Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Towards a Global Synthesis of Methane Fluxes
From Land Ecosystems Report from the ESF Exploratory Workshop held
in Hamburg (Germany), 10-12 April 2012 Lars Kutzbach, Miguel
Mahecha, Timo Vesala
http://www.klimacampus.de/esfworkshopch4.html
Slide 2
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Since the 1980s, hundreds of studies on CH 4
emission from various land ecosystems have been published, mostly
based on chamber methods. In the 1990s, the first eddy covariance
(EC) measurements of CH 4 fluxes were published; however, few
because of expensive and technically demanding instruments;
recently, the number of EC studies is strongly increasing due to
fast technical development of new trace gas analysers. There is no
global synthesis of these extensive datasets so far. Neither, there
are generally accepted best practices protocols for chamber and EC
methodologies. Recently, many different initiatives focusing on CH
4 were initiated. Stronger links between different networks appear
necessary. Motivation for the exploratory workshop
Slide 3
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems PERGAMON (COST, EU) GHG-Europe (EU) PAGE21
(EU) ABBA (COST, EU) MethaneNet (NERC, UK) DEFROST (Scandinavia)
(KoPF, BMBF, Germany) FLUXNET many smaller projects ICOS (EU) Now
many initiatives on CH 4 : need for networking between networks ?
InGOS (EU)
Slide 4
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems General goals of the exploratory workshop
Initiation of a global synthesis activity that aims at harmonizing
the steadily increasing number of methane (CH 4 ) measurements from
terrestrial ecosystems worldwide and evaluating them jointly
Cooperation of scientists with complementary experiences: field
measurements, advanced empirical data analyses, remote sensing,
mechanistic modeling Setting the stage for following larger-scale
international activities (e.g., open science workshop in Hyytil,
September 2012)
Slide 5
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems A global CH 4 -FLUXNET (or GHG-FLUXNET) could
. provide the scientific community with independent empirical
reference for: - Local terrestrial CH 4 dynamics - Empirical
relations e.g. temperature sensitivities - Up-scaled fluxes AND
this initiative could avoid many difficulties by learning from (and
being integrated in) the existing (CO 2 -)FLUXNET experience, e.g.,
Data policy PI involvement Data standardization Reference for
constraining diagnostic/predictive models Initiation of a CH 4
-FLUXNET
Slide 6
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Outline of the workshop 2.5 days 8 plenary
sessions: 6 topical scientific sessions, 14 scientific talks, 2
summarising discussion sessions 3 time slots (in total 5 hours) for
3 parallel break-out sessions in which subgroups focussed on
advancing the specific questions/deliverables
Slide 7
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Outline of the workshop 26 participants from
11 countries (10 European countries, US) 10 females, 16 males 15
young scientists, 11 experienced scientists (according to the ESF
definition)
Slide 8
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Outline of the workshop Tuesday, 10.04.12 A.
Plenary session: The need for a FLUXNET-CH 4 ; state of the art of
land-atmosphere CH 4 flux research (talks Kutzbach, Mahecha,
Scarascia- Mugnozza, Heimann) B. Plenary session: CH 4 flux data
availability from different land ecosystems (talks Rinne, Oechel,
Zona, Schrier) Wednesday, 11.04.12 C. Plenary session: Towards
standardized methodologies for CH 4 flux studies (talks Riis
Christiansen, Eugster, Dengel) D. Plenary session: Setting up a
FLUXNET-CH 4 initiative (talks Papale, Vesala, Sachs, v.
Huissteden)
Slide 9
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Outline of the workshop Wednesday, 11.04.12 E.
Break-out sessions a) Next steps for the initiation of a FLUXNET-CH
4 initiative b) Joint efforts on best practices for closed chamber
CH 4 flux studies c) Joint efforts on best practices for eddy
covariance CH 4 flux studies F. Break-out sessions Continuation G.
Plenary session: Representation of CH 4 processes in climate-carbon
cycle models (talks Heimann, v. Huissteden, Vesala)
Slide 10
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Outline of the workshop Thursday, 12.04.12 H.
Plenary session: Global-scale analyses/synthesis of CH 4 processes
and fluxes (talks Matthews, Mahecha, Bloom, Bousquet) I. Plenary
session: Summary and general discussion of break-out sessions J.
Plenary session: General discussion on next steps to achieve the
workshop deliverables, follow-up research activities and/or
collaborative actions or other specific outputs K. Break-out
sessions Continuation
Slide 11
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Outcomes: Next steps for the initiation of a
FLUXNET-CH 4 initiative The participants recognised the need for a
network of networks for CH 4 research within Europe but preferably
also on the global scale: a FLUXNET-CH 4 . This network of networks
primarily needs a functional and consistent database and a
well-maintained, functional and inspiring information exchange
platform. The participants suggested using existing infrastructure
to efficiently build up these two basic prerequisites for a global
CH 4 synthesis activity.
Slide 12
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Outcomes: Next steps for the initiation of a
FLUXNET-CH 4 initiative As information exchange platform, the
existing internet platform www.MethaneNet.org (currently funded by
the NERC, UK) is suggested. Recommendation to avoid redundant
databases and to establish the needed new CH 4 flux database as a
part of the already existing European Eddy Fluxes Databases Cluster
(www.europe-fluxdata.eu). For long-term archiving, using the open
access library PANGAEA (http://www.pangaea.de) should be
considered.
Slide 13
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Outcomes: Next steps for the initiation of a
FLUXNET-CH 4 initiative Dario Papale agreed to expand the European
Eddy Fluxes Databases Cluster so that it fits to the needs of a CH
4 flux synthesis. It was agreed that the new database should
include chamber measurements. Database structure and the required
content of the metadata information needs to be discussed. Much is
already implemented by Dario, but further discussion and
optimisation necessary.
Slide 14
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems ab Graphic: P. Schreiber Graphic: A. Hormann
Outcomes: Best practices for closed chamber CH 4 flux studies
Slide 15
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Outcomes: Best practices for closed chamber CH
4 flux studies In a recent extensive CH 4 flux chamber
intercomparison experiment (18 types), the tested chambers differed
widely in their performance to replicate a reference flux,
suggesting that published estimates of trace-gas fluxes are often
biased. Systematic errors derive from saturation of headspace, lack
of mixing and disturbance of the headspace. However, these biases
can be minimised by applying non-linear regression flux calculation
methods, increasing the chamber volume to basal area ratio,
sufficient headspace mixing and minimising manual gas sampling
volumes.
Slide 16
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Outcomes: Best practices for closed chamber CH
4 flux studies Chamber results are generally considered highly
valuable for budget considerations, characterisation of spatial
variability across scales, and validation of modelling results.
However, it is necessary to develop a strategy to correct or
post-calibrate existing chamber data based on metadata information
on the experimental set-up. ( New database!) Uncertainty ranges due
to different measurement designs have to be assigned to each
chamber data set following a standardised approach. Is it possible
to recommend the perfect chamber for future research? Yes.
Slide 17
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Outcomes: Best practices for eddy covariance
CH 4 flux studies
Slide 18
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Outcomes: Best practices for eddy covariance
CH 4 flux studies Currently, many new CH 4 analysers based on laser
spectroscopy are made available on the market. Large fluxes can be
measured with any of the currently available optical CH 4
analysers. Large fluxes can be measured also with weak pumps (even
with high damping losses). Small fluxes are still a challenge
making careful instrument selection important. Data processing is
still an issue as CH 4 analysers have different properties than CO
2 analysers, and additional or modified correction methods may be
needed.
Slide 19
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Outcomes: Best practices for eddy covariance
CH 4 flux studies Generally, most principles of flux processing
established for EC measurements of CO 2 are also valid for CH 4.
Major methodological differences between EC measurements of CH 4
and CO 2 are related to lower flux magnitudes and less or no
diurnal variability of CH 4 fluxes as well as to the differences in
the instrumentation needed to detect CH 4 concentration quickly and
and precisely enough for the EC approach. Need to better understand
the impact of the instrument design constraints (flow distortion,
sensor heating) on the accuracy of the CH 4 flux measurements.
Slide 20
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Outcomes: Best practices for eddy covariance
CH 4 flux studies Impact of advection and storage on the CH 4
fluxes needs to be systematically researched. The effect of density
corrections according to the Webb- Pearman-Leuning (WPL) on EC CH 4
flux estimates is not sufficiently investigated. Is density
correction better done by the classical WPL term on the fluxes or a
point-by-point dilution calculation on the rawdata? The detection
of CH 4 ebullition fluxes by the EC methodology needs to be studied
in depth. Hot spots and hot moments!!
Slide 21
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Outcomes: Initiation of several collaborative
synthesis papers E. Matthews: Meta-data analysis of the existing CH
4 flux literature, development of a methanocentric wetland
classification
Slide 22
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems E. Matthews: What are wetlands and where are
they? papyrus, Uganda Okavango, Botswana Zambezi River, Africa
Pantanal, Brazil Sudd Swamp, Sudan Amazon, Brazil Amazon, Peru N.
Australia Lake Jipe, Tanzania
Slide 23
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Outcomes: Initiation of several collaborative
synthesis papers E. Matthews: Meta-data analysis of the existing CH
4 flux literature, development of a methanocentric wetland
classification M. Mahecha et al.: Using new statistical time series
analysis methods to extract the temperature sensitivity of
ecosystem CH 4 fluxes W. Eugster, J. Rinne, L. Kutzbach et al.:
State of the art of CH 4 flux measurements by eddy covariance
methodology J. Riis Christiansen, S. Petersen, L. Kutzbach et al.:
State of the art of CH 4 flux measurements by closed chamber
methodology Many more ideas for papers and projects put forward in
Hyytil
Slide 24
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Next steps Largerscale, international open
science workshop on The importance of land-atmosphere fluxes of
methane and nitrous oxide for the global greenhousegas balance The
need for a FLUXNET-GHG Hyytil, Finland 27 September 2012 (95
participants incl. US, Europe, China, Japan, etc.)
Slide 25
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Next steps Working on the database structure
for CH 4 fluxes within the European Fluxes Database Cluster
(www.europe-fluxdata.eu) Which metadata needs to be included? What
needs to be incorporated in addition to the existing CO 2 flux
database? If you want to contribute ideas on these questions,
please contact Dario Papale ([email protected]) or Lars Kutzbach
([email protected])[email protected] Much is already
implemented, but further discussion and optimisation needed.
Slide 26
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Next steps Working on collaborative synthesis
papers either in small groups using CH 4 data from these groups (or
from literature reviews) and/or through contributing to the
proposed new larger- scale CH 4 database within the European Fluxes
Database Cluster (www.europe-fluxdata.eu) Register your site,
explore the database structure and provide feedback to Dario Papale
([email protected])
Slide 27
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Further need for integration ! Networking
between different CH 4 science communities still needs to be
intensified measurements experiments models land ocean atmosphere
different climate zones different continents Other CH 4 flux
database initiatives ? European? Global?
Slide 28
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems of field researchers and modellers
International teamwork needed German Russian Slovakian
Slide 29
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Thank you for your attention ! More
information on the ESF Exploratory workshop (e.g., programme, list
of participants, presentations):
http://www.klimacampus.de/esfworkshopch4.html Email:
[email protected] More information on the ESF Exploratory
workshop (e.g., programme, list of participants, presentations):
http://www.klimacampus.de/esfworkshopch4.html Email:
[email protected] Photo: H. Joosten
Slide 30
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems
Slide 31
Objectives of a CH 4 -FLUXNET: To provide a solid basis for a
global quantification of the natural spatial and temporal (seasonal
to interannual) variability of natural CH 4 -effluxes
Slide 32
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Objectives of a CH 4 -FLUXNET: e.g. via
upscaling fluxes (even if this sounds now too early for CH 4 ) To
provide a solid basis for a global quantification of the natural
spatial and temporal (seasonal to interannual) variability of
natural CH 4 -effluxes Example from CO2-fluxes to be adapted
Slide 33
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Objectives of a CH 4 -FLUXNET: Jung et al.
(2010) Nature. 467: 951-954. Monitoring of relationships between
drivers and fluxes at site level! Machine Learning of relationships
between drivers and fluxes Applying algorithm to gridded variables:
generating a quasi observational flux field e.g. via upscaling
fluxes (even if this sounds now too early for CH 4 ) To provide a
solid basis for a global quantification of the natural spatial and
temporal (seasonal to interannual) variability of natural CH 4
-effluxes Exploratory Workshop: Towards a global Synthesis of CH 4
fluxes from land ecosystems
Slide 34
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Objectives of a CH 4 -FLUXNET: To provide a
solid basis for a global quantification of the natural spatial and
temporal (seasonal to interannual) variability of natural CH 4
-effluxes Why this works? Monitoring of relationships between
drivers and fluxes at site level! Machine Learning of relationships
between drivers and fluxes Applying algorithm to gridded variables:
generating a quasi observational flux field
Slide 35
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Objectives of a CH 4 -FLUXNET: Sampling of the
climate space less dense! More drivers needed (wetland extend?) How
to deal with regime shifts? How to deal with the much higher
spatiotemporal resolution (heterogeneity!) To provide a solid basis
for a global quantification of the natural spatial and temporal
(seasonal to interannual) variability of natural CH 4 -effluxes
Complications in case of CH 4 fluxes Monitoring of relationships
between drivers and fluxes at site level! Machine Learning of
relationships between drivers and fluxes Applying algorithm to
gridded variables: generating a quasi observational flux field
Slide 36
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Objectives of a CH 4 -FLUXNET: Help
constraining terrestrial biosphere models -FLUXNET = becoming the
reference for structural adjustments or parameter optimization of
terrestrial biosphere models. -Are similar approaches thinkable for
a CH 4 initiative? ( At least for specific regions?) M. Williams et
al. (2009) Improving land surface models with FLUXNET data.
Biogeosciences, 6: 1341-1359. Data could be either eddy-covariance,
chamber, or upscaled data!
Slide 37
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Objectives of a CH 4 -FLUXNET: Help
constraining terrestrial biosphere models -FLUXNET = becoming the
reference for structural adjustments or parameter optimization of
terrestrial biosphere models. -Are similar approaches thinkable for
a CH 4 initiative? ( At least for specific regions?) Suzuki &
Iichi (2011) Evaluation of a terrestrial carbon cycle submodel in
an earth system model using FLUXNET observations. Tellus B, ?:
xxx-yyy. (CHECK REF, IS PUBLISHED)
Slide 38
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Expected deliverables The seed for an
international CH 4 -FLUXNET initiative which builds on and connects
previous synthesis and networking activities. Open science (!)
workshop in Hyytil, Finland 2-7 September 2012 The importance of
land-atmosphere fluxes of methane and nitrous oxide for the global
greenhouse-gas balance The need for a FLUXNET-GHG ( Sigrid Dengel)
A strategy for the implementation of a functional and consistent
database collecting CH 4 flux measurements from the global land
ecosystems applying different approaches, e.g. chamber and eddy
covariance methods. Papers on recommendations on best practices in
chamber and eddy covariance applications for CH 4 flux measurements
and standardized protocols for data processing and quality
control.
Slide 39
Exploratory Workshop: Towards a global synthesis of CH 4 fluxes
from land ecosystems Expected deliverables 4. Initialization of a
series of synthesis papers on different aspects of CH4 flux
processes, for instance on the temperature sensitivity of CH 4 5.
Strategy for the generation of scaled up CH 4 fields, a
quasi-observational space- time explicit picture, at least for the
northern temperate to arctic latitudes.