scholarly journals The Himalayan Uplift and the Evolution of Aquatic Biodiversity Across Asia: Snowtrout (Cyprininae: Schizothorax) as a Test Case

2020 ◽  
Author(s):  
Binod Regmi ◽  
Marlis R. Douglas ◽  
David R. Edds ◽  
Karma Wangchuk ◽  
Chang Lu ◽  
...  
Keyword(s):  
Large Scale ◽  
Global Climate ◽  
High Elevation ◽  
The Arctic ◽  
Test Case ◽  
Tectonic Event ◽  
Aquatic Biodiversity ◽  
Mountain System ◽  
The Himalaya ◽  
Do So

The Himalayan uplift, a tectonic event of global importance, seemingly disseminated aquatic biodiversity broadly across Asia. But surprisingly, this hypothesis has yet to be tested. We do so herein by sequencing 1,140 base-pair of mtDNA cytochrome-b for 72 tetraploid Nepalese/Bhutanese Snowtrout (Schizothorax spp.), combining those data with 67 GENBANK® sequences (59 ingroup/8 outgroup), then reconstructing phylogenetic relationships using maximum likelihood/ Bayesian analyses. Results indicate Snowtrout originated in Central Asia, dispersed across the Qinghai-Tibetan Plateau (QTP), then into Bhutan via south-flowing tributaries of the east-flowing Yarlung-Tsangpo River (YLTR). The headwaters of five large Asian rivers provided dispersal corridors into southeast Asia. South of the Himalaya, the YLTR transitions into a westward-flowing Brahmaputra River that facilitated successive colonization of Himalayan drainages: First Bhutan, then Nepal, followed by far-western drainages subsequently captured by the Indus River. We found greater species-divergences across rather than within-basins, implicating vicariant evolution as a driver. The Himalaya is a component of the “third-pole” [Earth’s largest (but rapidly shrinking) glacial reservoir outside the Arctic/Antarctic]. Its unique aquatic biodiversity must not only be recognized (as herein) but also conserved through broad, trans-national collaborations. Our results effectively contrast phylogeography with taxonomy as a necessary first step in this process.The Himalaya is the most extensive and recently evolved mountain system on Earth (length=2400km; width=240km; elevation=75-8800m), with a global significance underscored by its large-scale lithospheric, cryospheric, and atmospheric interactions [1]. These have not only driven global climate, but also defined the cultural and biological endemism of the region [2]. Massive, tectonically derived mountain chains such as the Alps and the Himalaya are hypothesized as being fundamental to the formation of global biodiversity gradients via vicariance and local adaptation, with a significantly stronger signal in terrestrial rather than aquatic systems [3]. Here we test how orogeny (the deformation and folding of Earth’s crust by lateral compression) has contributed to the diversification of freshwater fishes broadly across Asia. We do so by evaluating the phylogeography of an endemic high-elevation fish, the Snowtrout (Schizothorax: Cyprinidae).

The Frontier Research System for Global Change—The International Arctic Research Center (Frontier-IARC): its Origin and Tentative Science Plan

1999 ◽  
Vol 33 (1) ◽  
pp. 81-84
Author(s):  
Jinro Ukila ◽  
Moloyoshi Ikeda
Keyword(s):  
Climate Change ◽  
Global Change ◽  
Global Climate Change ◽  
Large Scale ◽  
Global Climate ◽  
Research Effort ◽  
Arctic Region ◽  
Research Center ◽  
The Arctic ◽  
Research System

The Frontier Research System for Global Change—the International Arctic Research Center (Frontier-IARC) is a research program funded by the Frontier Research System for Global Change. The program is jointly run under a cooperative agreement between the Frontier Research System for Global Change and the University of Alaska Fairbanks. The aim of the program is to understand the role of the Arctic region in global climate change. The program concentrates its research effort initially on the areas of air-sea-ice interactions, bio-geochemical processes and the ecosystem. To understand the arctic climate system in the context of global climate change, we focus on mechanisms controlling arctic-subarctic interactions, and identify three key components: the freshwater balance, the energy balance, and the large-scale atmospheric processes. Knowledge of details of these components and their interactions will be gained through long-term monitoring, process studies, and modeling; our focus will be on the latter two categories.

scholarly journals Pan-Eurasian Experiment (PEEX): towards a holistic understanding of the feedbacks and interactions in the land–atmosphere–ocean–society continuum in the northern Eurasian region

2016 ◽  
Vol 16 (22) ◽  
pp. 14421-14461 ◽  
Author(s):  
Hanna K. Lappalainen ◽  
Veli-Matti Kerminen ◽  
Tuukka Petäjä ◽  
Theo Kurten ◽  
Aleksander Baklanov ◽  
...  
Keyword(s):  
Research Agenda ◽  
Large Scale ◽  
System Analysis ◽  
Global Climate ◽  
The Arctic ◽  
Research Approach ◽  
Natural Environments ◽  
System Perspective ◽  
Holistic Understanding ◽  
Eurasian Region

Abstract. The northern Eurasian regions and Arctic Ocean will very likely undergo substantial changes during the next decades. The Arctic–boreal natural environments play a crucial role in the global climate via albedo change, carbon sources and sinks as well as atmospheric aerosol production from biogenic volatile organic compounds. Furthermore, it is expected that global trade activities, demographic movement, and use of natural resources will be increasing in the Arctic regions. There is a need for a novel research approach, which not only identifies and tackles the relevant multi-disciplinary research questions, but also is able to make a holistic system analysis of the expected feedbacks. In this paper, we introduce the research agenda of the Pan-Eurasian Experiment (PEEX), a multi-scale, multi-disciplinary and international program started in 2012 (https://www.atm.helsinki.fi/peex/). PEEX sets a research approach by which large-scale research topics are investigated from a system perspective and which aims to fill the key gaps in our understanding of the feedbacks and interactions between the land–atmosphere–aquatic–society continuum in the northern Eurasian region. We introduce here the state of the art for the key topics in the PEEX research agenda and present the future prospects of the research, which we see relevant in this context.

scholarly journals From ‘third pole’ to north pole: a Himalayan origin for the arctic fox

2014 ◽  
Vol 281 (1787) ◽  
pp. 20140893 ◽  
Author(s):  
Xiaoming Wang ◽  
Zhijie Jack Tseng ◽  
Qiang Li ◽  
Gary T. Takeuchi ◽  
Guangpu Xie
Keyword(s):  
Tibetan Plateau ◽  
High Altitude ◽  
Polar Region ◽  
High Elevation ◽  
Ice Age ◽  
The Arctic ◽  
Arctic Fox ◽  
Low Latitude ◽  
Kunlun Mountain ◽  
The Himalaya

The ‘third pole’ of the world is a fitting metaphor for the Himalayan–Tibetan Plateau, in allusion to its vast frozen terrain, rivalling the Arctic and Antarctic, at high altitude but low latitude. Living Tibetan and arctic mammals share adaptations to freezing temperatures such as long and thick winter fur in arctic muskox and Tibetan yak, and for carnivorans, a more predatory niche. Here, we report, to our knowledge, the first evolutionary link between an Early Pliocene (3.60–5.08 Myr ago) fox, Vulpes qiuzhudingi new species, from the Himalaya (Zanda Basin) and Kunlun Mountain (Kunlun Pass Basin) and the modern arctic fox Vulpes lagopus in the polar region. A highly hypercarnivorous dentition of the new fox bears a striking resemblance to that of V. lagopus and substantially predates the previous oldest records of the arctic fox by 3–4 Myr. The low latitude, high-altitude Tibetan Plateau is separated from the nearest modern arctic fox geographical range by at least 2000 km. The apparent connection between an ancestral high-elevation species and its modern polar descendant is consistent with our ‘Out-of-Tibet’ hypothesis postulating that high-altitude Tibet was a training ground for cold-environment adaptations well before the start of the Ice Age.

scholarly journals Assessing the efficiency of eDNA metabarcoding for documenting patterns of metazoan communities in the Arctic.

2018 ◽  
Author(s):  
Noémie Leduc ◽  
Louis Bernatchez ◽  
Philippe Archambault ◽  
Kimberly Howland ◽  
Antoine Dispas ◽  
...  
Keyword(s):  
Applied Sciences ◽  
Large Scale ◽  
Marine Invertebrates ◽  
Environmental Dna ◽  
The Arctic ◽  
Aquatic Biodiversity ◽  
Long Time ◽  
Austere Environment ◽  
Biodiversity Index ◽  
The Difference

Arctic biodiversity has been for a long time underestimated, situated in a region considered as an austere environment combined to the lack of knowledge. The analysis of environmental DNA (eDNA), a new method tracing DNA from macro-organisms, is changing the way we monitor aquatic biodiversity and has the potential to answer large-scale fundamental biodiversity questions in remote regions such as the Arctic. This study aims to evaluate the eDNA dispersal by contrasting the difference between eDNA metabarcoding and classical sampling methods of the alpha, beta and gamma biodiversity index across the Canadian Arctic latitudinal gradient. Water samples of 250mL were collected in 13 sites within three Arctic ports: Churchill, Iqaluit and Deception Bay. Our results showed a species richness of 422 marine invertebrates, while the number of species detected decreased with latitude with more than 100 less species in the northern port. Contrasting the alpha biodiversity index between eDNA metabarcoding and species spatial distribution may be used to evaluate the eDNA spatial dispersion, thus answering important questions related to the ecology of eDNA and improving the integration of this new molecular tool within applied sciences.

Surface reflectivity in polar regions retrieved from TDS-1 mission data

2021 ◽  
Author(s):  
Frederik Kreß ◽  
Maximilian Semmling ◽  
Estel Cardellach ◽  
Weiqiang Li ◽  
Mainul Hoque ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Surface Roughness ◽  
Sea Ice ◽  
Large Scale ◽  
Global Climate ◽  
Path Loss ◽  
Signal Strength ◽  
Global Navigation Satellite Systems ◽  
The Arctic ◽  
Polar Regions

<p>In current times of a changing global climate, a special interest is focused on the<br>large-scale recording of sea ice. Among the existing remote sensing methods, bi-<br>statically reflected signals of Global Navigation Satellite Systems (GNSS) could<br>play an important role in fulfilling the task. Within this project, sensitivity of<br>GNSS signal reflections to sea ice properties like its occurrence, sea ice thick-<br>ness (SIT) and sea concentration (SIC) is evaluated. When getting older, sea<br>ice tends go get thicker. Because of decreasing salinity, i.e. less permittivity,<br>as well as relatively higher surface roughness of older ice, it can be assumed<br>that reflected signal strength decreases with increasing SIT. The reflection data<br>used were recorded in the years 2015 and 2016 by the TechDemoSat-1 (TDS-1)<br>satellite over the Arctic and Antarctic. It includes a down-looking antenna for<br>the reflected as well as an up-looking antenna dedicated to receive the direct sig-<br>nal. The raw data, provided by the manufacturer SSTL, were pre-processed by<br>IEEC/ICE-CSIC to derive georeferenced signal power values. The reflectivity<br>was estimated by comparing the power of the up- and down-looking links. The<br>project focuses on the signal link budget to apply necessary corrections. For this<br>reason, the receiver antenna gain as well as the Free-Space Path Loss (FSPL)<br>were calculated and applied for reflectivity correction. Differences of nadir and<br>zenith antenna FSPL and gain show influence of up to 6 dB and −9 dB to 9 dB<br>respectively on the recorded signal strength. All retrieved reflectivity values are<br>compared to model predictions based on Fresnel coefficients but also to avail-<br>able ancillary truth data of other remote sensing missions to identify possible<br>patterns: SIT relations are investigated using Level-2 data of the Soil Moisture<br>and Ocean Salinity (SMOS) satellite. The SIC comparison was done with an<br>AMSR-2 product. The results show sensitivity of the reflectivity value to both<br>SIT and SIC simultaneously, whereby the surface roughness is also likely to<br>have an influence. This on-going study aims at the consolidation of retrieval<br>algorithms for sea-ice observation. The resolution of different ice types and the<br>retrieval of SIT and SIC based on satellite data is a challenge for future work<br>in this respect.</p>

scholarly journals The Timing of Initial Spring Melt in the Arctic from Nimbus-7 SMMR Data (Abstract)

1987 ◽  
Vol 9 ◽  
pp. 244-244
Author(s):  
Mark R. Anderson
Keyword(s):  
Sea Ice ◽  
Large Scale ◽  
Chukchi Sea ◽  
Global Climate ◽  
Arctic Basin ◽  
Temporal Variations ◽  
The Arctic ◽  
Energy Budgets ◽  
Polar Regions ◽  
Ice Surface

The ablation of sea ice is an important feature in the global climate system. During the melt season in the Arctic, rapid changes occur in sea-ice surface conditions and areal extent of ice. These changes alter the albedo and vary the energy budgets. Understanding the spatial and temporal variations of melt is critical in the polar regions. This study investigates the spring onset of melt in the seasonal sea-ice zone of the Arctic Basin through the use of a melt signature derived by Anderson and others from the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) data. The signature is recognized in the “gradient ratio” of the 18 and 37 GHz vertical brightness temperatures used to distinguish multi-year ice. A spuriously high fraction of multi-year ice appears rapidly during the initial melt of sea ice, when the snow-pack on the ice surface has started to melt. The brightness-temperature changes are a result of either enlarged snow crystals or incipient puddles forming at the snow/ice interface.The timing of these melt events varies geographically and with time. Within the Arctic Basin, the melt signatures are observed first in the Chukchi and Kara/Barents Seas. As the melt progresses, the location of the melt signature moves westward from the Chukchi Sea and eastward from the Kara/Barents Seas to the Laptev Sea region. The timing of the melt signal also varies with year. For example, the melt signature occurred first in the Chukchi Sea in 1979, while in 1980 the signature was first observed in the Kara Sea.There are also differences in the timing of melt for specific geographic locations between years. The melt signature varied almost 25 days in the Chukchi Sea region between 1979 and 1980. The other areas had changes in the 7–10 day range.The occurrence of these melt signatures can be used as an indicator of climate variability in the seasonal sea-ice zones of the Arctic. The timing of the microwave melt signature has also been examined in relation to melt observed on short-wave imagery. The melt events derived from the SMMR data are also related to the large-scale climate conditions.

scholarly journals The Atlantic inflow across the Greenland-Scotland ridge in global climate models (CMIP5)

Elem Sci Anth ◽  
2019 ◽  
Vol 7 ◽  
Author(s):  
Céline Heuzé ◽  
Marius Årthun
Keyword(s):  
Heat Transport ◽  
North Atlantic ◽  
Large Scale ◽  
Climate Models ◽  
Global Climate ◽  
Global Climate Models ◽  
The Arctic ◽  
Nordic Seas ◽  
The North ◽  
The North Atlantic

Oceanic heat transport from the North Atlantic to the Arctic through the Nordic Seas is a key component of the climate system that has to be modelled accurately in order to predict, for example, future Arctic sea ice changes or European climate. Here we quantify biases in the climatological state and dynamics of the transport of oceanic heat into the Nordic Seas across the Greenland-Scotland ridge in 23 state-of-the-art global climate models that participated in the Climate Model Intercomparison Project phase 5. The mean poleward heat transport, its seasonal cycle and interannual variability are inconsistently represented across these models, with a vast majority underestimating them and a few models greatly overestimating them. The main predictor for these biases is the resolution of the model via its representation of the Greenland-Scotland ridge bathymetry: the higher the resolution, the larger the heat transport through the section. The second predictor is the large-scale ocean circulation, which is also connected to the bathymetry: models with the largest heat transport import water from the European slope current into all three straits of the Greenland-Scotland ridge, whereas those with a weak transport import water from the Labrador Sea. The third predictor is the spatial pattern of their main atmospheric modes of variability (North Atlantic Oscillation, East Atlantic and Scandinavian patterns), where the models with a weak inflow have their atmospheric low-pressure centre shifted south towards the central Atlantic. We argue that the key to a better representation of the large-scale oceanic heat transport from the North Atlantic to the Arctic in global models resides not only in higher resolution, but also in a better bathymetry and representation of the complex ocean-ice-atmosphere interactions.

scholarly journals Model simulations of arctic biogeochemistry and permafrost extent are highly sensitive to the implemented snow scheme

2021 ◽  
Author(s):  
Alexandra Pongracz ◽  
David Wårlind ◽  
Paul A. Miller ◽  
Frans-Jan W. Parmentier
Keyword(s):  
Snow Cover ◽  
Large Scale ◽  
Global Climate ◽  
Single Layer ◽  
Physical Factor ◽  
Cold Season ◽  
The Arctic ◽  
Soil Conditions ◽  
Cold Bias ◽  
Climate Feedbacks

Abstract. The Arctic is warming rapidly, especially in winter, which is causing large-scale reductions in snow cover. Snow is one of the main controls on soil thermodynamics, and changes in its thickness and extent affect both permafrost thaw and soil biogeochemistry. Since soil respiration during the cold season potentially offsets carbon uptake during the growing season, it is essential to achieve a realistic simulation of the effect of snow cover on soil conditions to more accurately project the direction of arctic carbon-climate feedbacks under continued winter warming. The Lund-Potsdam-Jena General Ecosystem Simulator (LPJ-GUESS) dynamic vegetation model has used – up until now – a single layer snow scheme, which underestimated the insulation effect of snow, leading to a cold bias in soil temperature. To address this shortcoming, we developed and integrated a dynamic, multi-layer snow scheme in LPJ-GUESS. The new snow scheme performs well in simulating the insulation of snow at hundreds of locations across Russia compared to observations. We show that improving this single physical factor enhanced simulations of permafrost extent compared to an advanced permafrost product. Besides soil thermodynamics, the new snow scheme resulted in increased winter respiration and an overall lower soil carbon content due to warmer soil conditions. The Dynamic scheme also influenced vegetation dynamics, resulting in an improved vegetation distribution and tundra-taiga boundary simulation. This study highlights the importance of a correct representation of snow in ecosystem models to project biogeochemical processes that govern climate feedbacks. The new dynamic snow scheme is an essential improvement in the simulation of cold season processes, which reduces the uncertainty of model projections. These developments contribute to a better understanding of the Arctic's role in the global climate system.

scholarly journals Assessing the efficiency of eDNA metabarcoding for documenting patterns of metazoan communities in the Arctic.

2018 ◽  
Author(s):  
Noémie Leduc ◽  
Louis Bernatchez ◽  
Philippe Archambault ◽  
Kimberly Howland ◽  
Antoine Dispas ◽  
...  
Keyword(s):  
Applied Sciences ◽  
Large Scale ◽  
Marine Invertebrates ◽  
Environmental Dna ◽  
The Arctic ◽  
Aquatic Biodiversity ◽  
Long Time ◽  
Austere Environment ◽  
Biodiversity Index ◽  
The Difference

Arctic biodiversity has been for a long time underestimated, situated in a region considered as an austere environment combined to the lack of knowledge. The analysis of environmental DNA (eDNA), a new method tracing DNA from macro-organisms, is changing the way we monitor aquatic biodiversity and has the potential to answer large-scale fundamental biodiversity questions in remote regions such as the Arctic. This study aims to evaluate the eDNA dispersal by contrasting the difference between eDNA metabarcoding and classical sampling methods of the alpha, beta and gamma biodiversity index across the Canadian Arctic latitudinal gradient. Water samples of 250mL were collected in 13 sites within three Arctic ports: Churchill, Iqaluit and Deception Bay. Our results showed a species richness of 422 marine invertebrates, while the number of species detected decreased with latitude with more than 100 less species in the northern port. Contrasting the alpha biodiversity index between eDNA metabarcoding and species spatial distribution may be used to evaluate the eDNA spatial dispersion, thus answering important questions related to the ecology of eDNA and improving the integration of this new molecular tool within applied sciences.

scholarly journals The Timing of Initial Spring Melt in the Arctic from Nimbus-7 SMMR Data (Abstract)

1987 ◽  
Vol 9 ◽  
pp. 244
Author(s):  
Mark R. Anderson
Keyword(s):  
Sea Ice ◽  
Large Scale ◽  
Chukchi Sea ◽  
Global Climate ◽  
Arctic Basin ◽  
Temporal Variations ◽  
The Arctic ◽  
Energy Budgets ◽  
Polar Regions ◽  
Ice Surface

The ablation of sea ice is an important feature in the global climate system. During the melt season in the Arctic, rapid changes occur in sea-ice surface conditions and areal extent of ice. These changes alter the albedo and vary the energy budgets. Understanding the spatial and temporal variations of melt is critical in the polar regions. This study investigates the spring onset of melt in the seasonal sea-ice zone of the Arctic Basin through the use of a melt signature derived by Anderson and others from the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) data. The signature is recognized in the “gradient ratio” of the 18 and 37 GHz vertical brightness temperatures used to distinguish multi-year ice. A spuriously high fraction of multi-year ice appears rapidly during the initial melt of sea ice, when the snow-pack on the ice surface has started to melt. The brightness-temperature changes are a result of either enlarged snow crystals or incipient puddles forming at the snow/ice interface. The timing of these melt events varies geographically and with time. Within the Arctic Basin, the melt signatures are observed first in the Chukchi and Kara/Barents Seas. As the melt progresses, the location of the melt signature moves westward from the Chukchi Sea and eastward from the Kara/Barents Seas to the Laptev Sea region. The timing of the melt signal also varies with year. For example, the melt signature occurred first in the Chukchi Sea in 1979, while in 1980 the signature was first observed in the Kara Sea. There are also differences in the timing of melt for specific geographic locations between years. The melt signature varied almost 25 days in the Chukchi Sea region between 1979 and 1980. The other areas had changes in the 7–10 day range. The occurrence of these melt signatures can be used as an indicator of climate variability in the seasonal sea-ice zones of the Arctic. The timing of the microwave melt signature has also been examined in relation to melt observed on short-wave imagery. The melt events derived from the SMMR data are also related to the large-scale climate conditions.

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