This project is funded by the European Commission through the Environment and Climate Programme.
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POLINAT-2

PROJECT WORK PROGRAMME

(Version of Dec. 1, 1996)

1.    Title
2.    Objectives
3.    Project Methodology
4.    Project Milestones
5.    Role of Participants
6.    Deliverables and Work Planning/Schedule
7.    Complementary Projects
8.    Publications

1. TITLE

Pollution from Aircraft Emissions in the North Atlantic Flight Corridor (POLINAT-2)

2. OBJECTIVES

The overall objectives of the project are:
  1. To determine by measurements and analysis the relative contribution from air traffic exhaust emissions to the composition of the lower stratosphere and upper troposphere at altitudes between 9 and 13 km within and near the flight corridor over the North Atlantic.
  2. To assess the effects of air traffic emissions in that region in relation to clean background concentrations and pollutant concentrations from various sources and to analyse their importance for changes in ozone, oxidizing capacity, aerosols and clouds.
The main emphasis of this project is on the distribution of nitrogen oxides (NOx and NOy), sulphur compounds (SOx), water vapour (H2O), particles, and their effects on ozone, other reaction products, in the upper troposphere and lower stratosphere. Contrail formation aspects are also considered.

The investigation will cover two scale regimes: the corridor cross-section with multiple plumes as resulting from dense air traffic at plume ages of several minutes to hours, and the scale of the flight corridor within the region of the North Atlantic at time scales of several hours to days.

In particular, the project investigates the following questions:

  1. Which is the north-south extent and how strong are the gradients delimiting the large scale corridor? Is there a mean gradient in the abundances of air species along the corridor?
  2. To what height above the main flight corridor are air traffic emissions transported? What is the residence time of emissions at altitudes above the tropopause in view of stratosphere-troposphere exchange and strong vertical variations in tropopause altitude, tropopause folds, wave motions and small amounts of turbulence?
  3. How large are the contributions from air traffic sources in relation to surface emissions? How important are synoptic scale motions in comparison to convective events? How important are washout, homogeneous and heterogeneous air chemistry during this upward transport?
  4. How often is air at flight levels supersaturated with respect to the ice phase, i.e., how often is the atmosphere conditioned to form persistent and large-scale contrails?
  5. What is the dispersion and chemical conversion in multiple plumes resulting from contributions of several aircraft flying through essentially the same air mass and what are the consequences for particle formation, air chemistry and contrail formation?
  6. What are the consequences of the aircraft emissions of nitrogen and other trace substances on the formation of ozone and other chemicals in the troposphere and lower stratosphere?
In addition the project seeks for possibilities to verify the performance of the instruments, to investigate fresh air traffic emissions and to investigate large scale transport, dispersion, chemical and aerosol changes in airmasses which have been freshly polluted by aircraft emissions on their way across the North Atlantic.

3. PROJECT METHODOLOGY

The project consists of two major tasks (work packages), split further into sub-tasks (activities).
Task 1: "Measurements": Performance of in situ measurements within and near to the flight corridor extending over the whole corridor scale
Task 1.1: Improve and complete instruments to be used onboard the Falcon
Task 1.2: Performance of a Falcon measurement campaign including weather forecasts for the campaign planning
Task 1.3: Measurements with a B747 of NO, NO2, O3, and H2O along the North Atlantic route and coordination with MOZAIC measurements
Task 1.4: Set-up of data bank
Task 2: "Modelling": Analysis and interpretation of the previous and the additional measurements in correlation with the actual emissions, meteorology and background air chemistry conditions during the measurement periods.
Task 2.1: Refinement of models
Task 2.2: Analysis of the horizontal and vertical trace gas distributions
Task 2.3: Quantification of the relative contributions from surface emissions relative to air traffic emissions
Task 2.4: Determination of the frequency and area sizes of regions with ice supersaturation
Task 2.5: Analysis of interaction between multiple plumes
Task 2.6: Analysis of ozone chemistry, mainly in upper troposphere and also in lower stratosphere for measured situations

The measurements and the data analysis will be performed in coordination with the the NASA research program SONEX. SONEX is the abbreviation of :q.SASS (Subsonic Aircraft Assessment) Ozone and NOx Experiment.:eq. The Office of Aeronautics of NASA in Washington issued a NASA Research Announcement :q.Atmospheric Effects of Aviation/Subsonic Assessment:eq. in July 3, 1996. The SONEX experiment is planned to take place in August and September 1997. During SONEX, it is planned to perform extensive measurements with an instrumented DC-8 aircraft within the North Atlantic air traffic region.

Task 1: Measurements

The objective is to be achieved by performing long range aircraft measuring flights from 40°N to 70°N. The distinction of air masses with different origin (surface, stratosphere, air traffic corridor) will be done by measuring also tracers for the different source regions. The measurements will be performed with an instrumented research aircraft, the Falcon of DLR, and with an instrumented commercial airliner, a B747 of Swiss Air.

The Falcon flights will be conducted within a three weeks campaign. The Falcon will be equipped with new engines at that time which enables a flight duration and range of 5 hours and 3000 km, respectively, and an increased maximum cruise altitude of about 13 km. The B747 flights will be performed within a period of two months 1997 covering also the Falcon campaign period.

The POLINAT-2 measurements will be performed in temporal overlap with the SONEX experiment. The activities to be coordinated with SONEX enclose:

  1. Instrument comparisons.
  2. Investigation of fresh air traffic emissions.
  3. Investigation of large scale transport, dispersion, chemical and aerosol changes in airmasses which have been freshly polluted by aircraft emissions on their way across the North Atlantic.
These objectives are to be addressed as follows:
  1. Close parallel flights of the DC-8 and the Falcon.
  2. Coordinated measurements with the 2 instrumented aircraft in the plume of airliners
  3. Correlating measurements of the DC8 and Falcon in different regions of the the Atlantic such that the DC8 flies in an area with active air traffic and the Falcon flies later in the same airmass.
The SONEX experiment will begin taking measurements from Bangor, Maine and then move either to Reykavik or Azores (Tenerife). It has been agreed with NASA partners to effectively coordinate the SONEX and POLINAT activities. It was agreed that SONEX and POLINAT should be independent missions that coordinate only a subset of their activities. For the coordinated activities both partners agree to an open exchange of the relevant data.

Task 1.1: Improve and complete instruments to be used onboard the Falcon (DLR, MPI, LMD, UMR)

The instrumentation used for the current project will be based on the instrumental set up employed successfully during POLINAT-1. Important improvements and further additions to the instrumentation package will be made for the present measurements, in particular to measure NOy, and those compounds that can be used to identify the origin of the air masses. In addition, a development will be pursued to measure hydroxyl radicals (OH), which are of prime importance for the oxidizing capacity of the atmosphere.

In cooperation with the Brookhaven National Laboratory (BNL, Dr. Russel Dietz) and as possible part of SONEX, preparations are being made to release a tracer from the DC-8 and to measure the tracer on board the Falcon in order to make sure that both aircraft were measuring the same air masses. This option might require to reduce part of the particle measurement systems for some of the FALCON flights. If this option cannot be realized, the identification of airmasses must be made with trajectory computations and analysis of all other measured air constituents.

:tabref refid=techn page=no. lists the species which will be measured on board the Falcon during the present project together with the instrumental techniques used for the aircraft-based measurements.
Species Measuring technique
O3 UV-absorption
NO, NO2, NOy Chemiluminescence
H2O Frost point hygrometer
CO2 IR-absorption
HNO3, HNO2, SO2, H2SO4, Mass spectrometry Acetone, HCN 
Particulates CN-counter, Electrostatic aerosol classifier
Wind, Temperature, pressure Standard meteorological instrumentation PositionINS and GPS navigation system Table 1. Experimental techniques used for the POLINAT-2 Falcon

Subsequently the status of the instruments and the planned improvements are described briefly.

DLR:

CO2: Existing.

NO, NO2: Existing with present detection limits for NO/NO2 measurements, 50/70 pptv and 5/10 pptv in 1 s and 60 s, respectively. The detection limit of the NO and NO2 instruments will be lowered by a factor of about 5 for the POLINAT-2 measurements.

NOy: An instrument to measure the sum of reactive nitrogen oxides (NOy ~ NO + NO2 + NO3 + HNO2 + HNO3 + N2O5 + ClONO2 + aerosol nitrate + .. ) will be added to the POLINAT instrument package. NOy species are reduced to NO by reduction on the heated surface of a gold catalysator using CO as a reducing gas and measured with an additional NO detector. The expected detection limit is 100 pptv in 1s.

O3: Existing.

Basic meteorological parameters: Existing.

MPI:

AAMAS will measure HNO2, HNO3, SO2, H2SO4, HCN, and Acetone. The measurements will be made by a novel greatly improved aircraft-borne IMR-MS (Ion-Molecule Reaction Mass Spectrometer) instrument (AAMAS 2 = Automatic Aircraft-borne Mass Spectrometer 2). Optionally HO2 and OH may also become detectable. Here the detection method (IMR-MS with titration with SO2 and NO) is still under development and the number of racks required may limit its usage.

LMD:

Water vapour frost-point hygrometer: Existing.

UMR:

MASS (Mobile Aerosol Sampling System): existing. The MASS is provided in an upgraded form, to allow ice crystal sampling, aerosol volatility characterization, continuous concentration measurement at fixed particle size, higher efficiency total concentration measurement at high altitude, and impactor sampling of aerosols of larger size.

Task 1.2: Performance of a Falcon measurement campaign in 1997 (DLR, LMD, MPI, UMR, KNMI)

The improved altitude and duration capabilities of the Falcon will be used to perform flights along 10&s0.W along connections between Tenerife and Shannon or between Shannon and Iceland or Norway at various altitudes within and above the main traffic flight levels, to determine the whole north-south extent of the traffic corridor. Moreover, the flights will be coordinated in time and space to obtain data comparable locally with those obtained on the B747 and possibly with those obtained on the various Airbus aircraft within the MOZAIC project. The data will be used to determine combined north-south and west-east traverses of the concentration fields.

The project will include one major field campaign in 1997 with 40 flight hours. The base of the aircraft operations will be the airport of Shannon in Ireland or Tenerife. A local operation centre will be installed in Shannon or Tenerife during the campaign. The flight pattern will include long range flights between Tenerife, Shannon and Iceland or Norway. The cruising altitudes will be either below or above the local tropopause. The flight pattern will also include shorter legs at the maximum cruising altitude of the Falcon (about 13 km) at the end of the flights for measurements above the flight levels used by most of the commercial air traffic. The flight planning will start 24 hours ahead of the take-off time based on ECMWF forecasts, as provided by KNMI, and informations on the air traffic routes across the North Atlantic fixed for the next day by NATS in Prestwick. In addition forecasted 3-day backward-trajectories for air parcels ending at positions along the planned Falcon track will also be available for experiment planning.

Beside the data measured with the Falcon, also data of the North Atlantic air traffic for the campaign period will be collected for post campaign data analysis and interpretation.

Task 1.3: Measurements with a B747 of NO, NO2, O3, and H2O along the North Atlantic route and coordination with MOZAIC measurements (ETH)

The objective is to determine the concentration of NOx, ozone and water vapour within the flight corridor across the whole North Atlantic, in order to complete the data obtained in the eastern part of the North Atlantic region with the Falcon, to determine direct impact of aircraft emissions in terms of NOx on ozone, to relate the concentration fields to tropopause folding events, and to identify vertical transport effects. The data will allow to determine mean gradients in the concentration field across the North Atlantic. This would help to check for any changes in NOx and O3 during the transport of air masses from the North American continent to Europe.

For this purpose, the ETH will perform NO, NO2, O3, and water vapour measurements along the North-Atlantic route, using a Swissair B-747 Combi as measuring platform with the following instrumental set-up:

An instrument rack will be located in the freight compartment of Swissair B-747 Combi, including instruments for the measurements of NO, NO2 and O3. NO is measured based on chemiluminescence, NO2 is measured using a photolysis converter. The detection limits and its associated time constants are: NO: 50 ppt in 3 s; NO2: 65 ppt in 3 s. O3 is measured by UV-absorption, the detection limit and associated time constants are 0.5 ppb in 4 s. The water vapour will be measured by a dew point mirror with automatic cleaning mechanism. Resolution is 0.1 K, accuracy 0.25 K, the time constant depends on absolute humidity, a typical value is 10 s. Meteorological data will be computed from INS data and data collected by aircraft-integrated sensors. The secondary (i.e., computed) quantities include temperature and the three- dimensional wind vector with a time resolution of 2 seconds or better. (Note: Due to legal restrictions, the primary data from aircraft-integrated sensors cannot be made available.)

Attempts will be made to use so-called 'large eddy correlation techniques' to estimate vertical fluxes of the various constituents; an exact measurement, however, will not be possible with the available instrumentation due to too long time constants.

All measurements will be completely automated, a data download and re-calibration of the system is envisaged after each flight.

The entire instrumentation will be mounted on the airplane during a period of 2 months covering the field campaign of POLINAT-2 in 1997.

We plan to exchange the flight planning data with related projects for coincident measurements. The coordination will be organized by LMD.

Task 1.4: Set-up of data bank (DLR, LMD, MPI, UMR, KNMI, ETH)

All data will be collected in the existing POLINAT-data bank, organized by DLR, and accessible by ftp. The basic data reduction will be performed by the individual groups involved in the measurements. After cross examination of all individual instrument data, combined data sets will be produced and included in the data bank.

Task 2: Analysis

The objectives of POLINAT-2 require the combination of models with the observations. The strategy is to obtain insight by applying the models to describe the observed conditions as well as possible. The aim is to validate physical and chemical process descriptions in the small scale models as well as the large scale horizontal and vertical distribution of aircraft pollutants from the mesoscale and global scale models in typical synoptic weather conditions. Thereafter, interpretation of the model results and sensitivity studies will be used to answer the questions stated for the POLINAT-project.

The models used comprise the scales of individual plumes, multiple plumes, the North Atlantic and the global scale. Global and regional chemical transport models (CTM) will be applied which use the actual weather analysis data from numerical weather prediction (NWP) models, as provided e.g. by ECMWF. The same data will be used to compute trajectories of the air masses reaching or leaving the measured flight paths. Along these trajectories, various plume models are used to compute the lateral and vertical turbulent dispersion, the chemical transformations and aerosol formation.

Table 2 collects the models to be applied in POLINAT-2.
Name Type Scales For tasks Scientist 
GLOBAL MODELS 
UiO 3d, global, CTM (chemical transport model) 8x10°, 9 layers up to 10 hPa 2.2, 2.3, 2.6 Isaksen, UiO 
CTMK 3d, global, CTM 4° x 5°, 15 levels up to 30hPa 1.2, 2.2, 2.3, 2.6 Kelder, KNMI 
STOCHEM 3d, global, Lagrangian CTM 10x10°, 20000 Lagrangian particles 2.6 Johnson, UK Met. Office 
ECHAM 3d, global, GCM T21 2.3 Sausen, DLR
REGIONAL MODELS 
HIRLAM 3d regional NWP (numerical weather prediction) 50km x 50 km cells, 16 levels up to 25 hPa 1.2, 2.2, 2.3, 2.4, 2.5 Kelder, KNMI 
HIRLAM - CTM 3d, North Atlantic, CTM 10 layers up to 100 hPa, 50-100 km grid 2.1, 2.2, 2.3, 2.6 Hov, UiB 
PLUME, PUFF and TRAJECTORY MODELS 
FLOW3D 3d flow field and dilution in jet plume 1 m to 1 km 2.5 Ford, Hayman, AEA 
AEA Plume chemistry with aerosols and hydrocarbons 2d, along trajectory of FLOW3D 2.5 Ford, Hayman, AEA 
KTM Trajectory model trajectories based on ECMWF analysis 1.2, 2.2, 2.3, 2.5, 2.6 Kelder, KNMI 
GAUSS 3d Gaussian plume model with LES (Large-Eddy Simulation) diffusivities analytical solution, domain of 500 km x 500 km x 5 km 2.5 Schumann, Konopka, DLR 
NILU puff-model with gas and aerosol chemistry along long-range trajectory 1d, trajectory model 2.5, 2.6 Stordal, NILU Table 2. Models used for POLINAT-2.

Task 2.1: Refinement of models (KNMI, NILU, UiB, UiO, DLR, AEA)

The models are applied as they are or refined as required for answering the given questions.

Task 2.2: Analysis of the horizontal and vertical trace gas distributions (KNMI, UiB, UiO, DLR, MPI, LMD, ETH, UMR, AEA)

The questions to be answered in this task are: Which is the north-south extent and how strong are the gradients delimiting the large scale corridor? Is there a mean gradient in the abundances of air species along the corridor? To what height above the main flight corridor are air traffic emissions transported? What is the residence time of emissions at altitudes above the tropopause in view of the strong vertical variations in tropopause altitude, tropopause folds, wave motions and small amounts of turbulence?

The questions will be investigated by analyzing the measurements in comparison to the weather conditions, background concentrations, and by model analysis.

Task 2.3: Quantification of the relative contributions from surface emissions relative to air traffic emissions (KNMI, UiB, UiO, DLR, MPI, LMD, ETH, UMR, AEA)

The questions to be answered in this task are: How large are the contributions from air traffic sources in relation to surface emissions? How important are synoptic scale motions in comparison to convective events? How important are washout, homogeneous and heterogeneous air chemistry during this upward transport?

The nature of air masses will be identified based on the relative magnitude of various measured tracer concentrations by DLR, MPI, LMD, ETH and UMR. Apart from trajectory analysis, KNMI will use backward time-integrations of the CTMK-model to decide on the origin of air masses in the past (up to five days). Three-dimensional model simulations with analysed wind fields and run for emission data bases including surface and aircraft emissions will be used (by UiB, KNMI, UiO, DLR, AEA-UKMetOff.) to determine the relative contribution from various emission sources. The change in sulphate chemistry during these transports will be addressed through simulations with the CTMK model (KNMI) and by means of box models along trajectories (NILU). By means of ECHAM runs transporting tracers with and without subgrid-scale model contributions, DLR will determine the relative importance of synoptic scale motions compared to subgrid scale convective motions.

Task 2.4: Determination of the frequency and area sizes of regions with ice supersaturation (LMD, ETH, DLR, KNMI)

The questions to be answered in this task are: How often is air at flight levels supersaturated with respect to the ice phase, i.e., how often is the atmosphere conditioned to form persistent and large-scale contrails?

Regions with ice supersaturation will be identified based on the measurements with the LMD water vapour frost point hygrometer, which offers the necessary accuracy for such measurements. The limitation of POLINAT in this task is the relatively small number of measurements, resulting in possibly a pure statistics. However, it can be checked how far the measured data compare with the weather analysis (it appears that these are sometimes better than previously thought) and with the data obtained on the B747 or within other projects. As far as possible with the given ressources, satellite data will be used to check for regions with persistent contrails and to investigate the frequency and size of regions which are conditioned for persistent contrails.

Task 2.5: Analysis of interaction between multiple plumes (NILU, KNMI, DLR, AEA, UMR, MPI, LMD)

The questions to be answered in this task are: What is the dispersion and chemical conversion in multiple plumes resulting from contributions of several aircraft flying through essentially the same air mass and what are the consequences for particle formation, air chemistry and contrail formation?

This objective will be addressed by identification of measured concentration peaks of exhaust species (DLR, MPI, LMD, UMR), identification of the source aircraft (DLR), backward trajectory analysis (KNMI), modelling of air parcel mixing and chemistry along the trajectory with aircraft sources (NILU), modelling and analysis of aerosol formation (AEA) and comparison with measured particle spectra (UMR). The modelling of the species in the plumes will describe the chemical reactions, diffusion, and the interactions between different plumes that cross each other. This will give a more realistic description of the chemical composition in the plumes when they reach the grid size of the global models (50-150 km).

Task 2.6: Analysis of ozone chemistry in upper troposphere and lower stratosphere for measured situations (UiB, UiO, NILU, DLR, AEA, KNMI)

The questions to be answered in this task are: What are the consequences of the aircraft emissions of nitrogen species and other trace substances on the formation of ozone and other chemicals in the troposphere and lower stratosphere?

For the weather conditions corresponding to the measurement campaigns, chemical transport models will be applied for analysis of ozone production rates and resultant ambient concentrations at global scales (UiO, KNMI, AEA-UKMetOffice) and regional scales (KNMI, UiB) for specific time periods using 3-d CTM coupled to limited area numerical weather prediction models. Moreover, models will be applied to analyse the ozone production rates and resultant concentrations along trajectories (NILU).

Special emphasis will be put on the calculation of the relationship between the local chemical production (or loss) rate of ozone and the local concentration of nitrogen oxides. Another topic to be addressed in the calculations will be to evaluate the competition between chemical and physical processes in the upper troposphere which determine the fate of the precursors (in particular NOx) and the formation of ozone and products of NOx (PAN, HO2NO2).

4. PROJECT MILESTONES

Milestone scheduled description
M0 01/96 Start of the POLINAT-2 project
M1 07/96 Workshop with presentations of analysis results based on previous measurements
M2 07/97 Workshop with presentations of analysis results based on previous measurements and detailed planning of the experiment
M3 07/97 Refined instruments ready for flight
M4 10/97 End of measurement campaign, data available as quicklooks
M5 12/97 All measurement data in POLINAT database
M6 12/97 Set-up of input data for final model runs
M7 01/98 Drafts for final report by the partners
M8 02/98 Final workshop
M9 04/98 Delivery of final report Table 3. Milestones

5. ROLE OF PARTICIPANTS

Coordinator: DLR: Deutsche Forschungsanstalt für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany
Contractors: MPG/MPI: Max-Planck-Institut für Kernphysik (Bereich Atmosphärenphysik), Heidelberg, Germany
KNMI: Koninklijk Nederlands Meteorologisch Instituut, AE de Bilt, the Netherlands
CNRS/LMD: Laboratoire de Meteorologie du CNRS, Ecole Polytechnique, Palaiseau, France
NILU: Norsk institutt for luftforskning, Lillestrom, Norway
AEA: National Environmental Technology Centre, AEA Technology, Culham, United Kingdom
ETH: Eidgenössische Technische Hochschule, Atmosphärenphysik, Zürich, Switzerland
Associated Contractors: UiB: University of Bergen, Institute of Geophysics, Norway
UiO University of Oslo, Department of Geophysics, Norway
in collaboration with
UMR: University of Missouri-Rolla, Laboratory for Cloud and Aerosol Sciences, Rolla, MO, USA
MetOff: UK Meteorological Office, Bracknell, United Kingdom

A list of main scientific contact partners is included. For each task, one group has the prime responsibility, see Table 4. Table 5 shows how the partners share in the work.
Coordinator Task 1 Task 2 
DLR, Prof. Dr. U. Schumann DLR, Dr. H. Schlager KNMI, Dr. H. Kelder 
MPI NILU
LMD UiB
KNMI UiO
ETH DLR
UMR AEA Table 4. Scientific project structure
Task DLR MPI LMD KNMI ETH NILU UiB UiO AEA UMR
1.1 X + +             +
1.2 X + + +           +
1.3     +   X          
1.4 X + + + +         +
2.1 +     X   + + + +  
2.2 + + + X +   + + + +
2.3 + + + X +   + + + +
2.4 + + X +            
2.5 + + +   + X     + +
2.6 +     +   + X + +   Table 5. Workshare (X: responsible group, +: participant)

Each group will provide data and other information, participate in meetings and workshops, as required, and provide the necessary reports to the coordinator on request.

All data will be collected in the already existing POLINAT-data bank, organized by DLR.

The results will be published as soon as possible, preferably in reviewed journals. The final project report will document the work performed, list the results obtained, and summarize the conclusions drawn.

Subsequently, the role of individual partners is described:

DLR (Coordinator)

The DLR owns and operates the Falcon. DLR will be responsible for tasks 1.1, 1.2, and 1.4, and contribute as follows:
1.1 Improvement and completion of the POLINAT instrumentation: The detection limit of the NO and NO2 instruments will be lowered by a factor of five. This is helpful for the background NOx measurements outside the polluted North Atlantic corridor region. In addition, a NOy detector will be added to the POLINAT instrument package to cover also the sum of the reactive nitrogen species.
1.2: Performance of a measurement campaign in 1997: DLR will organize the field campaign in 1997 with 40 flight hours. The base of the aircraft operations will be Shannon in Ireland or Tenerife. A local operation centre will be installed during the campaign.

DLR will also organize all coordination activities as required to coordinate the SONEX experiment with the POLINAT activities.

In particular, DLR negotiates with the Brookhaven National Laboratory (Dr. Russel Dietz) to seek for possible tracer release and analysis facilities.
1.4: Set-up of data bank: DLR has set-up the data bank for POLINAT-1 and will organize the data collection for POLINAT-2.
2.1: Refinement of models: DLR will contribute the emissions data base for the air traffic in the North Atlantic, refine plume models to analyse the mixing in the plumes, and provide the global circulation model ECHAM for transport analysis.
2.2: Analysis of the horizontal and vertical trace gas distributions: DLR will analyse the measured data in relation to model analysis
2.3: Quantification of relative contributions from surface emissions relative to air traffic emissions: The global climate circulation model ECHAM is applied to analyse the relative importance of subgrid scale compared to synoptic scale vertical transport contributions.
2.4: As far as possible with the given ressources, satellite data (NOAA AVHRR) will be analysed for contrail formation to investigate the relation between humidity and contrails.
2.5: Analysis of multiple plumes: We compute the expected concentrations using a simple plume model.
The costs for the Falcon operation (40 flight hours) will be split between DLR, MPI and LMD.

MPI (Partner 1)

MPIK Heidelberg will carry out measurements of trace gases on board the Falcon. The measurements will be made by a novel greatly improved aircraft-borne IMR-MS (Ion-Molecule Reaction Mass Spectrometer) instrument (AAMAS 2 = Automatic Aircraft-borne Mass Spectrometer 2). These investigations will be supported by accompanying laboratory investigations of ion-molecule and gas-phase reactions and investigations of jet engine exhaust in a test channel at the ground.

The following trace gases are to be measured by AAMAS 2:

NO, NO2, HNO2, HNO3, HNO4, NH3,
SO2, SO3, H2SO4
HF, HCl
Ketones, particularly :f.(CH3)2CO
Other NMHC (particularly also: HCN, HCOOH, CH3COOH)
H2O2
Optionally HO2 and OH may become detectable with a new detection method (IMR-MS with titration with SO2 and NO) under development.

The MPI takes over a share of 30 KECU of the Falcon operation costs.

KNMI (Partner 2)

KNMI will be responsible for tasks 2.1, 2.2 and 2.3, and contribute to 1.2., 1.4, and 2.6.

KNMI will perform weather forecasting and post-campaign meteorological analysis in the planned measurement campaign. The KNMI trajectory model will be used for qualifying the transport of aircraft and other anthropogenic emissions, and its use will be extended to domain-filling trajectories.

A regional version of the CTMK model embedded in the global version will be used for chemistry-transport studies of the measurement episodes.

KNMI will provide the trajectory information as required for coordination of the DC-8 and Falcon flights during the coordinated POLINAT-2-SONEX experiments.

LMD (Partner 3)

LMD will contribute to task 1 by providing a frost-point hygrometer for use on the Falcon aircraft, and to task 2 by analysis of the distribution of water vapour and its relation to air masses, transport effects, and cirrus formation. In addition LMD will be responsible for task 2.4, and organize the contacts to related projects. The frost-point hygrometer is designed, built and calibrated at LMD and has been used successfully before.

LMD carries a share of the Falcon operation costs (30 KECU).

NILU (Partner 4)

NILU will focus on model activities and will be responsible for the coordination of the Norwegian work, with the Universities of Bergen and Oslo as associated partners. NILU will be responsible for task 2.5 and participate in tasks 2.1 and 2.6.

In particular, NILU will contribute with an expanding plume and chemistry model to the POLINAT-2 project, with emphasis on multiple plume calculations. Measurements of several chemical species, e.g. NOx, HNO3 and O3 and turbulence data available from POLINAT-1 and -2 will be used in order to give a more realistic description of both the chemical composition of the background atmosphere and the meteorological conditions in the model. Both tropospheric and stratospheric chemistry will be included.

AEA (Partner 5)

AEA with UK Meteorological Office, Bracknell, United Kingdom (MetOff):

AEA will contribute to the analysis tasks, in particular by modelling the aerosol formation in the exhaust plume of aircraft. In collaboration with UK Met. Office (C. Johnson), global model analysis will be contributed to task 2.5.

At the end of POLINAT-1 it is expected that a model of the generation and evolution of an exhaust aerosol will have been established. A certain amount of model validation using data from the two experimental campaigns will have been completed. In the light of this comparison, it will undoubtedly be necessary to develop some aspects of the model to improve the correspondence with reality, as explained for task 2.1.

Having developed an aerosol/chemistry plume model, it will be put to use in interpreting new data obtained in the experimental campaigns planned under POLINAT-2, and in taking a closer look at some aspects of POLINAT-1 data. In addition, it would be valuable to make use of aerosol and chemistry data taken by the same instrumentation on board the DLR Falcon on behalf of other programmes (for example the German national programme to study aircraft emissions).

The global model STOCHEM will be used by UK Met. Office to assess the relative contribution of convective transport of boundary layer pollution compare to that arising from the emissions of subsonic aircraft, and to apply the model to investigate the large scale effects of the current air corridors on the background atmosphere. As a subsidiary, but important, objective, the validation of the model through its ability to reproduce the temporal and spatial behaviour of trace constituents in the atmosphere.

ETH (Partner 6)

The ETH will be responsible for task 1.3 and perform NO, NO2, O3, and water vapour measurements along the North-Atlantic route, using a Swissair B-747 Combi as measuring platform.

The system without the water vapour instrument is prepared for measurements on routine flights before this project starts. The complete installation will be mounted on a Swissair airliner, and the measurements will be performed during the campaign of POLINAT-2.

UMR (collaborative partner to DLR)

The UMR will contribute the MASS (Mobile Aerosol Sampling System) on the Falcon to provide for particulate sampling and characterization.

Particle measurements will include total concentration, size distribution, hydration information, and morphology. In this proposed POLINAT campaign the gaps in the measurement matrix from the initial POLINAT campaign will be filled in, and the particle - gas phase species correlations observed in the initial POLINAT campaign will be explored. The MASS will be upgraded to allow ice crystal sampling, aerosol volatility characterization, continuous concentration measurement at fixed particle size, higher efficiency total concentration measurement at high altitude, and impactor sampling of aerosols of larger size.

The participation of the University of Missouri-Rolla group includes no funding from the CEC. UMR, as an American institute, did participate in POLINAT-1 with funding by various sources including the Univ. of Missouri and NASA.

6. DELIVERABLES AND WORK PLANNING/SCHEDULE

Among the items to be delivered with the final report are
  1. dataset on disk containing the data measured during POLINAT-2, combined with those from POLINAT-1
  2. dataset on disk containing air traffic data and the emissions input as used for the model analysis
  3. mid-term report and final report on the methods used, studies performed, and results obtained
  4. summary of the conclusions
The scientific results will be published in refereed journals and technical reports.

The instruments and analysis tools remain in the property of each group and will be used for follow-on projects by them.

Press releases will be provided at proper times to inform the public on major interim findings and the final result.

Any publication using data from various groups will include co-authors from all those groups. The principal author will be listed first; the ordering of the other authors depends on the relative contributions, as decided by the principal author. No publication is permitted without the written agreement of each input providing group, under control of the project coordinator.

The POLINAT data-set will be made available for free or for a modest copy charge one year after the project terminates. It can be made available to other groups earlier under special agreements if there is a mutual interest in such an exchange, and if all partners agree.

The data exchange between POLINAT-2 and SONEX partners will be organized between the POLINAT-2 and SONEX coordinators as far as required for optimal use of the measurements results of both groups and such that the rights of the individual groups creating the data are satisfied.

Table 6 gives the expected time plan.
Task 1996 1997 1998 
1.1 Instrumentation 
   XXXXXXXXX
 
XXXXXX      
 
            
1.2 Falcon campaign 
            
 
       XX   
 
            
1.3 B747 measurements 
            
 
       XX   
 
            
1.4 Data bank 
            
 
        XXXX
 
XXX         
2.1 Model preparations 
   XXXXXXXXX
 
            
 
            
2.2 Concentration fields 
            
 
   XXXXXXXXX
 
XXX         
2.3 Surface contributions 
            
 
   XXXXXXXXX
 
XXX         
2.4 Ice supersaturation 
            
 
      XXXXXX
 
XXX         
2.5 Multiple plumes 
            
 
XXXXXXXXXXXX
 
XXX         
2.6 Ozone chemistry 
            
 
XXXXXXXXXXXX
 
XXX         
Table 6. Timetable, each x represents one month

7. COMPLEMENTARY PROJECTS

POLINAT-2 is based on the results obtained within the project POLINAT, same title as POLINAT-1, same partners, except ETH, contract no.: EV5V-CT93-0310 (DG12 DTEE). POLINAT started 1 Jan. 94 and was finished by 31 August 96. All results obtained within POLINAT are available for POLINAT-2.

POLINAT-2 will also gain form the experience obtained within AERONOX (1991-1994, CEC Contract EV5V-CT91-0044), follow-on projects suggested there, and related national programmes, e.g., in the Netherlands, France, Germany, and USA.

The partners of POLINAT-2 are willing to coordinate their activities with related projects for optimization of mutual benefits.

Moreover, as stated before, POLINAT-2 will be performed in coordination with the the research program SONEX, the "SASS (Subsonic Aircraft Assessment) Ozone and NOx Experiment.", funded by the Office of Aeronautics of NASA in Washington, DC, USA.

Main scientific contact person for each participant:

Dr. Ulrich Schumann
DLR Oberpfaffenhofen
Institut für Physik der Atmosphäre
Postfach 1116
D-82230 Wessling
Germany
Tel. (49) 8153-28-2510, 2500, 2520
Fax. (49) 8153-28-1841
email: Ulrich.Schumann@dlr.de

Priv.-Doz. Dr. Frank Arnold
Max-Planck-Institut für Kernphysik
Postfach 103980
69117 Heidelberg
Fax: 06221-516 324
Tel: 06221-516 467 (229, Sekretariat)
email: schneid@kosmo.mpi-hd.mpg.de

Dr. Joelle Ovarlez
Laboratoire de Meteorologie Dynamique
du CNRS
Ecole Polytechnique
F-91128 Palaiseau Cedex
Frankreich
Tel: 0033-1 69 33 48 00
Fax: 0033-1 69 33 30 05
email: ovarlez@LMDX04.polytechnique.fr

Dr. Hennie Kelder
Koninklijk Nederlands Meteorologisch Instituut
Postbus 201
NL-3730 AE de Bilt
Niederlande
Fax: 0031 30 2 210407
Tel: 0031 30 2 206472
email: kelder@knmi.nl

Dr. Garry D. Hayman
National Environm. Techn. Centre
AEA Technology
E5 Culham
Culham
Abingdon, Oxon. OX14 2DB
U.K., England
Tel 0044 1235 463108
Fax 0044 1235 463005
email: garry.hayman@aeat.co.uk

Dr. Frode Stordal
Norsk institutt for luftforskning
P.O. Box 64
N-2001 Lillestrom
Norwegen
Tel: +47 63 898 175
Fax: 0047 63 89 80 50
email: frode@nilu.no

Dr. I.S.A. Isaksen
University of Oslo
PB 1022 Blindern
N-0315 Oslo
Norway
Tel.: +47 22 85 58 22
Fax: +47 22 85 52 69
email: ivar.isaksen@geofysikk.uio.no

Dr. Oystein Hov
Norsk institutt for luftforskning
P.O. Box 64
N-2001 Lillestrom
Norwegen
Tel: +47 63 898 000
Fax: 0047 63 898 050
email: hov@nilu.no

Dr. Philip D. Whitefield
University of Missouri-Rolla
Cloud and Aerosol Sciences Lab.
Rolla, MO 65401
USA
Tel: 001-314-341-4340
Fax: 001-314-341-4891
email: WHITEFIE@UMRVMB.UMR.EDU

Dr. J. Staehelin, ETH,
Eidgenössische Technische Hochschule,
Institute for Atmospheric Science,
ETH-Hönggerberg,
CH-8093 Zürich,
Switzerland
fax: 0041 1 633 10 58
Tel: 0041 1 633 27 48
email: STAEHELIN@ATMOS.UMNW.ETHZ.CH
 

8. PUBLICATIONS

List 1: List of papers in the special Section of the Geophysical Research Letters - Vol. 26, No. 20, 1999:

  1. Singh, H. B., A. M. Thompson, and H. Schlager, 1999: SONEX airborne mission and coordinated POLINAT-2 activity: overview and accomplishments, Geophys. Res. Lett., 26, 3053-3056.
  2. Talbot, R. W., J. E. Dibb, E. M. Scheuer, Y. Kondo, M. Koike, H. B. Singh, L. B. Salas, Y. Fukui, J. O. Ballenthin, R. F. Meads, T. M. Miller, D. E. Hunton, A. A. Viggiano, D. R. Blake, N. J. Blake, E. Atlas, F. Flocke, D. J. Jacobs, and L. Jaeglé, 1999: Reactive nitrogen budget during the NASA SONEX mission, Geophys. Res. Lett., 26, 3057-3060.
  3. Schlager, H., P. Schulte, F. Flatoy, F. Slemr, P. van Velthoven, H. Ziereis, and U. Schumann, 1999: Regional nitric oxide enhancements in the North Atlantic flight corridor observed and modeled during POLINAT 2, a case study, Geophys. Res. Lett., 26, 3061-3064.
  4. Kondo, Y., M. Koike, H. Ikeda, B. E. Anderson, K. E. Brunke, Y. Zhao, K. Kita, T. Sugita, H. B. Singh, S. C. Liu, A. Thompson, G. L. Gregory, R. Shetter, G. Sachse, S. A. Vay, E. V. Browell, and M. J. Mahoney, 1999: Impact of aircraft emissions on NOx in the lowermost stratosphere at northern midlatitudes, Geophys. Res. Lett., 26, 3065-3068.
  5. Anderson, B. E., W. R. Cofer, J. Crawford, G. L. Gregory, S. A. Vay, K. E. Brunke, Y. Kondo, M. Koike, H. Schlager, S. L. Baughcum, E. Jensen, Y. Zhao, and K. Kita, 1999: An assessment of aircraft as a source of particles to the upper troposphere, Geophys. Res. Lett., 26, 3069-3073.
  6. Thompson, A. M., L. C. Sparling, Y. Kondo, B. E. Anderson, G. L. Gregory, and G. W. Sachse, 1999: Perspectives on NO, NOy and fine aerosol sources and variability during SONEX, Geophys. Res. Lett., 26, 3073-3076.
  7. Brune, W. H., D. Tan, I. F. Faloona, H. Jaeglé, D. J. Jacob, B. G. Heikes, J. Snow, Y. Kondo, R. Shetter, G. W. Sachse, B. Anderson, G. L. Gregory, S. Vay, H. B. Singh, D. D. Davis, J. H. Crawford, and D. R. Blake, 1999: OH and HO2 chemistry in the North Atlantic free troposphere, Geophys. Res. Lett., 26, 3077-3080.
  8. Jaeglé, L., D. J. Jacob, W. H. Brune, I. C. Faloona, D. Tan, Y. Kondo, G. W. Sachse, B. Anderson, G. L. Gregory, S. Vay, H. B. Singh, D. R. Blake, and R. Shetter, 1999: Ozone production in the upper troposphere and the influence of aircraft during SONEX: Approach of NOx-saturated conditions, Geophys. Res. Lett., 26, 3081-3084.
List 2: List of papers in the Journal of Geophysical Research, 2/16/2000:issue, SONEX/POLINAT 2 Special Section.
  1. Thompson, A. M., H. B. Singh, and H. Schlager, 2000: Introduction to special section: Subsonic Assessment Ozone and Nitrogen Oxide Experiment (SONEX) and Pollution From Aircraft Emissions in the North Atlantic Flight Corridor (POLINAT 2), J. Geophys. Res., 105, 3595.
  2. Schumann, U., H. Schlager, F. Arnold, J. Ovarlez, H. Kelder, Ø. Hov, G. Hayman, I. S. A. Isaksen, J. Staehelin, and P. D. Whitefield, 2000: Pollution from aircraft emissions in the North Atlantic flight corridor: Overview on the POLINAT projects, J. Geophys. Res., 105, 3605.
  3. Fuelberg, H. E., J. R. Hannan, P. F. J. van Velthoven, E. V. Browell, G. Bieberbach Jr., R. D. Knabb, G. L. Gregory, K. E. Pickering, and H. B. Selkirk, 2000: A meteorological overview of the Subsonic Assessment Ozone and Nitrogen Oxide Experiment (SONEX) period, J. Geophys. Res., 105, 3633.
  4. Ziereis, H., H. Schlager, P. Schulte, P. F. J. van Velthoven, and F. Slemr, 2000: Distributions of NO, NOx, and NOy in the upper troposphere and lower stratosphere between 28° and 61°N during POLINAT 2, J. Geophys. Res., 105, 3653.
  5. Koike, M., Y. Kondo, H. Ikeda, G. L. Gregory, B. E. Anderson, G. W. Sachse, D. R. Blake, S. C. Liu, H. B. Singh, A. M. Thompson, K. Kita, Y. Zhao, T. Sugita, R. E. Shetter, and N. Toriyama, 2000: Impact of aircraft emissions on reactive nitrogen over the North Atlantic Flight Corridor region, J. Geophys. Res., 105, 3665.
  6. Jeker, D. P., L. Pfister, A. M. Thompson, D. Brunner, D. J. Boccippio, K. E. Pickering, H. Wernli, Y. Kondo, and J. Staehelin, 2000: Measurements of nitrogen oxides at the tropopause: Attribution to convection and correlation with lightning, J. Geophys. Res., 105, 3679.
  7. Miller, T. M., J. O. Ballenthin, R. F. Meads, D. E. Hunton, W. F. Thorn, A. A. Viggiano, Y. Kondo, M. Koike, and Y. Zhao, 2000: Chemical ionization mass spectrometer technique for the measurement of HNO3 in air traffic corridors in the upper troposphere during the SONEX campaign, J. Geophys. Res., 105, 3701.
  8. Dibb, J. E., R. W. Talbot, and E. M. Scheuer, 2000: Composition and distribution of aerosols over the North Atlantic during the Subsonic Assessment Ozone and Nitrogen Oxide Experiment (SONEX), J. Geophys. Res., 105, 3709.
  9. Paladino, J. D., D. E. Hagen, P. D. Whitefield, A. R. Hopkins, O. Schmid, M. R. Wilson, H. Schlager, and P. Schulte, 2000: Observations of particulates within the North Atlantic Flight Corridor: POLINAT 2, September-October 1997, J. Geophys. Res., 105, 3719.
  10. Pueschel, R. F., S. Verma, H. Rohatschek, G. V. Ferry, N. Boiadjieva, S. D. Howard, and A. W. Strawa, 2000: Vertical transport of anthropogenic soot aerosol into the middle atmosphere, J. Geophys. Res., 105, 3727.
  11. Ovarlez, J., P. van Velthoven, G. Sachse, S. Vay, H. Schlager, and H. Ovarlez, 2000: Comparison of water vapor measurements from POLINAT 2 with ECMWF analyses in high-humidity conditions, J. Geophys. Res., 105, 3737-3744.
  12. Vay, S. A., B. E. Anderson, E. J. Jensen, G. W. Sachse, J. Ovarlez, G. L. Gregory, S. R. Nolf, J. R. Podolske, T. A. Slate, and C. E. Sorenson, 2000: Tropospheric water vapor measurements over the North Atlantic during the Subsonic Assessment Ozone and Nitrogen Oxide Experiment (SONEX), J. Geophys. Res., 105, 3745.
  13. Grant, W. B., E. V. Browell, C. F. Butler, M. A. Fenn, M. B. Clayton, J. R. Hannan, H. E. Fuelberg, D. R. Blake, N. J. Blake, G. L. Gregory, B. G. Heikes, G. W. Sachse, H. B. Singh, J. Snow, and R. W. Talbot, 2000: A case study of transport of tropical marine boundary layer and lower tropospheric air masses to the northern midlatitude upper troposphere, J. Geophys. Res., 105, 3757.
  14. Faloona, I., D. Tan, W. H. Brune, L. Jaeglé, D. J. Jacob, Y. Kondo, M. Koike, R. Chatfield, R. Pueschel, G. Ferry, G. Sachse, S. Vay, B. Anderson, J. Hannon, and H. Fuelberg, 2000: Observations of HOx and its relationship with NOx in the upper troposphere during SONEX, J. Geophys. Res., 105, 3771.
  15. Simpson, I. J., B. C. Sive, D. R. Blake, N. J. Blake, T.-Y. Chen, J. P. Lopez, B. E. Anderson, G. W. Sachse, S. A. Vay, H. E. Fuelberg, Y. Kondo, A. M. Thompson, and F. S. Rowland, 2000: Nonmethane hydrocarbon measurements in the North Atlantic Flight Corridor during the Subsonic Assessment Ozone and Nitrogen Oxide Experiment, J. Geophys. Res., 105, 3785.
  16. Singh, H., Y. Chen, A. Tabazadeh, Y. Fukui, I. Bey, R. Yantosca, D. Jacob, F. Arnold, K. Wohlfrom, E. Atlas, F. Flocke, D. Blake, N. Blake, B. Heikes, J. Snow, R. Talbot, G. Gregory, G. Sachse, S. Vay, and Y. Kondo, 2000: Distribution and fate of selected oxygenated organic species in the troposphere and lower stratosphere over the Atlantic, J. Geophys. Res., 105, 3795.
  17. Hannan, J. R., H. E. Fuelberg, A. M. Thompson, G. Bieberbach Jr., R. D. Knabb, Y. Kondo, B. E. Anderson, E. V. Browell, G. L. Gregory, G. W. Sachse, and H. B. Singh, 2000: Atmospheric chemical transport based on high-resolution model-derived winds: A case study, J. Geophys. Res., 105, 3807.
  18. Bieberbach, G., Jr., H. E. Fuelberg, A. M. Thompson, A. Schmitt, J. R. Hannan, G. L. Gregory, Y. Kondo, R. D. Knabb, G. W. Sachse, and R. W. Talbot, 2000: Mesoscale numerical investigations of air traffic emissions over the North Atlantic during SONEX flight 8: A case study, J. Geophys. Res., 105, 3821.
  19. Meijer, E. W., P. F. J. van Velthoven, A. M. Thompson, L. Pfister, H. Schlager, P. Schulte, and H. Kelder, 2000: Model calculations of the impact of NOx from air traffic, lightning, and surface emissions, compared with measurements J. Geophys. Res., 105, 3833.
  20. Allen, D., K. Pickering, G. Stenchikov, A. Thompson, and Y. Kondo, 2000: A three-dimensional total odd nitrogen (NOy) simulation during SONEX using a stretched-grid chemical transport model, J. Geophys. Res., 105, 3851.
  21. Jaeglé, L., D. J. Jacob, W. H. Brune, I. Faloona, D. Tan, B. G. Heikes, Y. Kondo, G. W. Sachse, B. Anderson, G. L. Gregory, H. B. Singh, R. Pueschel, G. Ferry, D. R. Blake, and R. E. Shetter, 2000: Photochemistry of HOx in the upper troposphere at northern midlatitudes, J. Geophys. Res., 105, 3877.
List 3: List of all POLINAT and POLINAT 2 publications.
  1. Anderson, B. E., W. R. Cofer, J. Crawford, G. L. Gregory, S. A. Vay, K. E. Brunke, Y. Kondo, M. Koike, H. Schlager, S. L. Baughcum, E. Jensen, Y. Zhao, and K. Kita, An assessment of aircraft as a source of particles to the upper troposphere, Geophys. Res. Lett., 26, 3069-3073,1999.
  2. Arnold, F., J. Schneider, K. Gollinger, H. Schlager, P. Schulte, P. D. Whitefield, D. E. Hagen, and P. van Velthoven, Observation of upper tropospheric sulfur dioxide and acetone pollution: Potential implications for hydroxyl radical and aerosol formation, Geophys. Res. Lett., 24, 57-60, 1997a.
  3. Arnold, F., V. Bürger, B. Droste-Franke, F. Grimm, A. Krieger, J. Schneider, and T. Stilp, Acetone in the upper troposphere and lower stratosphere: Impact on trace gases and aerosols, Geophys. Res. Lett., 24, 3017-3020, 1997b.
  4. Arnold, F., K.-H. Wohlfrom, T. Hauler, M. Klemm, V. Bürger, B. Preissler, and A. Jung, Trace gas measurements by ion molecule reaction mass spectrometry during the POLINAT 2 campaign, in POLINAT 2, edited by U. Schumann, EUR 18877 EN, pp. 89-109, Eur. Comm., Luxembourg, 1999.
  5. Berntsen, T., and I. S. A. Isaksen, A global 3-D chemical transport model for the troposphere, 1, Model description and CO and O3 results, J. Geophys. Res., 102, 21,239-21,280, 1997.
  6. Brasseur, G. P., R. A. Cox, D. Hauglustaine, I. Isaksen, J. Lelieveld, D. H. Lister, R. Sausen, U. Schumann, A. Wahner, and P. Wiesen, European scientific assessment of the atmospheric effects of aircraft emissions, Atmos. Environ., 32, 2327-2422, 1998.
  7. Dürbeck, T., and T. Gerz, Large-eddy simulation of aircraft exhaust plumes in the free atmosphere: Effective diffusivities and cross sections, Geophys. Res. Lett., 22, 3203-3206, 1995.
  8. Dürbeck, T., and T. Gerz, Dispersion of aircraft exhausts in the free atmosphere, J. Geophys. Res., 101, 26,007-26,015, 1996.
  9. Emmons, L.K., M.A. Carroll, C. Atherton, D. Hauglustaine, H. Levy II, F. Rohrer, A. Volz- Thomas, C. Gerbig, W.M.F. Wauben, P.F.J. van Velthoven, P. Bakwin, J. Bradshaw, S. Sandholm, B. Doddridge, R. Dickerson, R. Honarth, G. Hübler, D. Jaffe, Y. Kondo, J.W. Munger, S. Wofsy, B.A. Ridley, and A. Torres, Climatologies of NOx and NOy: A comparison of data and models. Atmos. Environm., 31, 1851-1903, 1997.
  10. Flatøy, F., and Ø. Hov, Three-dimensional model studies of the effect of NOx emissions from aircraft on ozone in the upper troposphere over Europe and the North Atlantic, J. Geophys. Res., 101, 1401-1422, 1996.
  11. Flatøy, F., and Ø. Hov, NOx from lightning and the calculated chemical composition of the free troposphere, J. Geophys. Res., 102, 21,373-21,381, 1997.
  12. Ford, I., An analytical model of the nucleation of a volatile aerosol in jet aircraft exhaust plumes, in POLINAT 2, edited by U. Schumann, EUR 18877 EN, pp. 249-268, Eur. Comm., Luxembourg, 1999a.
  13. Ford, I., Ice Nucleation in jet aircraft exhaust plumes, in POLINAT 2, edited by U. Schumann, EUR 18877 EN, pp. 269-287, Eur. Comm., Luxembourg, 1999b.
  14. Ford, I., R. Kingdon, and G. Hayman, Numerical modeling of the optical properties of contrails, in POLINAT 2, EUR 18877 EN, edited  by U. Schumann, pp. 233-248, Eur. Comm., Luxembourg, 1999.
  15. Fuelberg, H. E., J. R. Hannan, P. F. J. van Velthoven, E. V. Browell, G. Bieberbach Jr., R. D. Knabb, G. L. Gregory, K. E. Pickering, and H. B. Selkirk, A meteorological overview of the Subsonic Assessment Ozone and Nitrogen Oxide Experiment (SONEX) period, J. Geophys. Res., 105, 3633, 2000.
  16. Gerz, T., T. Dürbeck, and P. Konopka, Transport and effective diffusion of aircraft emissions, J. Geophys. Res., 103, 25,905-25,913, 1998.
  17. Grewe, V., M. Dameris, R. Hein, I. Köhler, and R. Sausen, Impact of future subsonic aircraft NOx emissions on the atmospheric composition, Geophys. Res. Lett., 26, 47-50, 1999.
  18. Hagen, D. E., P. D. Whitefield, and H. Schlager, Particulate emissions in the exhaust plume from commercial jet aircraft under cruise conditions, J. Geophys. Res., 101, 19,551-19,557, 1996.
  19. Hayman, G. D., and M. Markiewicz, Chemical modeling of the aircraft exhaust plume, in POLINAT, EUR 16978 EN, edited by U. Schumann, pp. 280-303, Off. for Offi. Publ. of the Eur. Comm., Luxembourg, 1997.
  20. Hayman, G., R. Kingdon, and D. Lee, Impact of different NOx sources on ozone production in the upper troposphere, in POLINAT 2, edited by U. Schumann, EUR 18877 EN, pp. 191-215, Eur. Comm., Luxembourg, 1999.
  21. Helten, M., H. G. J. Smit, D. Kley, J. Ovarlez, H. Schlager, R. Baumann, U. Schumann, P. Nedelec, and A. Marenco, In-flight intercomparison of MOZAIC and POLINAT water vapor measurements, J. Geophys. Res., 104, 26,087-26,096, 1999.
  22. Hov, Ø., and F. Flatøy, Convective redistribution of ozone and oxides of nitrogen in the troposphere over Europe in summer and fall, J. Atmos. Chem., 28, 319-337, 1997.
  23. Huntrieser, H., H. Schlager, P. van Velthoven, P. Schulte, H. Ziereis, U. Schumann, F. Arnold, and J. Ovarlez, In-situ trace gas observations in dissipating thunderclouds during POLINAT, in Proceedings of the 12th International Conference on Clouds and Precipitation, pp. 1058-1061, Zürich, Amer. Meteorol. Soc., Boston, Mass., 1996.
  24. Huntrieser, H., H. Schlager, C. Feigl, and H. Höller, Transport and production of NOx in electrified thunderstorms: Survey of previous studies and new observations at midlatitudes, J. Geophys. Res., 103, 28,247-28,264, 1998.
  25. Jeker, D. P., L. Pfister, A. M. Thompson, D. Brunner, D. J. Boccippio, K. E. Pickering, H. Wernli, Y. Kondo, and J. Staehelin, Measurements of nitrogen oxides at the tropopause: Attribution to convection and correlation with lightning, J. Geophys. Res., 105, 3679, 2000.
  26. Jonson, J. E., L. Tarrason, and J. Sundet, Calculation of ozone and other pollutants for the summer 1996, Environ. Manage. Health, 10, 245-257. 1999a.
  27. Jonson, J. E., I. S. A. Isaksen, and J. Sundet,  Calculated effects of aircraft emissions in the North Atlantic flight corridor, in POLINAT 2, edited by U. Schumann, EUR 18877 EN, pp. 177-190, Luxembourg, Eur. Comm., 1999b.
  28. Kärcher, B., R. Busen, A. Petzold, F. P. Schröder, U. Schumann, and E. J. Jensen, Physicochemistry of aircraft-generated liquid aerosols, soot, and ice particles, 2, Comparison with observations and sensitivity studies, J. Geophys. Res., 103, 17,129-17,147, 1998.
  29. Köhler, I., and R. Sausen, Contributions of various NOx sources to the atmospheric NOx content in the POLINAT region, in POLINAT, EUR 16978 EN, edited by U. Schumann, pp. 139-147, Eur. Comm., Luxembourg, 1997.
  30. Köhler I., R. Sausen, and R. Reinberger, Contributions of aircraft emissions to the atmospheric NOx content, Atmos. Environ., 31, 1801-1818, 1997.
  31. Köhler, I., R. Sausen, V. Grewe, and H. Ziereis, Intercomparison of global model simulations and aircraft measurements in the NAFC, in POLINAT 2, edited by U. Schumann, EUR 18877 EN, pp. 217-232, Luxembourg, Eur. Comm., 1999.
  32. Kraabøl, A. G., F. Stordal, I. Ford, and I. Fløisand, Particles and heterogeneous chemistry in aircraft plumes, in POLINAT 2, edited by U. Schumann, EUR 18877 EN, pp. 289-306, Eur. Comm., Luxembourg, 1999.
  33. Lee, D. S., I. Köhler, E. Grobler, F. Rohrer, R. Sausen, L. Gallardo-Klenner, J. J. G. Olivier, F. J. Dentener, and A. F. Bouwman, Estimates of global NOx emissions and their uncertainties, Atmos. Environ., 31, 1735-1749, 1997.
  34. Meijer, E.W., P.F.J. van Velthoven, W.M.F. Wauben, J.P. Beck, and G.J.M. Velders, The Effect of the Conversion of Nitrogen Oxides in Aircraft Exhaust Plumes in global Models. Geophys. Res. Lett., 24, 3013-3016, 1997.
  35. Meijer, E. W., P. F. J. van Velthoven, A. M. Thompson, L. Pfister, H. Schlager, P. Schulte, and H. Kelder, Model calculations of the impact of NOx from air traffic, lightning, and surface emissions, compared with measurements J. Geophys. Res., 105, 3833, 2000.
  36. Moustaoui, M., H. Teitelbaum, P. F. J. van Velthoven, and H. Kelder, Analysis of gravity waves during the POLINAT experiment and some consequences for stratosphere-troposphere exchange, J. Atmos. Sci., 56, 1019-1030, 1999.
  37. Ovarlez, J., and P. van Velthoven, Comparison of water vapor measurements with data retrieved from ECMWF analysis during the POLINAT experiment, J. Appl. Meteorol., 36, 1329-1335, 1997.
  38. Ovarlez, J., P. F. J. van Velthoven, and H. Schlager, Water vapor measurements from the troposphere to the lowermost stratosphere: Some signatures of troposphere to stratosphere exchanges, J. Geophys. Res., 104, 16,973-16,978, 1999.
  39. Ovarlez, J., P. van Velthoven, G. Sachse, S. Vay, H. Schlager, and H. Ovarlez, Comparison of water vapor measurements from POLINAT 2 with ECMWF analyses in high-humidity conditions, J. Geophys. Res., 105, 3737, 2000.
  40. Paladino, J., P. Whitefield, D. Hagen, A. R. Hopkins, and M. Trueblood, Particle concentrations characterization for jet engine emissions under cruise conditions, Geophys. Res. Lett., 25, 1697-1700, 1998.
  41. Paladino, J. D., D. E. Hagen, P. D. Whitefield, A. R. Hopkins, O. Schmid, M. R. Wilson, H. Schlager, and P. Schulte, Observations of particulates within the North Atlantic Flight Corridor: POLINAT 2, September-October 1997, J. Geophys. Res., 105, 3719, 2000.
  42. Schlager, H., P. Schulte, H. Ziereis, F. Arnold, J. Ovarlez, P. van Velthoven, and U. Schumann, Airborne observations of large-scale accumulations of air traffic emissions in the North Atlantic flight corridor within a stagnant anticyclone, in Proceedings International Colloquium Impact of Aircraft Emissions Upon the Atmosphere, 1, pp. 247-252, Off. Natl. d’Etudes et de Rech.. Aerosp., Chatillon, Paris, October 15-18, 1996.
  43. Schlager, H., P. Schulte, H. Ziereis, P. Konopka, U. Schumann, C. Feigl, R. Marquardt, and H. Huntrieser, Aircraft-borne measurements of NOx, O3, and CO2, in POLINAT, EUR 16978 EN, edited by U. Schumann, pp. 20-47, Off. for Offi. Publ. of the Eur. Comm., Luxembourg, 1997a.
  44. Schlager, H., P. Konopka, P. Schulte, U. Schumann, H. Ziereis, F. Arnold, M. Klemm, D. E. Hagen, P.D. Whitefield, and J. Ovarlez, In situ observations of air traffic emission signatures in the North Atlantic flight corridor, J. Geophys. Res., 102, 10,739-10,750, 1997b.
  45. Schlager, H., P. Schulte, and H. Ziereis, In-situ measurements in aircraft exhaust plumes and in the North Atlantic flight corridor, edited by U. Schumann, DLR-Mitt. 97-04, pp. 57-66, DLR, Köln, Germany, 1997c.
  46. Schlager, H., P. Schulte, F. Flatoy, F. Slemr, P. van Velthoven, H. Ziereis, and U. Schumann, Regional nitric oxide enhancements in the North Atlantic flight corridor observed and modeled during POLINAT 2, a case study, Geophys. Res. Lett., 26, 3061-3064, 1999.
  47. Schneider, J., et al., Nitric acid (HNO3) in the upper troposphere and lower stratosphere at midlatitudes: New results from aircraft-based mass spectrometric measurements, J. Geophys. Res., 103, 25,337-25,343, 1998.
  48. Schulte, P., H. Schlager, H. Ziereis, U. Schumann, S. L. Baughcum, and F. Deidewig, NOx emission indices of subsonic long-range jet aircraft at cruise altitude: In situ measurements and predictions, J. Geophys. Res., 102, 21,431-21,442, 1997.
  49. Schumann, U. (Ed.), Pollution From Aircraft Emissions in the North Atlantic Flight Corridor (POLINAT), Air pollution research rep. 58, Rep. EUR 16978 EN, 303 pp., Off. for Offi. Publ. of the Eur. Communities, Luxembourg, 1997b.
  50. Schumann, U. (Ed.), Pollution from Aircraft Emissions in the North Atlantic Flight Corridor (POLINAT 2), Air pollution research report, Rep. EUR 18877 EN, 308 pp., Off. for Offi. Publ. of the Eur. Communities, Luxembourg, 1999.
  51. Schumann, U., and P. Konopka, A simple estimate of the concentration field in a flight corridor, in Impact of Emissions From Aircraft and Spacecraft Upon the Atmosphere, edited by U. Schumann and D. Wurzel, DLR-Mitt. 94-06, pp. 354-359, DLR, Köln, Germany, 1994.
  52. Schumann, U., P. Konopka, R. Baumann, R. Busen, T. Gerz, H. Schlager, P. Schulte, and H. Volkert, Estimate of diffusion parameters of aircraft exhaust plumes near the tropopause from nitric oxide and turbulence measurements, J. Geophys. Res., 100, 14,147-14,162, 1995.
  53. Schumann U., H. Schlager, F. Arnold, R. Baumann, O. Haschberger, and O. Klemm, Dilution of aircraft exhaust plumes at cruise altitudes, Atmos. Environ., 32, 3097-3104, 1998.
  54. Schumann, U., H. Schlager, F. Arnold, J. Ovarlez, H. Kelder, Ø. Hov, G. Hayman, I. S. A. Isaksen, J. Staehelin, and P. D. Whitefield, Pollution from aircraft emissions in the North Atlantic flight corridor: Overview on the POLINAT projects, J. Geophys. Res., 105, 3605, 2000.
  55. Singh, H. B., A. M. Thompson, and H. Schlager, SONEX airborne mission and coordinated POLINAT-2 activity: overview and accomplishments, Geophys. Res. Lett., 26, 3053-3056, 1999.
  56. Singh, H., Y. Chen, A. Tabazadeh, Y. Fukui, I. Bey, R. Yantosca, D. Jacob, F. Arnold, K. Wohlfrom, E. Atlas, F. Flocke, D. Blake, N. Blake, B. Heikes, J. Snow, R. Talbot, G. Gregory, G. Sachse, S. Vay, and Y. Kondo, Distribution and fate of selected oxygenated organic species in the troposphere and lower stratosphere over the Atlantic, J. Geophys. Res., 105, 3795, 2000.
  57. Thompson, A. M., H. B. Singh, and H. Schlager, Introduction to special section: Subsonic Assessment Ozone and Nitrogen Oxide Experiment (SONEX) and Pollution From Aircraft Emissions in the North Atlantic Flight Corridor (POLINAT 2), J. Geophys. Res., 105, 3595, 2000.
  58. Tremmel, H. G., H. Schlager, P. Konopka, P. Schulte, F. Arnold, M. Klemm, and B. Droste-Franke, Observations and model calculations of jet aircraft exhaust products and cruise altitude and inferred initial OH emissions, J. Geophys. Res., 103, 10,803-10,816, 1998.
  59. Vay, S. A., B. E. Anderson, E. J. Jensen, G. W. Sachse, J. Ovarlez, G. L. Gregory, S. R. Nolf, J. R. Podolske, T. A. Slate, and C. E. Sorenson, Tropospheric water vapor measurements over the North Atlantic during the Subsonic Assessment Ozone and Nitrogen Oxide Experiment (SONEX), J. Geophys. Res., 105, 3745, 2000.
  60. Velthoven, P. van, Meteorological support for the POLINAT 2 flights, in POLINAT 2, edited by U. Schumann, EUR 18877 EN, pp. 139-147, Eur. Comm., Luxembourg, 1999.
  61. Velthoven, P. F. J. van, et al., The passive transport of NOx emissions from aircraft studied with a hierarchy of models, Atmos. Environ., 31, 1783-1799, 1997.
  62. Wauben, W. M. F., P. F. J. van Velthoven, and H. Kelder, A 3-D chemical transport model study of changes in atmospheric ozone due to aircraft emissions, Atmos. Environ., 31, 1819-1736, 1997a.
  63. Wauben, W. M. F., P. F. J. van Velthoven, and H. Kelder, The impact of air traffic in the NAFC: Model results and measurements, in POLINAT, edited by U. Schumann, EUR 16978 EN, pp. 122-133, Off. for Offi. Publ. of the Eur. Comm., Luxembourg, 1997b.
  64. Wohlfrom, K.-H., T. Hauler, F. Arnold, and H. Singh, Acetone in the free troposphere and lower stratosphere: Aircraft-based CIMS and GC measurements over the North Atlantic and a first comparison, Geophys. Res. Lett., 26,  2849-2852, 1999.
  65. Ziereis, H., H. Schlager, P. Schulte, I. Köhler, R. Marquardt, and C. Feigl, In situ measurements of the NOx distribution and variability over the eastern North Atlantic, J. Geophys. Res., 104, 16,021-16,032, 1999a.
  66. Ziereis, H., H. Schlager, and P. Schulte, NO, NOy, and O3 Intercomparisons during POLINAT 2, in POLINAT 2, edited by U. Schumann, EUR 18877 EN, pp. 55-63, Eur. Comm., Luxembourg, 1999b.
  67. Ziereis, H., H. Schlager, P. Schulte, P. F. J. van Velthoven, and F. Slemr, Distributions of NO, NOx, and NOy in the upper troposphere and lower stratosphere between 28° and 61°N during POLINAT 2, J. Geophys. Res., 105, 3653-3664, 2000.