Article
Oceanography
D. G. Babb, R. J. Galley, S. Kirillov, J. C. Landy, S. E. L. Howell, J. C. Stroeve, W. Meier, J. K. Ehn, D. G. Barber
Summary: The loss of multiyear sea ice in the Arctic Ocean has occurred primarily through two stepwise reductions: in 1989 and in 2006-2008. The first reduction was due to high export of multiyear ice, while the second reduction was a result of both high export and melt, as well as limited replenishment of multiyear ice. Although currently stable, reduced retention of older multiyear ice has led to a younger and thinner multiyear ice pack, potentially setting the stage for another reduction.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Environmental Sciences
Claire L. Parkinson, Nicolo E. DiGirolamo
Summary: The satellite dataset spanning 42 years from 1979 to 2020 reveals recent losses in sea ice coverage in both the Arctic and Antarctic, with the Arctic experiencing record low sea ice extents while the Antarctic has seen record lows since 2015. The data also shows that globally, every calendar month has recorded a new monthly record low within the past 5 years, indicating a rapid decline in global sea ice coverage.
REMOTE SENSING OF ENVIRONMENT
(2021)
Article
Environmental Sciences
Jong -Min Kim, Sang -Woo Kim, Byung-Ju Sohn, Hyun-Cheol Kim, Sang-Moo Lee, Young-Joo Kwon, Hoyeon Shi, Andrey V. Pnyushkov
Summary: A method was developed to estimate pan-Arctic ice draft using spaceborne passive microwave measured brightness temperatures. The method was validated using upward-looking sonar measurements and ice mass balance buoy measurements. The results showed good agreement between the estimated ice draft and the measurements, suggesting the robustness of the estimation method.
REMOTE SENSING OF ENVIRONMENT
(2023)
Article
Environmental Sciences
Seungmok Paik, Daehyun Kim, Soon-Il An, Yoo-Geun Ham
Summary: This study evaluates the projections of September sea ice area (SIA) in the Arctic using CMIP6 model simulations and taking into account Arctic sub-regions. Findings show that the models overestimate the historical SIA decreasing trend in the central Arctic but underestimate it in the surrounding shelf seas. The central Arctic, which is expected to retain sea ice for the longest period, is of particular significance in predicting the first ice-free September. Observationally-constrained projections suggest a delay of 12 years compared to raw/unconstrained projections, highlighting the importance of considering model biases in central Arctic SIA.
Article
Geosciences, Multidisciplinary
Lars Aue, Timo Vihma, Petteri Uotila, Annette Rinke
Summary: Based on the ERA5 reanalysis, this study examines the impacts of transient cyclones on sea ice concentration (SIC) in the Atlantic sector of the Arctic Ocean under New Arctic conditions (2000-2020). The results show a pattern of reduced SIC prior to and during cyclones for the entire study area, with a regional difference of increased SIC in the Barents Sea and reduced SIC in the Greenland Sea from 3 days before to 5 days after the cyclone passage. The study suggests that both thermodynamic and dynamic effects contribute to the SIC changes, particularly in the Barents Sea, compared to the Old Arctic (1979-1999).
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Oceanography
Victoria Hill, Bonnie Light, Michael Steele, Andrew Lowy Sybrandy
Summary: Novel observations were collected on the seasonal evolution of an ice algal bloom on the Chukchi shelf using two autonomous buoys. The differences in ice algae biomass under each buoy were driven by variations in snow thickness, with nutrients being limiting at the low snow site and light being limiting at the high snow site.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Geosciences, Multidisciplinary
Jinlun Zhang
Summary: The model study indicates that the slowdown in the decline of Arctic sea ice volume during 2007-2020 is a result of decreased ice export exceeding the decrease in net ice production. Thinner ice grows faster than thicker ice under freezing conditions, and benefits from enhanced ice divergence and shear.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Environmental Sciences
Xiao Zhou, Bin Wang, Fei Huang
Summary: The rapid decline of Arctic sea ice is a clear indication of global climate change. Existing evaluation metrics are insufficient, leading to the proposal of two new metrics based on sea ice thickness. Good models project the first ice-free year in the Arctic to be 2049.
ENVIRONMENTAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Jianxiang Xu, Jing-Jia Luo, Chaoxia Yuan
Summary: The Arctic is currently experiencing significant warming, which has widespread impacts on global climate. A new study suggests that Indian Ocean warming contributes to the Arctic warming through enhancing the Atlantic Meridional Overturning Circulation, leading to increased ocean heat transport from the North Atlantic to the Arctic. This results in upper ocean warming dominating the surface warming in the Arctic. Additionally, despite the net negative contribution of atmospheric heat transport, more warm air is conveyed to the Kara Seas, North Eurasia, and North America sectors, contributing to local warming.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Jingwen Zeng, Qinghua Yang, Xuewei Li, Xiaojun Yuan, Mitchell Bushuk, Dake Chen
Summary: This study investigates the potential influence of surface heat flux, cloud, and water vapor anomalies on the monthly to seasonal predictions of Arctic sea ice concentration (SIC) anomalies. The results show that models using surface fluxes, clouds, or water vapor in combination with SIC and surface sea temperature as predictors can enhance the skill in predicting Arctic September SIC when initialized in spring. This suggests that including the surface heat budget has the potential to reduce the spring barrier for Arctic SIC predictions.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
A. Sledd, T. S. L'Ecuyer, J. E. Kay, M. Steele
Summary: As Arctic sea ice retreats, the warming of the upper ocean in response to atmospheric heat fluxes is influenced by the timing of sea ice retreat and the radiative impacts of clouds. Clouds can reflect solar radiation and counteract summer warming, explaining up to 13% more variability in maximum annual sea surface temperatures under modern-day CO2 concentrations. Summer clouds have little direct effect on maximum annual SST under pre-industrial CO2 concentrations, but they become three times more sensitive when CO2 concentrations are four times pre-industrial levels.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Meteorology & Atmospheric Sciences
Yunhe Wang, Xiaojun Yuan, Haibo Bi, Yibin Ren, Yu Liang, Cuihua Li, Xiaofeng Li
Summary: The study developed a linear Markov model for the seasonal prediction of sea ice thickness (SIT). The model performed better in the cold season and up to 12 months in advance in the Arctic basin. The model skill remained high even after removing trends and the upper-ocean heat content (OHC) was found to contribute more to SIT prediction skill than other variables.
JOURNAL OF CLIMATE
(2023)
Article
Environmental Sciences
Andrew M. Chiodi, Chidong Zhang, Edward D. Cokelet, Qiong Yang, Calvin W. Mordy, Chelle L. Gentemann, Jessica N. Cross, Noah Lawrence-Slavas, Christian Meinig, Michael Steele, Don E. Harrison, Phyllis J. Stabeno, Heather M. Tabisola, Dongxiao Zhang, Eugene F. Burger, Kevin M. O'Brien, Muyin Wang
Summary: More high-quality, in situ observations of essential marine variables are needed to better understand Arctic (or Antarctic) weather, climate, and ecosystems. This study analyzes the challenges and opportunities for improving remote ice navigation strategies with uncrewed surface vehicles (USVs).
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Geosciences, Multidisciplinary
David G. Babb, Ryan J. Galley, Stephen E. L. Howell, Jack C. Landy, Julienne C. Stroeve, David G. Barber
Summary: Research shows that there has been an increasing loss of multiyear sea ice in the Arctic region in recent years. Data from 1997 to 2021 reveals that while the import of multiyear ice into the Beaufort Sea has increased, less of it now survives through the summer and is transported in the Gyre. The annual average loss of multiyear ice has quadrupled over the study period, accounting for about 33% of the annual Fram Strait multiyear ice export. The loss of multiyear ice is attributed to the ice-albedo feedback and the transition towards younger, thinner ice.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Environmental Sciences
Shengkai Zhang, Yue Xuan, Jiaxing Li, Tong Geng, Xiao Li, Feng Xiao
Summary: Arctic sea ice variations are sensitive to environmental and global changes, with freeboard and thickness being important parameters in research. Utilizing Envisat satellite altimetry data, the study estimated Arctic sea ice freeboard and variations from 2002 to 2012, showing good agreement with other freeboard estimates.
Article
Microbiology
Anabel von Jackowski, Kevin W. Becker, Matthias Wietz, Christina Bienhold, Birthe Zancker, Eva-Maria Noethig, Anja Engel
Summary: The seasonal variations in biopolymers, microbial abundance, and microbial composition in the upper 100 meters of the Fram Strait were investigated during summer and fall. The study found a shift in the autotrophic community from picoeukaryotes dominating in summer to an increase of Synechococcus by fall. Additionally, a decline in biopolymers concentrations was observed along with increasing microbial diversity and a community shift towards fewer polymer-degrading genera in fall.
ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Engineering, Environmental
Luisa Galgani, Isabel Gossmann, Barbara Scholz-Boettcher, Xiangtao Jiang, Zhanfei Liu, Lindsay Scheidemann, Cathleen Schlundt, Anja Engel
Summary: Understanding the residence times of plastic in the ocean is crucial for plastic pollution studies. Current observations show a mismatch between estimated plastic loads and actual floating plastics in the sea. Surveys of the water column are limited. Recent research proposes biofouling and degradation as the main processes for plastic removal. Plastic can affect the biogeochemical and microbial cycling of carbon and nutrients through organic matrices.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Oceanography
Luisa Galgani, Helmke Hepach, Kevin W. Becker, Anja Engel
Article
Environmental Sciences
Luisa Galgani, Eleni Tzempelikou, Ioanna Kalantzi, Anastasia Tsiola, Manolis Tsapakis, Paraskevi Pitta, Chiara Esposito, Anastasia Tsotskou, Iordanis Magiopoulos, Roberto Benavides, Tobias Steinhoff, Steven A. Loiselle
Summary: In this study, the effects of microplastic contamination on the dynamics of microbial organic matter in the sea-surface microlayer were investigated. It was found that microplastics increased biomass production and enrichment of carbohydrate-like and proteinaceous marine gel compounds. Additionally, microplastics caused a reduction in the concentration of dissolved CO2 in the underlying water by approximately 3%.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Marine & Freshwater Biology
A. E. Stuart-Lee, J. Mortensen, T. Juul-Pedersen, J. J. Middelburg, K. Soetaert, M. J. Hopwood, A. Engel, L. Meire
Summary: The release of meltwater from marine-terminating glaciers influences primary production in fjords along Greenland's coastline. However, it is still unclear how local ecosystems will adapt and how it will affect hydrography as these glaciers retreat onto land. In this study, we examined how marine- and land-terminating glaciers respectively influence bloom dynamics in two fjords in west Greenland.
ESTUARINE COASTAL AND SHELF SCIENCE
(2023)
Article
Limnology
Zhongwei Yuan, Eric P. Achterberg, Anja Engel, Zuozhu Wen, Linbin Zhou, Xunchi Zhu, Minhan Dai, Thomas J. Browning
Summary: Atmospheric aerosol deposition is an important nutrient source for primary production in the low latitude oligotrophic ocean. However, the response of phytoplankton to aerosol deposition events, in terms of magnitude and community composition, is not well understood. In this study, we investigated this using field and satellite observations in the subtropical North Atlantic. We found that wet deposition events led to a doubling of chlorophyll a and a shift in dominance from Synechococcus to Prochlorococcus, suggesting the importance of aerosol-derived nitrogen in alleviating nutrient limitation and driving rapid phytoplankton response.
LIMNOLOGY AND OCEANOGRAPHY
(2023)
Article
Multidisciplinary Sciences
Thomas J. Browning, Mak A. Saito, Shungudzemwoyo P. Garaba, Xuechao Wang, Eric P. Achterberg, C. Mark Moore, Anja Engel, Matthew R. Mcllvin, Dawn Moran, Daniela Voss, Oliver Zielinski, Alessandro Tagliabue
Summary: The impact of climate change on ocean net primary productivity is highly uncertain, with phytoplankton nutrient limitation in the low-latitude Pacific Ocean playing a crucial role, but poorly constrained by observations. We found that changes in physical forcing resulted in consistent fluctuations in the strength of equatorial Pacific iron limitation through El Nino/Southern Oscillation (ENSO) cycles, which were overestimated by a state-of-the-art climate model. Our assessment provides a powerful approach for evaluating the realism of model projections of net primary productivity to climate changes.
Article
Environmental Sciences
Jana Krause, Xunchi Zhu, Juan Hofer, Eric P. Achterberg, Anja Engel, Lorenz Meire, Alice E. Stuart-Lee, Mark J. Hopwood
Summary: Studies have shown that concentrations of dissolved lead (dPb) are consistently higher than expected along glaciated coastlines, suggesting a net release of dPb from glacier-derived sediments. The distribution of dPb across salinity gradient is unique and implies a reversible exchange between dissolved and labile particulate Pb. The net release of dPb into seawater is predominantly influenced by sediment loading, but temperature also plays a role.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2023)
Article
Oceanography
Quentin Devresse, Kevin W. Becker, Ahmad Fehmi Dilmahamod, Eva Ortega-Retuerta, Anja Engel
Summary: This study investigated the optical properties of dissolved organic matter in two cyclonic eddies in the Eastern Tropical North Atlantic (ETNA). The results revealed suitable indicators for tracing the transport of freshly produced organic matter and remineralized organic matter within offshore eddies.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Environmental Sciences
Francesco Di Grazia, Xavier Garcia, Vicenc Acuna, Oriana Llanos-Paez, Luisa Galgani, Bruna Gumiero, Steven A. Loiselle
Summary: A mass balance modeling approach and open-source plugin were developed to estimate organic carbon fluxes at sub-basin and basin scales, allowing stakeholders to explore the impacts of alternative river basin management scenarios and climate change on riverine DOC and POC dynamics.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Environmental Sciences
Anja Engel, Carolina Cisternas-Novoa, Helena Hauss, Rainer Kiko, Frederic A. C. Le Moigne
Summary: This study provides evidence of hypoxia-tolerant zooplankton feeding on sinking particles in the extensive Oxygen Minimum Zone (OMZ) off Peru, and shows significant control of carbon export by these organisms. These findings challenge the assumption of consistently efficient biological carbon pump in OMZs and highlight the importance of considering mesopelagic organisms in studying oceanic carbon sequestration.
COMMUNICATIONS EARTH & ENVIRONMENT
(2023)
Article
Ecology
Lin Yang, Jing Zhang, Anja Engel, Gui-Peng Yang
Summary: The sea-surface microlayer (SML) plays a significant role in the biogeochemical cycles of dissolved organic matter (DOM) and nutrients in marine environments. This study compared the optical properties of DOM between the sub-surface water (SSW) and the SML in the East China Sea (ECS) and the Yellow Sea (YS). The results showed that DOM was more enriched and more photochemically degraded in the SML compared to the SSW.
Review
Environmental Sciences
Tao Wang, Shiye Zha, Lixin Zhu, James C. McWilliams, Luisa Galgani, Roswati Md Amin, Ryota Nakajima, Wensheng Jiang, Mengli Chen
Summary: This Perspective discusses the occurrence, transformation, and impact of plastic waste in estuaries and highlights the importance of these processes in reducing plastic pollution. Large amounts of plastic waste enter the ocean through estuaries annually, where they accumulate, fragment, mix, and interact with organisms. The formation of microplastic hotspots in estuarine fronts could be a target for future plastic pollution mitigation efforts.
NATURE REVIEWS EARTH & ENVIRONMENT
(2022)
Article
Ecology
Theresa Barthelmess, Anja Engel
Summary: This study investigated the biogenic sources of surfactants in the sea surface microlayer (SML) and the underlying water, revealing that surfactant concentrations are closely related to the abundance of nano-phytoplankton and have a pronounced diel cycle. Surfactants are enriched in the SML and are possibly linked to microbial processing and/or photo-processing.
Article
Environmental Sciences
Manuela van Pinxteren, Tiera-Brandy Robinson, Sebastian Zeppenfeld, Xianda Gong, Enno Bahlmann, Khanneh Wadinga Fomba, Nadja Triesch, Frank Stratmann, Oliver Wurl, Anja Engel, Heike Wex, Hartmut Herrmann
Summary: Transparent exopolymer particles (TEPs) are widely found in the oceans and exhibit gel-like properties. They can enter the atmosphere as part of sea-spray aerosol. Through experiments and analysis, it was found that TEP concentrations in the atmosphere are significantly higher compared to seawater, with enrichment factors of 50. The sources of atmospheric TEPs include bubble bursting and secondary in-situ formation. Additionally, the concentration of TEPs in the atmosphere is two orders of magnitude higher than ice nucleating particles (INPs) at the same location.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2022)
