOC is determined by the two competing effects, surface wind and surface cooling. The relative strength of surface wind and surface cooling effects depends on the ice sheet configuration, and the strength of the surface cooling can be comparable to that of surface wind when changes in the extent of ice sheet are prominent.</p>

scholarly journals Three-dimensional hydrostratigraphy of the Orangeville Moraine area, southwestern Ontario, Canada

2018 ◽  
Vol 55 (7) ◽  
pp. 802-828 ◽  
Author(s):  
Abigail Burt
Keyword(s):  
Regional Scale ◽  
Three Dimensional ◽  
Late Glacial ◽  
Northwestern Part ◽  
Glacial Ice ◽  
Hydraulic Gradients ◽  
Bedrock Aquifer ◽  
Bedrock Aquifers ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Regional-scale three-dimensional modelling of Quaternary sediments in the Orangeville Moraine area of southwestern Ontario has been completed as part of the Ontario Geological Survey groundwater initiative and provides an improved understanding of the glacial history and conceptual hydrostratigraphic framework for that region. Older (Marine Isotope Stage (MIS) 3–5) diamicton, glaciolacustrine, glaciofluvial, and rare nonglacial deposits forming regional aquitards and local aquifers are found in the northwestern part of the area. Catfish Creek Till, deposited during the Last Glacial Maximum (LGM) (MIS 2), forms a key aquitard and stratigraphic marker at depth. Diamicton, fine-textured glaciolacustrine sediments, and the gravel, sand, and silt conduit and subaqueous fan sediments that constitute the overlying Orangeville Moraine were deposited in an ice-walled lake formed between ice lobes during retreat from the LGM. Diamicton deposited during late-glacial ice margin fluctuations forms the upper aquitard unit and buries the edges of the moraine. The Orangeville Moraine is the largest aquifer in the area, and is partially confined by the upper tills. Thick fine-textured glaciolacustrine deposits, Catfish Creek Till, and older aquitards separate the moraine from bedrock aquifers across most of the area. Depending on hydraulic gradients, buried bedrock valleys with gravel and sand fills have the potential to recharge the bedrock aquifer.

scholarly journals Impact of mid-glacial ice sheets on deep ocean circulation and global climate

2021 ◽  
Vol 17 (1) ◽  
pp. 95-110
Author(s):  
Sam Sherriff-Tadano ◽  
Ayako Abe-Ouchi ◽  
Akira Oka
Keyword(s):  
North Atlantic ◽  
Global Climate ◽  
Surface Wind ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Meridional Overturning Circulation ◽  
Strengthening Effect ◽  
Surface Cooling ◽  
Glacial Ice ◽  
Cooling Effects

Abstract. This study explores the effect of southward expansion of Northern Hemisphere (American) mid-glacial ice sheets on the global climate and the Atlantic Meridional Overturning Circulation (AMOC) as well as the processes by which the ice sheets modify the AMOC. For this purpose, simulations of Marine Isotope Stage (MIS) 3 (36 ka) and 5a (80 ka) are performed with an atmosphere–ocean general circulation model. In the MIS3 and MIS5a simulations, the global average temperature decreases by 5.0 and 2.2 ∘C, respectively, compared with the preindustrial climate simulation. The AMOC weakens by 3 % in MIS3, whereas it strengthens by 16 % in MIS5a, both of which are consistent with an estimate based on 231Pa ∕ 230Th. Sensitivity experiments extracting the effect of the southward expansion of glacial ice sheets from MIS5a to MIS3 show a global cooling of 1.1 ∘C, contributing to about 40 % of the total surface cooling from MIS5a to MIS3. These experiments also demonstrate that the ice sheet expansion leads to a surface cooling of 2 ∘C over the Southern Ocean as a result of colder North Atlantic Deep Water. We find that the southward expansion of the mid-glacial ice sheet exerts a small impact on the AMOC. Partially coupled experiments reveal that the global surface cooling by the glacial ice sheet tends to reduce the AMOC by increasing the sea ice at both poles and, hence, compensates for the strengthening effect of the enhanced surface wind over the North Atlantic. Our results show that the total effect of glacial ice sheets on the AMOC is determined by two competing effects: surface wind and surface cooling. The relative strength of surface wind and surface cooling effects depends on the ice sheet configuration, and the strength of the surface cooling can be comparable to that of surface wind when changes in the extent of ice sheet are prominent.

scholarly journals A Classical-Theory-Based Parameterization of Heterogeneous Ice Nucleation by Mineral Dust, Soot, and Biological Particles in a Global Climate Model

2010 ◽  
Vol 67 (8) ◽  
pp. 2483-2503 ◽  
Author(s):  
Corinna Hoose ◽  
Jón Egill Kristjánsson ◽  
Jen-Ping Chen ◽  
Anupam Hazra
Keyword(s):  
Climate Model ◽  
Mineral Dust ◽  
Global Climate ◽  
Global Climate Model ◽  
Ice Nucleation ◽  
Nucleation Theory ◽  
Ice Formation ◽  
Biological Particles ◽  
Ice Nuclei ◽  
Immersion Freezing

Abstract An ice nucleation parameterization based on classical nucleation theory, with aerosol-specific parameters derived from experiments, has been implemented into a global climate model—the Community Atmosphere Model (CAM)-Oslo. The parameterization treats immersion, contact, and deposition nucleation by mineral dust, soot, bacteria, fungal spores, and pollen in mixed-phase clouds at temperatures between 0° and −38°C. Immersion freezing is considered for insoluble particles that are activated to cloud droplets, and deposition and contact nucleation are only allowed for uncoated, unactivated aerosols. Immersion freezing by mineral dust is found to be the dominant ice formation process, followed by immersion and contact freezing by soot. The simulated biological aerosol contribution to global atmospheric ice formation is marginal, even with high estimates of their ice nucleation activity, because the number concentration of ice nucleation active biological particles in the atmosphere is low compared to other ice nucleating aerosols. Because of the dominance of mineral dust, the simulated ice nuclei concentrations at temperatures below −20°C are found to correlate with coarse-mode aerosol particle concentrations. The ice nuclei (IN) concentrations in the model agree well overall with in situ continuous flow diffusion chamber measurements. At individual locations, the model exhibits a stronger temperature dependence on IN concentrations than what is observed. The simulated IN composition (77% mineral dust, 23% soot, and 10−5% biological particles) lies in the range of observed ice nuclei and ice crystal residue compositions.

scholarly journals Standardization of human activities as the component of a workflow efficiency model – a research experiment from a meat producing plant

2020 ◽  
Vol 26 (2) ◽  
pp. 73-77 ◽  
Author(s):  
Joanna Bartnicka ◽  
Patrycja Kabiesz ◽  
Jan Kaźmierczak
Keyword(s):  
Human Activities ◽  
Activity Patterns ◽  
Working Environment ◽  
Process Efficiency ◽  
Main Method ◽  
Workflow Efficiency ◽  
Research Experiment ◽  
Operational Activities ◽  
Human Activity Patterns ◽  
Main Components

AbstractThe aim of the following research it to provide assumptions for creating workflow efficiency model that can be implemented in repeatable production workstations. One of the main components of this model are human activities and their interactions with other elements of working environment: human and artefacts. Recognition of patterns of human behaviours within working processes gives the opportunity to find critical points that influence workflow efficiency.The subject of research is a working process existing in meat producing plant. The main method used for recognizing human activity patterns was observation and qualitative and quantitative assessments of operational activities based on video registration. Particularly, human activities were analyzed under ergonomics criteria in order to proof dependencies between process efficiency and specific ergonomic factors forming working conditions at meat plant.

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