Mika Aurela

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Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate–carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO 2 exchange with the atmosphere(More)
[1] Basal ecosystem respiration rate (BR), the ecosystem respiration rate at a given temperature, is a common and important parameter in empirical models for quantifying ecosystem respiration (ER) globally. Numerous studies have indicated that BR varies in space. However, many empirical ER models still use a global constant BR largely due to the lack of a(More)
Significant climate risks are associated with a positive carbon-temperature feedback in northern latitude carbon-rich ecosystems, making an accurate analysis of human impacts on the net greenhouse gas balance of wetlands a priority. Here, we provide a coherent assessment of the climate footprint of a network of wetland sites based on simultaneous and(More)
The timing of the disappearance of the snow cover in spring, or snow melt day (SMD), is a key parameter controlling the carbon dioxide balance between the northern mire and heath ecosystems and the atmosphere. We present a simple method for the determination of the SMD using a satellite-based surface albedo product (SAL). The method is based on the local(More)
and climatic controls on interannual variability in carbon fluxes across terrestrial ecosystems" (2015). Keywords: Net ecosystem exchange Interannual variability Biotic effect Climatic effect Relative importance Climatic stress a b s t r a c t Interannual variability (IAV, represented by standard deviation) in net ecosystem exchange of CO 2 (NEE) is mainly(More)
The TROICA-9 expedition (Trans-Siberian Observations Into the Chemistry of the Atmosphere) was carried out at the Trans-Siberian railway between Moscow and Vladivostok in October 2005. Measurements of aerosol physical and chemical properties were made from an observatory carriage connected to a passenger train. Black carbon (BC) concentrations in fine(More)
This paper represents the results of one year long measurement period of the size distributions of water-soluble organic carbon (WSOC), inorganic ions and gravimetric mass of particulate matter. Measurements were done at an urban background station (SMEAR III) by using a micro-orifice uniform deposit impactor (MOUDI). The site is located in northern(More)
Aerosol chemical composition was measured over the Atlantic Ocean in November– December 1999 and at the Finnish Antarctic research station Aboa in January 2000. The concentrations of all anthropogenic aerosol compounds decreased clearly from north to south. An anthropogenic influence was still evident in the middle of the trop-5 ical South Atlantic,(More)
The possibility for the extraction of spring phenological events of boreal evergreen forest from Moderate Resolution Imaging Spectrometer (MODIS) time-series was evaluated in this study. The beginning of the photosynthetically active period, determined from CO 2 fluxes measured with the eddy covariance method, was used as primary reference for the onset of(More)