Soil Chamber Calibration Campaign 2008
Duration: 17/8/2008 - 3/10/2008
Location: Hyytiälä forestry field stationhttp://www.mm.helsinki.fi/hyytiala/english/eng_index.htm
Organizing team: Mari Pihlatie1, Jesper Riis Christiansen2, Jukka Pumpanen3
1Department of Physics, Division of Atmospheric Sciences and Geophysics, University of Helsinki,Finland, 2Department of Forest & Landscape Ecology, Forest & Landscape Denmark, University of Copenhagen,Denmark, 3Department of Forest Ecology, University of Helsinki,Finland
New 1: The campaign is fully booked except for the week 35 (place for one small chamber).
New 2: Workshop on Comparison of static chambers to measure N2O, CH4 and CO2 fluxes from soils in Denmark*,* 15 - 17 December 2008
Background
In many environmental studies the soil fluxes of the greenhouse gasses (GHG) nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) are measured by closed static chambers. Due to large spatial and temporal variability of GHG production and consumption in soils, a large number of replicate chambers are often required. Static chambers can be constructed using inexpensive materials, enabling the researcher to install a large number of replicate chambers. Dependent on the chamber design the magnitude of impact in the surroundings vary, and is difficult to assess in quantitative terms. To obtain information on the differences between static chambers we will organize a chamber calibration campaign. The purpose of the campaign is to test different types of static chambers for N2O, CH4 and CO2 fluxes under controlled conditions using a constant flux calibration tank. The overall aims of the campaign are to quantitatively assess the uncertainties and errors related to static chamber measurements, and to bring together and discuss these problems with researchers working in the field of GHG fluxes from different ecosystems.
The overall aim of the measurement campaign is to improve measurement quality in gas fluxes of N2O, CH4 and CO2 from soils, to provide guidelines for chamber designs and sampling procedures, and to share knowledge on chamber measurement techniques between flux measurement communities. For the comparison, ten chambers with different dimensions, material and sampling protocol will be selected and tested.
The results from the calibration campaign can be used in the ongoing research projects NitroEurope, ESF-NinE, Carboeurope, Fluxnet, IMECC and Scandinavian network of flux towers (e.g. NECC). As the chamber calibration aims at providing error estimates for static chambers, this campaign gives tools to compare flux estimates across Europe from a wide range of locations and experimental setups.
In November 2008 we will organize a workshop in Copenhagen,Denmark dealing with the results of this measurement campaign.
PRACTICAL INFORMATION
The calibration campaign will last for 5-8 weeks depending on the number of participants. It will be organized in small groups where a maximum of 3 chambers will be calibrated at a time during 6-day periods between Monday and Saturday. The chambers will be calibrated with soils of 2 different porosities and this is why each calibration session will take approximately 5-6 days. We will start each session on Monday noon and try to finish it by Friday evening. If possible try to arrange your flight tickets so that you will arrive at Hyytiälä on Sunday evening or Monday morning and leave on Saturday.
The N2O, CH4 and CO2 emissions measured by individual chambers will be compared to known gas fluxes generated by a calibration chamber described by Pumpanen et al. (2004). During the calibration, the chamber being tested will be placed on a layer of quartz sand (150 mm thick) on top of the calibration chamber. The sand layer is 990 mm in diameter and your chamber has to fit within this diameter. The maximum size of a rectangular chamber, which fits into this space is about 650 mm x 650 mm. Longer and narrower chambers up to 200 mm x 900 mm can also be calibrated. Remember to tell the size of your chamber when making the reservation (chamber questionnaire). If you use collars with your chamber, please take 3 collars with you.