Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Sonne	SO284	27.06.2021 - 16.08.2021	TRIATLAS EUROSEA	Tropical NW Atlantic

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Brandt Peter	Helmholtz Centre for Ocean Research Kiel (GEOMAR)	Emden	Emden

Ziel der Reise / Objectives of Cruise:

RV Sonne cruise SO284 was set up to rescue long-term moorings in the central and western tropical Atlantic. During the cruise the Cape Verde Ocean Observatory (CVOO), the equatorial mooring at 23?W (in cooperation with the international PIRATA program), and the western boundary current mooring array at 11?S off Brazil were recovered and redeployed ensuring the continuity of longterm observations of tropical circulation, water-mass distribution, and biogeochemical parameters. SO284 is also based on a cruise proposal for the measurement of the western boundary circulation that included hydrographic and current measurements along repeat sections along 11?S, 5?S, and 35?W. CTD measurements along these sections included biochemical measurements using water samples of the CTD rosette and optical measurements for particle counts and phyto- and zooplankton identification with an underwater vision profiler (UVP). The physical oceanography program additionally included a study of upper ocean mixing processes using an autonomous glider and a freely drifting buoy. SO284 is a contribution to the GEOMAR research program OCEANS, to the EU projects TRIATLAS, NextGEMS, and EuroSea, and to the ?Make Our Planet Great Again" project by R. Kiko. In addition to the oceanographic measurements, a set of atmospheric measurements was performed during SO284. The region of key interest was the Atlantic Intertropical Convergence Zone (ITCZ), which plays a central role for the tropical weather and climate and structures the large-scale circulation. The thermodynamic and dynamic state of the atmosphere was measured by frequent radiosonde launches, providing atmospheric profiles with high vertical resolution extending from the surface through the lower stratosphere. These measurements were complemented by continuous measurements of the atmospheric boundary layer and lower free troposphere, including optical measurements of water vapour, aerosol, precipitation, wind speed and direction as well as cloud base height. These measurements specifically address the question of how convective scale processes in the atmosphere, and their coupling to the ocean, shape the ITCZ. The collected data will help to prepare the strategy for more extensive measurements of the ITCZ planned for the BOW-TIE campaign in 2023/4 and for airborne measurements in Aug 2024 through MPI/DFG/DLR led Tropical-Ocean and Organized Convection Field study. In addition, the data will serve as a benchmark to the first international intercomparison of global storm-resolving models (DYAMOND, Stevens et al., 2019) and support the EU project NextGEMS.

Messungen / Measurements

Verankerungen / Moorings