First Sampling Station and a Polar Depression

© Yann Chavance / Fondation Tara Expéditions

23 May 2013

When planning a tour of the Arctic in just over six months, the Tara teams expected to encounter many difficult circumstances, especially when it comes to handling an armada of measuring and sampling instruments on deck. However, no one thought that weather obstacles would occur so early. 

The first sampling station, scheduled well-ahead of time, should have taken place around the 26-27th of May, at the border of Icelandic waters. But no one reckoned with a large depression coming from the west, the center of which would touch exactly this area at exactly the same time. ” If we had continued as planned, we would have confronted 40 or 45 knot winds during the station” says Loïc Vallette, the captain. Under these conditions, the safety of the instruments, but also that of the scientists on deck would have been compromised. In other words, we had to change plans, and advance the date of the sampling station to avoid the  depression. 

“We didn’t have a lot of choice”, explains Lionel Guidi, chief scientist on board for this leg of the expedition. “We juggled with several parameters: the presence of territorial waters, the depth of the area (because we need at least 1000 meters for sampling), and of course with the time remaining before the depression arrives.” Finally, the first station will be much further south-east than expected, and the sampling will start early on Friday morning. “We’re still waiting for the latest satellite data to determine the best place,” continues the oceanographer. “There’s a shallow shelf in this area which should be rich in plankton. We have to find exactly the right place — the most productive area where there’s still sufficient depth for our instruments.”

Since this first station starts earlier than expected, the whole team had to work extra hard these last few days to prepare: calibrating instruments, checking the software and preparing all the bottles that store samples — with a barcode indicating type of sample collected, station, depth, etc. “Everything must be ready before the station, because afterwards we won’t have the time!” warns Lionel. It must be said that the program for the first station will be full, occupying the entire scientific team this Friday from dawn to dusk. An additional half-day on Saturday is even planned — if the depression allows. “In any case, we’ll know when it passes!” exclaims Loïc. “After the station, we’ll take advantage of the wind generated by the depression to advance as much as possible under sail. Then before reaching the Faroe Islands, we should have milder weather.” We’re hoping above all to have accommodating weather… during the station.

Yann Chavance