Oxidation Mechanism Observation

Mission status: Completed

Persons in Charge


  • Prof. Dr. Jos Lelieveld, Max Planck Institute for Chemistry, Mainz
  • Dr. Hartwig Harder, Max Planck Institute for Chemistry, Mainz

Mission coordinator​

Dr. Marcel Dorf, Max Planck Institute for Chemistry, Mainz

Contact point at DLR-FX for this mission:

HALO Project Management: Martina Hierle

Postal address:
DLR Oberpfaffenhofen
Flugexperimente (FX)
Münchener Str. 20
82234 Weßling

Office phone:
+49 (0)8153 28-1792

HALO Deployment Base

HALO was operated from different bases during this mission:

Time Period

The OMO mission with HALO consisted of two field campaigns: OMO-EU and OMO-Asia.

OMO-EU campaign phases:

Mission phaseDates
Preparation incl. EMI testing24 Nov 2014 - 21 Jan 2015
Mission Oberpfaffenhofen22 Jan 2015 - 27 Jan 2015
Dismounting of payload28 Jan 2015 - 30 Jan 2015


OMO-Asia campaign phases:

Mission phaseDates
Preparation incl. EMI testing26 May 2015 - 10 Jul 2015
Mission Oberpfaffenhofen11 Jul 2015 - 20 Jul 2015
Mission Paphos Phase 121 Jul 2015 - 1 Aug 2015
Mission Gan1 Aug 2015 - 10 Aug 2015
Mission Paphos Phase 210 Aug 2015 - 27 Aug 2015
Dismounting of payload28 Aug 2015 - 4 Sep 2015

Project description

The OMO aircraft measurement campaign addressed the „self-cleaning capacity“ of the atmosphere. It focused on oxidation processes and air pollution chemistry downwind of South Asia during the summer monsoon. The self-cleaning mechanism converts natural and human-made pollutants into more soluble products that can be removed by rain. This is critical for air quality and climate change, both regionally and worldwide considering rapidly growing pollution emissions, especially in Asia.

HALO on the airport of Gan (Maldives)
during the OMO-Asia campaign

The measurements took place in July and August 2015 in the upper troposphere at 10-15 km altitude. The goal was to study the influence of convective clouds and rainfall on atmospheric composition during the monsoon. While soluble gases and aerosol particles can rain out, the removal efficiency is poorly known. Monsoon clouds can have a strong and large-scale impact on atmospheric chemistry through the vertical redistribution of sunlight, pollutants and humidity. The chemical, transport and deposition processes are investigated to advance computer models and improve air quality and climate change calculations.

The German institutions of the consortium belong to the Max Planck Society, the Helmholtz Association and universities that have a track record in airborne atmospheric research, for example in the Indian Ocean Experiment, conducted in the dry season, to which the OMO measurements can be contrasted. The consortium has recently developed a comprehensive set of instrumentation for the HALO aircraft.

The flight patterns included tracks across the Arabian Sea, the Arabian Peninsula, the Indian Ocean and the Mediterranean Sea to study zonal and meridional concentration gradients and large-scale impacts of the monsoon. Vertical (stack) flights were performed in regions of particular interest, so that a range of atmospheric conditions could be analyzed and the extent of pollution layers investigated. The measurements document long-distance pollution transports and their influence on regional-to-global atmospheric composition and climate.


    • Max Planck Institute for Chemistry, Mainz (MPIC)
    • Forschungszentrum Jülich (FZ Jülich)
    • Karlsruhe Institute of Technology (KIT)
    • University of Bremen
    • Heidelberg University
    • University of Wuppertal
    • German Aerospace Center, Institute of Atmospheric Physics (DLR-IPA)

Scientific instruments and payload configuration

  • List of scientific instruments for the mission:

DescriptionPrincipal investigatorInstitution
HORUSOH/HO2/NO2Hartwig HarderMPIC, Mainz
AIR LIFOH/HO2/NO2Frank HollandFZ Jülich
PERCEASRO2Lola Andrés HernándezUniv. Bremen
SRActinic FluxBirger Bohn,
Manfred Wendisch
FZ Jülich,
Leipzig Univ.
FAIROFast ozone measurementAndreas ZahnKIT
MGCNMVOCJonathan WilliamsMPIC, Mainz
TRIHOPTotal Peroxides, H2O2 / CO, HCHO, CO2Horst FischerMPIC, Mainz
CPCCondensation particle counterHans SchlagerDLR-IPA
MIRAHVOC + isotopesRalf KoppmannUniv. Wuppertal
miniDOASDifferential Optical Absorption SpectroscopyKlaus PfeilstickerUniv. Wuppertal
BAHAMASHALO basic data acquisition systemAndreas GiezDLR-FX

Cabin and exterior configuration of HALO for the mission

HALO cabin layout for OMO

HALO exterior configuration for POLSTRACC

Halo flights for this mission


Aircraft registrationDateTake off - Landing / UTTotal flight time / hFrom - ToMission #
D-ADLR2015-01-2110:45:00 - 13:00:002.250EDMO - EDMOFlight test
D-ADLR2015-01-2410:15:00 - 13:40:003.417EDMO - EDMOMission flight
D-ADLR2015-01-2509:30:00 - 15:10:005.667EDMO - EDMOMission flight
D-ADLR2015-01-2710:30:00 - 15:25:004.917EDMO - EDMOMission flight



Aircraft registrationDateTake off - Landing / UTTotal flight time / hFrom - ToMission #
D-ADLR2015-07-1007:40:00 - 09:30:001.833EDMO - EDMOMission flight
D-ADLR2015-07-1309:35:00 - 11:55:002.333EDMO - EDMOMission flight
D-ADLR2015-07-1610:00:00 - 12:40:002.667EDMO - EDMOMission flight
D-ADLR2015-07-2109:00:00 - 12:25:003.417EDMO - LCPHMission flight
D-ADLR2015-07-2505:55:00 - 11:10:005.250LCPH - LCPHMission flight
D-ADLR2015-07-2806:10:00 - 14:00:007.833LCPH - LCPHMission flight
D-ADLR2015-08-0105:50:00 - 14:35:008.750LCPH - VRMGMission flight
D-ADLR2015-08-0602:00:00 - 06:40:004.667VRMG - OBBIMission flight
D-ADLR2015-08-0607:45:00 - 12:55:005.167OBBI - VRMGMission flight
D-ADLR2015-08-0807:30:00 - 11:25:003.917VRMG - VRMGMission flight
D-ADLR2015-08-0901:50:00 - 06:30:004.667VRMG - OBBIMission flight
D-ADLR2015-08-0907:40:00 - 12:35:004.917OBBI - VRMGMission flight
D-ADLR2015-08-1004:50:00 - 09:35:004.750VRMG - OBBIMission flight
D-ADLR2015-08-1010:55:00 - 14:30:003.583OBBI - LCPHMission flight
D-ADLR2015-08-1306:00:00 - 14:55:008.917LCPH - LCPHMission flight
D-ADLR2015-08-1505:50:00 - 15:10:009.333LCPH - LCPHMission flight
D-ADLR2015-08-1806:15:00 - 15:10:008.917LCPH - LCPHMission flight
D-ADLR2015-08-2305:55:00 - 12:40:006.750LCPH - LCPHMission flight
D-ADLR2015-08-2506:05:00 - 14:35:008.500LCPH - LCPHMission flight
D-ADLR2015-08-2708:40:00 - 14:35:005.917LCPH - EDMOMission flight

More information

Scientific background and links to more information


Campaign reports and stories:

Press releases, media etc

Press release German Embassy Nicosia (August 11, 2015):
German research aircraft in Cyprus

Press release Max-Planck-Institut für Chemie (May 17, 2015)
Flying 100,000 kilometers through the monsoon

Report in „in-cyprus“ (August 14, 2015):
Monsoon research in Paphos

Report on DLR-FX homepage (August 6, 2015):
HALO auf Kampagne „OMO-Asien“

Press release DLR (July 17, 2015):
Forschungsflugzeug HALO: Auf der Langstrecke für Messungen im asiatischen Sommermonsun