Thomas Krumpen

Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Stefan Hendricks

Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung

Christian Haas

University of Alberta

Robert Ricker

NORCE Norwegian Research Centre

Marcel Nicolaus

Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung

Ilka Peeken

Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung

Jens Hölemann

Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung

Hans Jakob Belter

Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung

Melanie Bergmann

Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung

Markus Janout

Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung

Benjamin Rabe

Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung

Cooperative Institutions

Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung

260

University of Bremen

Norwegian Polar Institute

Arctic and Antarctic Research Institute

GEOMAR Helmholtz Centre for Ocean Research Kiel

Centre National de la Recherche Scientifique

Universität Hamburg

Cooperative Institute for Research in Environmental Sciences

University of Colorado Boulder

Finnish Meteorological Institute

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Satellite-derived sea ice export and its impact on Arctic ice mass balance

The cryosphere (2018)

Robert Ricker Fanny Girard‐Ardhuin Thomas Krumpen Camille Lique

Abstract. Sea ice volume export through the Fram Strait represents an important freshwater input to the North Atlantic, which could in turn modulate the intensity of the thermohaline circulation. It also contributes significantly to variations in Arctic ice mass balance. We present the first estimates of winter sea ice volume export through the Fram Strait using CryoSat-2 sea ice thickness retrievals and three different ice drift products for the years 2010 to 2017. The monthly export varies between −21 and −540 km3. We find that ice drift variability is the main driver of annual and interannual ice volume export variability and that the interannual variations in the ice drift are driven by large-scale variability in the atmospheric circulation captured by the Arctic Oscillation and North Atlantic Oscillation indices. On shorter timescale, however, the seasonal cycle is also driven by the mean thickness of exported sea ice, typically peaking in March. Considering Arctic winter multi-year ice volume changes, 54 % of their variability can be explained by the variations in ice volume export through the Fram Strait.

10.5194/tc-12-3017-2018

Cite

Citations (72)

The importance of sea ice biota for the ecosystem in the northwestern Weddell Sea

Ilka Peeken Stefanie Arndt Markus Janout Thomas Krumpen Christian Haas

<p>The western Weddell Sea along the northward branch of the Weddell Gyre is a region of major outflow of various water masses, thick sea ice, and biogeochemical matter, linking the Antarctic continent to the world oceans. It features a deep shelf and the second largest ice shelf (Larsen C) in the WS, and its perennial sea ice cover is among the thickest on earth. This region is undergoing dramatic changes due to the breakup of ice shelves along the Antarctic Peninsula, which results in oceanographic conditions unprecedented in the past 10,000 years. Since this region is difficult to access, comprehensive physical and biogeochemical information is still lacking. During the interdisciplinary Weddell Sea Ice (WedIce) expedition to the northwestern Weddell Sea on board the German icebreaker RV Polarstern in spring 2019, oceanographic and biogeochemical studies were conducted together with in-situ snow and ice sampling. Most stations visited contained second- and third-year ice. Additional airborne ice-thickness surveys revealed a mean ice thicknesses between 2.6 and 5.4&#8201;m, increasing from the Antarctic Sound towards the Larsen B region. Usually rotten ice was present below a solid, ~30&#8201;cm thick surface-ice layer, however, pronounced gap layers, typical for late summer ice in the marginal ice zone, were rare. The associated high algal biomass was only found north of the Antarctic Sound. Nevertheless, diatom-dominated standing stocks of integrated sea ice algae biomass were among the highest, previously described in Antarctic waters. In contrast, despite overall high macro-nutrient concentrations in the water, the biomass of the flagellate dominated phytoplankton was negligible for primary production in the entire region. Overall, it seems that despite changing light conditions for the phytoplankton due to the loss of ice shelves, the sea ice-derived carbon represents an important control variable for higher trophic levels in the western Weddell Sea.</p>

Fast ice

Biogeochemical Cycle

10.5194/egusphere-egu2020-20152

Cite

Citations (0)

Pelagic-benthic coupling on the Laptev Sea continental slope between two contrasting years (1993 and 2012)

Christina Bienhold Frank Wenzhöfer Vibe Schourup‐Kristensen Eva‐Maria Nöthig Thomas Krumpen

The Laptev Sea plays an important role for sea ice formation in the Arctic Ocean, but very little is known about the biodiversity and ecosystem structure in this region. Sea ice dynamics in the Laptev Sea have undergone dramatic changes in the past decades, with negative trends in ice area and earlier ice retreat in summer. This in turn has led to increases in primary production observed by satellite measurements, which may result in higher carbon export fluxes from the surface to the seafloor. The effects of these changes on ecosystem structure and pelagic-benthic coupling are largely unknown. Here we investigated differences between benthic stations down the Laptev Sea continental slope (60-3400 m water depth) sampled two decades apart. Our results suggest that environmental changes in the past two decades have led to a substantial increase in phytodetritus availability at the seafloor along the entire transect, which is in contrast to hypotheses suggesting a decrease in carbon flux to the seabed as a potential result of increased zooplankton grazing in the water column. Bacterial communities play an essential role in carbon and nutrient cycling at the seafloor, and we therefore specifically investigated changes in their biomass, community structure and activity. While bacterial abundances (biomass) and overall community structure showed no systematic changes between the two years, extracellular enzymatic activities and to some extent also oxygen uptake had increased as a result of higher food availability. This indicates a direct effect of sea ice retreat and changes in primary production on the function of benthic microbial communities. Although the increase in bacterial community activity is not reflected in an increase of benthic bacterial standing stock, the response of larger benthic size classes remains unknown and would require additional comparative surveys. This study carried out in the framework of the ERC project ABYSS (no. 294757) reveals a close coupling between pelagic and benthic ecosystem processes in a region dramatically influenced by global change over a time frame of two decades.

Phytodetritus

Seafloor Spreading

Source

Cite

Citations (0)

AWI ICETrack - Antarctic and Arctic Sea Ice Monitoring and Tracking Tool

Thomas Krumpen

Purpose of this document is the documentation of the ICETrack application developed at the Alfred Wegener Institute for Polar and Marine Research. This document will give a short description of the routines and methods applied to monitor key areas and calculate sea ice trajectories using sea ice motion and concentration data from satellites and additional parameters extracted along pathways of sea ice. Some of the results of the ICETrack application are publically available for download and a technical description of the data format is given here.

Tracking (education)

Source

Cite

Citations (4)

Dynamic benthic megafaunal communities: Assessing temporal variations in structure, composition and diversity at the Arctic deep-sea observatory HAUSGARTEN between 2004 and 2015

Deep Sea Research Part I Oceanographic Research Papers (2017)

James Taylor Thomas Krumpen Thomas Soltwedel Julian Gutt Melanie Bergmann

Established in the Fram Strait in 1999, the LTER (Long-Term Ecological Research) observatory HAUSGARTEN enables us to study ecological changes on the deep Arctic seafloor. Repeated deployments of a towed camera system (Ocean Floor Observation System) along the same tracks allowed us to build a time series longer than a decade (2004–2015). Here, we present the first time-series results from a northern and the southernmost station of the observatory (N3 and S3, ~2650 m and 2350 m depth respectively) obtained via the analysis of still imagery. We assess temporal variability in community structure, megafaunal densities and diversity, and use a range of biotic factors, environmental sediment parameters and habitat features to explain the patterns observed. There were significant temporal differences in megafaunal abundances, diversity and habitat features at both stations. A particularly high increase in megafaunal abundance was recorded at N3 from 12.08 (±0.39; 2004) individuals m−2 to 35.21 (±0.97; 2007) ind. m−2 alongside a ten-fold increase in (drop-)stones. At S3, megafaunal densities peaked in 2015 (22.74±0.61 ind. m−2) following a general increase since 2004 (12.44±0.32 ind. m−2). Sea cucumbers showed particularly striking temporal differences: densities of the small holothurian Elpidia heckeri rose ten-fold from 0.31 ind. m−2 (±0.04; 2004) to 3.74 ind. m−2 (±0.14; 2015) at S3, and 24-fold from 0.09 ind. m−2 (±0.02; 2004) to 2.20 ind. m−2 (±0.10; 2015). Initially entirely absent from N3, densities of the larger holothurian Kolga hyalina peaked in 2007 (5.87±0.22 ind. m−2) and declined continuously since then. Overall diversity (γ) increased at both stations over the course of the study, however, with varying contributions of α and β diversities. Our results highlight the importance of time-series studies as megafaunal community structure is characterised by continuous changes. This indicates that epibenthic communities from the deep seafloor are reactive and dynamic, with no consistent community state. To continue to monitor them is therefore crucial in understanding natural and anthropogenic impacts in an area exposed to the effects of climate change.

Megafauna

Marine protected area

Seafloor Spreading

10.1016/j.dsr.2017.02.008

Cite

Citations (36)

The role of sea ice for plastic pollution in the Arctic

Ilka Peeken Elisa Bergami Ilaria Corsi Benedikt Hufnagl Christian Katlein

<p>Marine plastic pollution is a growing worldwide environmental concern as recent reports indicate that increasing quantities of litter disperse into secluded environments, including Polar Regions. Plastic degrades into smaller fragments under the influence of sunlight, temperature changes, mechanic abrasion and wave action resulting in small particles < 5mm called microplastics (MP). Sea ice cores, collected in the Arctic Ocean have so far revealed extremely high concentrations of very small microplastic particles, which might be transferred in the ecosystem with so far unknown consequences for the ice dependant marine food chain.&#160; Sea ice has long been recognised as a transport vehicle for any contaminates entering the Arctic Ocean from various long range and local sources. The Fram Strait is hereby both, a major inflow gateway of warm Atlantic water, with any anthropogenic imprints and the major outflow region of sea ice originating from the Siberian shelves and carried via the Transpolar Drift. The studied sea ice revealed a unique footprint of microplastic pollution, which were related to different water masses and indicating different source regions. Climate change in the Arctic include loss of sea ice, therefore, large fractions of the embedded plastic particles might be released and have an impact on living systems. By combining modeling of sea ice origin and growth, MP particle trajectories in the water column as well as MPs long-range transport via particle tracking and transport models we get first insights &#160;about the sources and pathways of MP in the Arctic Ocean and beyond and how this might affect the Arctic ecosystem.</p>

Marine debris

Plastic pollution

Marine ecosystem

10.5194/egusphere-egu21-13366

Cite

Citations (0)

Under-ice distribution, population structure and feeding ecology of polar cod Boreogadus saida in the Central Arctic Ocean

Carmen David Hauke Flores Benjamin Lange Thomas Krumpen Doreen Kohlbach

Source

Cite

Citations (0)

Marine litter on deep Arctic seafloor continues to increase and spreads to the North at the HAUSGARTEN observatory

Deep Sea Research Part I Oceanographic Research Papers (2016)

Mine Banu Tekman Thomas Krumpen Melanie Bergmann

The increased global production of plastics has been mirrored by greater accumulations of plastic litter in marine environments worldwide. Global plastic litter estimates based on field observations account only for 1% of the total volumes of plastic assumed to enter the marine ecosystem from land, raising again the question 'Where is all the plastic? '. Scant information exists on temporal trends on litter transport and litter accumulation on the deep seafloor. Here, we present the results of photographic time-series surveys indicating a strong increase in marine litter over the period of 2002–2014 at two stations of the HAUSGARTEN observatory in the Arctic (2500 m depth). Plastic accounted for the highest proportion (47%) of litter recorded at HAUSGARTEN for the whole study period. When the most southern station was considered separately, the proportion of plastic items was even higher (65%). Increasing quantities of small plastics raise concerns about fragmentation and future microplastic contamination. Analysis of litter types and sizes indicate temporal and spatial differences in the transport pathways to the deep sea for different categories of litter. Litter densities were positively correlated with the counts of ship entering harbour at Longyearbyen, the number of active fishing vessels and extent of summer sea ice. Sea ice may act as a transport vehicle for entrained litter, being released during periods of melting. The receding sea ice coverage associated with global change has opened hitherto largely inaccessible environments to humans and the impacts of tourism, industrial activities including shipping and fisheries, all of which are potential sources of marine litter.

Marine debris

Litter

Plastic pollution

Marine ecosystem

10.1016/j.dsr.2016.12.011

Cite

Citations (172)

Empirical sea ice thickness retrieval during the freeze-up period from SMOS high incident angle observations

The cryosphere (2014)

Marcus Huntemann Georg Heygster Lars Kaleschke Thomas Krumpen Marko Mäkynen

Abstract. Sea ice thickness information is important for sea ice modelling and ship operations. Here a method to detect the thickness of sea ice up to 50 cm during the freeze-up season based on high incidence angle observations of the Soil Moisture and Ocean Salinity (SMOS) satellite working at 1.4 GHz is suggested. By comparison of thermodynamic ice growth data with SMOS brightness temperatures, a high correlation to intensity and an anticorrelation to the difference between vertically and horizontally polarised brightness temperatures at incidence angles between 40 and 50° are found and used to develop an empirical retrieval algorithm sensitive to thin sea ice up to 50 cm thickness. The algorithm shows high correlation with ice thickness data from airborne measurements and reasonable ice thickness patterns for the Arctic freeze-up period.

Sea ice concentration

10.5194/tc-8-439-2014

Cite

Citations (129)

AWI ICETrack: Antarctic and Arctic Sea Ice Monitoring and Tracking Tool, Vers. 1.3

EPIC3 (2018)

Thomas Krumpen

Source

Cite

Citations (1)