A taste of the science

I stood for about an hour on the Monkey Island overlook (above the navigation bridge). I was unsure where the sea stopped and the sky started. It is rather meditative to watch and feel the swells, and to follow the albatross as they skim the wave tops.

First Argo float deployed on 19 March

The main science room on the ship consists of an open space with computers and large flat tables with maps and charts. There are broad windows looking out to the back deck where the gear is stored and thrown overboard. It offers a great view of the ocean and makes you feel like a real ocean scientist!

Unfortunately, we are unable to turn on any measurement devices until outside of Argentinian waters, such as the ship's ADCP (acoustic Doppler current profiler, to measure current velocity), as we did not get clearance for such measurements. There are in fact heaps of territorial issues that oceanographers must consider when studying the oceans, requiring lots of diplomatic prep-work. 

The daily work schedule will start Tuesday morning, March 21. It will be split into eight hour shifts. I have the "civilized" schedule, from 8am to 4pm. I will be learning about my duties over the next days, which will be a combination of manning the measurements and performing basic quality control data analysis.

Yesterday, 18 March, we had a brief discussion about the ADCP mounted to the ship's hull and the two ADCPs attached to the rosette wheel along with the CTD (conductivity, temperature, depth devices) and measurement bottles. ADCPs work by sending out pulses of acoustic waves into the ocean along two distinct beams. The acoustic wave packets then scatter from small objects in the water, such as plankton, with some of the energy returning to the ship or to a lowered instrument. Through knowledge of the sound speed and other geometric properties, one can perform an inverse calculation (algorithm for the rosette mounted ADCP due to a colleague Martin Visbeck in Germany; the ship-board ADCP uses another method making use of GPS) to determine the ocean current velocity vector.

Title from Alberto's lecture today

Two Argo floats in their crates

Today (19 March) we had 2.5 hours of science discussion, led by Alberto with presentations also from Povl, Sonya, and Kurt. I will try to summarize some of it in a later post. The discussion was partly for the crew, so they could understand what science is being done on the cruise, but mostly turned into a general science discussion among the oceanographers. We are about 80% set on the details of the cruise, with the other 20% flexible, depending on weather and sea ice. We wish to avoid the sea ice, as it makes most of our work difficult if not impossible. To our advantage, this year has been among the lowest sea ice extents recorded, so there should be ample time to do our job. But the season is changing, with autumn bringing rapid growth of sea ice, so we may in fact need to alter the schedule. The most likely reason to alter schedule will be the normal synoptic weather patterns that pass through the Southern Ocean every 3-5 days, bringing yet another storm with rough seas. We have yet to encounter a storm, though forecasts suggest Tuesday will be rough.

Later in the afternoon today, we did our first deployment of an Argo float. There are a total of four to deploy during the cruise, which will add to the nearly 4000 such floats around the planet. Argo floats record basic properties of the ocean such as temperature, salinity, pressure, from the surface to 2000m depth. They send signals to satellites every 10 days. These floats have a finite lifetime (few years), so it is desirable for research cruises to deploy a handful in order to keep the array strong. These floats are the main method used to determine how much the ocean is warming due to human effects. They are quite simple to deploy: merely remove them from their crate and toss overboard. I will have the privilege of doing so myself in a few weeks.

Stephen (me) on deck with a VMP (details in a later post)