POET

The meeting started at 1:00 p.m. on April, 2^nd and finished around 4:00 p.m. on April, 3^rd. We met the first afternoon with the coordinators of the projects which are part of our EU clusters. Everybody liked the very interesting discussions we have between the different projects, and we plan to continue to have meetings with these other projects during our next POET meetings.

EU cluster:

Rainer Steinbrecher, Paul Monks and Frode Stordal gave overviews of the TROTREP, FUTURE_VOC and SUB-AERO projects, wihich are part of the same EU clusters as POET.

TROTREP:

Paul Monks from the University of Leicester is the coordinator of TROTREP : Tropospheric ozone and precursors, trends, budget and policy.

Coordinator : P. Monks, Univ. Leicester, UK

Participants : Univ. Berne, IVL Gothenburg, TNO Apeldoorn, Norwegian Meteo Oslo, NILU, Univ. Utrecht

The goals of TROTREP are to evaluate/validate and predict the effectiveness of past and future EU policies. The project will look at how much ozone change is due to abatement measures in the past and how much more current and future changes will impact ozone.

The project consists of an integrated measurement and modeling approach, through the collection and detailed analysis of observational data, as well as through the analysis of model results. The project will also look at the origin of the trends in ozone and its precursors over the past 100 years.

The seasonal cycles of ozone and its precursors will be studied, using 2-D trajectories for the 1988-1996 period for about 70 sites. The impact of NOx and VOCs emissions will be evaluated.

Paul described the space-state model developed by the University of Berne, which will be used in the project (Schuepbach et al., 2001, in press). He also gave details on the FREETEX campaign, which aims at quantifying the role of the in situ photochemistry versus long-range transport in the control of ozone in the free troposphere.

FUTURE_VOC

Rainer Steinbrecher from the IFU in Garmisch is the coordinator of FUTURE-VOC project. The goal of the project is the study of the volatile organic compound emissions (VOC) of European forests under future CO2 levels, and more particularly to study the carbon metabolism of plants and its effect on the potential volatile organic compound emission in an elevated CO2 atmosphere.

The participants to the project are the University of Basel, the CNR in Rome, the Instituto Miglioramento Genetico Alberi forestali Firenze, and the Lancaster University.

Rainer described the current field (Mediterranean area and the Swiss canopy crane) and chamber experiments under way within the group, and described how the VOC emission measurements are performed to account for an elevated CO2 level in the background atmosphere. He described the different chemical species which are emitted by the major forests forming trees at different spatial and temporal scales.

The first observations collected by the group seem to show that emissions of species such as isoprene and terpenes do not show a significant change under higher CO2 levels. But Rainer reminded us that it is expected that future forested areas may contain more emitting biomass than current forests leading to an increased biogenic VOC emission per ground area in an future environment.

A Gordon Conference on biogenic hydrocarbons in the atmosphere will take place in 2002 in the UK. Informations on this meeting can be obtained from Rainer.

SUB-AERO :

This project, which concerns the study of subgrid scale investigations of factors determining the occurrence of ozone and fine particles is coordinated by K. Lazaridis from NILU. The main objectives of the project are to study the characteristics of the distributions of photochemical gases and fine particles in summer and winter from ground-based and ship-based observations platforms.

The Participants are the University of Athens, the NCSR Demokritos Athens, the University of Essex, the Academy of Sciences Czech. Republic, and the JRC Ispra.

SOGE:

Frode presented an overview of this project, which deals with a System for Observations of Greenhouse gases in Europe. The project has started in December 2000, and Frode is the coordinator. During the project, high resolution measurements of CFCs and HFCFs gases will be performed, and they will be analyzed using the Oslo model.

1^st yearly POET report

The 1^st yearly report on POET activities is due April, 30 2001.

A few groups have sent their workpackages report in March, which have been included in the first draft of the report that was distributed during the Bremen meeting.

The details of the different parts of the report were discussed. The groups who have not sent their contributions should send them not later than April, 17^th to Claire. All groups should also, if they have not done it, send to Claire the names of all conferences attended by people working on POET in their groups, plus a list of publications (referred or not).

The cost statements for each groups need to be provided by April, 26^th to Claire (signed, please!!).

Workpackage 1: Distribution of ozone precursors from satellite data

Andreas presented the currently available data concerning tropospheric columns as observed by GOME since 1996. He showed the average NO2 tropospheric columns from 1996 to 2000, discussed some regional features corresponding to anthropogenic emissions, lightning and biomass burning emissions. For example, he showed very good correlations between elevated CO levels in the tropics and fire locations observed from space.

Andreas discussed uncertainties associated with the treatment of clouds and correction algorithms. He discussed new methods using different wavelengths regions that shoe promising results. He showed also results concerning formaldehyde, and showed strong CH2O maxima in regions where high isoprene emissions are expected, as well as during biomass burning events. He also presented indications for enhanced CH2O levels above snow and ice in polar latitudes.

People who would like to have access to the data should contact Andreas Richter.

Juliette gave an update of the retrieval of CO tropospheric columns from IMG, which provides satellite observations of the tropospheric columns of O3, CH4 and CO. She gave details on the retrieval algorithm, and its most recent updates. The data for the June 16-19 1997 period have been published. Data for April 1997 are also ready. The retrieval of ozone tropospheric columns for June 1997 is in progress, and the retrieval of methane should start in a few months.

We will ask Cathy to provide the CO IMG weighting functions, so that the models can be compared more accurately with the satellite observations.

Workpackage 2: Emission inventories

Jos gave an introduction on the regulations decided within the Kyoto Protocol, and within the UNFCCC (UN Framework Convention on Climate Change). Countries who have signed the UNFCCC (most) have agreed to report their emissions annually, and to report their national policies every 3-4 years. Jos gave details on the agreements signed by the countries on emissions limitations for the coming years.

The countries have agreed to report their emissions under a common format, and they report their emissions of CO2, CH4, N2O + f-gases, CO, NOx, NMVOCs, SO2 from 1990 onwards, and by IPCC source categories.

Each country uses its own method to calculate the emissions, which leads to rather significant uncertainties. Some countries also report only their anthropogenic emissions, some other report all anthropogenic+natural emissions.

Jos gave a presentation of the current status of the version 3 of the EDGAR inventory for anthropogenic emissions. The 1990 emissions totals have been revised, some categories have been added, emission factors have been updated The inventories by large areas of the world are available since January. The gridded inventories will be available over the next few weeks.

Claire has used the 1995 emissions available for large areas of the world to update the EDGAR v2.0 that were used in most models. These updated emissions are available in the zardoz data base (for those who have signed the data protocol!), an a description of all the elements of this emissions data base has been sent to everybody in February by email.

Jos also gave indications on the changes of anthropogenic emissions for some species from 1970 to 1995. He also gave some indications on the strong seasonality of some emissions such as emissions from fuel consumption. He also mentioned the overview of IGAC inventories that was published in the December 2000 issue of the IGAC newsletter.

The full set of Edgar v3 files at a 1x1 degree resolution will be ready around April, 15^th. Jos will send them to Claire, who will put them in the same format as the emissions files currently on zardoz. Claire will send a POET/TROTREP email when the files are available.

Workpackage 3: Intercomparison of CTMs

4 models are participating in POET: TOMCAT from Cambridge, OSLO-CTM2 from the University of Oslo, MOZART from CNRS in Paris, and IMAGES from BISA, Brussels.

The models are not yet fully ready for all planned intercomparison exercises, due to machine changes for some groups or for major improvements in the model. Each group has however done at least some parts of the planned intercomparisons.

Radon simulation: The simulations have been dome by 3 groups, and the results have been compared with the results discussed in an earlier comparison (from the Jacob et al., JGR 1997 paper). The models give very similar results. For a better view at the results, the groups will send their 300 hPa maps (ASCII format) for an Jun-Jul-Aug average to Nick, who will make a plot with the same color/level scale. The Rn zonal average should also be sent to Nick to plot Rn cross-sections.

Nick has started to convert his model results into the HDF format. He discussed in details with Bojan about the metadata. He will work over the next few weeks with Frode, in order to provide fortran codes that can convert ASCII files into the required HDF format. All groups will then start to convert their output into the HDF format and send them to the NILU database.

Claire and Jean-Francois have used the emissions data set in the zardoz data base and run their model. They have started to compare their results. This process will be made more simple after conversion to HDF. The other model will perform the same type of simulations over the next few months.

We agreed to save in the NILU data base the following species: O3, CO, OH, HO2, H2O2, NO, NO2, CH4, CH2O, Aceton, PAN and HNO3. We need to discuss more on the frequency of the output that will be saved.

Most of us will attend the GEIA/GIM meeting in Paris on June, 18^th. We could propose during this meeting that the POET intercomparison framework (emissions, meteorology, format, etc.) could be used by other people who would like to compare their models with the 4 POET participating models.

Workpackage 4: Inverse modeling

Claire gave an update of the current work done on inverse modeling. First attempts of the optimization of CO emissions have been performed, using the IMAGES model, together with the observations from the CMDL/NOAA network, which provides observations of surface CO at about 30 surface stations over the past 6-8 years. The work has been done using the inventory of surface emissions currently used in the MOZART model, which is detailed in the http://acd.ucar.edu/models/MOZART/emissions/emissions.html web site ; the anthropogenic emissions used correspond to the EDGAR v2.0 inventory. Several assumptions are made in this first step : errors on model results and observations are known, they are gaussian and independent, and there exist a linear relationship between CO emission and concentration. In this study, only direct surface emissions of CO were optimized, which means it was assumed that the production of CO from hydrocarbons oxidation is well quantified. The optimization of surface emissions was done over 12 large areas, assuming a fixed distribution of emissions inside these areas.

The first results show a large deficit in the surface emissions over Asia, that are, according to the inversion scheme, due to missing emissions from agriculture waste and fuelwood burning. However, due to the location of most of the CMDL stations, they are not sensitive to all types of emissions, such as the one from forest or savanna burning for example. The results that have been obtained need to be validated and studied in more details. The study has however shown that more data are needed to obtain better results, and the use of satellite data such as the ones provided by the IMG instrument will be used. Similar studies will also soon start, which will use the MOZART model, which allows the used of analyzed meteorological fields corresponding to the measurement period.

The development of the adjoint of MOZART has just started. The adjoint generator TAMC will be used for these developments, in collaboration with people from NCAR (Boulder, USA) and from the Max Planck Institut of Meteorology in Hamburg).

During the next months, a similar method will be developed, for the use of the results of the MOZART model in which the emissions as developed in WP2 will be used.

Workpackage 5: Isotopes

Valerie gave an overview of the origin of CO and CH₄ isotopes and of currently available measurements. There are 10 stations measuring CO isotopes. The data from available stations have been compiled in a single format. The data will be put in the POET database as soon as the corresponding procedures are defined by the NILU group.

Valerie discussed the uncertainties on the isotopic ratios in different categories of emissions. -The isotopic ratios are rather well defined for the primary sources of CO (combustion). However, the fossil combustion source signatures are better defined as those from biomass burning. For the secondary source of CO (hydrocarbon oxidation), the isotopic ratio are well defined for d¹³C(CO) but there is a large uncertainty concerning d¹⁸O(CO).

Valerie gave also a list of recent model studies on CO/CH4 isotopes.

Workpackage 6: ozone precursors/OH feedback

We discussed the work we plan for the next months on this topics.

The impact of changes in emissions on ozone concentrations depends on the CO/NOx ratio. We will look at the impact of uncertainties on emissions, of the trends in emissions, and on the difference in model results due to different parameterizations of transport processes.

We will look at trends in atmospheric species, to changes in the HOx budget and the CH4 lifetime.

Workpackage 7: tagging of ozone

Claire has started the tagging of CO, in preparation of the tagging of other ozone precursors. We will have to discuss and agree over the next few weeks on what we want to tag.

We also discussed in some details about the tagging of ozone. Nick prepared a few pages discussing this topics that were distributed to the modelers. We need to think about it over the next few weeks, and discuss again this topics in Paris in June.

Status of the Workshop on emissions of chemical species and aerosols :

Dates of the workshop : June 19-22 2001 in Paris

All the details concerning the workshop are on the NILU/POET web site http://nadir.nilu.no. This includes the goals of the workshop, the abstracts format, and practical informations.

About 85 abstracts have been received, and a preliminary program has been written, which will be sent shortly to the program committee.

After a discussion, we decided that there will be an oral presentation of the cluster. We decided a power-point presentation, which will be given by Paul Monks (or Rainer?) on the 1^st day of the workshop. Each project will also make a poster on the goals/first results of the project.

A reminder to all groups: in order to have enough drinks/pastries, each group leader should send to Claire the numbers of the people who will attend from the group.

European meeting in Torino:

We will submit an abstract for the European meeting

The deadline is May 1^st.

Next POET meeting:

We all found that we have very fruitful discussions with our partners from the other groups in the EU cluster, and we propose to have our next meeting at the same time as the TROTREP, FUTURE-VOC and SUB-AERO groups if possible. The next meeting would be over 2 days, the first day being a common meeting of the cluster, and each group will meet separately on the second day. A tentative date is November 5-6 2001, in the RIVM/TNO buildings. Jos Olivier will check if this is possible with the TNO colleagues.