A5081177756- Plant Water Relations and Carbon Dynamics
- Atmospheric chemistry and aerosols
- Wind and Air Flow Studies
- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Meteorological Phenomena and Simulations
- Fire effects on ecosystems
- Air Quality and Health Impacts
- Aeolian processes and effects
- Atmospheric aerosols and clouds
- Fluid Dynamics and Turbulent Flows
- Tree Root and Stability Studies
- Forest ecology and management
- Wind Energy Research and Development
- Plant responses to elevated CO2
- Vehicle emissions and performance
- Forest Biomass Utilization and Management
- Radioactive contamination and transfer
- Hydrology and Sediment Transport Processes
- Peatlands and Wetlands Ecology
- Climate variability and models
- Remote Sensing and LiDAR Applications
- Air Quality Monitoring and Forecasting
- Landslides and related hazards
- Geology and Paleoclimatology Research
Technical University of Denmark
2011-2025
Severtsov Institute of Ecology and Evolution
1997-2024
Roskilde University
2013
National Institute of Meteorology
2008-2011
University of Helsinki
2004-2009
Centre for Sustainable Energy
2008
Max Planck Institute for Biogeochemistry
2001-2004
Max Planck Society
2001-2004
Summary Based on review and original data, this synthesis investigates carbon pools fluxes of Siberian European forests (600 300 million ha, respectively). We examine the productivity ecosystems, expressed as positive rate when amount in ecosystem increases, while (following micrometeorological convention) downward from atmosphere to vegetation (NEE = Net Ecosystem Exchange) are negative numbers. Productivity parameters Primary (NPP=whole plant growth), (NEP CO 2 assimilation minus...
Abstract. Aerosol physical and chemical properties trace gas concentrations were measured during the QUEST field campaign in March–April 2003, Hyytiälä, Finland. Our aim was to understand role of oxidation products VOC's such as mono- sesquiterpenes atmospheric nucleation events. Particle compositions using Aerodyne Mass Spectrometer, aerosol samples collected with low-pressure impactors a high volume sampler analysed number techniques. The results indicate that after new particle formation,...
Long-term measurements of fluxes sensible heat (H), latent (LE) and carbon dioxide (Fc) were made from December 2005 to August 2006 over an urban landscape in Helsinki, Finland using the direct micrometeorological eddy covariance technique. Three distinguished sectors land-use cover (vegetation, roads buildings) allowed comparisons different surfaces. The normalized standard deviation wind scalars as a function atmospheric stability typical for rough surfaces, turbulence spectra cospectra....
Long‐term measurements of sensible and latent heat carbon dioxide fluxes were performed over a boreal lake in southern Finland using the direct micrometeorological eddy covariance (EC) technique. The water column was sampled weekly for dissolved dioxide, CO 2 flux estimated also applying concentration gradient method. Temperature oxygen profiles measured twice week. covered one full open‐water period from April to November 2003, it is longest continuous record ever by EC. H positive, that...
Abstract. Chemistry in the atmospheric boundary layer (ABL) is controlled by complex processes of surface fluxes, flow, turbulent transport, and chemical reactions. We present a new model SOSA (model to simulate concentration organic vapours sulphuric acid) attempt reconstruct emissions, transport chemistry ABL above vegetation canopy using tower measurements from SMEAR II at Hyytiälä, Finland available soundings data neighbouring meteorological stations. Using sounding for upper condition...
Abstract. Using the 1-D atmospheric chemistry transport model SOSAA, we have investigated reactivity of a boreal forest ecosystem during HUMPPA-COPEC-10 campaign (summer 2010, at SMEAR~II in southern Finland). For very first time, present vertically resolved simulations NO3 and O3 (R) together with modelled measured OH. We find that OH is most reactive oxidant (R ∼ 3 s-1) followed by 0.07 2 × 10-5s-1). The missing was found to be large accordance measurements (∼ 65%) as would expected from...
We present a numerical model capable of computing the physical processes within both plant canopy and planetary boundary layer (PBL), offering potential benefit wide applicability due to reduced computational requirements. The model, named SCADIS (scalar distribution), synthesizes existing knowledge surface turbulence vegetative was tested using several data sets from European part Russia Siberia obtained as EUROSIBERIAN CARBONFLUX project. Despite simplifications which were necessary in...
Abstract. We have modelled the total atmospheric OH-reactivity in a boreal forest and investigated individual contributions from gas phase inorganic species, isoprene, monoterpenes, methane along with other important VOCs. Daily seasonal variation for year 2008 was examined as well vertical profile. used SOSA; one dimensional chemistry-transport model (Boy et al., 2011a) together measurements Hyytiälä, SMEAR II station, Southern Finland, conducted August 2008. Model simulations only account...
To investigate oasis-desert microclimate effects, we performed a series of numerical simulations in an idealized system based on improved computational fluid dynamics (CFD) model for simulating atmospheric boundary layer flows, air temperature and humidity. Numerical were designed the hydrometeorological observations obtained during HiWATER-MUSOEXE (Heihe Watershed Allied Telemetry Experimental Research, Multi-Scale Observation Experiment Evapotranspiration over heterogeneous land surfaces)...
During the pre-release and early phase of an accidental release radionuclides into atmosphere there are few or no measurements, dispersion models used to assess consequences assist in determining appropriate countermeasures. However, uncertainties high during this it is important characterise these and, if possible, include them any modelling. In paper we examine three sources uncertainty modelling; source term, meteorological information drive model intrinsic within model. We also explore...
ABSTRACT Hybrid power plants (HPPs) combining multiple generation and/or storage sources behind a single connection point are becoming popular due to their capability provide additional value for both plant owners and systems compared individual technology renewable plants. However, the research on HPPs is still in nascent stage. This article comprehensively overviews utility‐scale (power ranging from hundreds of MW GW scale). It primarily addresses that combine such as wind solar (PV...
On July 15 and 16, 1996, profiles of temperature, water vapor, carbon dioxide concentration, its isotopic composition were made within above the convective boundary layer (CBL), near village Zotino in central Siberia (60°N, 89°E). both days CBL grew to a height around 1000 m at midday after which little further growth was observed. This despite high rates sensible heat flux into from predominantly coniferous vegetation below attributable subsidence velocity. For all flights, marked...
Abstract. Long-term eddy covariance particle number flux measurements for the diameter range 6 nm to 5 μm were performed at SMEAR III station over an urban area in Helsinki, Finland. The heterogeneity of measurement location allowed us study effect different land-use classes wind directions on measured fluxes. fluxes highest direction a local road weekdays, with daytime median 0.8×109 m−2 s−1. showed clear dependence traffic rates and mixing conditions boundary layer. footprint was estimated...
[1] Accurate quantification of evaporation from small water storages is essential for management and planning, particularly in water-scarce regions. In order to ascertain suitable methods direct measurement bodies, this study presents a comparison eddy covariance scintillometry measurements reservoir southeast Queensland, Australia. The work presented expands on short by McJannet et al. (2011) include comparisons scintillometer-derived predictions surface energy fluxes under wide range...
In July 1993, we measured leaf conductance, carbon dioxide (CO(2)) assimilation, and transpiration in a Larix gmelinii (Rupr.) Rupr. ex Kuzen forest eastern Siberia. At the CO(2) concentration of ambient air, maximum values (mean 10 highest values) for conductance water vapor were 10.1 micro mol m(-2) s(-1), 3.9 mmol s(-1) 365 respectively. The corresponding mean values, which much lower than 2.7 1.0 56 s(-1). similar to those Vaccinium species herb layer. large differences between actual...
The climate system and terrestrial ecosystems interact as they change. In northern Eurasia these interactions are especially strong, span all spatial timescales, thus have become the subject of an international program: Northern Earth Science Partnership Initiative (NEESPI). Without trying to cover areas interactions, this paper introduces three examples principal micrometeorological, mesometeorological subcontinental feedbacks that control climate–terrestrial ecosystem in boreal zone...