The APE-THESEO tropical campaign: An overview

Year: 2004

Authors: Stefanutti L., Mackenzie A. R., Santacesaria V, A. Adriani, Balestri S., Borrmann S., Khattatov S., Mazzinghi P., Mitev V., Rudakov V., Schiller C., Toci G., Volk C. M., Yushkov V., Flentje H., Kiemle C., Redaelli G., Carslaw K. S., Noone K., Peter Th.

Autors Affiliation: Geophysica-EEIG, Polo Scientifico, Campus CNR, via Madonno del Piano, Sesto Fiorentino,Firenze, Italy;
University of Lancaster, Department of Environmental Science, Lancaster, U.K.;
Istituto per la Scienza dell’Atmosfera e del Clima-CNR, via del Fosso del Cavaliere, Roma, Italy;
APE-Srl, via J. Nardi 63, Firenze, Italy;
University of Mainz, Germany;
Central Aerological Observatory, Dolgoprudny, Moscow Region, Russian Federation;
Observatoire Neuchatel, Switzerland;
MPI-Chemie, Mainz, Germany. Now with ETH, Zurich, Switzerland;
Forschungszentrum Jülich GmbH, Institute I: Stratosphere (ICG-I), Germany;
Quantum Electronics Institute, National Research Council, Firenze, Italy;
Istituto di Elettronica Quantistica-CNR, via Pancaldo, Firenze, Italy;
Universität Frankfurt, Germany;
Istituto Nazionale di Ottica Applicata, Largo E. Fermi 6, 50125 Firenze, Italy;
Deutsches Zentrum für Luft- und Raumfahrt (DLR), Oberpfaffenhofen, Germany;
Department of Physics, University of L’Aquila, Italy;
The Environment Centre, University of Leeds, U.K.;
Department of Meteorology, Stockholm University, Sweden

Abstract: The APE-THESEO campaign was held from 15 February to 15 March 1999 from the Seychelles in the western Indian Ocean. APE-THESEO stands for ‘Airborne Platform for Earth
observation – (contribution to) the Third European Stratospheric Experiment on Ozone’. The campaign aimed to study processes controlling the low water content of the stratosphere, including the mechanisms of cloud formation in the tropical tropopause region, and transport processes, studied using measurements of long-lived trace gases and ozone. Two aircraft were used: the high-altitude research aircraft, M-55 Geophysica, which can fly up to 21 km, and the Falcon of the Deutsches Zentrum für Luft- und Raumfahrt, a tropospheric aircraft. Seven flights were performed, including the first simultaneous in situ and remote sensing of subvisible cirrus clouds, the first interception of sub-visible cirrus using in-flight guidance from a pathfinding aircraft, and guided descent of a high-altitude research aircraft into the anvil cloud at the top of a tropical cyclone. In this paper we describe the payload used, the objectives for each flight, and the meteorological conditions encountered. First results show that a new type of cloud, which we have dubbed ultra-thin tropical tropopause cloud (UTTC), has been observed frequently, and observed to cover areas of 105 km2. The frequent coincidence of the tropopause and hygropause implies that the western Indian Ocean played an important role in the dehydration of the lower tropical stratosphere during the season of the mission. UTTCs, sub-visible cirrus, and visible cirrus, have all been implicated in the observed dehydration. Tracer measurements indicate little mixing of stratospheric air into the upper tropical troposphere.

Journal/Review: JOURNAL OF ATMOSPHERIC CHEMISTRY (PRINT)

Volume: 48 (1)      Pages from: 1  to: 33

KeyWords: ozone; tracer, atmospheric chemistry; cirrus; ozone; satellite data; stratosphere; tropopause; water vapor, air analysis; air monitoring; air temperature; aircraft; altitude; article; atmospheric pressure; atmospheric transport; cloud; dehydration; gas; Indian Ocean; latitude; meteorological phenomena; Seychelles; stratosphere; tropics; water content, Indian Ocean; Indian Ocean islands; Seychelles
DOI: 10.1023/B:JOCH.0000034509.11746.b8

Citations: 23
data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-11-17
References taken from IsiWeb of Knowledge: (subscribers only)
Connecting to view paper tab on IsiWeb: Click here
Connecting to view citations from IsiWeb: Click here