DRAKE 2009-ANTXXV/4

Type Oceanographic cruise
Ship Polarstern
Ship owner Alfred Wegener Institut (AWI)
Dates 21/03/2009 - 09/04/2009
Chief scientist(s) PROVOST Christine

LABORATOIRE D'OCÉANOGRAPHIE ET DU CLIMAT : EXPÉRIMENTATIONS ET APPROCHES NUMÉRIQUES - UMR 7159

Institut Pierre Simon Laplace

Boîte 100

4 place Jussieu

75005 Paris

+33 (1) 44 27 32 48

https://www.locean.ipsl.fr/

Objective

The Antarctic Circumpolar Current (ACC), the world largest current, is a key element of the global climate system. The ACC is constricted to its narrowest extent (700 km) in Drake Passage thus a convenient place for observations. Monitoring the ACC transport and water mass characteristics is essential for understanding the coupling of this major current with climate change. It is not an easy matter since the current is concentrated in highly variable narrow bands of swifts currents and energetic eddies of all sizes are numerous. Our experimental set up is designed to use the complementarity between satellite and in situ observations. Satellite altimetry measures the sea level of the ocean along tracks every 10 days with an horizontal resolution of 7 km. The in situ measurements will provide information on the vertical structure of the ocean. The two main tasks of the expedition were the deployment of a currentmeter mooring array along a ground track of Jason altimetric satellite and the realization of a refined array of hydrographic stations with numerous chemical tracers to properly examine the water masses. 105 CTD/LADCP/ rosette stations have been carried out and 10 current meter moorings have been deployed. The Drake cruise is also an opportunity to test the ability of kinematic GPS to measure sea level over a distance of 800 km with a few cm accuracy. Biologists studying thermal adaptation strategies colleted alive fish (fishtraps).

Published data

Park Young-Hyang, Durand Isabelle, Lee Jae-Hak, Provost Christine (2022). Raw CTD data and microstructure measurements for revisiting Thorpe scale analysis of diapycnal mixing in the Southern Ocean. https://doi.org/10.17882/89861