COST 723 11-13 March 2004

ESTEC

Working Group 3

Assessing the State of the UTLS and Understanding the Relevant Processes

(ASU2RP)

Tasks1) Assess the UTLS climatology2) Assess the trends3) Study dynamical processes in the UTLS4) Quantify the anthropogenic effects on the UTLS

EOCs (4 not yet received)

●Ozone: assessment and variability (De Backer)●Ozone radiosoundings (Michaelides)●Vertical diffusivity in the UTLS (Legras)●Cirrus clouds and supersaturation (Gierens)●Control mechanisms of UT moisture (Smit)●Climatology of Be isotops, cirrus and tropopause (Zanis, Promodos)

●O3 and H2O assimilation from ENVISAT (Fierli)

●STE modelling and ozone budget (Serafini)

●O3 variability and trends from soundings

(Cuevas)

●O3 trend over Iceland. STE at northern

subtropics. N2O increase (Gil)●Gravity waves and mixing in the UTLS (Vaughan)

Present activities

●4 groups of studies

O3 variability and trends

Moisture and cirrus clouds in the UTLS

Mixing processes

STE assessment and modelling●The first three goals of the WG3 are covered by the EOCs, but the fourth (anthropogenic effects) is marginal.● Focus is on the extratropics. Complementary of SCOUT which is focused on the tropical region.●Usage of O3 radiosoundings, balloon and aircraft measurements and satellite data (ENVISAT, ODIN)

WG3 agenda for ESTEC meeting

Thursday 11 March17:00 Posters

Friday 12 March9:00 Peter Haynes Trajectory based studies of the tropopause region

11:00 WG3 sessionK. Gierens Ice supersaturated regions in the tropopause region P. Keckhut Climatology of the upper troposphere with lidar D. Hauglustaine Global modelling of the upper-troposphere and lower stratosphere composition

13:00 joint session with WG2

14:15 WG3 meeting

WG3 Points to be discussed

- How to assess climatology and trends from available datasets-> requirements to WG1 and WG2 - Modelling studies in the UTLS-> dedicated meetings, short-term visits- Coordination with SCOUT- UTLS summer school- Consolidate plans

UTLS Summer school

26 September 8 October 2005Cargese, Corsica

Topics:- data assimilation- modelling studies of the UTLS

Audience - researchers + students (school/workshop)

Format- no more than 15 lecturers, 50-60 participants- main courses + group work - posters- computer practice

Funding - COST - FP6 - space agencies - other sponsors

Cargese Institute of Scientific Studies