2.1 IAGOS in-situ data (WP-B_I.2)

Responsible partners

MPI-BGC, Dr. habil. Christoph Gerbig, @Christoph Gerbig

Primary Work Packages in ITMS

https://itmsgermany.atlassian.net/browse/IB-17

Data description

In-situ measurements along flight corridors with profiles at German airports. About 75 flights per month all over the world, with a subset in and over Germany (Petzold et al., 2015). Many instruments measuring the respective gases with temporal sampling usually in the order of a few seconds. Different instrumentation for IAGOS-CARIBIC (instrumented container deployed once or twice per month) and IAGOS-CORE (instruments permanently installed onboard a fleet of aircraft). For further details, also about uncertainties of the instruments, see e.g. Petzold et al. (2015). Measurements started in the 90’s within the research projects MOZAIC and CARIBIC. More and improved instrumentation has been developed and implemented within IAGOS since 2005. An overview of the various parameters can be found here: https://www.iagos.org/iagos-data/

Parameters of particular relevance for ITMS

Of particular interest for ITMS are the greenhouse gases (continuous CO2 and CH4 from IAGOS-CORE and IAGOS-CARIBIC as well as analysis of flasks collected within IAGOS-CARIBIC for CO₂, CH₄, N₂O, SF₆, and isotopes ¹³C and ¹⁸O in CO₂) reactive gases (O₃, CO, NO_x, NO_y) from both, IAGOS-CORE and IAGOS-CARIBIC. IAGOS-CORE data final data is usually available 1 year after the observation date, NRT data available approximately in 1-3 months, depending on the variable. IAGOS-CARIBIC data provision is currently (April 2023) on hold as the instrument is in platform transition period. For availability of the data for specific time frames consider this page: https://iagos.aeris-data.fr/download/

Data format

The data are available as text files or in netcdf. Detailed description of the format can be found here: https://iagos.aeris-data.fr/download/

Data access and interface definition

Information about the data access for IAGOS can be found here : https://iagos.aeris-data.fr/download/. Data include near-real-time (NRT) data from IAGOS-CORE as also provided to CAMS, however, those are not yet of interest to ITMS in this phase. Module M will be using GHG data from IAGOS-CORE, first as diagnostics of the models developed within the module and in the future as an observational constraint.

Schedule of data delivery

Performance indicator (PI) definitions

Usage in Module M

https://itmsgermany.atlassian.net/browse/IM-5

Usage in Module Q&S

Currently no Work Packages in Module Q&S.

References

• Petzold, A., Valerie Thouret, Christoph Gerbig, Andreas Zahn, Carl A. M. Brenninkmeijer, Martin Gallagher, Markus Hermann, Marc Pontaud, Helmut Ziereis, Damien Boulanger, Julia Marshall, Philippe Nédélec, Herman G. J. Smit, Udo Friess, Jean-Marie Flaud, Andreas Wahner, Jean-Pierre Cammas, Andreas Volz-Thomas & IAGOS TEAM (2015) Global-scale atmosphere monitoring by in-service aircraft – current achievements and future prospects of the European Research Infrastructure IAGOS, Tellus B: Chemical and Physical Meteorology, 67:1, DOI:10.3402/tellusb.v67.28452

2.2 ICOS in-situ data (WP-B_I.2 and WP-B_I.3)

Responsible partners

DWD, Dr. Dagmar Kubistin, @Dagmar Kubistin

DWD, Dr. Jennifer Müller-Williams, @Jennifer.Mueller-Williams

Primary Work Packages in ITMS

https://itmsgermany.atlassian.net/browse/IB-17

https://itmsgermany.atlassian.net/browse/IB-18

Data description

Continuous in-situ observations of the greenhouse gases CO₂ and CH₄ at 12 tall towers distributed over Germany (ICOS Handbook, 2022) fulfilling the data quality objectives of the World Meteorological Organisation (WMO GAW Report No. 255, 2020) with CO₂ better than 0.1 ppmv and CH₄ better than 2 ppbv (ICOS RI 2020, Levin et al., 2020). Continuous N₂O and CO data are available from 11 German ICOS Atmosphere Stations with an extended data quality objective of 0.3 ppbv for N₂O and 2 ppbv for CO. The data is available as dry mole fraction with a typical cycle of 5 mins at each level and provided within 24 hours with automatic quality control (Level 1 NRT data, https://data.icos-cp.eu/portal/ ). Manually and ICOS community approved ICOS data (Level 2) are available once a year at the end of June (https://data.icos-cp.eu/portal/ ). Data from the neighbouring countries are also available via the ICOS Carbon Portal.

The ICOS observations have been successively expanded starting with 2015 at HPB. Detailed description of the metadata is provided by the ICOS Carbon portal . Pre-ICOS data exists for several stations, with historical data going back to 1972 (e.g. SSL, https://doi.org/10.18160/CEC4-CAGK )

The sensors for CO₂ and CH₄ measurements are commercial cavity ring-down spectroscopy instruments at all German ICOS sites. N₂O and CO observations are performed by commercial instruments based on off-axis integrated cavity output spectroscopy or cavity ring-down spectroscopy.

Data volume per year: ICOS data search (icos-cp.eu) shows for Germany there are 416 files available (186 NRT files, growing in size up to the annual L2 data release and 230 L2 files, currently varying in size from 2KB to 2MB depending on timeseries length and type of data (flask vs continuous time series).

Data format

Semicolon-separated ASCII, with #-prefixed multi-line header and machine readable landing page at the ICOS Carbon Portal. Interest of Modules M and Q&S probably in the level 1 near real time data. Higher time resolution is possible on request.

Parameters of particular relevance for ITMS

Continuous in-situ concentration measurements of CO₂, CH₄, CO, N₂O. Discrete C¹⁴(CO2) observations (~weekly at noon time, with 1 hour integration time), and integrated C¹⁴ observations (fortnight) at six ICOS Class 1 stations. ICOS Class 1 stations also provide discrete observations ~every third day (noon time, 1 hour integration time) of SF₆ and H₂. Four tall tower sites will also provide NO_x observations from 2026. Eight sites with ²²²Rn continuous observations. All stations provide meteorological parameters (wind speed and direction, humidity, air pressure, ambient air temperature)

Data access and interface definition

Data can be accessed via https://data.icos-cp.eu/portal/ . Depending on the needs of the partners in Module M, higher time resolution in the order of minutes is possible.

Schedule of data delivery

Performance indicator (PI) definitions

Usage in Module M

https://itmsgermany.atlassian.net/browse/IM-2

https://itmsgermany.atlassian.net/browse/IM-5

https://itmsgermany.atlassian.net/browse/IM-6

https://itmsgermany.atlassian.net/browse/IM-8

Usage in Module Q&S

Currently no Work Packages in Module Q&S.

References

• ICOS Handbook, 2022, https://www.icos-cp.eu/sites/default/files/2022-03/ICOS_Handbook_2022_web.pdf

• WMO/GAW Report No. 255, 20 th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse
  Gases and Related Measurement Techniques (GGMT-2019), 2020, https://library.wmo.int/doc_num.php?explnum_id=10353

• ICOS RI (2020): ICOS Atmosphere Station Specifications V2.0 (editor: O. Laurent). ICOS ERIC. https://doi.org/10.18160/GK28-2188

• Levin, I., Karstens, U., Eritt, M., Maier, F., Arnold, S., Rzesanke, D., Hammer, S., Ramonet, M., Vítková, G., Conil, S., Heliasz, M., Kubistin, D., and Lindauer, M.: A dedicated flask sampling strategy developed for Integrated Carbon Observation System (ICOS) stations based on CO₂ and CO measurements and Stochastic Time-Inverted Lagrangian Transport (STILT) footprint modelling, Atmos. Chem. Phys., 20, 11161–11180, doi:10.5194/acp-20-11161-2020, 2020.

• ICOS data at ICOS Carbon portal database, https://data.icos-cp.eu/portal/

2.3 ICOS flux data (WP-B_I.3)

Responsible partners

Thünen Institute, Dr. Christian Brümmer, @Christian Brümmer

Thünen Institute, Dr. John Akubia, @John Akubia

Primary Work Packages in ITMS

https://itmsgermany.atlassian.net/browse/IB-18

Data description

ICOS flux data represents 30-min estimates of CO₂ and water vapor exchange between the land surface and the atmosphere based on the eddy-covariance method. Currently, i.e. in the year 2023, there are 20 flux stations in the German ICOS terrestrial ecosystem network. Thirteen of these stations are labelled, either as Class-1 (n=3) or as so-called associated (n=10) sites.

Class-1 sites provide near-real-time data, whereas data from associated sites are published as Level-2 data products twice a year. The official ICOS time series for each station start during the period when the station was labelled, which means that there is a different start date for each site. First sites were labelled in 2018. Data volume per site and year is approximately 30 to 50 MB at a half-hourly time resolution.

The station network covers the most abundant land uses in Germany. Currently the ICOS Germany ecosystem network covers 8 forest, 6 grassland, 4 crop, 1 peatland, and 1 urban site distributed in a cluster-based approach across Germany. For geographical location, see map on https://www.icos-cp.eu/ .

Every station is equipped with a sonic anemometer and a fast-response gas analyzer for in-situ measurements of CO₂ and H₂O mixing ratios. Class-1 sites use the Gill HS anemometer and the LI-7200 enclosed-path gas analyzer. Further devices include radiometers, air and soil temperature and moisture probes, soil heat flux plates, and rain gauges. The latter instruments are used for the meteorological parameters that are monitored at each site.

Uncertainty estimates are given in the data files. Detailed description about the uncertainty estimation can be found in Pastorello et al. (2020).

Parameters of particular relevance for ITMS

Currently, i.e. in the year 2023, the stations are equipped with CO₂ and H₂O analyzers. CH₄ and N₂O are planned for Class-1 sites where the respective gas is relevant, for example CH₄ at natural peatlands or N₂O at fertilized grasslands and crop sites.

Data processing

Class-1 ICOS sites:

Near-real-time data is directly provided to the ICOS-ETC, where the data is processed centrally by ETC by applying the standardized FLUXNET protocol (ONEFlux).

Class-2 ICOS sites/ICOS-associated:

Associated sites send to ETC half-hourly data (processed with EddyPro or another software). The data must not be filled, and they can be filtered only for issues not reported by the standard quality check (Foken qc). All following processing (despiking, star filtering, gap filling, partitioning, etc.) is done centrally by ETC applying the standardized FLUXNET protocol (ONEFlux).

Once a year, ETC releases the processed data (L2 products) for all datasets of Associated sites that have completed the labelling phase and are, therefore, officially ICOS sites. The data are made available to users in the ICOS Carbon Portal. Additionally, the data is transferred to the main databases, e.g. FLUXNET and European Fluxes Database Cluster.

Non-ICOS sites:

The non-ICOS send data in the same way as the ICOS-associated sites to the European Fluxes Database Cluster (EFDC). Half-hourly data processed with EddyPro or other software must be sent without using ustar filters, without gap filling, etc.. (but filtered for disturbances not included in the Foken quality flags, such as rain).

The format in which the data is sent is also the same, and in the case of the EFDC, you can find it in the guidelines (Here). The data is received by the DB and then processed with the same FLUXNET protocol (ONEFlux), producing filtered, gap-filled, and partitioned data. EFDC is working on distributing this data on the ICOS portal itself, but this has not yet been implemented.

Data format

Comma-separated .csv file with one header line. Format description, metadata, and information on variables are given in the “…VARINFO…” files and on the landing pages of each flux station. Further details are in Pastorello et al. (2020).

The interest in Modules M is probably in the level 1 near real-time data.

The interest in Module Q&S is in long-term data of different sites.

Data access and interface definition

Data from the labelled stations are available in the ICOS Carbon Portal, https://data.icos-cp.eu/portal/. Sites from before 2018, so-called pre-ICOS data, may be available through the European Fluxes Database Cluster, http://www.europe-fluxdata.eu/home, also for sites that have not yet received an official ICOS label. The specific interface for Modules M and Q&S has to be discussed further, and it depends on the needs of these modules.

Schedule of data delivery

Performance indicator (PI) definitions

Usage in Module M

Currently no Work Packages in Module M.

Usage in Module Q&S

https://itmsgermany.atlassian.net/browse/IQS-26

References

• ICOS Handbook, 2022, https://www.icos-cp.eu/sites/default/files/2022-03/ICOS_Handbook_2022_web.pdf

• ICOS Ecosystem Thematic Centre documentation: http://www.icos-etc.eu/icos/documents/instructions

• ICOS data at ICOS Carbon portal database, https://data.icos-cp.eu/portal/

• Pastorello G, Trotta C, Canfora E, Chu H, Christianson D, Cheah Y-W, Poindexter C, Chen J, Elbashandy A, Humphrey M, Isaac P, Polidori D, Ribeca A, van Ingen C, Zhang L, Amiro BD, Ammann C, Brümmer C, Lucas-Moffat AM, Schrader F, et al (2020) The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data. Sci Data 7:225, DOI:10.1038/s41597-020-0534-3

2.4 TERENO flux data (WP-B_I.3)

Responsible partners

KIT, Dr. Ralf Kiese, @Ralf Kiese

KIT, Dr. Hannes Imhof, @Hannes Imhof

Primary Work Packages in ITMS

https://itmsgermany.atlassian.net/browse/IB-18

Data description

Flux estimations from in-situ eddy-covariance measurements at specific stations distributed over Germany. Most of the TERENO stations of interest for ITMS are on the same time TERENO and ICOS Class 1/2 labelled and classified sites. Therefore, for descriptions we refer to the ICOS sites, see Section 2.3 ICOS flux data.
A limited amount of TERENO sites are on-top of the ICOS sites Class 1/2 sites, they are either associated ICOS sites, non-ICOS sites on FLUXNET or non-ICOS sites on the European Flux Database. Such sites do partially flux data calculations not by the highly standardized ONEFLUX protocol. Currently, the ETC (ICOS) is also endeavouring to provide flux measurements from ICOS-associated and non-ICOS sites that are based on the ONEFLUX process chain. These activities are currently ongoing, and it can be expected in the further course of ITMS Phase 2 to 3 that a number of sites not currently reporting to the ONEFLUX Protocol will provide data with ONEFLUX processing.

Parameters of particular relevance for ITMS

Fluxes of CO₂, H₂O, CH₄ and N₂O especially with respect to process studies in Module Q&S.

Data format

See ICOS Portal and description in Section 2.3.

Data processing

See description in Section 2.3.

Data access and interface definition

The TERENO data of co-located ICOS stations are available via the ICOS Data Portal: https://data.icos-cp.eu/portal/. Non-ICOS site TERENO data is available via the European Flux Database Cluster http://www.europe-fluxdata.eu/.

Schedule of data delivery

Performance indicator (PI) definitions

Usage in Module M

Currently no Work Packages in Module M.

Usage in Module Q&S

https://itmsgermany.atlassian.net/browse/IQS-22

https://itmsgermany.atlassian.net/browse/IQS-26

References

https://www.tereno.net/