Anna Silyakova

Anna Silyakova
UiT The Arctic University of Norway · Centre for Arctic Gas Hydrate, Environment and Climate

Ph.D.

About

40
Publications
8,612
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
837
Citations
Introduction
Additional affiliations
August 2013 - present
UiT The Arctic University of Norway
Position
  • PostDoc Position
Description
  • Water column, methane release and gas quantification; Undersea methane as a contributor to the Arctic Ocean acidification
October 2008 - October 2012
University of Bergen
Position
  • PhD Student
Description
  • PhD thesis "Arctic Ocean carbon biogeochemistry under climate change and ocean acidification"
June 2007 - August 2007
MARUM Center for Marine Environmental Sciences
Position
  • Summer Student Fellow
Description
  • Project "Phosphate speciation in sediments offshore Morocco: application of the SEDEX protocol"
Education
October 2008 - May 2013
University of Bergen
Field of study
  • Chemical Oceanography
September 2003 - June 2008
Saint Petersburg State University
Field of study
  • Physical Oceanography

Publications

Publications (40)
Article
Full-text available
Hydrothermal vents modify and displace subsurface dissolved organic matter (DOM) into the ocean. Once in the ocean, this DOM is transported together with elements, particles, dissolved gases and biomass along with the neutrally buoyant plume layer. Considering the number and extent of actively venting hydrothermal sites in the oceans, their contrib...
Article
Full-text available
Improved quantification techniques of natural sources are needed to explain variations in atmospheric methane. In polar regions, high uncertainties in current estimates of methane release from the seabed remain. We present unique 10- and 3-month time series of bottom water measurements of physical and chemical parameters from two autonomous ocean o...
Preprint
Full-text available
Hydrothermal vents modify and displace subsurface dissolved organic matter (DOM) into the ocean. Once in the ocean, this DOM is transported together with elements, particles, dissolved gases, and biomass along with the neutrally buoyant plume layer. Considering the number and extent of actively venting hydrothermal sites in the oceans, their contri...
Preprint
Improved quantification techniques of natural sources is needed to explain variations in atmospheric methane. In polar regions, high uncertainties in current estimates of methane release from the seabed remain. We present two unique 10 and 3 months long time-series of bottom water measurements of physical and chemical parameters from two autonomous...
Article
Full-text available
The Arctic Ocean subseabed holds vast reservoirs of the potent greenhouse gas methane (CH 4), often seeping into the ocean water column. In a continuously warming ocean as a result of climate change an increase of CH 4 seepage from the seabed is hypothesized. Today, CH 4 is largely retained in the water column due to the activity of methane-oxidizi...
Article
Full-text available
Dissociating gas hydrates, submerged permafrost, and gas bearing sediments release methane to the water column from a multitude of seeps in the Arctic Ocean. The seeping methane dissolves and supports the growth of aerobic methane oxidizing bacteria (MOB), but the effect of seepage and seep related biogeochemical processes on water column dissolved...
Article
Full-text available
We investigate methane seepage on the shallow shelf west of Svalbard during three consecutive years, using discrete sampling of the water column, echosounder-based gas flux estimates, water mass properties, and numerical dispersion modelling. The results reveal three distinct hydrographic conditions in spring and summer, showing that the methane co...
Article
Full-text available
Methane (CH4) in marine sediments has the potential to contribute to changes in the ocean and climate system. Physical and biochemical processes that are difficult to quantify with current standard methods such as acoustic surveys and discrete sampling govern the distribution of dissolved CH4 in oceans and lakes. Detailed observations of aquatic CH...
Article
Full-text available
Methane (CH4) in marine sediments has the potential to contribute to changes in the ocean- and climate system. Physical and biochemical processes that are difficult to quantify with current standard methods such as acoustic surveys and discrete sampling govern the distribution of dissolved CH4 in oceans and lakes. Detailed observations of aquatic C...
Article
Full-text available
We present a marine two‐phase gas model in one dimension (M2PG1) resolving interaction between the free and dissolved gas phases and the gas propagation toward the atmosphere in aquatic environments. The motivation for the model development was to improve the understanding of benthic methane seepage impact on aquatic environments and its effect on...
Article
Full-text available
Methane (CH4) is a powerful greenhouse gas. Its atmospheric mixing ratios have been increasing since 2005. Therefore, quantification of CH4 sources is essential for effective climate change mitigation. Here we report observations of the CH4 mixing ratios measured at the Zeppelin Observatory (Svalbard) in the Arctic and aboard the research vessel (R...
Article
Full-text available
Methane (CH4) is a powerful greenhouse gas and atmospheric mixing ratios have been increasing since 2005. Therefore, quantification of CH4 sources is essential for effective climate change mitigation. Here we report observations of the CH4 mixing ratios measured at Zeppelin Observatory (Svalbard) in the Arctic and aboard the Research Vessel (RV) He...
Article
Full-text available
Rare CO2 flux measurements from Arctic pack ice show that two types of ice contribute to the release of CO2 from the ice to the atmosphere during winter and spring: young, thin ice with a thin layer of snow and older (several weeks), thicker ice with thick snow cover. Young, thin sea ice is characterized by high salinity and high porosity, and snow...
Article
Full-text available
Rare CO2 flux measurements from Arctic pack ice show that two types of ice contribute to the release of CO2 from the ice to the atmosphere during winter and spring: young, thin ice with a thin layer of snow and older (several weeks), thicker ice with thick snow cover. Young, thin sea ice is characterized by high salinity and high porosity, and snow...
Conference Paper
Full-text available
Methods  Methane emanates from gas bearing sediments into the water column through a number of seeps in the Arctic Ocean 1 , but methane driven processes remain poorly understood  The goal of this study is to investigate changes in DOM compositions, nutrient regime and biochemical properties of the water column under the influence of methane driv...
Article
Full-text available
Greenhouse gas methane trapped in sub-seafloor gas hydrates may play an important role in a potential climate feedback system. The impact of future Arctic Ocean warming on the hydrate stability and its contribution to atmospheric methane concentrations remains an important and unanswered question. Here, we estimate the climate impact of released me...
Article
Full-text available
Cold seeps can support unique faunal communities via chemosynthetic interactions fueled by seabed emissions of hydrocarbons. Additionally, cold seeps can enhance habitat complexity at the deep-sea floor through the accretion of methane derived authigenic carbonates (MDAC). We examined infaunal and megafaunal community structure at high-Arctic cold...
Article
The impacts of oceanic CO2 uptake and global warming on the surface ocean environment have received substantial attention, but few studies have focused on shelf bottom water, despite its importance as habitat for benthic organisms and demersal fisheries such as cod. We used a downscaling ocean biogeochemical model to project bottom water acidificat...
Article
Seafloor methane release due to the thermal dissociation of gas hydrates is pervasive across the continental margins of the Arctic Ocean. Furthermore, there is increasing awareness that shallow hydrate-related methane seeps have appeared due to enhanced warming of Arctic Ocean bottom water during the last century. Although it has been argued that a...
Article
Continued warming of the Arctic Ocean in coming decades is projected to trigger the release of teragrams (1 Tg = 10(6) tons) of methane from thawing subsea permafrost on shallow continental shelves and dissociation of methane hydrate on upper continental slopes. On the shallow shelves (<100 m water depth), methane released from the seafloor may rea...
Presentation
While the Arctic is warming at a rate of almost twice the global average and needs particular attention for climate impacts, it is a challenging place to perform oceanic measurement, especially in regions of seasonal sea ice cover and stormy seasons. The Centre for Arctic Gas Hydrate, Environment and Climate (CAGE) aims at understanding the impact...
Article
Full-text available
We find that summer methane (CH4) release from seabed sediments west of Svalbard substantially increases CH4 concentrations in the ocean but has limited influence on the atmospheric CH4 levels. Our conclusion stems from complementary measurements at the seafloor, in the ocean, and in the atmosphere from land-based, ship and aircraft platforms durin...
Article
Full-text available
The Arctic Ocean is one of the fastest changing oceans, plays an important role in global carbon cycling, and yet is a particularly challenging ocean to study, hence observations tend to be relatively sparse in both space and time. How the Arctic functions, geophysically, but also ecologically, can have significant consequences for the internal cyc...
Article
Full-text available
A large scale multidisciplinary mesocosm experiment in an Arctic fjord (Kongsfjorden, Svalbard; 78° 56.2´ N) was used to study Arctic marine food webs and biogeochemical elements cycling at natural and elevated future carbon dioxide (CO2) levels. At the start of the experiment marine-derived chromophoric dissolved organic matter (CDOM) dominated th...
Article
Full-text available
Studying more than 3600 observations of particulate organic carbon (POC) and particulate organic nitrogen (PON), we evaluate the applicability of the classic Redfield C:N ratio (6.6) and the recently proposed Sterner ratio (8.3) for the Arctic Ocean and pan-Arctic shelves. The confidence intervals for C:N ranged from 6.43 to 8.82, while the average...
Article
Full-text available
Net community production (NCP) and carbon to nutrient uptake ratios were studied during a large-scale mesocosm experiment on ocean acidification in Kongsfjorden, western Svalbard, during June–July 2010. Nutrient depleted fjord water with natural plankton assemblages, enclosed in nine mesocosms of �50m3 in volume, was exposed to pCO2 levels ranging...
Article
Full-text available
Recent studies on the impacts of ocean acidification on pelagic communities have identified changes in carbon to nutrient dynamics with related shifts in elemental stoichiometry. In principle, mesocosm experiments provide the opportunity of determining temporal dynamics of all relevant carbon and nutrient pools and, thus, calculating elemental budg...
Article
Full-text available
The effect of ocean acidification on the balance between gross community production (GCP) and community respiration (CR) (i.e. net community production, NCP) of plankton communities was investigated in summer 2010 in Kongsfjorden, West of Svalbard. Surface water, which was characterized by low concentrations of dissolved inorganic nutrients and chl...
Article
Full-text available
Ocean acidification and carbonation, driven by anthropogenic emissions of carbon dioxide (CO2), have been shown to affect a variety of marine organisms and are likely to change ecosystem functioning. High latitudes, especially the Arctic, will be the first to encounter profound changes in carbonate chemistry speciation at a large scale, namely the...
Article
Full-text available
A major, potential stressor of marine systems is the changing water chemistry following increasing seawater carbon dioxide concentration (CO2), commonly termed ocean acidification. In order to understand how an Arctic pelagic ecosystem may respond to future CO2, a deliberate ocean acidification and nutrient perturbation study was undertaken in an A...
Article
Full-text available
Net community production (NCP) and ratios of carbon to nutrient consumption were studied during a large-scale mesocosm experiment on ocean acidification in Kongsfjorden, West Spitsbergen, during June-July 2010. Nutrient-deplete fjord water with natural phyto- and bacteriaplankton assemblages, enclosed in nine mesocosms of ~ 50 m3 volume, was expose...
Preprint
Full-text available
Recent studies on the impacts of ocean acidification on pelagic communities have identified changes in carbon to nutrient dynamics with related shifts in elemental stoichiometry. In principle, mesocosm experiments provide the opportunity of determining the temporal dynamics of all relevant carbon and nutrient pools and, thus, calculating elemental...
Article
Ocean acidification may stimulate primary production through increased availability of inorganic carbon in the photic zone, which may in turn change the biogenic flux of dissolved organic carbon (DOC) and the growth potential of heterotrophic bacteria. To investigate the effects of ocean acidification on marine bacterial assemblages, a two-by-three...
Data
Ocean acidification may stimulate primary production through increased availability of inorganic carbon in the photic zone, which may in turn change the biogenic flux of dissolved organic carbon (DOC) and the growth potential of heterotrophic bacteria. To investigate the effects of ocean acidification on marine bacterial assemblages, a two-by-three...

Network

Cited By

Projects

Project (1)
Project
Experiment designed to understand the effects of the shift to a younger and thinner sea ice regime in the Arctic on energy flux, ice dynamics and the ice associated ecosystem, and local and global climate. And to improve our capacity to model the future more direct observations in the Arctic are needed. Objectives: Understand how ocean heat is mixed upwards towards the sea ice and to what extent it influences the sea ice energy budget. Understand the fate of solar radiation incident how its fate is affected by properties of the atmosphere, snow, ice, and ocean. Quantify the changing mass balance of Arctic sea ice and its snow cover. Improve modeling of the dynamics of the drifting ice Understand the ice associated ecosystem and model future changes. Effects on local and global weather systems