Large-Scale Variations of Sea Level in the Laptev Sea

1999 ◽  
pp. 25-36 ◽  
Author(s):  
G. N. Voinov ◽  
E. A. Zakharchuk
Keyword(s):  
Sea Level ◽  
Large Scale ◽  
Laptev Sea ◽  
The Laptev Sea

scholarly journals Sea-level evolution of the Laptev Sea and the East Siberian Sea since the last glacial maximum

arktos ◽  
2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Volker Klemann ◽  
Birgit Heim ◽  
Henning A. Bauch ◽  
Sebastian Wetterich ◽  
Thomas Opel
Keyword(s):  
Sea Level ◽  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Laptev Sea ◽  
Last Glacial ◽  
East Siberian Sea ◽  
The Last Glacial Maximum ◽  
The Laptev Sea ◽  
The Last Glacial

scholarly journals Variability and trends in Laptev Sea ice outflow between 1992–2011

2013 ◽  
Vol 7 (1) ◽  
pp. 349-363 ◽  
Author(s):  
T. Krumpen ◽  
M. Janout ◽  
K. I. Hodges ◽  
R. Gerdes ◽  
F. Girard-Ardhuin ◽  
...  
Keyword(s):  
Sea Ice ◽  
Large Scale ◽  
Ice Cover ◽  
Late Winter ◽  
Laptev Sea ◽  
Concentration Data ◽  
Sea Ice Extent ◽  
Ice Drift ◽  
Wind Velocities ◽  
The Laptev Sea

Abstract. Variability and trends in seasonal and interannual ice area export out of the Laptev Sea between 1992 and 2011 are investigated using satellite-based sea ice drift and concentration data. We found an average total winter (October to May) ice area transport across the northern and eastern Laptev Sea boundaries (NB and EB) of 3.48 × 105 km2. The average transport across the NB (2.87 × 105 km2) is thereby higher than across the EB (0.61 × 105 km2), with a less pronounced seasonal cycle. The total Laptev Sea ice area flux significantly increased over the last decades (0.85 × 105 km2 decade−1, p > 0.95), dominated by increasing export through the EB (0.55 × 105 km2 decade−1, p > 0.90), while the increase in export across the NB is smaller (0.3 × 105 km2 decade−1) and statistically not significant. The strong coupling between across-boundary SLP gradient and ice drift velocity indicates that monthly variations in ice area flux are primarily controlled by changes in geostrophic wind velocities, although the Laptev Sea ice circulation shows no clear relationship with large-scale atmospheric indices. Also there is no evidence of increasing wind velocities that could explain the overall positive trends in ice export. The increased transport rates are rather the consequence of a changing ice cover such as thinning and/or a decrease in concentration. The use of a back-propagation method revealed that most of the ice that is incorporated into the Transpolar Drift is formed during freeze-up and originates from the central and western part of the Laptev Sea, while the exchange with the East Siberian Sea is dominated by ice coming from the central and southeastern Laptev Sea. Furthermore, our results imply that years of high ice export in late winter (February to May) have a thinning effect on the ice cover, which in turn preconditions the occurence of negative sea ice extent anomalies in summer.

scholarly journals Variability and trends in Laptev Sea ice outflow between 1992–2011

2012 ◽  
Vol 6 (4) ◽  
pp. 2891-2930 ◽  
Author(s):  
T. Krumpen ◽  
M. Janout ◽  
K. I. Hodges ◽  
R. Gerdes ◽  
F. Girard-Ardhuin ◽  
...  
Keyword(s):  
Sea Ice ◽  
Large Scale ◽  
Back Propagation ◽  
Late Winter ◽  
Laptev Sea ◽  
Concentration Data ◽  
Sea Ice Extent ◽  
Ice Drift ◽  
Wind Velocities ◽  
The Laptev Sea

Abstract. Variability and trends in seasonal and interannual ice area export out of the Laptev Sea between 1992 and 2011 are investigated using satellite-based sea ice drift and concentration data. We found an average winter (October to May) ice area transport across the northern and eastern Laptev Sea boundaries (NB and EB) of 3.48 × 105 km2. The average transport across the NB (2.87 × 105 km2) is thereby higher than across the EB (0.61 × 105 km2), with a less pronounced seasonal cycle. The total Laptev Sea ice area flux significantly increased over the last decades (0.85 × 105 km2/decade, p > 0.95), dominated by increasing export through the EB (0.55 × 105 km2/decade, p > 0.90), while the increase in export across the NB is small (0.3 × 105 km2/decade) and statistically not significant. The strong coupling between across-boundary SLP gradient and ice drift velocity indicates that monthly variations in ice area flux are primarily controlled by changes in geostrophic wind velocities, although the Laptev Sea ice circulation shows no clear relationship with large-scale atmospheric indices. Also there is no evidence of increasing wind velocities that could explain the overall positive trends in ice export. Following Spreenet al. (2011), we therefore assume that changes in ice flux rates may be related to changes in the ice cover such as thinning and/or a decrease in concentration. The use of a back-propagation method revealed that most of the ice that is incorporated into the Transpolar Drift is formed during freeze-up and originates from the central and western part of the Laptev Sea, while the exchange with the East Siberian Sea is dominated by ice coming from the Central and South-Eastern Laptev Sea. Furthermore, our results imply that the late winter (February to May) ice area flux may at least partially control the summer sea ice extent in the Laptev Sea.

Multiyear variability of atmospheric processes and ice cover in the Laptev Sea since 1942 to 2019

2020 ◽  
Author(s):  
Anna Timofeeva ◽  
Vladimir Ivanov ◽  
Alexander Yulin ◽  
Stepan Khotchenkov
Keyword(s):  
Sea Ice ◽  
Large Scale ◽  
Ice Cover ◽  
Laptev Sea ◽  
Positive Temperature ◽  
Sea Ice Extent ◽  
Air Masses ◽  
Ice Conditions ◽  
The Laptev Sea ◽  
Melting Season

<p>The Laptev Sea is influenced by synoptic regions of the Atlantic-Eurasian sector of the Northern Hemisphere. Types of large-scale processes are consider according to the G. J. Vangengeim typization: West (W) circulation form, with dominating zonal transport of air masses, East (E) and meridional (C) circulation forms with opposite phases of geographic orientation in the troposphere of the anticyclones ridges axes, blocking the Western transfer of air masses and developing the meridional circulation at high and middle latitudes. The Laptev Sea ice extent at the end of the melting season has a strong interannual variability, the oscillations amplitude reaches 86%.</p><p>The paper considers analysis of long-term trends of the large-scale atmosphere processes realignment and multiyear variability of the air temperature and ice cover anomalies in the Laptev Sea. According to multiyear course of integral anomalies values four steady periods of homogeneous  tendency of climatic processes revealed and described for data series from 1942 to 2019 (air reconnaissance and satellite data).</p><p>The types of ice conditions development (severe, medium, mild) at the end of the melting season were determined for the entire series of observations. More than half of cases during 78 years are distinguished as medium type of ice conditions. The repeatability of severe and mild types is almost the same numerically but varies in time according to revealed periods.</p><p>During 1942-1947 years in the Laptev Sea the “warming” period occurred (same for the whole polar region), known as the warming of the Arctic of 30th. At this period positive temperature anomalies and negative anomalies of sea ice extent (mean -2%) were dominated. During subsequent period 1948-1989 years the positive temperature trend has changed to the steady negative. The most dramatic temperature drops were observed in the 60-70<sup>th</sup>. Positive ice anomalies increased (mean 9%), in August Laptev Sea remained mostly covered by ice. Of the 42 years 28 refer to the medium type of ice conditions, 11 to the severe. During the period 1990-2004 years frequent interannual rearrangements of the atmosphere circulation and multidirectional fluctuations of temperature and ice cover anomalies were observed. On average, the temperature and ice cover during the period are close to the long-term norm. After 2005 temperature regime in the polar climate system has changed. This period is the warmest for the whole observations series in the Laptev Sea. Ice extent at the end of the melting season steady decreases and shows dramatic growth of negative anomalies values and occur of extremely low anomaly for the entire observation period (up to -54-55%). The average negative ice anomaly for the period is -26.4 %. Of the 15 years 9 refer to the mild type of ice conditions.</p>

scholarly journals Changes in the paleohydrological conditions in the Laptev Sea during the late Pleistocene and Holocene based on a study of aquatic palynomorphs

2019 ◽  
Vol 59 (3) ◽  
pp. 433-448
Author(s):  
T. S. Klyuvitkina ◽  
Ye. I. Polyakova
Keyword(s):  
Environmental Change ◽  
Sea Level ◽  
Continental Margin ◽  
Cold Water ◽  
Sediment Cores ◽  
Atlantic Water ◽  
Time Interval ◽  
Laptev Sea ◽  
Global Sea Level ◽  
The Laptev Sea

On the basis of aquatic palynomorph assemblages in sediment cores obtained from the eastern Laptev Sea shelf, major phases of environmental change associated with the last postglacial global sea-level rise can be recognized for the time since 17.5 calendar years BP (cal. ka). It is shown that in the time interval of 17.5–13.0 cal. ka in the western part of the sea there was a very cold-water sea basin with permanent sea-ice cover, 12.3–11.2 cal. ka the outer shelf were characterized by increased precipitation of river-loaded matter in a river-proximal environment of Anabara and Khatanga rivers, and the period of 11.2–7.0 cal ka was marked by enhanced influence of Atlantic water at the Laptev Sea continental margin. Modern-like environments were established in this part of the sea approximately 7.0 cal. ka.

scholarly journals An observational and modelling analysis of Laptev Sea (Arctic Ocean) ice variations during summer

2001 ◽  
Vol 33 ◽  
pp. 533-538 ◽  
Author(s):  
K. Görgen ◽  
J. Bareiss ◽  
A. Helbig ◽  
A. Rinke ◽  
K. Dethloff
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Large Scale ◽  
Climate Model ◽  
Regional Climate ◽  
Laptev Sea ◽  
Simple Relationship ◽  
Cyclone Activity ◽  
Sea Ice Concentration ◽  
The Laptev Sea

AbstractIn this study we investigate the relationship of the atmospheric circulation and the sea-ice distribution in the Laptev Sea, Arctic Ocean, in the summers 1979−96. Sea-ice data from passive-microwave radiometers, global atmospheric data analyses, cyclone statistics and simulations of the regional climate model HIRHAM4 were analyzed to find out if periods of reduced or increased sea-ice concentrations are linked to synoptic patterns (circulation anomalies, cyclone activity). A canonical correlation analysis between Arctic sea-level pressure and sea-ice concentration anomalies confirms large-scale relationships among these variables. We did not find a simple relationship between sea-ice area anomalies and cyclone activity in the Laptev Sea area

scholarly journals Analyzing links between simulated Laptev Sea sea ice and atmospheric conditions over adjoining landmasses using causal-effect networks

2020 ◽  
Vol 14 (11) ◽  
pp. 4201-4215
Author(s):  
Zoé Rehder ◽  
Anne Laura Niederdrenk ◽  
Lars Kaleschke ◽  
Lars Kutzbach
Keyword(s):  
Sea Ice ◽  
Large Scale ◽  
Causal Effect ◽  
Ice Cover ◽  
Meridional Wind ◽  
Specific Humidity ◽  
Laptev Sea ◽  
Atmospheric Conditions ◽  
Thermodynamic Variables ◽  
The Laptev Sea

Abstract. We investigate how sea ice interacts with the atmosphere over adjacent landmasses in the Laptev Sea region as a step towards a better understanding of the connection between sea ice and permafrost. We identify physical mechanisms as well as local and large-scale drivers of sea-ice cover with a focus on one region with highly variable sea-ice cover and high sea-ice productivity: the Laptev Sea region. We analyze the output of a coupled ocean–sea-ice–atmosphere–hydrological-discharge model with two statistical methods. With the recently developed causal-effect networks we identify temporal links between different variables, while we use composites of high- and low-sea-ice-cover years to reveal spatial patterns and mean changes in variables. We find that in the model local sea-ice cover is a driven rather than a driving variable. Springtime melt of sea ice in the Laptev Sea is mainly controlled by atmospheric large-scale circulation, mediated through meridional wind speed and ice export. During refreeze in fall thermodynamic variables and feedback mechanisms are important – sea-ice cover is interconnected with air temperature, thermal radiation and specific humidity. Though low sea-ice cover leads to an enhanced southward transport of heat and moisture throughout summer, links from sea-ice cover to the atmosphere over land are weak, and both sea ice in the Laptev Sea and the atmospheric conditions over the adjacent landmasses are mainly controlled by common external drivers.

scholarly journals The hydrocarbon compounds sources in surface sediments of the Laptev Sea shelf

2021 ◽  
Vol 266 ◽  
pp. 08006
Author(s):  
I.A. Oberemok ◽  
E.V. Gershelis
Keyword(s):  
Large Scale ◽  
Surface Sediments ◽  
Outer Shelf ◽  
The Arctic ◽  
Grain Size Analysis ◽  
Shelf Zone ◽  
Size Analysis ◽  
Laptev Sea ◽  
Sediment Grain Size ◽  
The Laptev Sea

Rapid warming of the Arctic provokes large-scale degradation of permafrost on land terrestrial and in submarines. A vast amount of remobilized organic matter (OM) is involved in the modern biogeochemical cycle. Understanding of the fate of terrestrial OM moving from the land to the Arctic shelf is essential for predicting the potential feedback of Arctic ecosystems. In our research, an attempt was made to characterize the modern OM stored in the surface sediments of the Laptev Sea to estimate its composition variability and to identify the OM sources along with the “coastline - outer shelf” profile. Here we discuss the OM features revealed by Rock-Eval pyrolysis (RE) and the distribution of n-alkanes in combination with sediment grain-size analysis. The GC/MS records are directly comparable with RE data tracing the terrestrial OM along with the entire studied profile. However, we observe both a significant decline of terrestrial input and the rise of hydrobiont in the outer shelf zone. We assume that different OM sources may produce different ranges of RE values.

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