WP2: Regional scale applications: benchmark studies on hotspot areas 


WP2-1 The role of deltas as carbon sinks and sources – a study of the Danube

Specific objectives:  The objective of ESR6 is to determine the influence of the Danube delta region on the flux and composition of organic carbon discharged into the Black Sea. The Danube delta represents a hotspot as it lies at the terminus of the second largest river system in Europe. The river, together with its delta, has a long history of human influence. Moreover, due to its west-to-east orientation, the river traverses diverse climate and ecological regimes before it enters the delta and ultimately empties into the Black Sea. This complex mosaic of natural and anthropogenic factors modulates the provenance, flux and composition of materials exported by the river main stem in a major manner. The ESR will conduct a series of field experiments in this delta system, analyzing the transformation and storage processes using biogeochemical and molecular marker substances.

Expected Results: a) Determination of the flux and composition of organic carbon discharged to the Black Sea by the Danube river. b) Development of a conceptual model that links these results to the upstream conditions and fluxes and to the physico-chemical setting of the delta.

Host institution: ETHZ Secondment(s):  EPFL

Primary Supervisor: Prof. Bernhard Wehrli (ETHZ); Secondary Supervisor: Prof. Tom Battin (EPFL)


WP2-2  Catchment / continent scale model for organic carbon and particle dynamics in Malaysia and Europe including the Arctic section

Specific objectives: ESR7 will develop an improved version of a catchment/continent scale model for organic carbon and particle dynamics and then apply it to two very different systems, namely, the European continent including the Arctic section, and the tropical Malaysian river catchments directly adjacent to Singapore. The open source modelling framework D-WAQ for spatially and temporally distributed hydro modelling (http://oss.deltares.nl/web/delft3d) will be used to simulate fluxes of carbon and particles over the land-ocean interface, taking into account the relevant sinks, sources and transformations. It will contribute to associated models simulating nutrient fluxes and fluxes of (emerging) pollutants. The model will be used to assess the expected changes of such fluxes as a result of climate change, land use changes, demographic changes etc. As such, it will offer many interesting applications related to the management of water resources, in river systems, estuaries and coastal waters.

Expected Results: (i) Improved generic model to simulate fluxes of carbon and particles over the land-ocean interface, (ii) parameterizations for connecting inputs and outputs of carbon for river systems.

Host institution: DELTARES Secondment(s): CRNS-IPSL

Primary Supervisor: Jos Van Gils (Deltares); Secondary Supervisor: Dr. James Orr (CNRS-IPSL)


WP2-3  The imprint of the Amazon river system on the Atlantic Ocean carbon cycle 

Specific objectives: The aim of ESR8 is to investigate the potential long-range transport and fate of organic matter injected into the Atlantic ocean by the Amazon river using a combined data analysis and modelling approach. For the data analysis part, we aim to collect and synthesize organic matter measurements taken across the Atlantic ocean in order to identify spatial pattern, temporal evolution, and chemical alterations of the matter relative to the originally injected matter. In the modelling part, we will employ an “Amazon” setup of the Regional Oceanic Modeling System (ROMS) with a telescoping grid in the Amazon mouth region, permitting us to simultaneously simulate the Amazon plume region with a full eddy-resolving resolution of 5 km and less, while resolving the entire Atlantic ocean at the same time. We plan to augment the currently coupled Biogeochemical Elemental Cycling Model (BEC) with a more finely resolved sub-module describing the fate and reactivity of different classes of organic matter, including a more detailed sediment model. With this augmented model, we will undertake a large series of simulations exploring the impact of this injected organic matter on the carbon cycle of the Atlantic Ocean, namely its air-sea CO2 exchange and the burial of organic matter. Special emphasis will be given to the investigation of the changes in this fate that may have occurred since pre- industrial times, so as to determine the anthropogenic perturbation fluxes (Regnier et al., 2013).

Expected Results: (i) Quantification of impact of Amazon river plume on Atlantic ocean air-sea CO2 exchange, nutrient cycling, and N2-fixation. (ii) Parameterization for the transport of organic carbon and nutrients from the nearshore environments to the offshore.

Host institution: ETHZ Secondment(s): MPG

Primary Supervisor: Prof. Nicolas Gruber (ETHZ); Secondary Supervisor: Dr. Tatiana Ilyina (MPG)


WP2-4  Effects of river delivery of nutrients and carbon on biogeochemistry of the Arctic Ocean under future climate change

Specific objectives: ESR9 will focus on the Arctic, where he will (1) couple a high-resolution model of ocean circulation (1/4°) including sea ice to a marine biogeochemical model; (2) test the sensitivity of simulated primary productivity and acidification to different scenarios of riverine nutrient delivery and terrestrial carbon input; and (3) project impacts from future climate change on the same factors, i.e., due to modifications in circulation, ice cover, riverine nutrient delivery, and erosion of permafrost regions.

Expected Results: Quantification of the extent to which enhanced loads of organic matter and nutrients delivered by Arctic rivers to the Arctic Ocean will alter ocean biogeochemistry, enhance air-to-sea CO2 fluxes, and exacerbate ocean acidification during the 21st century and beyond.

Host institution: CRNS-IPSL Secondment(s): ULB

Primary Supervisor: Dr. James Orr (CNRS-IPSL); Secondary Supervisor: Prof. Lei Chou and Prof. Pierre Regnier (ULB)


WP2-5  The role of Arctic sub-sea permafrost in the carbon cycle

Specific objectives: Arctic shelf regions contain large amount of organic carbon in frozen sea floor sediments left from the last glacial periods when exposed shelves were a part of the terrestrial carbon cycle. A thawing of permafrost due to shelf flooding during deglaciation and recent anthropogenic warming leads to accelerated decomposition of organic matter and release of CO2 and CH4. This response of sub-sea permafrost organic carbon provides a positive feedback to natural and anthropogenic climate change. To understand the role of sub-sea permafrost carbon in the carbon cycle, ESR10 will implement sub-sea permafrost carbon component into the MPG Earth System Model. The model will be developed based on the existing terrestrial permafrost module in MPG-ESM (Ekici et al., 2013, GMDD) using climate forcing from the Last Glacial Maximum experiments with MPG-ESM as boundary conditions. The permafrost model will be coupled to the reaction-transport model to simulate processes of degradation of organic matter in marine sediments. The coupled model will be applied in the ESM framework to quantify climatic effects of sub-sea permafrost carbon degradation in future climate projections.

Expected Results: (i) Implementation of sub-sea permafrost model into the MPG-ESM; (ii) Quantification of the potential threat posed by the release of CO2 and other greenhouse gases from sub-sea permafrost.

Host institution: MPG Secondment(s): UNIBRIS

Primary Supervisor: Dr. Victor Brovkin (MPG); Secondary Supervisor: Dr. Sandra Arndt and Prof. Andy Ridgwell (UNIVBRIS)