Current projects

Here I have some information of ongoing projects.

ARIMETH (ERC Starting Grant): A mechanistic understanding of Arctic river methane emissions

Collaborators: Many

I just got funded an ERC Starting grant (1.9M €) to study methane emissions from Arctic rivers. The goal is to study the methane dynamics in Arctic rivers from an ecosystem ecology perspective, and develop a model to predict river methane emissions across the Arctic.

There are several positions available, brief description below. The official ads will be published in January 2025 but you’re encouraged to contact me interested:

PhD student 1: Linking aerobic and anaerobic metabolism in Arctic stream networks

River networks receive large amounts of carbon from terrestrial ecosystems, which is processed and “respired” into carbon dioxide (CO2) and methane (CH4), the most important greenhouse gases. Norther rivers emit large amounts of CO2 and CH4 to the atmosphere, but the main controls on the production and delivery of CO2 and CH4 is still unclear. Ongoing climate change is particularly severe at high latitudes and has the potential to massively increase the delivery of carbon to river networks and emissions to the atmosphere.

This PhD project will investigate carbon cycling in Arctic river networks, with a focus on CH4, and an emphasis on the groundwater-surface water connectivity. We will combine novel sensors, remote sensing products, microbial studies and large-scale isotopic analysis to unravel how the anaerobic carbon cycle shapes CO2 and CH4 dynamics in Arctic rivers. The project is part of an ERC Starting grant focused on Arctic CH4 emissions, which provides generous resources and important synergies with other researchers in the group performing modelling research on the same topic. The empirical part of the project will largely take in the Abisko Research Station, which is accessible by train from Umeå, and where stays of several months during 2-3 years are expected. Start date should be first half of 2025, but is flexible.

Position is fully funded for four years, and can be extended up to five years if the person does some teaching. Co-advisors will be Ylva Sjöberg and Jan Karlsson (Umeå University).

PhD student 2: Modelling river carbon cycling in northern river networks.

River networks receive large amounts of carbon from terrestrial ecosystems, which is processed and “respired” into carbon dioxide (CO2) and methane (CH4), the most important greenhouse gases. Rivers emit large amounts of CO2 and CH4 to the atmosphere, but future projections of river CO2 and CH4 emissions are lacking because we lack predictive models. Ongoing climate change is particularly severe at high latitudes and has the potential to massively increase the delivery of carbon to river networks and emissions to the atmosphere.

This PhD project will explore conceptually patterns of river carbon processing, and develop reaction-transport models of carbon in river networks, both at fine-spatial resolution within small watersheds as well as at a pan-Arctic scale. The models will be used to predict future river emissions of CO2 and CH4, under distinct climate scenarios.

The project will use models currently being developed in the research group, linking aquatic metabolism and greenhouse gas emissions in river networks. The project will interface two distinct communities, on one hand will be part of the empirical component in Arctic biogeochemistry in Abisko, and on the other hand will be part of a Research school in IceLab focusing on “System stress responses” with a larger cohort of PhDs that will jointly explore modelling approaches (across scientific disciplines).

Position is fully funded for four years, and can be extended up to five years if the person does some teaching. Co-advisors will be Martin Roswall and Ryan Sponseller (Umeå University).

Postdoc 1: Links between permafrost thaw and CH4 emissions from streams

The goal here will be to explore how permafrost thaw exports carbon to stream networks, and to quantify how old the C is in the different carbon components. The hypothesis is that because methanogenesis occurs in the deeper layers in the soils compared to respiration, CH4 is substantially older than the CO2 produced in soils, and this should be reflected in the recipient aquatic systems. This project involves fieldwork in Alaska, Canada, Greenland, Norway and Sweden, and measurements of 14C composition in CO2, CH4 and DOC. Start also in 2025 but is flexible. Position is for 2 years but can be prolonged to a third year.

Postdoc 2: Exploring how temperature impacts anaerobic and aerobic processes in northern streams

This project will focus on how temperature and the supply of organic matter from land will impact metabolic processes and the release of greenhouse gasses to the atmosphere. The goal is to be holistic, to look at multiple metabolic pathways, with an emphasis in methane cycling, and at a whole ecosystem scale. So to work at a whole-ecosystem scale we will need to warm up a whole stream, which we are starting to design. The work will take place in the Krycklan catchment study, a flagship infrastructure in northern catchments, which is close to Umeå. Start is flexible.

Research engineer: (4 years)

The person here would provide support the field and laboratory aspects of the project, it would involve carrying out sampling campaigns, coordinating experiments, leading field expeditions across the arctic, laboratory work helping with the analysis, and building DIY custom-made chambers with sensors. There is money for a 4-year position, starting in 2025.

Timeline 2025 – 2029

Summary figure of the experimental part of ARIMETH

Top-down controls from Arctic terrestrial herbivores on aquatic biogeochemistry

Collaborators: Ryan Sponseller, Johan Olofsson, Matthias Siewert (Umeå University), Karin Nilsson (Swedish University of Agricultural Sciences)

Here we have been exploring how major Arctic terrestrial hervivores (reindeers, rodents, moths) have the capacity to propagate biogeochemical effects from land to recipient aquatic systems. We are focused on two aspects: one is how the fine-scale landscape use of herbivores overlaps with hydrological connectivity in the Arctic. For example, rodents such as lemmings and voles have a winter activity pattern characterized by making nests in snowbeds, which provide large insulation. The second aspect is to combine monitoring data, large-scale herbivore exclosures, and remote sensing tools to detect biogeochemical signals in aquatic systems that can be related to herbivory in terrestrial ecosystems. For example, rodent and moth outbreaks have a profound impact in terrestrial ecosystems by supressing primary productivity and generating litter, and we are able to detect this signal in the recipient streams and lakes.

Timeline 2020 – 2024

Example of two adjacent streams in northern Norway, separated by a large-scale fence that causes high grazing intensity by reindeers in one of the sides

A reaction-transport model for Carbon processing in stream networks across land productivity gradients

Collaborators: Susana Bernal (CEAB-CSIC, Spain), Hjalmar Laudon (SLU, Sweden)

In this project we are developing a whole-stream network transport-reaction model for carbon, that captures the inputs, transport and processing of carbon within the stream networks. The project has currently two parts, first one is to use the model to explore how multiple physical, chemical and biological processes affect the temporal patterns and coupling of O₂ and CO₂ in rivers. The second part consists in applying the model in space, in two fully forested catchments but with very dramatic differences in climate and in sources of organic carbon (Regàs in Spain is dominated by litter fall, Krycklan in Sweden is dominated by dissolved organic Carbon).

This project is funded by a mobility grant from the Swedish Research Council, where I have the opportunity to do a research stay in the Blanes Centre of Advanced Research (CSIC, Spain).

Timeline 2022 – 2025

Conceptual represention of the model we are working on, an a picture by Emma Lannergård during the sampling in 2023

Archive of some past projects

Global river methane emissions

Collaborators: Emily Stanley (University of Wisconsin-Madison), Ryan Sponseller (Umeå University), Luke Loken (USGS), Nora Casson (University of Winnipeg), Samantha Oliver (USGS), Peter Raymond (Yale University), Shaoda Liu (Peking Normal University), Giuseppe Amatulli (Yale University)

In this project, led by E. Stanley, we have been compiling a large database of river methane concentrations and fluxes, published in Earth System Science Data.

We are also been exploring how this database can be used to answer questions on methane processes in river ecosystems. The result is a global assessment of river methane emissions, out in Nature.

Timeline: 2020 – 2023