INTRODUCTION TO BIOSPHERE-ATMOSPHERE INTERACTIONS Timo Vesala Department of Physics Department of Forest Sciences

Carbon and water cycles in forests Wetlands Lakes and rivers Urban surface Comparison of different surfaces ICOS and databases

Carbon and water cycles in forests

Evaporation + transpiration Evapotranspiration = Evaporation + transpiration Evaporation from wet surfaces Evaporation from stomata

Decomposition Net ecosystem exchange (NEE) = - (growth – decomposition) = - NEP Photosynthesis (assimilation) Autotrophic respiration Heterotrophic respiartion Growth Decomposition

Water vapour and CO2 exchange in Hyytiälä (40-year-old pine) Evapo- Transpir. Water vapour Source CO2 Sink

Gap-filled carbon balance (Hyytiälä Scots pine) g per m2 = 10 kg per ha

Hyytiälä energy fluxes EC Launiainen et al. 2010

Weekly average NEE, pine forest, Hyytiälä S. Launiainen

Wetlands

Siikaneva fen, Southern Finland Methane (CH4)

Siikaneva fen, Southern Finland J. Rinne, P. Alekseychik

Carbon balance of Siikaneva fen, about 1/5 of that for Hyytiälä forest gC m-2 a-1 CO2 2005 - 51 CH4 2005-2006 10 Total C 41 J. Rinne

Lakes and rivers

Freshwaters in global carbon cycle Regnier et al. 2013

Lake Valkea-Kotinen, Southern Finland A. Ojala

We need method development to ensure representative data! Single lake fluxes are heterogenous in space and time! 3 We need method development to ensure representative data! 4 2 1 Examples for CH4: Diffusive flux from wind exposed central parts (Schilder et al. 2013). Shallow water with high ebullition (Bastviken et al. 2004). High plant mediated flux (Bergström et al. 2007). Hot spot zones with high sediment deposition (DelSontro et al. 2012) D. Bastviken

EC over rivers Huotari et al., JGR, 2013

Stepanenko et al. 2016

Urban surface

Measurement sites and measurements in Helsinki Built Road SMEAR III station (since 2005) QH, QE, Fc and Fp using EC technique Basic meteorology Weather radar EC campaign for N2O and CO Vegetation A.-J. Kieloaho b) Erottaja firestation (Jul 2010 – Jan 2011) QH, QE, Fc and Fp using EC Radiation , Tsurf (FMI) c) Hotel Torni(since Sep 2010 ) Tsurf The most direct way to measure directly emissions and/or sinks 24.6.2018

CO2 flux and traffic density in Kumpula Campus

Comparison of different surfaces

Comparison of 3 different surfaces Average diurnal courses in June 2009

Lake Pallasjärvi region, Finnish Lapland M. Aurela, Boreal Env. Res. 2015

Lake-forest-wetland comparison (CO2 and CH4) Kuivajärvi (Lake) SMEAR II (Scots Pine Forest) Siikaneva (Wetland) CO2 +116 -280 -51 CH4 0.2 NA 10 I.Mammarella

ICOS (Integrated Carbon Observation System) and databases

FLUXNET & ICOS FLUXNET = Global flux tower network (CO2 and water) ICOS = European network for GHG monitoring (standardized sensors, centralized data processing etc.) http://fluxnet.ornl.gov https://www.icos-ri.eu

Petrescu et al. PNAS

CH4 is offset by CO2 uptake over several centuries Increased forcing for wetland converted to cropland www.pnas.org/cgi/doi/10.1073/pnas.1416267112

You, the researhers/students, are the end-users of the data; you can also actively affect how well the data is used Remember that the whole ICOS-Europe is available Kuva: Sakari Uusitalo

Dario Papale quoted someone: “Sharing data is like sharing wife…”