1. TITLE
Vertical ozone transports in the Alps (Acronym VOTALP).
2. OBJECTIVES
The project "Vertical ozone transports in the Alps" (VOTALP) is
a contribution to research task 5 of area 1.2.1.2. of the EU work program
on Environment and Climate ("Assessment of the temporal and spatial dynamics
of ozone in mountain regions") and will investigate the transport and formation
of ozone and other photooxidants in the Alps and in the Northern Apennines.
The general strategy of VOTALP is to combine measurements and models
of varying complexity. Four major questions will be addressed:
-
How do stratospheric intrusions influence ozone concentrations on Alpine
peaks?
Stratospheric intrusions reaching Alpine peaks will be identified and their
frequency be examined with the help of extensive meteorological and trace
substance measurements and back trajectories. In individual case studies,
the processes leading to stratospheric intrusions will be investigated.
-
How important is the advection of polluted air towards the Alps, for
instance during foehn?
Horizontal transports of pollutants towards and across the Alps will be
investigated using aircraft measurements, photochemical models and trajectory
statistics.
-
What is the effect of exchange processes between the valley atmosphere
and the free troposphere on the ozone concentrations in the valleys and
in the free troposphere?
The exchange of pollutants between the valley atmosphere and the free troposphere
caused by valley winds, slope winds and convection will be examined during
one extensive measurement campaign in an Alpine valley. Exchange processes
will be studied with a Lagrangian and a high-resolution Eulerian model
coupled with a non-hydrostatic meteorological model. Results will be compared
with aircraft measurements.
-
How important is the in-situ production of photooxidants in Alpine valleys?
The in-situ production of photooxidants will be investigated with aircraft
measurements and small scale model calculations, and its importance will
be compared to that of transport processes.
3. PROJECT METHODOLOGY
The VOTALP project will be divided into four work packages which
will focus on different processes important for the dynamics and chemistry
of ozone in the Alps. Each work package is broken down into activities
which are further divided into tasks. For each task, an acronym representing
the responsible institution is given in italic letters in brackets.
3.1 Package I: Effects of stratospheric intrusions on
ozone concentrations at Alpine peaks
3.1.1. Activity 1: Identification of stratospheric intrusions reaching
Alpine peaks
For the duration of the project, data will be collected at four stations:
Mte.
Cimone (CNR), Jungfraujoch
(PSI, LRU), Sonnblick
(IMP) and Zugspitze
(FhG). These data will be supplemented by routine measurements from
other sites (IMP, PSI, FhG, CNR). The data
set will consist of:
-
Ozone measurements at Jungfraujoch, Zugspitze, Sonnblick, Mte. Cimone and
routine measurements at other Alpine monitoring stations.
-
Ozone soundings in Payerne (acquired by PSI), Hohenpeissenberg
(acquired by IMP) and San Pietro Capofiume (CNR).
-
Lidar measurements in Garmisch-Partenkirchen (FhG).
-
Meteorological data (especially water vapor mixing ratio, potential temperature
and atmospheric stability) at the mountain top stations.
-
Measurements of the decay products of radon and thoron at Jungfraujoch
(LRU); gross- aerosol measurements at Zugspitze; radon at Mte. Cimone.
-
Daily beryllium-7 measurements at Jungfraujoch (LRU), Zugspitze,
Sonnblick, Mte. Cimone.
-
Measurements of aerosols and their sulfur content at Jungfraujoch and Sonnblick.
-
Carbon monoxide measurements at Zugspitze and Mte. Cimone.
In addition, for a period of one year, three-dimensional and isentropic
back trajectories arriving at the four receptor stations will be calculated
four times daily (IMP). Combining these data, it will be tried to
identify stratospheric intrusions and to investigate their frequency.
3.1.2. Activity 2: Case studies
Selected cases of stratospheric intrusions will be studied in more detail.
For this purpose, routine ozone and meteorological measurements, ozone
soundings at Payerne, Hohenpeissenberg and S. P. Capofiume, and high-density
lidar measurements in Garmisch-Partenkirchen will be used. If necessary
for a better understanding of the meteorological processes, these data
will be supplemented by measurements of total column ozone on Sonnblick,
Arosa and Mte. Cimone, meteorological fields of the ECMWF and satellite
images (IMP, CNR). One tropopause folding event of particular
interest will be simulated with the EURAD (European Acid
Deposition) model to estimate the downward flux of ozone (IGM-K).
The model simulations will be compared with measured data.
3.2. Package II: Influence of synoptic scale transport on
photooxidant concentrations in the Alpine region
3.2.1. Activity 1: Synoptic scale transports of photooxidants towards the
Alps
-
The importance of synoptic scale transports and the advection of reservoir
layers will be investigated using a regional-scale Lagrangian photochemical
model with high vertical resolution (IMP). For one summer, daily
model runs will be performed for four selected locations in the Alps. The
modeled vertical profiles of O3, NOx,
VOC and PAN will be analyzed in case studies and with statistical methods.
The results for the lowest model layers will be compared with measurements
at stations in Alpine foothills and the Po Valley, while those for the
upper reservoir layers will be compared with measurements at high-Alpine
sites.
-
Recently developed methods of trajectory statistics will be applied to
measured ozone concentrations at Jungfraujoch, Sonnblick, Zugspitze and
Mte. Cimone. This analysis is done to identify transport patterns yielding
high ozone concentrations on Alpine peaks (IMP).
-
Ozone measurements on Alpine summits will be compared with those at Mte.
Cimone for cases of northerly and southerly advection to assess the impact
of transports across the Po Valley on the ozone concentrations in the Alps
and Northern Apennines. Budgets along this north-south transect will be
calculated for different meteorological conditions (CNR, IMP).
Aircraft measurements shall be performed during one episode for which the
advection of Po Valley air towards the Alps is expected from the weather
forecast. This would be valuable to investigate the vertical and horizontal
extension and structure of the polluted air and its penetration into Alpine
valleys (MetAir-PSI). These measurements, however, depend
on additional funding provided by the Swiss Government. Additional ozone
soundings at S. P. Capofiume will be performed to supplement the study
(CNR).
3.2.2. Activity 2: Ozone concentrations and origin
of ozone during foehn events
-
One intensive measurement campaign will be performed during one weather
situation with south foehn forecasted. It consists of measurements with
one aircraft (MetAir-PSI), additional vertical ozone soundings
on the southern side of the Alps (PSI) and in the Po Valley (CNR),
and lidar measurements in Garmisch-Partenkirchen (FhG). It will
also be tried to use a mobile ozone lidar system for this campaign (FhG).
Subject is the determination of the origin of air masses reaching the north
side of the Alps. This shall be done with chemical (e.g., SO2)
and meteorological (e.g., potential temperature) tracers. The aircraft
will try to perform flights on the southern side of the Alps, in the Inn
valley and on the northern side of the Alps. The final route and flight
pattern will of course depend on flight limitations imposed by the authorities
and due to the weather situation. Parameters that will be measured with
the aircraft for the individual campaigns are given in the annex.
-
The EURAD modeling system will be applied to calculate the transport, chemical
transformation and deposition of ozone, other photooxidants and their precursors
(IGM-K). The simulation will be performed on a coarse grid covering
whole Europe with a horizontal resolution of 60 km and for a time span
of up to two weeks. The model in that case extends from the surface up
to 100 hPa. In the Alpine region, additional calculations will be performed
with a nested grid of 20 km resolution. The results of the simulations
will be analyzed to specify the contribution of the different dynamical
and chemical processes to the budget of ozone and its precursors. In particular,
the effect of large-scale advection of polluted air from the Po Valley
will be investigated. Data of the measurement campaign will provide valuable
information for comparison with model simulations.
3.3 Package III: Photooxidant formation and thermally
driven transports in Alpine valleys
3.3.1. Activity 1: Effects of valley winds and slope winds
One valley will be selected and intensively studied. This valley shall
meet the following requirements: pronounced thermally driven wind systems,
available routine observations, significant local emissions and suitable
technical infrastructure. Additionally, the valley shall be closed by a
high mountain range and shall be small enough to be sufficiently covered
by intensive measurements. The following measurements will be performed
during one summer:
-
Up to four coupled SCIDAR/DOAS systems for the continuous determination
of trace gas fluxes will be operated during a full summer half year (PSI).
The DOAS system is able to determine the trace gases NO2,
O3, SO2, NH3,
NO, HCHO, benzene, toluene, NO3 and HNO2.
The detection limit lies below 1 ppb for most of the species and for a
path-length of 2 km and an integration time of 5 minutes. The SCIDAR/DOAS
systems will be placed at the end of a valley to give a cross-section of
the valley top region. It will be possible to determine the fluxes of air
and chemical species out of the valley and into the valley.
The following measurements will be done in one intensive campaign during
a summerly weather situation, where significant ozone production can be
expected:
-
One Doppler sodar system (IMP) and three sonic anemometers (two
by PSI, one by IMP) will be set up on the valley ground and
on the slopes.
-
A mobile aerosol lidar system will be set up at the valley ground to measure
the three-dimensional distribution of aerosol, with particular emphasis
on the investigation of the planetary boundary layer (PBL) structure (FhG).
-
Ozone profile measurements will be done with a mobile lidar system (PSI).
-
Along a wooded slope, a profile of meteorological parameters and pollutants
will be measured. Two monitoring stations will be located near the valley
ground and just below the crest, respectively, where continuous measurements
of O3, NO and NO2 will be performed
(FKKT). Local authorities will be encouraged to set up an additional
mobile monitoring station. Two hourly measurements of anthropogenic and
biogenic NMVOC (FKKT) will be done. One mobile 30 m high measurement
platform (provided by PSI) with meteorological equipment will be
used. Comparisons of the data from the different sites will allow to make
a budget of source and loss processes and to investigate the chemical fate
of an air parcel moving along the slopes.
-
An instrumented aircraft (MetAir-PSI) will meander along
the crest lines of the investigated valley for two days. It will scan the
crest lines repeatedly to allow both statistical evaluations and the investigation
of the daily variation of PBL air injections into the free troposphere
(FT).
-
Additional aircraft measurements will be done for validation of the models
used in activity 2 (MetAir-PSI). One flight pattern will
be applied for the validation of the Lagrangian models. Constant level
balloons (CLB) will be released at a valley entrance as a Lagrangian tracer.
The aircraft will try to follow the CLB into the valley and to scan its
vicinity, additionally measuring vertical profiles. Ozone soundings along
the CLB's path will be done with a mobile radiosonde. A second flight will
be performed to yield data for the validation of Eulerian models. In that
case, the aircraft will scan larger areas than in the valley experiment
(see activity 1) to measure spatial pollutant distributions.
3.3.2. Activity 2: Modeling of photooxidant formation and transport
Two models of different complexity will be used to study the in-situ formation
and transport of photooxidants, namely a Lagrangian model (PSI, IMP)
and a high resolution Eulerian model coupled with a non-hydrostatic meteorological
model (FhG). The PSI/IMP model will be based on the ALPTHERM
model which simulates the vertical exchange in complex terrain and will
include the CBM-IV chemical mechanism. The trajectories will be calculated
from wind fields of the high resolution model operated by the Swiss Meteorological
Institute in combination with a vorticity based slope wind model. The PSI/IMP
model will be used for the simulation of vertical pollutant profiles from
valley ground to the FT. A simplified parameterization of PBL-FT exchange
due to slope winds is tried. In a second step, the budgets of ozone and
NOx will be tried to estimate, including dry deposition
on the slopes and net export into the FT. The chemical fate (= time development
of chemical species) of an air parcel injected from the PBL into the FT
over the crest will be investigated with a simple box model (PSI).
In the Eulerian model simulation (FhG), emphasis will be laid
on the diurnal variation of the PBL in valleys, the transport of pollutants
across the mountain ridges, the exchange of Alpine air masses with air
masses from surrounding planes and the influence of local emissions. The
simulation will be done on a coarse grid with 2 km and a nested fine grid
with 0.5 km horizontal resolution. A non-hydrostatic three-dimensional
meteorological model is combined with a chemistry-transport model. The
photochemistry is represented by the RADM2.0 mechanism. Available high-resolution
emission inventories will be used. The boundary conditions for this model
will be taken from a EURAD simulation (IGM-K).
3.4 Package IV: VOTALP database and synthesis
3.4.1. Activity 1: VOTALP database
A database will be created (IMP), in which the following data shall
be available for all partners in a standardized format:
-
Routine measurements performed during VOTALP
-
Data measured during the VOTALP intensive measurement campaigns
-
Supplemental routine measurements at air quality and weather monitoring
stations
-
Trajectory calculations
-
Selected model results
3.4.2. Activity 2: Integration of the findings from work packages I, II
and III
A climatological study of the frequencies of meteorological conditions
leading to the different processes will be done (IMP). Rough estimations
of the relative importances of the processes investigated in the work packages
1-3 will be done by the VOTALP partners. For this purpose, it will
be tried to differentiate between conditions favorable to stratospheric
intrusions, synoptic scale transports and in-situ ozone production (all
partners).
Preliminary investigations of simple emission reduction scenarios (e.g.,
30% reduction of total emissions) will be done (FhG, PSI).
One of the questions which shall be addressed, is the impact of NOx
versus VOC control.
ANNEX:
Table indicating which parameters are measured by aircraft during the
different observation phases.
| Parameter |
Observation Phase
|
|
|
Po-Valley
|
Valley
|
Foehn
|
| Position, temperature, dewpoint |
S
|
S
|
S
|
| Down-looking video (land use, etc.) |
S
|
S
|
S
|
| Horizontal wind low resolution |
S
|
S
|
S
|
| O3, NO2 |
S
|
S
|
S
|
| NMHC (C4 .. C11) with GC-FID |
S
|
N
|
N
|
| Peroxides |
S/F2
|
N
|
N
|
| 3-d-wind high resolution |
P
|
P
|
P
|
| SO2 |
P/F2
|
P
|
P
|
| Aerosols (CCN) |
P/AF
|
P/AF
|
P/AF
|
| Radioaltimeter |
P
|
P
|
P
|
| NOy |
P/AF
|
N
|
N
|
| Vertical CO2/H2O-fluxes |
N
|
P/AF
|
N
|
codes:
S Standard, can be guaranteed
P Planned, likely to be realized
N Not essential, will only be measured when capacity is not used by
other instruments
/F2 If second aircraft is available
/AF If additional funding is available
4. MILESTONES
Work to achieve the following milestones will be done during the time period
indicated by the black bars.
|
Milestone
|
Year 1
|
Year 2
|
| VOTALP database |
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
| Measurements at mountain tops |
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
| Selection of a valley for the field campaign |
X
|
|
|
|
|
|
|
|
|
|
|
|
| Back trajectories for mountain tops |
X
|
X
|
X
|
X
|
X
|
X
|
X
|
|
|
|
|
|
| EURAD simulation stratospheric intrusion |
X
|
X
|
X
|
X
|
X
|
|
|
|
|
|
|
|
| Case studies stratospheric intrusion |
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
|
|
|
|
| Valley field campaign |
|
|
X
|
X
|
|
|
|
|
|
|
|
|
| Model validation measurements |
|
|
X
|
X
|
|
|
|
|
|
|
|
|
| Synoptic scale Lagrangian model simulations |
|
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
|
|
|
| Eulerian photochemical smog model simulations |
|
|
|
|
X
|
X
|
X
|
X
|
X
|
X
|
|
|
| Local scale Lagrangian model simulations |
|
|
|
|
X
|
X
|
X
|
X
|
X
|
X
|
|
|
| VOTALP progress report |
|
|
|
|
|
X
|
|
|
|
|
|
|
| Valley wind parameterization |
|
|
|
|
|
|
X
|
X
|
X
|
X
|
|
|
| Trajectory statistics |
|
|
|
|
|
|
X
|
X
|
X
|
X
|
|
|
| Foehn field campaign |
|
|
|
|
|
|
|
X
|
X
|
|
|
|
| EURAD simulation foehn |
|
|
|
|
|
|
|
|
X
|
X
|
X
|
X
|
| Preliminary emission reduction studies |
|
|
|
|
|
|
|
|
X
|
X
|
X
|
X
|
| Climatological study |
|
|
|
|
|
|
|
|
|
X
|
X
|
X
|
| VOTALP final report |
|
|
|
|
|
|
|
|
|
|
|
X
|
5. ROLE OF PARTICIPANTS
The VOTALP project will be carried out by the following institutions:
|
Acronym
|
Status
|
Institution
|
| IMP |
Coordinator |
Institut für Meteorologie und Physik der Universität für
Bodenkultur, Vienna, Austria |
| IGM-K |
Contractor |
Institut für Geophysik und Meteorologie der Universität zu
Köln, Cologne, Germany |
| FhG |
Contractor |
Fraunhofer-Institut für Atmosphärische Umweltforschung, Garmisch-Partenkirchen,
Germany |
| PSI |
Contractor |
Paul Scherrer Institut, Villigen, Switzerland |
| LRU |
Associated Contractor |
Labor für Radio- und Umweltchemie, Universität Bern, Bern,
Switzerland |
| FKKT |
Associated Contractor |
Fakulteta za kemijo in kemijsko tehnologijo, Univerza v Ljubljani,
Ljubljana, Slovenia |
| CNR |
Contractor |
Istituto FISBAT - C.N.R., Bologna, Italy |
| MetAir |
Subcontractor of PSI |
MetAir AG, Illnau, Switzerland |
The responsibility of the institutions for the individual research
tasks have already been indicated in chapter 3 and will be summarised in
this section. All partners are required to deliver a report on their activities
to the coordinator 10 months after the start of the project and their contribution
to the final report at the end of the project. The final report will be
completed and submitted by the project coordinator. All partners have to
deliver their measurement data to the coordinator in time and well-documented
for use in the VOTALP database.
IMP participates in all four work packages (WP). Tasks of IMP
are the coordination of VOTALP, the acquisition of Sonnblick data,
the calculation of backward trajectories, case studies of stratospheric
intrusions, the application of a Lagrangian photochemical model and of
trajectory statistics, a comparison of ozone concentrations in the Alps
and at Mte. Cimone, the setup of a sodar and a sonic anemometer during
the valley experiment, the development of a simple model for budget calculations
of the valley experiment, a climatological study of the different processes
investigated in WP I-III and the management of the VOTALP database.
IGM-K participates in all four WP. Tasks of IGM-K are
the simulation of a stratospheric intrusion event, a foehn episode and
a summerly photochemical smog episode using the EURAD modeling system.
While the former two simulations are evaluated and interpreted in detail,
the latter one is only done to supply the boundary conditions for the modeling
activities of FhG.
FhG participates in all four WP. Tasks of FhG are all
measurements done at Zugspitze, lidar measurements in Garmisch-Partenkirchen,
the setup of a mobile ozone lidar (which is currently in development) during
the foehn experiment, the setup of a mobile aerosol lidar during the valley
experiment, and the application of a high-resolution Eulerian photochemical
model to investigate photooxidant formation and transport in Alpine valleys.
PSI participates in all four WP. Tasks of PSI are acquisition
of measurement data from Jungfraujoch, ozone soundings with a mobile radiosonde,
the setup of four coupled SCIDAR/DOAS systems, two sonic anemometers and
one mobile instrumented measurement platforms during the valley experiment,
a parameterization of PBL-FT exchange, modeling of the fate of an air parcel
injected into the FT, and the application of a Lagrangian photochemical
model to investigate photooxidant formation and transport in Alpine valleys.
PSI subcontractor MetAir will be responsible for aircraft
measurements during an episode of advection of Po Valley air, a foehn episode,
the valley experiment and the validation experiments for the Lagrangian
and Eulerian models.
LRU participates in WP I and IV. Tasks of LRU are daily
measurements of 7Be, the decay products of radon and thoron,
and the aerosol sulfur concentration at Jungfraujoch.
FKKT participates in WP III and IV. Tasks of FKKT are
the setup of two measurement stations during the valley experiment and
the measurements of anthropogenic and biogenic NMVOCs.
CNR participates in WP I, II and IV. Tasks of CNR are
all measurements at Mte. Cimone, routine and additional ozone soundings
at S. P. Capofiume, case studies of stratospheric intrusions and a comparison
of ozone measurements at Mte. Cimone with Alpine measurements.
6. DELIVERABLES AND WORK PLANNING/SCHEDULE
The VOTALP project lasts for two years.
Contract deliverables:
After one year, a progress report will be provided, describing all activities
done so far. At the end of the project, the VOTALP final report
will be supplied, covering detailed reports on the activities of every
work package and a detailed synthesis of the results.
Technical deliverables:
Because of the relatively short duration of the project, all technical
deliverables will be supplied at the end of VOTALP. The following
technical deliverables can be expected:
| Content of technical deliverable |
Type |
| Measurements at mountain tops |
data set |
| Results of field campaigns (foehn, valley, model vaildation) |
data set |
| Back trajectories from mountain tops |
data set |
| EURAD model simulations |
model results |
| Photochemical smog model simulations |
model results |
| Synoptic scale Lagrangian model simulations |
model results |
| Local scale Lagrangian model simulations |
model results |
| valley wind parameterization |
method |
| Trajectory statistics |
data set |
| VOTALP database |
database |
Access to reports/data/results:
All VOTALP reports are public. The access to foreground information,
especially measurement data and models, is restricted until one year after
the ending date of VOTALP. The publication of data and results during
the project will be regulated in a consortium agreement.
7. COMPLEMENTARY PROJECTS
There are not yet any complementary projects.
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Last update: 16 February 1999 by Thomas
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