Cruise inventory

FS Sonne SO235

Cruise plan

Cruise Info. 
Ship name (ship code)FS Sonne (06BE)
Cruise identifierSO235
Cruise period2014-07-23 — 2014-08-07
StatusCompleted
Port of departurePort Louis, Mauritius
Port of returnMale, Maldives
PurposeResearch
ObjectivesThe OASIS (Organic very short lived substances and their Air sea Exchange from the Indian Ocean to the Stratosphere) cruise will focus on surface ocean trace gas cycling, flux to the atmosphere, and transport to upper troposphere and lower stratosphere. The gases that will be measured are mainly brominated and iodinated halocarbon compounds and dimethylsulphide, both in the ocean and in the atmosphere. CO2, N2O, and CH4 will also be measured. The Indian Ocean, with high influx of nutrients from land and special current and eddy systems, supports phytoplankton blooms that generate trace gases in the surface ocean. In addition, the western Indian Ocean experiences areas of high wind speed, related to the monsoon systems there. Both the high ocean production and wind speed events enhance air-sea exchange. The convective area above India/ Bay of Bengal is instrumental for transporting ocean-derived trace gases to the upper troposphere/lower stratosphere. The
work program of the OASIS cruise includes underway sampling as well as measurements at three 24 hour stations and 8 other shorter CTD stations to fulfill the goals of the project.

- Continuous water sampling in the hydrographic shaft to measure hydrology, trace gases and biological parameters in surface water.
- Collection of discrete air and aerosol samples.
- Atmospheric chemical and meteorological measurements.
- Ocean profiles.
- Surface current measurements.
Chief scientistKirstin Krüger (Department of Geosciences, University of Oslo)
Ocean/sea areas 
GeneralIndian Ocean