RV Polarstern, tropical South Atlantic, 03 April 2017

The weather of the last days was exactly as expected. The south-easterly trade winds blew with force 5 Beaufort and brought a wind sea of about 1m and an additional swell of another 1.5m with them.

The expected swell from the north was hardly recognizable on Saturday evening and become clearly observable until Sunday morning. It was so long that it was a hard thing to monitor a height or a period, and it did not have much influence to the ship movement.

Also as expected was the cloud image on the sky. Nice flat cumuli, with a base somewhere at 2000ft that increased a little over the morning, and tops that reached about 5000-6000ft on Saturday and kept a little lower on Sunday.

On Saturday, only a few clouds showed some overshooting, for example the cloud close left of the centre in Image 1, which brought a few rain drops over the vessel about half an hour later.

The tops observed on Saturday corresponded well with an inversion layer visible in the radiosonde data of that morning. On Sunday the inversion weakened. Nevertheless the cumuli remained smaller, with the tops well below 5000ft.

The explanation could be found in the profiles again: the lower atmosphere got warmer, with a more or less constant temperature at the sea surface, and this means a more stable atmosphere, which means less (or smaller) convective clouds.

Life on the Polarstern

Aside from the weather, there is not much change in life on board from one day to the other.

Depending on their duty, everybody finds their own rhythm.

The navigational crew and their attached seaman established their change of four hours on watch, eight hours off, with the only change when the time zone is shifted – within the next 12 hours, all watches are 20 minutes shorter (or longer) than usual.

Tobias, our forecaster, currently has two set times each day, presenting his newest forecast to the bridge at 8 am local and 6 pm local. The captain gets an additional briefing at about 8:30 am.

With more science on board, there would be another science presentation at a time arranged with the chief scientist and individual briefings of helicopter pilots. For the weather technician it's even more complicated as her fixed dates are given in UTC, every three hours a SYNOP and the launch of the radiosonde at about 11 UTC (beside of her other obligations). So, for her, the daily time schedule shifts each time we change the time zone. Beat of time for all on board are the times of meals. The most important law at sea: good food. So we have the opportunity to have breakfast at 07:30 am, lunch at 11:30 am, coffee break at 15:30 pm and dinner at 17:30 pm.

The men on watch always have the possibility to get something. A menu card will follow on a later blog day… 

Also important is to make some sport, to compensate the good food. For that we have the chance to use the gym room or the pool (Image 2 and 3).

The sauna is useful for trips in polar regions, but at the moment we only need to go outside to have best sauna conditions… 

To make the days slightly different, there are some daily changes. For example the daily shop (opens in the evening for fifteen minutes) sells water and soft drinks, another day it sells wine, and on a third day you can buy cosmetic articles.

Everything that provides a diversion is welcome. Over the weekends, German soccer league is an important thing, a bet on the pool is organized as a game. Some people are celebrating their club during the games… (Image 4) – good that LED candles are available these days. And of course the birthday of three people within three days is an excellent reason to organize a barbecue on Sunday evening.