Arctic Biosphere-Atmosphere Coupling across multiple Scales (ABACUS).

Lead Research Organisation: Durham University
Department Name: Biological and Biomedical Sciences


Climate warming is resulting from disruption of the global carbon cycle. The Arctic is already warming significantly, and warming is expected to be fastest and greatest at high latitudes, 4-7 degrees C over the next century. However, there are complex links among climate, the carbon cycle and the global energy balance which mean that the details of such global changes remain poorly understood. We propose a major, linked programme of plant and soil studies, atmospheric measurements, aircraft and satellite observations, and modelling, to improve our understanding of the response of the arctic terrestrial biosphere to climate change. Our overall aim is to determine what controls the temporal and spatial variability of carbon, water and energy exchange between arctic ecosystems and the atmosphere. Our field sites are based at Abisko, Sweden (with one focus area in dry tundra, the other in birch forest), and Kevo, Finland (with one focus on wet tundra, the other on dry tundra). At Kevo and Abisko both satellite imagery and aircraft flights will encompass an area of 10 km x 10 km, including both focus areas. The project has eight work-packages: WP1 Studies on plant allocation and phenology, and respiration-production ratios for major community types (via harvests, root measurement and isotope tracer experiments). WP2 Turnover of litter, soil organic matter (SOM), landscape distribution of soils (via soil surveys, isotope labelled litter, bomb C dating to determine SOM age), CH4 emissions. WP3 Chamber measurements of C and water exchanges from soils and vegetation at fine scales (a resolution of ~1m). WP4 Continuous tower measurements of CO2 and water exchange between the soils/vegetation and the atmosphere at scales of ~100 m, and records of snow depth, soil moisture and climate. WP5 Aircraft measurements over the two study regions, recording CO2 and water exchanges and images of the land surface and profiles of CH4. These measurements will extend over areas of many km squared. WP6 Earth Observation via satellites. We will link observations from several satellite instruments to measurements of plant cover recorded in field campaigns. WP7 We use models to connect the information connected at different time and space scales. The models represent our best understanding of the system, and we check and improve our understanding against independent observations, whether from chambers, towers, aircraft or satellites. We test whether we can understand the data from satellites and aircraft in terms of the detail recorded at the chambers and towers and with the WP1 and WP2 experiments. WP8 We will run an international workshop to share our ideas with colleagues from around the world. We will train post-graduates with a summer-school based around field measurement, and provide undergraduates with summer field experience.
Description Objective: To test whether regional estimates of the C cycle derived from atmospheric sampling by aircraft are consistent with upscaled measurements from the land surface
Objective: To determine regional budgets of net CH4 emissions and their repose to the hydrological drivers.
Chamber measurements were used to calculate net CH4 fluxes in the main plant communities found at our Kevo field site in Finland, an area of mires and woodlands. These fluxes were then scaled up to the landscape (10 x 10 km) based on the results of an intercomparison between high-resolution aerial photography provided by the Edinburgh aircraft and earth observation data. In addition, based on plant community coverage within the tower footprint, these fluxes were compared with those calculated by eddy covariance instrumentation set up on a mire (additional NERC funding attracted to this project). As expected, mires were important point sources of CH4 but other landscape units, including mountain birch forest, oxidised a significant proportion of the CH4 released. In determining whether these landscapes are significant CH4 sources it is therefore essential to classify correctly the land-cover.
Outcome: A unique multi-scale comparison of CH4 fluxes over an arctic mire.
Exploitation Route Supporting the development of methane modelling capacity
Sectors Environment

Description To support public outreach activities, at science exhibitions and festivals, on climate change at high latitudes
First Year Of Impact 2009
Sector Education
Impact Types Societal