Mika Aurela
A5031651964- Peatlands and Wetlands Ecology
- Atmospheric and Environmental Gas Dynamics
- Remote Sensing and LiDAR Applications
- Cryospheric studies and observations
- Plant Water Relations and Carbon Dynamics
- Climate change and permafrost
- Remote Sensing in Agriculture
- Climate variability and models
- Fire effects on ecosystems
- Botany and Plant Ecology Studies
- Satellite Image Processing and Photogrammetry
- Coastal wetland ecosystem dynamics
- Arctic and Antarctic ice dynamics
- Geology and Paleoclimatology Research
- Hydrology and Watershed Management Studies
- Atmospheric chemistry and aerosols
- Methane Hydrates and Related Phenomena
- Tree-ring climate responses
- Remote Sensing and Land Use
- Scientific Research and Discoveries
- Forest ecology and management
- Plant responses to elevated CO2
- Science and Climate Studies
- Infrared Target Detection Methodologies
- Advanced Measurement and Detection Methods
Finnish Meteorological Institute
2016-2025
Polar Knowledge Canada
2024
University of Helsinki
2005-2020
Google (United States)
2020
Roshydromet
2018
Commonwealth Scientific and Industrial Research Organisation
2009
Stockholm University
2002
Environment and Climate Change Canada
2002
Quality Research
1998
Abstract The FLUXNET2015 dataset provides ecosystem-scale data on CO 2 , water, and energy exchange between the biosphere atmosphere, other meteorological biological measurements, from 212 sites around globe (over 1500 site-years, up to including year 2014). These sites, independently managed operated, voluntarily contributed their create global datasets. Data were quality controlled processed using uniform methods, improve consistency intercomparability across sites. is already being used...
Abstract Many wetland ecosystems such as peatlands and wet tundra hold large amounts of organic carbon (C) in their soils, are thus important the terrestrial C cycle. We have synthesized data on dioxide (CO 2 ) exchange obtained from eddy covariance measurements 12 sites, covering 1–7 years at each site, across Europe North America, ranging ombrotrophic minerotrophic to ecosystems, spanning temperate arctic climate zones. The average summertime net ecosystem CO (NEE) was highly variable...
Rapidly rising temperatures in the Arctic might cause a greater release of greenhouse gases (GHGs) to atmosphere. To study effect warming on GHG dynamics, we deployed open-top chambers subarctic tundra site Northeast European Russia. We determined carbon dioxide (CO2 ), methane (CH4 and nitrous oxide (N2 O) fluxes as well concentration those gases, inorganic nitrogen (N) dissolved organic (DOC) along soil profile. Studied surfaces ranged from mineral soils vegetated unvegetated areas. As...
Significance Wetlands are unique ecosystems because they in general sinks for carbon dioxide and sources of methane. Their climate footprint therefore depends on the relative sign magnitude land–atmosphere exchange these two major greenhouse gases. This work presents a synthesis simultaneous measurements methane fluxes to assess radiative forcing natural wetlands converted agricultural or forested land. The net impact is strongly dependent whether managed. Here we show that conversion...
Abstract. Methane (CH4) emissions from natural landscapes constitute roughly half of global CH4 contributions to the atmosphere, yet large uncertainties remain in absolute magnitude and seasonality emission quantities drivers. Eddy covariance (EC) measurements flux are ideal for constraining ecosystem-scale due quasi-continuous high-temporal-resolution measurements, coincident carbon dioxide, water, energy lack ecosystem disturbance, increased availability datasets over last decade. Here, we...
Abstract While wetlands are the largest natural source of methane (CH 4 ) to atmosphere, they represent a large uncertainty in global CH budget due complex biogeochemical controls on dynamics. Here we present, our knowledge, first multi‐site synthesis how predictors fluxes (FCH4) freshwater vary across wetland types at diel, multiday (synoptic), and seasonal time scales. We used several statistical approaches (correlation analysis, generalized additive modeling, mutual information, random...
Arctic-boreal landscapes are experiencing profound warming, along with changes in ecosystem moisture status and disturbance from fire. This region is of global importance terms carbon feedbacks to climate, yet the sign (sink or source) magnitude budget within recent years remains highly uncertain. Here, we provide new estimates (2003-2015) vegetation gross primary productivity (GPP), respiration (Reco ), net CO2 exchange (NEE; Reco - GPP), terrestrial methane (CH4 ) emissions for zone using...
Climate change mitigation requires, besides reductions in greenhouse gas emissions, actions to increase carbon sinks terrestrial ecosystems. A key measurement method for quantifying such and calibrating models is the eddy covariance technique, but it requires imputation, or gap-filling, of missing data determination annual balances Previous comparisons gap-filling methods have concluded that commonly used methods, as marginal distribution sampling (MDS), do not a significant impact on...
Abstract The timing of the commencement photosynthesis ( P * ) in spring is an important determinant growing‐season length and thus productivity boreal forests. Although controlled experiments have shed light on environmental mechanisms triggering release from photoinhibition after winter, quantitative research for trees growing naturally field scarce. In this study, we investigated cues initiating recovery coniferous forest ecosystems under conditions. We used meteorological data...
The northern wetlands are one of the major sources methane into atmosphere. We measured annual emission from a boreal minerotrophic fen, Siikaneva, by eddy covariance method. average wintertime emissions were below 1 mg m-2 h-1, and summertime about 3.5 h-1. water table depth did have any clear effect on emissions. During most year depended temperature peat table. However, during high late summer was independent as well. No diurnal cycle flux found. total Siikaneva site 12.6 g m-2. snow free...
The first continuous multi‐year measurements of the CO 2 exchange between a subarctic fen and atmosphere were conducted at Kaamanen in northern Finland (69°N). According to our six‐year data‐set, is presently sink atmospheric with mean rate −22 g C m −2 yr −1 . interannual variation balances originates almost completely from variations during snow‐free period, but efflux wintertime constitutes significant part annual balance. snow melt timing most important single determinant carbon In...
The annual balance of CO 2 was measured on a subarctic flark fen located in northern Finland (69°08′N, 27°17′E). Measurements were conducted using the micrometeorological eddy covariance method during period from April 1998 to 1999. Special emphasis put importance wintertime as component budget. fluxes observed winter relatively small (0.0055 mg m −2 s −1 ), but due long duration snow cover period, they play an important role . efflux coldest periods, when soil surface temperatures fell...
Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric dioxide because potential accelerating effects positive climate–carbon cycle feedbacks. However, directly observed CO2 with atmosphere across biomes continents are lacking. Here we present data describing net ecosystem (NEE) factors as measured using eddy covariance method at 125 unique sites in various over six a total 559 site-years. We find that...
The aim of this study was to asses how the variability in carbon gas exchange at plant community scale affected C estimates ecosystem a fen that homogeneous micrometeorological sense, is, had an even surface topography and cover. CO2 CH4 measured with chambers eddy covariance (EC) technique. Community-scale measurements were upscaled by weighting community-specific area community. All communities net sinks sources during growing season, but production (NEP) emissions ranged from 21 190 g...
Eddy covariance (EC) measurements of net ecosystem CO2 exchange (NEE) were conducted on a boreal sedge fen in southern Finland (61°50'N, 24.12'E) during 1.5-yr period covering two summers 2004.2005. The EC data complemented by chamber measurements, which enabled the partition daytime NEE into respiration and photosynthesis. A special emphasis was put hydrometeorological responses drought July 2005. mean efflux 0.009 mg m-2 s-1 observed mid-winter (January.February), while night-time Julys...
Significance We quantified a 36-y trend of advanced spring recovery carbon uptake across the northern hemisphere boreal evergreen forest zone. From this trend, we estimated corresponding change in global gross primary production (GPP) and further magnitude spatiotemporal variability GPP, that is, cross-photosynthetic by forest. Our main findings are following: ( i ) developed proxy indicator for from situ flux data on CO 2 exchange recent satellite snowmelt products ii established relation...
Abstract We have analyzed decade‐long methane flux data set from a boreal fen, Siikaneva, together with on environmental parameters and carbon dioxide exchange. The showed seasonal cycle but no systematic diel cycle. highest fluxes were observed in July–August average value of 73 nmol m −2 s −1 . Wintertime small positive, January–March 6.7 Daily emission correlated best peat temperatures at 20–35 cm depths. second correlation was gross primary production (GPP). correspondence between...
Abstract. Four years of continuous aerosol number size distribution measurements from the Arctic Climate Observatory in Tiksi, Russia, are analyzed. Tiksi is located a region where situ information on particle properties has not been previously available. Particle distributions were measured with differential mobility sizer (in diameter range 7–500 nm) and an aerodynamic 0.5–10 μm). Source effects modal features number, mass concentrations presented for different seasons. The monthly median...
Abstract. Natural wetlands constitute the largest and most uncertain source of methane (CH4) to atmosphere a large fraction them are found in northern latitudes. These emissions typically estimated using process (“bottom-up”) or inversion (“top-down”) models. However, estimates from these two types models not independent each other since top-down usually rely on priori estimation obtained with Hence, spatially explicit validation data needed. Here we utilize random forest (RF)...
Abstract. Since the advancement in CH4 gas analyser technology and its applicability to eddy covariance flux measurements, monitoring of emissions is becoming more widespread. In order accurately determine greenhouse balance, high quality gap-free data required. Currently there still no consensus on gap-filling methods, methods applied are study-dependent often carried out low resolution, daily data. current study, we artificial neural networks six distinctively different time series from...
[1] Basal ecosystem respiration rate (BR), the at a given temperature, is common and important parameter in empirical models for quantifying (ER) globally. Numerous studies have indicated that BR varies space. However, many ER still use global constant largely due to lack of functional description BR. In this study, we redefined be mean annual temperature. To test validity concept, conducted synthesis analysis using 276 site-years eddy covariance data, from 79 research sites located...
Abstract Commercially available fast-response analysers for methane (CH 4 ) and nitrous oxide (N 2 O) have recently become more sensitive, robust easier to operate. This has made their application long-term flux measurements with the eddy-covariance method feasible. Unlike carbon dioxide (CO water vapour (H O), there so far been no guidelines on how optimise standardise measurements. paper reviews state-of-the-art of various steps discusses aspects such as instrument selection, setup...