Program and Agenda

Abstract

NITROUS OXIDE IN THE EASTERN TROPICAL SOUTH PACIFIC OCEAN

Continuous measurements of surface oceanic, and atmospheric nitrous oxide (N2O) were carried out in the eastern tropical South Pacific during the R/V Meteor cruise M91. A novel system based upon off-axis integrated cavity output spectroscopy (OA-ICOS) was used to perform by the first time a detailed survey of surface distributions of this climate relevant gas on the area. Supersaturated waters were found all along the cruise track with values ranging between 109-2350%, from which the highest saturations were observed on the near-coastal area. An offshore-inshore gradient was observed with extremely high seawater N2O concentrations east of 78°W (up to 216 nmol L-1) in consistency with low SST (~14°C) as a result of coastal upwelling off Peru. Analysis of individual sections between 8°-16°S showed also latitudinal differences on the concentration gradients, suggesting the area close to 10.5-12°S as a main site of outgassing to the atmosphere wherein the N2O anomalies were the highest. Our measurements show that the Peruvian upwelling is a significant “hotspot” of N2O emissions which has not been previously taken into account.

Authors

Arévalo-Martínez, D. L., GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany, darevalo@geomar.de

Bange, H. W., GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany, hbange@geomar.de

Kock, A., GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany, akock@geomar.de

Körtzinger, A., GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany, akoertzinger@geomar.de

Steinhoff, T., GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany, tsteinhoff@geomar.de

Details

Oral presentation

Session #:043
Date: 2/24/2014
Time: 14:00
Location: 319 AB

Presentation is given by student: Yes