PS102 - Weekly Report No. 2 | 20 - 27 November 2016
Working near the Equator
In the past week we have been travelling from 30° N towards the Equator and it has been getting steadily warmer with each mile traversed.
We reached 05°N today as planned, and the surface water temperature was measured at 29°C. Working on in the tropical heat is a new experience for most on board and for our “Scholars” from northern climes in particular. In contrast, our southern colleagues are now in their element and are happy to work in the heat. Every hundred kilometers we measure the temperature and salinity combined with many chemical and biological parameters of the water masses right down to the darkest deep. This we combine with atmospheric measurements to a height of 32 Kilometers (Figure 1). The interesting layers of different water masses, e.g. of Mediterranean water, which flows out of the Strait of Gibraltar into the north Atlantic and which then form a layer of warm water in these were measured in detail. We found our first “Advent Stars” in microscopic analyses of the sampling water- in the form of beautiful Radiolarians (Figure 2).
At night the heavens above were gigantic with stars, mirrored by a flat ocean. The constellations of the north became harder to recognize and Orion was very low in the sky. The bow wave was, already north of the Canaries a surfing paradise for flying fish, which „flew“ out of the water like silver arrows in the darkness of the night. In the night of the 20th to the 21st of November we saw the orange glow of the Canaries from a long way off on the horizon and arrived in Las Palmas, where unfortunately we had to say good-bye to many colleagues but who were partly replaced by new persons.
For a few days now we have been testing a new instrument: an underway CTD. We are using it to measure temperature and salinity in the water masses without having to stop. This was a fantastic learning experience for the “Scholars” to deploy a new instrument with the crew.
Currently we are steaming through an area with a lot of Sargasso weed. In the night, on station many large fish and Squid swam interestedly around us in the light of the ships´ flood-lights. At day we are escorted by swarms of flying fish which seem to “fly” for up to a hundred m stretches (figure 3).
It is strange to celebrate the 1st of Advent in the heat of 29°C close to the equator, but it was wonderful to be greeted by seasonal decorations and a delicious breakfast and the first cookies today.
We send you our „Advent Stars“ from the sea and a bunch of happy seasons´ greetings, from out here on the tropical Atlantic.
Best wishes Karen Wiltshire