scholarly journals Wind-Driven Coastal Upwelling near Large River Deltas in the Laptev and East-Siberian Seas

2020 ◽  
Vol 12 (5) ◽  
pp. 844 ◽  
Author(s):  
Alexander Osadchiev ◽  
Ksenia Silvestrova ◽  
Stanislav Myslenkov
Keyword(s):  
Coastal Upwelling ◽  
Large River ◽  
Sea Surface ◽  
The Arctic ◽  
Biological Processes ◽  
Study Region ◽  
River Deltas ◽  
East Siberian Sea ◽  
Southeasterly Wind ◽  
The Laptev Sea

The Lena, Kolyma, and Indigirka rivers are among the largest rivers that inflow to the Arctic Ocean. Their discharges form a freshened surface water mass over a wide area in the Laptev and East-Siberian seas and govern many local physical, geochemical, and biological processes. In this study we report coastal upwelling events that are regularly manifested on satellite imagery by increased sea surface turbidity and decreased sea surface temperature at certain areas adjacent to the Lena Delta in the Laptev Sea and the Kolyma and Indigirka deltas in the East-Siberian Sea. These events are formed under strong easterly and southeasterly wind forcing and are estimated to occur during up to 10%–30% of ice-free periods at the study region. Coastal upwelling events induce intense mixing of the Lena, Kolyma, and Indigirka plumes with subjacent saline sea. These plumes are significantly transformed and diluted while spreading over the upwelling areas; therefore, their salinity and depths abruptly increase, while stratification abruptly decreases in the vicinity of their sources. This feature strongly affects the structure of the freshened surface layer during ice-free periods and, therefore, influences circulation, ice formation, and many other processes at the Laptev and East-Siberian seas.

scholarly journals Shine a light: Under-ice light and its ecological implications in a changing Arctic Ocean

AMBIO ◽  
2021 ◽  
Author(s):  
Giulia Castellani ◽  
Gaëlle Veyssière ◽  
Michael Karcher ◽  
Julienne Stroeve ◽  
S. Neil Banas ◽  
...  
Keyword(s):  
Sea Ice ◽  
Light Field ◽  
Marine Ecosystem ◽  
Sea Surface ◽  
The Arctic ◽  
Future Research ◽  
Biological Processes ◽  
Underwater Light Field ◽  
Sea Ice Algae ◽  
Ecological Implications

AbstractThe Arctic marine ecosystem is shaped by the seasonality of the solar cycle, spanning from 24-h light at the sea surface in summer to 24-h darkness in winter. The amount of light available for under-ice ecosystems is the result of different physical and biological processes that affect its path through atmosphere, snow, sea ice and water. In this article, we review the present state of knowledge of the abiotic (clouds, sea ice, snow, suspended matter) and biotic (sea ice algae and phytoplankton) controls on the underwater light field. We focus on how the available light affects the seasonal cycle of primary production (sympagic and pelagic) and discuss the sensitivity of ecosystems to changes in the light field based on model simulations. Lastly, we discuss predicted future changes in under-ice light as a consequence of climate change and their potential ecological implications, with the aim of providing a guide for future research.

Variability in Sea Ice Melt Onset in the Arctic Northeast Passage: Seesaw of the Laptev Sea vs. the East Siberian Sea

2021 ◽  
Author(s):  
Hongjie Liang ◽  
Jie Su
Keyword(s):  
Heat Flux ◽  
Sea Ice ◽  
Sensible Heat Flux ◽  
Storm Tracks ◽  
The Arctic ◽  
Laptev Sea ◽  
Easterly Wind ◽  
East Siberian Sea ◽  
Atmospheric Circulation Indices ◽  
The Laptev Sea

<p>The ice/snow melt onset (MO) is a critical triggering signal for ice-albedo positive feedback in the Arctic. Concerning the Northeast Passage (NEP), for 1979-1998, the MO in the East Siberian Sea (ESS) occurred generally earlier than that in the Laptev Sea (LS). However, for 1999-2018, the LS experienced significantly earlier MO than did the ESS in several years. This phenomenon is identified as the MO Seesaw (MOS), i.e., the MO difference between the LS and ESS. For the positive MOS, storm tracks in May tend to cover the ESS rather than the LS and easterly wind prevails and shifts slightly to a northerly wind in the ESS, resulting in higher surface air temperature (SAT) and total-column water vapor (TWV) and earlier MO in the ESS. For the negative MOS, storm tracks are much stronger in the LS than in the ESS and prominent southerly/southwesterly wind brings warm air from coastal land towards the LS. The effect of the Barents Oscillation (BO) on the MOS could be dated back to April. When the Barents Sea is centered with a low SLP in April, sea ice in the LS would be driven away from the coasts, leading to a lower sea ice area (SIA), which increases the surface latent heat flux and humidifies the overlying atmosphere. Along with an enhanced downward sensible heat flux, earlier regional average MO occurs in the LS. For 1999-2018, the MOS was more closely related to both the local variables and the large-scale atmospheric circulation indices.</p>

LAPTEV AND EAST SIBERIAN SEA COASTAL DYNAMICS, SEDIMENT FLUXES, AND COASTAL DATABASE

2018 ◽  
Author(s):  
М. Григорьев ◽  
M. Grigor'ev
Keyword(s):  
Organic Material ◽  
Warming Trend ◽  
The Arctic ◽  
Coastal Zones ◽  
Arctic Seas ◽  
Study Region ◽  
Erosion Rates ◽  
East Siberian Sea ◽  
Coastal Landscapes ◽  
Key Sites

The coastal zones of the Laptev and East-Siberian seas are characterized by the highest erosion rates in the Arctic. Thermal abrasion is the leading geomorphological process in the region, with average rates of 1 to 4 m/yr. On the basis of shore segmentation, coastal erosion rates were analysed for each segment of coast. The mean rate of coastal retreat for the Laptev and East-Siberian seas was calculated and estimated to be 0,8 m/yr. In recent decades, the Laptev and East-Siberian sea regions have experienced a warming trend. Under these conditions, erosion rates of ice rich coasts on several key sites have increased 1,5–2 times during the last 10–12 years. Sediment and organic material inputs for the Laptev and East-Siberian seas were estimated and found to be respectively (1,6 and 2,4 103 t/yr for sediment and 62,2 and 90,2 103 t/yr for organic material). The data obtained were compiled into an electronic coastal database for the study region. Using the database, 16 lithologic, morphologic, morphometric and dynamic parameters were determined for each coastal section. The processes of cryogenic morphogenesis form rather specific coastal landscapes within the studied coasts. In studied region the rates of coastal transformation is much faster then in other Arctic areas. This study has shown that 10,7 km2/yr of land is lost annually along the Arctic seas of East Siberia.

Methane oxidation processes in sediment of the Laptev and East Siberian Seas indicated from microbial lipids and carbon isotope composition

2021 ◽  
Author(s):  
Weichao Wu ◽  
Henry Holmstrand ◽  
Birgit Wild ◽  
Natalia Shakhova ◽  
Denis Kosmach ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Arctic Ocean ◽  
Water Column ◽  
Marine Sediment ◽  
The Arctic ◽  
Laptev Sea ◽  
Microbial Lipids ◽  
East Siberian Sea ◽  
Siberian Arctic ◽  
The Laptev Sea

<p>The East Siberian Arctic Shelf is an integrated coastal sea system with complex biogeochemical processes influenced by underlying subsea permafrost, hydrates and thermogenic compartments. Methane is released from the marine sediments to the water column, which serves as an interphase between the lithosphere and the atmosphere. Before escaping into water column and atmosphere, methane has potentially experienced extensive aerobic and anaerobic oxidation by microbes in the marine sediment. In particular, the aerobic process is assumed to be dominant in the surface oxic/suboxic marine sediment (upper 1cm) after anaerobic processes in deeper zones. However, these processes are insufficiently understood in sediments of the Arctic Ocean. To probe these, we investigated the microbial lipids and their stable carbon composition in surface marine sediment (upper 1 cm) from two active methane seep areas in the Laptev Sea and the East Siberian Sea.</p><p>The microbial fatty acids (C12 to C18 fatty acids) were relatively enriched in <sup>13</sup>C (δ<sup>13</sup>C -18.8 to -31.2‰) compared to that of dissolved CH<sub>4</sub> in nearby bottom water (-54.6 to -29.7‰). This contrasts to previous reports of strongly depleted δ<sup>13</sup>C signals in microbial lipids (e.g., -100‰) at active marine mid-ocean ridges and mud volcanoes, from quite different ocean areas. The absence of a depleted δ<sup>13</sup>C signal in these general microbial biomarkers suggest that these reflect substrates other than methane such as other parts of the sediment organic matter, indicated by the stronger correlation of δ<sup>13</sup>C between fatty acids and bulk organic carbon than that between fatty acid and CH<sub>4</sub>. However, the putatively more specific biomarkers for aerobic methanotrophic bacteria (mono-unsaturated C16 and C18 fatty acids) show a distinct pattern in the Laptev Sea and East Siberian Sea: C16:1 and C18:1 were enriched in <sup>13</sup>C (up to 4.5 ‰) relative to their saturated analogs in the Laptev Sea; whereas, C18:1 was depleted in <sup>13</sup>C (up to 4.5 ‰) compared to C18 in the East Siberian Sea. This could be because the relative populations of Type I and II methanotrophs were different in the two areas with different carbon assimilation pathways. Our results cannot exclude a slowly active aerobic methanotrophs at methane seeps in the East Siberian Arctic Ocean and thus call for more information from molecular microbiology.</p>

scholarly journals MARINE HEATWAVES IN THE LAPTEV SEA IN 2019-2020

2021 ◽  
Vol 4 (1) ◽  
pp. 145-151
Author(s):  
Marina V. Kraineva ◽  
Elena N. Golubeva
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Observational Data ◽  
Heat Waves ◽  
Bottom Layer ◽  
Ocean Model ◽  
Sea Surface ◽  
The Arctic ◽  
Laptev Sea ◽  
The Laptev Sea

Marine heat waves are extreme events that represent a significant excess of average climatic temperatures. In this study marine heat waves calculated both from observational data and from numerical modeling data in the Laptev Sea region are analyzed. The regional numerical model SibCIOM (Siberian Coupled Ice-Ocean Model) is used to study the variability of the hydrological characteristics of the Arctic Ocean and its shelf seas. Observational data shows an increase in the frequency and intensity of the marine heat waves in recent years in this region. On the basis of numerical experiments, the work demonstrates intense warming in the bottom layer, as a consequence of the increase in the sea surface temperature of the Laptev Sea in recent years. The paper analyzes the possible causes and consequences of an increase in the sea surface temperature of the Laptev Sea.

scholarly journals Spatial and temporal variability of Arctic ice thickness

1995 ◽  
Vol 21 ◽  
pp. 323-329 ◽  
Author(s):  
Gregory M. Flato
Keyword(s):  
Temporal Variability ◽  
The Arctic ◽  
Ice Thickness ◽  
Spatial And Temporal Variability ◽  
Ice Volume ◽  
Auto Correlation ◽  
Air Temperatures ◽  
East Siberian Sea ◽  
Arctic Ice ◽  
The Laptev Sea

A numerical model is used to study the spatial and temporal variability of ice thickness in the Arctic. The model is run to cyclo-stationary equilibrium, forced with daily varying geostrophic winds and monthly varying surface air temperatures from 1951 to 1990. Decadal-average winter ice-thickness fields exhibit a trend of increasing ice thickness in the East Siberian Sea and somewhat thicker ice overall in the 1980s. Inter-annual variability was largest in the Beaufort and East Siberian Seas and generally lower in the Laptev Sea and central Arctic. Spatial correlation patterns show that ice thickness at a point is correlated with ice thickness over a surrounding area of roughly 4 × 105 km2 with a correlation coefficient of 0.7. Temporal auto-correlation functions indicate that the total ice volume has a correlation time-scale of roughly 7 years, while the volume of ice between 2 and 5 m thick and the volume of ice less than 1 m thick have correlation times of roughly 2 years and 2 months, respectively.

scholarly journals Spatial and temporal variability of Arctic ice thickness

1995 ◽  
Vol 21 ◽  
pp. 323-329 ◽  
Author(s):  
Gregory M. Flato
Keyword(s):  
Temporal Variability ◽  
The Arctic ◽  
Ice Thickness ◽  
Spatial And Temporal Variability ◽  
Ice Volume ◽  
Auto Correlation ◽  
Air Temperatures ◽  
East Siberian Sea ◽  
Arctic Ice ◽  
The Laptev Sea

A numerical model is used to study the spatial and temporal variability of ice thickness in the Arctic. The model is run to cyclo-stationary equilibrium, forced with daily varying geostrophic winds and monthly varying surface air temperatures from 1951 to 1990. Decadal-average winter ice-thickness fields exhibit a trend of increasing ice thickness in the East Siberian Sea and somewhat thicker ice overall in the 1980s. Inter-annual variability was largest in the Beaufort and East Siberian Seas and generally lower in the Laptev Sea and central Arctic. Spatial correlation patterns show that ice thickness at a point is correlated with ice thickness over a surrounding area of roughly 4 × 105 km2 with a correlation coefficient of 0.7. Temporal auto-correlation functions indicate that the total ice volume has a correlation time-scale of roughly 7 years, while the volume of ice between 2 and 5 m thick and the volume of ice less than 1 m thick have correlation times of roughly 2 years and 2 months, respectively.

scholarly journals Correlation between Arctic river discharge and sea ice formation in Laptev Sea using sea surface salinity from SMOS satellite

2020 ◽  
Author(s):  
Carolina Gabarro ◽  
Justino Martinez ◽  
Veronica Gonzalez-Gambau ◽  
Cristina González-Haro ◽  
Estrella Olmedo ◽  
...  
Keyword(s):  
Sea Ice ◽  
Spatial Resolution ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
The Arctic ◽  
Laptev Sea ◽  
Ice Melting ◽  
Surface Salinity ◽  
The Laptev Sea

<p>During the last 3<span> dec</span><span>ades, the Arctic rivers have increased their discharge around 10%, mainly due to the increase of the</span> <span>g</span><span>lobal atmospheric </span>temperature. The increase of the river discharge carries higher loads of dissolved organic matter (DOM) and suspended matter (SM) entering to the Arctic Ocean. This results in increased absorption of solar energy in the mixed layer, which can potentially contribute to the general sea ice retreat. Observation based studies (e.g. Bauch et al., 2013) showed correlation between river water discharge and local sea ice melting on the Laptev sea shelf due to the change on the ocean heat. Previous studies are based with a limited number of observations, both in space and in time.</p><p>Thanks to the ESA SMOS (Soil Moisture and Ocean Salinity) and NASA SMAP (Soil Moisture Active Passive) missions we have daily the sea surface salinity (SSS) maps from the Arctic, which permit to observe the salinity variations due to the river discharges. The Arctic sea surface salinity products obtained from SMOS measurements have been improved considerable by the Barcelona Expert Center (BEC) team thanks to the project Arctic+Salinity, funded by ESA. The new version of the product (v3) covers the years from 2011 up to 2018, have a spatial resolution of 25km and are daily maps with 9 day averages. The Arctic+ SSS maps provide a better description of the salinity gradients and a better effective spatial resolution than the previous versions of the Arctic product, so the salinity fronts are better resolved. The quality assessment of the Arctic+SSS product is challenging because, in this region, there are scarce number of in-situ measurements.</p><p>The high effective spatial resolution of the Arctic+ SSS maps will permit to study for the first time scientific physical processes that occurs in the Arctic. We will explore if a correlation between the Lena and Ob rivers discharge with the sea ice melting and freeze up is observed with satellite data, as already stated with in-situ measurements by Bauch et al. 2013. Salinity and sea ice thickness maps from SMOS and sea ice concentration from OSISAF will be used in this study.</p><p> </p><p>Bauch, D.,Hölemann, J. , Nikulina, A. , Wegner, C., Janout, M., Timokhov, L. and Kassens, H. (2013): Correlation of river water and local sea-ice melting on the Laptev Sea shelf (Siberian Arctic) , Journal of Geophysical Research C: Oceans, 118 (1), pp. 550-561 . doi: 10.1002/jgrc.20076</p>

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