Remote and in situ bio-optical determinations during the 2002-03 Italian oceanographic campaign in Western Ross Sea

Antonio Palucci, Roberta Fantoni, Luca Fiorani
ENEA, Frascati, 00044, Italy
palucci@frascati.enea.it

ABSTRACT

The inner Antarctic basins, Weddel and Ross Seas, play a pivotal rule in the fertilization and ventilation of the global oceanographic conveyor belt due to the export of nutrients and biological matter from different highly productive coastal zones such as polynya areas. How efficient is the up take of atmospheric carbon dioxide in these areas still remains the key question concerning the Southern Ocean. In fact, like all high latitude areas, it is potentially strong in sequestering CO₂ from the atmosphere, but unfortunately data near Antarctica are still scanty, especially in winter when the weather conditions are particularly severe.

Since 1997, ELF (ENEA Lidar Fluorosensor) participated in oceanographic campaigns in Antarctica on board the research vessel Italica. ELF is based on laser-induced fluorescence and continuously provides concentrations of chromophoric dissolved organic matter and phytoplankton pigments all along the ship track. In the frame of the XVIII Italian Antarctic expedition, ELF provided continuous data, in-situ bio-optical measurements as well as satellite SeaWiFS frames were jointly collected and analysed along the cruise during the late Austral summer 2002/03.

Bio-optical measurements were crucial for ELF calibration and moreover to provide greater detail of the investigated seawaters. Specifically, particulate, detritus and phytoplankton spectral absorption on filters, as well as seawater absorption, attenuation and spectral irradiance at different depths were measured in relation with biological (algal species, pigment discrimination and relative concentration determinations.

The present study has the main aim to contribute to a better understanding of primary productivity in the world ocean carbon cycle.

Last Update: 2005-03-15