PHILEAS - Probing HIgh Latitude Export of Air from the Asian Summer Monsoon

Anchorage (Alaska) and Oberpfaffenhofen (Germany) - August/September 2023

The mission focused on the export of air from the Asian summer monsoon (ASM) into the extratropical lowermost stratosphere. The ASM circulation is characterized by fast convective transport of boundary layer emission in Southeast Asia in the upper troposphere and lower stratosphere (UTLS). This air, enriched in water vapor, pollutants, and aerosol particulate matter, can be advected into more northen latitudes across the subtropical jet. As a consequence,  the northward transport can alter the chemical composition of the extratropical UTLS region. The key research questions are:

  1. What are the chemical composition and microphysical properties of the gas and particulate phase of large-scale eddies which are shed from the monsoon anticyclone?
  2. What are the main transport pathways (advection and mixing) and time scales of polluted and moist air from the monsoon into the extratropical UTLS?
  3. How do these shed eddies impact on the extratropical UTLS, and in particular on the water vapour and aerosol budget?

The mission was separated in three phases. The first phase aimed to sample the extratropical stratospheric background and the western flank of the ASM anticyclone in the Mediterranean Sea. The second phase was conducted from Anchorage, in order to measure the filaments of ASM anticyclone in the northern Pacific. The third phase aimed to sample the altered stratospheric background in autumn after the break-up of the ASM anticyclone. In total, we successfully conducted 19 research flights out of Oberpfaffenhofen (Germany) and Anchorage (Alaska). Airborne measurements were performed onboard the German research aircraft HALO (High Altitude and Long Range Research Aircraft).


ERICA (ERC Instrument for the Chemical composition of Aerosols)


F. Ekinci, O. Eppers, P. Brauner, S. Molleker, A. Dragoneas, J. Schneider, F. Köllner, S. Borrmann

Outreach and blogs

PHILEAS video on YouTube channel of Research Center Jülich

Blog on IPA website (JGU)

Blog on FZ Jülich website

Zeit online article

MPIC Press release


M. Riese (FZ Jülich), P. Hoor (JGU Mainz), Main coordinators

C. Rolf, J.-U. Grooß, J. Ungermann, P. Preuße, M. von Hobe, R. Müller, M. Krämer, F. Plöger, B. Vogel (FZ Jülich)

D. Kunkel, H. Bozem, L. Tomsche (JGU Mainz)

C. Voigt, H. Ziereis, T. Jurkart-Witschas, A. Giez (DLR)

A. Engel, T. Schuck (GU Frankfurt)

F. Friedel-Vallon, A. Zahn (KIT)

M. Volk (U Wuppertal)

M. Pöhlker, K. Barmpoudis (TROPOS) 

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