Emergent constraint on Arctic Ocean acidification in the twenty-first century
"The ongoing uptake of anthropogenic carbon by the ocean leads to ocean acidification, a process that results in a reduction in pH and in the saturation state of biogenic calcium carbonate minerals aragonite (Ωarag) and calcite (Ωcalc). Because of its naturally low Ωarag and Ωcalc (refs.), the Arctic Ocean is considered the region most susceptible to future acidification and associated ecosystem impacts. [...]"
Authors: Jens Terhaar et al.
Read the full article here.
Twenty-first century ocean warming, acidification, deoxygenation, and upper-ocean nutrient and primary production decline from CMIP6 model projections
"Anthropogenic climate change is projected to lead to ocean warming, acidification, deoxygenation, reductions in near-surface nutrients, and changes to primary production, all of which are expected to affect marine ecosystems. Here we assess projections of these drivers of environmental change over the twenty-first century from Earth system models (ESMs) participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6) that were forced under the CMIP6 Shared Socioeconomic Pathways (SSPs). [...]"
Authors: Lester Kwiatkowski et al.
Is there warming in the pipeline? A multi-model analysis of the Zero Emissions Commitment from CO2
"The Zero Emissions Commitment (ZEC) is the change in global mean temperature expected to occur following the cessation of net CO2 emissions and as such is a critical parameter for calculating the remaining carbon budget. The Zero Emissions Commitment Model Intercomparison Project (ZECMIP) was established to gain a better understanding of the potential magnitude and sign of ZEC, in addition to the processes that underlie this metric. [...]"
Authors: Andrew H. MacDougall et al.
How ocean deoxygenation enters the global agenda
A Story of the Collaborative Research Centre "Climate-Biogeochemistry Interactions in the Tropical Ocean"
After 12 years of intensive research, the Collaborative Research Centre 754 "Climate-Biogeochemical Interactions in the Tropical Ocean" ended in winter 2019 with a final symposium in Heiligenhafen.
More than 100 scientists involved in the large-scale project over its entire running time were able to gain numerous new insights into the processes of nutrient cycling, the interaction between ocean and atmosphere and the ecosystems in the tropical oceans. Above all, however, they drew attention to a phenomenon that affects the entire ocean: global oxygen loss and the spread of oxygen minimum zones in the ocean. With this video, the SFB 754 now draws a conclusion and at the same time points out the new research tasks that have resulted from its work. These include improved ocean observation and the question of how to prevent further oxygen loss.
For more information please look at www.sfb754.de
For a german version of the video please follow this link.
Additive impacts of deoxygenation and acidification threaten marine biota
"Deoxygenation in coastal and open‐ocean ecosystems rarely exists in isolation but occurs concomitantly with acidification. Here, we first combine meta‐data of experimental assessments from across the globe to investigate the potential interactive impacts of deoxygenation and acidification on a broad range of marine taxa. [...]"
Source: Global Change Biology
Authors: Alexandra Steckbauer et al.
Anammox bacteria generate energy from wastewater while taking a breath
"A type of anaerobic bacteria responsible for more than 50 percent of nitrogen loss from marine environments has been shown to use solid-state matter present outside their cells for respiration. The finding by KAUST researchers adds to knowledge of the global nitrogen cycle and has important energy-saving potential for wastewater treatment. [...]"
Operationalizing Ocean Health: Toward Integrated Research on Ocean Health and Recovery to Achieve Ocean Sustainability
"Protecting the ocean has become a major goal of international policy as human activities increasingly endanger the integrity of the ocean ecosystem, often summarized as ‘‘ocean health.’’ By and large, efforts to protect the ocean have failed because, among other things, (1) the underlying socio-ecological pathways have not been properly considered, and (2) the concept of ocean health has been ill defined. Collectively, this prevents an adequate societal response as to how ocean ecosystems and their vital functions for human societies can be protected and restored. We review the confusion surrounding the term ‘‘ocean health’’ and suggest an operational ocean-health framework in line with the concept of strong sustainability. [...]"
Source: One Earth
Authors: Andrea Franke et al.
Slightly smaller-than-average 2020 ‘dead zone’ predicted for Chesapeake Bay
"Researchers from the University of Michigan, the Chesapeake Bay Program and the University of Maryland Center for Environmental Science are forecasting a slightly smaller-than-average Chesapeake Bay “dead zone” this year, due to reduced rainfall and less nutrient-rich runoff flowing into the bay from the watershed this spring. [...]"
Source: University of Michigan
Larger-than-average ‘dead zone’ expected for Gulf of Mexico
"NOAA scientists are forecasting this summer’s Gulf of Mexico hypoxic area or “dead zone” – an area of low to no oxygen that can kill fish and other marine life – to be approximately 6,700 square miles, larger than the long-term average measured size of 5,387 square miles but substantially less than the record of 8,776 square miles set in 2017. The annual prediction is based on U.S. Geological Survey river-flow and nutrient data. [...]"
Spatial variations in sedimentary N-transformation rates in the North Sea (German Bight)
"In this study, we investigate the role of sedimentary N cycling in the southern North Sea. We present a budget of ammonification, nitrification and sedimentary NO−3 consumption and denitrification in contrasting sediment types of the German Bight (southern North Sea), including novel net ammonification rates. [...]"
Authors: Alexander Bratek et al.