scholarly journals The role of tropopause polar vortices in the intensification of summer Arctic cyclones

2021 ◽  
Author(s):  
Suzanne Louise Gray ◽  
Kevin Ivan Hodges ◽  
Jonathan Luke Vautrey ◽  
John Methven
Keyword(s):  
Three Dimensional ◽  
Relative Vorticity ◽  
The Arctic ◽  
North Coast ◽  
Polar Regions ◽  
The North ◽  
Observation Network ◽  
Long Lifetime ◽  
Cyclone Genesis

Abstract. Human activity in the Arctic is increasing as new regions become accessible, with a consequent need for improved understanding of hazardous weather there. Arctic cyclones are the major weather systems affecting the Arctic environment during summer, including the sea ice distribution. Meso- to synoptic-scale tropopause polar vortices (TPVs) frequently occur in polar regions and are a proposed mechanism for Arctic cyclone genesis and intensification. However, while the importance of pre-existing tropopause-level features for cyclone development, and their existence as part of the three-dimensional mature cyclone structure, is well established in the mid-latitudes, evidence of the importance of pre-existing TPVs for Arctic cyclone development is mainly limited to a few case studies. Here we examine the extent to which Arctic cyclone growth is coupled to TPVs by analysing a climatology of summer Arctic cyclones and TPV characteristics produced by tracking both features in the latest ECMWF reanalysis (ERA5). The annual counts of Arctic cyclones and TPVs are significantly correlated for features with genesis either within or outside the Arctic, implying that TPVs have a role in the development of Arctic cyclones. However, from their proximity, only about one third of Arctic cyclones intensify while influenced by a TPV and a maximum of 10 % have a nearby TPV at their genesis time. Consistent with the track densities of the full sets of Arctic cyclones and TPVs, cyclones associated with TPVs during their intensification phase (matched cyclones) track preferentially over the Arctic Ocean along the North American coastline and Canadian Archipelago. In contrast, cyclones intensifying distant from any TPV (unmatched cyclones) track preferentially along the north coast of Eurasia. Composite analysis reveals the presence of a distinct relative vorticity maximum at and above the tropopause level associated with the TPV throughout the intensification period for matched cyclones and that these cyclones have a reduced upstream tilt compared to unmatched cyclones. Interaction of cyclones with TPVs has implications for the predictability of Arctic weather, given the long lifetime, but relatively small spatial scale of TPVs compared with the density of the polar observation network.

scholarly journals The role of tropopause polar vortices in the intensification of summer Arctic cyclones

2021 ◽  
Vol 2 (4) ◽  
pp. 1303-1324
Author(s):  
Suzanne L. Gray ◽  
Kevin I. Hodges ◽  
Jonathan L. Vautrey ◽  
John Methven
Keyword(s):  
Three Dimensional ◽  
Relative Vorticity ◽  
The Arctic ◽  
Polar Regions ◽  
Northern Coast ◽  
The North ◽  
Observation Network ◽  
Long Lifetime ◽  
Cyclone Genesis

Abstract. Human activity in the Arctic is increasing as new regions become accessible, with a consequent need for improved understanding of hazardous weather there. Arctic cyclones are the major weather systems affecting the Arctic environment during summer, including the sea ice distribution. Mesoscale to synoptic-scale tropopause polar vortices (TPVs) frequently occur in polar regions and are a proposed mechanism for Arctic cyclone genesis and intensification. However, while the importance of pre-existing tropopause-level features for cyclone development, as well as being an integral part of the three-dimensional mature cyclone structure, is well established in the mid-latitudes, evidence of the importance of pre-existing TPVs for Arctic cyclone development is mainly limited to a few case studies. Here we examine the extent to which Arctic cyclone growth is coupled to TPVs by analysing a climatology of summer Arctic cyclones and TPVs produced by tracking both features in the latest ECMWF reanalysis (ERA5). The annual counts of Arctic cyclones and TPVs are significantly correlated for features with genesis either within or outside the Arctic, implying that TPVs have a role in the development of Arctic cyclones. However, only about one-third of Arctic cyclones have their genesis or intensify while a TPV of Arctic origin is (instantaneously) within about twice the Rossby radius of the cyclone centre. Consistent with the different track densities of the full sets of Arctic cyclones and TPVs, cyclones with TPVs within range throughout their intensification phase (matched cyclones) track preferentially over the Arctic Ocean along the North American coastline and Canadian Arctic Archipelago. In contrast, cyclones intensifying distant from any TPV (unmatched cyclones) track preferentially along the northern coast of Eurasia. Composite analysis reveals the presence of a distinct relative vorticity maximum at and above the tropopause level associated with the TPV throughout the intensification period for matched cyclones and that these cyclones have a reduced upstream tilt compared to unmatched cyclones. Interaction of cyclones with TPVs has implications for the predictability of Arctic weather, given the long lifetime but relatively small spatial scale of TPVs compared with the density of the polar observation network.

scholarly journals The role of tropopause polar vortices in the intensification of Summer Arctic cyclones

2021 ◽  
Author(s):  
Suzanne L. Gray ◽  
Kevin Hodges ◽  
Jonathan Vautrey ◽  
John Methven
Keyword(s):  
Three Dimensional ◽  
Arctic Region ◽  
The Arctic ◽  
Polar Regions ◽  
Synoptic Scale ◽  
Coherent Vortices ◽  
Cyclone Genesis ◽  
Ecmwf Reanalysis ◽  
The Arctic Region

<p>Human activity in the Arctic is expected to increase as new regions become accessible, with a consequent need for reliable forecasts of hazardous weather. Arctic cyclones are synoptic-scale cyclones developing within or moving into the Arctic region. Meso- to synoptic-scale tropopause-based coherent vortices called tropopause polar vortices (TPVs) are frequently observed in polar regions and are a proposed mechanism for Arctic cyclone genesis and intensification. While the importance of pre-existing tropopause-level features for cyclone development, and their existence as part of the three-dimensional mature cyclone structure, is well established in the mid-latitudes, evidence of the importance of pre-existing TPVs for Arctic cyclone development is more limited. Here we present a climatology and characteristics of summer Arctic cyclones and TPVs, produced by tracking them in the latest global ECMWF reanalysis (ERA5), and determine the role of pre-existing TPVs in the initiation and intensification of these cyclones.</p>

Benjamin Leigh Smith's second Arctic expedition: Svalbard and Jan Mayen, 1872

Polar Record ◽  
2008 ◽  
Vol 44 (3) ◽  
pp. 255-264 ◽  
Author(s):  
P.J. Capelotti
Keyword(s):  
The Arctic ◽  
Research Vessel ◽  
North Coast ◽  
Primary Research ◽  
The North ◽  
Arctic Exploration ◽  
Ice Conditions

ABSTRACTIn 1872, the British yachtsman and explorer Benjamin Leigh Smith led his second expedition to the Arctic. Seeking to further the impressive oceanographic and geographic research of his first expedition in the summer of the previous year, Leigh Smith first explored Jan Mayen and then sailed to Svalbard. There, after investigating Moffen, adverse ice conditions precluded effective continuation of the voyage and almost wrecked his research vessel,Sampson. During a brief meeting with Adolf Erik Nordenskiöld's Swedish polar expedition, a bond was formed between the two explorers with fortuitous benefits for the Swedish expedition the following year as it struggled to escape from the north coast of Svalbard. Leigh Smith was forced to make for England in September 1872, without sailing nearly as far to the north or east as during his first expedition. His 1872 experiences led him to reconsider his method for Arctic exploration, and consequently, for his third expedition in 1873, he decided to include a chartered steamer as his primary research vessel withSampsonrelegated to the role of support vessel.

The system-forming role of the Arctic cluster in the development of the economy of the North of Russia (on the example of the Murmansk region)

2020 ◽  
pp. 96-104
Author(s):  
Е.С. Хаценко ◽  
Л.С. Лычкина
Keyword(s):  
Economic Policy ◽  
Legal Aspects ◽  
The Arctic ◽  
Russian Arctic ◽  
The North ◽  
Murmansk Region ◽  
The Creation

Представленная статья посвящена теоретико-правовым аспектам формирования экономической политики Российской Арктики, создание и регулирование Арктического экономического кластера. The presented article is devoted to the theoretical and legal aspects of the formation of the economic policy of the Russian Arctic, the creation and regulation of the Arctic economic cluster.

scholarly journals Evolution in the cold

2000 ◽  
Vol 12 (3) ◽  
pp. 257-257 ◽  
Author(s):  
Andrew Clarke
Keyword(s):  
Evolutionary Biology ◽  
Antarctic Fish ◽  
The Arctic ◽  
Polar Regions ◽  
Evolutionary Studies ◽  
Adaptive Radiations ◽  
The Antarctic ◽  
The Impact ◽  
Insight Into

Theodosius Dobzhansky once remarked that nothing in biology makes sense other than in the light of evolution, thereby emphasising the central role of evolutionary studies in providing the theoretical context for all of biology. It is perhaps surprising then that evolutionary biology has played such a small role to date in Antarctic science. This is particularly so when it is recognised that the polar regions provide us with an unrivalled laboratory within which to undertake evolutionary studies. The Antarctic exhibits one of the classic examples of a resistance adaptation (antifreeze peptides and glycopeptides, first described from Antarctic fish), and provides textbook examples of adaptive radiations (for example amphipod crustaceans and notothenioid fish). The land is still largely in the grip of major glaciation, and the once rich terrestrial floras and faunas of Cenozoic Gondwana are now highly depauperate and confined to relatively small patches of habitat, often extremely isolated from other such patches. Unlike the Arctic, where organisms are returning to newly deglaciated land from refugia on the continental landmasses to the south, recolonization of Antarctica has had to take place by the dispersal of propagules over vast distances. Antarctica thus offers an insight into the evolutionary responses of terrestrial floras and faunas to extreme climatic change unrivalled in the world. The sea forms a strong contrast to the land in that here the impact of climate appears to have been less severe, at least in as much as few elements of the fauna show convincing signs of having been completely eradicated.

scholarly journals The Role of the Disaster Preparedness Group in Adapting Abrasion to Communities Affected by Abrasion on the North Coast of Rembang, Central Java

2021 ◽  
Author(s):  
Dewi Liesnoor Setyowati ◽  
Puji Hardati ◽  
Andi Irwan Benardi ◽  
Nur Hamid ◽  
Yohanes Dwi Anugrahanto
Keyword(s):  
Disaster Preparedness ◽  
North Coast ◽  
The North ◽  
Central Java

Chapter 20 Paleogene history

1997 ◽  
Vol 17 (1) ◽  
pp. 388-417
Keyword(s):  
Early Cretaceous ◽  
The Arctic ◽  
North Coast ◽  
Western Coast ◽  
Central Basin ◽  
Oblique Collision ◽  
The North ◽  
Western Border ◽  
Paleozoic Rocks ◽  
West Spitsbergen

The Paleogene chapter of Svalbard history is a quite distinct one. It begins with an unconformity, albeit a sub-parallel one representing a late Cretaceous hiatus. Resting on Albian and older strata, the Van Mijenfjorden Group of six formations totals a thickness of about 2500 m in the Central Basin of Spitsbergen. The outcrop is ringed by Early Cretaceous strata in a broad syncline (Fig. 20.1). The strata are largely non-marine, coal-bearing sandstones, with interbedded marine shales and they range in age through Paleocene and Eocene.From latest Paleocene through Eocene time the West Spitsbergen Orogeny caused (Spitsbergian) deformation along the western border of the Central Basin, but it is most conspicuous in the folding and thrusting of Carboniferous through Early Cretaceous rocks. The orogen extended westwards to and beyond the western coast of central and southern Spitsbergen including Precambrian and Early Paleozoic rocks, which had already been involved in earlier tectogenesis. The eastward-verging thrusting extended beneath the Tertiary basin and reactivated older faults to the east.In the wider context Svalbard, adjacent to the north coast of Greenland, had been an integral part of Pangea from Carboniferous through Cretaceous time. The northward extension of the Atlantic opening reached and initiated the spreading of the Arctic Eurasia Basin at the beginning of the Paleogene Period. This led to the separation of Svalbard together with the Barents Shelf and northern Europe from Greenland by dextral strike-slip transform faulting. In the course of this progression, oblique collision between northeast Greenland and Svalbard caused

3D Structure of Striations in the North Pacific

2021 ◽  
Author(s):  
YU ZHANG ◽  
YU PING GUAN ◽  
RUI XIN HUANG
Keyword(s):  
North Pacific ◽  
3D Structure ◽  
Three Dimensional ◽  
Vertical Plane ◽  
Dimensional Structure ◽  
The North ◽  
Layer Analysis ◽  
Fluid Potential ◽  
The North Pacific

AbstractOcean striations are composed of alternating quasi-zonal band-like flows; this kind of organized structure of currents be found in all world’s oceans and seas. Previous studies have mainly been focused on the mechanisms of their generation and propagation. This study uses the spatial high-pass filtering to obtain the three-dimensional structure of ocean striations in the North Pacific in both the z-coordinate and σ-coordinate based on 10-yr averaged SODA3 data. First, we identify an ideal-fluid potential density domain where the striations are undisturbed by the surface forcing and boundary effects. Second, using the isopycnal layer analysis, we show that on isopycnal surfaces the orientations of striations nearly follow the potential vorticity (PV) contours, while in the meridional-vertical plane the central positions of striations are generally aligned with the latitude of zero gradient of the relative PV. Our analysis provides a simple dynamical interpretation and better understanding for the role of ocean striations.

A levee breach induced by internal erosion in Western Australia.

2021 ◽  
pp. qjegh2021-037
Author(s):  
Scott Davidson ◽  
Paul Baker
Keyword(s):  
Western Australia ◽  
Internal Erosion ◽  
North Coast ◽  
Sandy Gravel ◽  
Content Type ◽  
The North ◽  
Levee Breach ◽  
Piping Erosion ◽  
A Site

This case study presents a levee breach induced by piping erosion under cyclonic conditions in 2019. The levee is a 2.5 m high, 500 m long, mass earth fill embankment; with no cut-off trench, core, or ancillary structures. Located near Port Hedland on the north coast of Western Australia; its purpose is diversionary, to redirect cyclonic surface water away from the nearby Great Northern Highway. The levee was founded directly on Alluvium in 1987; and formed of locally sourced clayey sandy gravel. In 2003, the levee was partially excavated to enable the placement of a buried pipeline through the levee.Following a cyclonic event in 2019, a 27 m length of the levee breached, resulting in significant scour of the foundation and downstream soil. A site visit and investigation were conducted shortly thereafter, where in situ testing and laboratory soil tests on the levee and foundation materials were conducted.Analysis of the site observations and laboratory testing data led to the probable failure mechanism being theorised as having been initiated within the foundation by piping erosion within sand-rich beds of Alluvium. The large quantity of water ponding upstream of the levee then caused a progressive washout and breach of the levee.Thematic collection: This article is part of the Role of water in destabilizing slopes collection available at: https://www.lyellcollection.org/cc/Role-of-water-in-destabilizing-slopes

Sign in / Sign up

Export Citation Format

Share Document