Noble gases measured on water bottle samples during METEOR cruise M91


Coastal upwelling regions as the research area of the Metor cruise M91 off Peru belong to the most productive regions of the world ocean. Oceanic upwelling velocities, however, are too small to be measured directly. We will thus exploite the deviations of the helium-3/helium-4 ratio from the atmospheric solubility equilibrium in the case of upwelling to infer the vertical velocities. This method has already been applied in the equatorial eastern Atlantic and the coastal region off Mauritania. The resulting vertical velocities will be compared with Ekman theory. In conjunction with other measurements perfomed during M91, the upwelling velocities can be used to estimate advective transport of heat, nutrients and climate relevant trace gases into the mixed layer. Measurement and scientific evaluation of the helium data will be done in the framework of the German project SOPRAN (phase III). 335 helium samples in copper tubes have been taken from the Niskin bottles. Sampling focuses on the mixed layer and the upper 200 m of the water column. The aim of the sampling strategy is to minimize the error of the mixed layer concentration of helium-3 and to get mean values of the helium-3 concentration and gradient below the surface in order to estimate the advective and diffusive input of helium-3 into the mixed layer. In a first step, the gas has to be extracted from the water stored in the copper tubes, and this gas will then be transferred to a high resolution mass spectrometer. In addition to the helium isotopes helium-3 and helium-4, also the neon concentration of the water samples will be analysed.See "Further details:" for information on measurement technique.

Related Identifier
Metadata Access
Creator Steinfeldt, Reiner ORCID logo; Rhein, Monika ORCID logo
Publisher PANGAEA
Contributor Institut für Umweltphysik, Universität Bremen
Publication Year 2015
Funding Reference German Research Foundation Crossref Funder ID 27542298 Climate - Biogeochemistry Interactions in the Tropical Ocean
Rights Creative Commons Attribution 3.0 Unported;
OpenAccess true
Resource Type Dataset
Format text/tab-separated-values
Size 1635 data points
Discipline Biogeochemistry; Biospheric Sciences; Geosciences; Natural Sciences
Spatial Coverage (-82.000W, -16.156S, -75.332E, -5.000N); South Pacific Ocean
Temporal Coverage Begin 2012-12-03T15:53:00Z
Temporal Coverage End 2012-12-23T20:13:00Z