XIV TROBADES CIENTÍFIQUES DE LA MEDITERRÀNIA

 

SUMMER SCHOOL OF METEOROLOGY AT THE BALEARIC ISLANDS

 

Maó (Menorca) 9, 10 and 11 September 1998

 Pre-inscription form

 

 

 STRATOSPHERE-TROPOSPHERE INTERCHANGE PHENOMENA

The school will be held at the Biblioteca Pública, Plaça de la Conquesta nº 8, Maó.

 

Organisation:

Societat Catalana de Física de l’Institut d’Estudis Catalans

Secció de Ciència i Tècnica de l’Institut Menorquí d’Estudis

 

Scientific Committee

S. Alonso (UIB), A. Jansà (INM), J. Lorente (UB), C. Ramis (UIB), J. Vilà (UPC)

 

Secretary:

M. Dolors Bruguera

Societat Catalana de Física

Institut d’Estudis Catalans

Carrer del Carme, 47

08001 Barcelona. Spain

Tel: +34.3.270 16 20

Fax: +34.3.270 11 80

 Sponsors:

Comissionat per a Universitats i Recerca

Consell Insular de Menorca

Institut d’Estudis Catalans

Universitat de Barcelona

Universitat Politècnica de Catalunya

Universitat de les Illes Balears

e-mail information scf@iec.es

dfscrn0@ps.uib.es

 

 

STRATOSPHERE-TROPOSPHERE INTERACHANGE PHENOMENA

 

Since the middle of the century the amounts and varieties of trace gases in the atmosphere have increased strongly. A large part of the waste from traffic, industry, agriculture and society in general, is emitted into the atmosphere where is transported. Sometimes the pollutants are transformed by chemical reactions before their removal. This fact produces many environmental problems, which cover all scales in space and time. For example, air pollution can be an immediate local threat; on the other hand, the Antarctic ozone hole develops in a region remote from all large sources.

 

Tropospheric ozone has been considered one of the most critical gaseous pollutants, as it affects the tropospheric oxidation capacity, as it has adverse effects on human health, on vegetation and on soil microbes and also is a powerful greenhouse gas. The troposphere contains about 10% of the ozone in the atmosphere; 90% is located in the stratosphere between 15-30 km. Major part of the tropospheric ozone has stratospheric origin as consequence of the stratospheric intrusions associated with tropopause folding in cyclogenetic processes. However there is substantial evidencing that production and destruction of ozone within the troposphere is significantly larger than the stratospheric input. Since the precursor gases of ozone formation (mainly NOx) are emitted in increasing quantities there is evidence of an increase in tropospheric ozone.

 

Dynamic processes leading to tropopause folding in mid-latitude cyclones are related to upper-level frontogenesis acting on the potential vorticity interface between the troposphere and the stratosphere. Tropopause folds can have consequences on the mesoscale weather and develop hazardous meteorological phenomena as deep convection. Convective cells can produce severe weather since the dry air transported form the stratosphere to medium levels provides appropriate environment for supercell development.

 

Long term declines in stratospheric ozone has been observed at both mid- and high-latitudes in both Hemispheres, although the best known manifestation is the Antarctic ozone hole which occurs during the austral spring. Similar ozone depletion in the Arctic regions occurs but it is not as severe although in the 1997 spring an ozone destruction of up to 50% has been observed in the 15-20 km altitude range. Antropogenic emissions of organic halogen compounds (CFCs) are known to be responsible for the spring time ozone depletions in the polar regions. Heterogeneous chemical on the surface of polar stratospheric clouds (PSC) primes the air for ozone depletion in the presence of sunlight. Mid-latitude decline of ozone is less understood, but chlorine and bromine abundance causes the mid-latitude ozone layer to become more vulnerable to natural phenomena. CFCs, bromine and chlorine, released at the surface level have to be transported to the stratosphere. The reduction of the ozone layer increases the UV radiation to the surface and then can result an element for climatic change.

 

In addition to the surface pollutants, upper troposphere and lower stratosphere received directly gases and particles from aircraft engines. Air traffic, then, contributes to changes in large-scale environmental problems. Although the amounts of the emission are small compared to the antropogenic global emissions (2% for CO2, 2-3% for NOx), these emissions occur in the critical altitude region (9-14 km altitude) and concentrate mainly between 40-60º N. Special attention merits the situation in the north Atlantic flight corridor where more than 600 aircraft per day fly between Europe and North America. Furthermore, global air traffic is increasing by 6 to 8% annually. The future supersonic aviation will emit its products at a more critical level, between 16 and 22 km. The question of how large the emissions and their effects are is of particular importance in the study of the environmental problems.

 

The school will provide a broad information about these problems from the most recent findings.

 

 

 

 

PROGRAM:

 

Wednesday, 9 September

 

09.30-10.45.- K. P. Hoinka (Deutsches Zentrum für Luft- und Raumfahrt)

Climatology of the global tropopause

 

10.45-11.15.- Coffee break and poster visit.

 

11.15-12.30.- J. Lelieveld (Institute for Marine and Atmospheric Research Utrech)

Ozone formation in the stratosphere

 

16.00-17.00.- M. Gil (Instituto Nacional de Técnicas Aeroespaciales)

Ozone depletion in the lower stratosphere as observed with the help of isentropic forward trajectories

 

17.00-17.30.- Coffee break and poster visit

 

17.30-18.30.- E. Cuevas (Instituto Nacional de Meteorología)

The role of the stratosphere-troposphere exchange processes on the subtropical troposphere

 

Thursday, 10 September

 

09.30-10.45.- J. Lelieveld (Institute for Marine and Atmospheric Research Utrech)

Stratosphere-troposphere exchange of ozone

 

10.45-11.15.- Coffee break and poster visit

 

11.15-12.30.- A. J. Thorpe (University of Reading)

Basic dynamic processes leading to the tropopause folding in extra-tropical cyclones

 

16.00-20.00.- trip around the island of Menorca

 

 

Friday, 11 September

 

09.30-10.45.- A. J. Thorpe (University of Reading)

Mesoscale forcing of convection by tropopause folding

 

10.45-11.15.- Coffee break and poster visit.

 

11.15-12.30.- K.P.Hoinka (Deutsches Zentrum für Luft- und Raumfahrt)

On the effects of emissions from aircraft engines on te state of the atmosphere

 

 

16.00-17.00.- E. Cuevas (Instituto Nacional de Meteorología)

The total ozone as viewed from TOMS and its relationship with the tropopause height

 

17.00-17.30.- Coffee break and poster visit

 

17.30-18.30.- M. Gil (Instituto Nacional de Técnicas Aeroespaciales)

The role of source species of tropospheric origin in the stratosphere

 

 

 

CALL FOR POSTERS

 

Assistants to the school who are interested may present a poster. Organisation will provide poster board and material necessary for attaching the poster to the poster board. The abstract will be included in the Programme Book, which will be distributed at the beginning of the school. Deadline for the receipt of abstracts is 30 June 1998.

 

Abstracts (maximum 2 pages, including figures) should be sent in hard copy or by e-mail to

 

Clemente Ramis

Departament de Física

Universitat de les Illes Balears

07071 Palma de Mallorca

Spain

e-mail: dfscrn0@ps.uib.es

 

 

REGISTRATION

 

Participants are advised to register in advance by using the Pre-Registration Form. Registration form should be sent to

 

Societat Catalana de Física

Carrer del Carme, 47

08001 Barcelona

Spain

Fax: +34. 3. 270.11.80

 

The registration fee is 10000 ptas, but for young students is 5000 ptas. The fee includes a dinner and a tourist trip around the island.

 

 

PRE-RESERVATION OF ACCOMODATION

 

Participants are advised to book their accommodation in advance by using the Hotel Reservation form. The final deadline for pre-reservation will be 15 August 1998.