Polar bear photos from a cruise last year. Just because.
Imagine you are on a research ship somewhere in the Greenland Sea. You are, as you have been for the previous days and weeks, standing in your lab, titrating oxygen. While you are rinsing bottles, you look out of the lab’s window. Your thoughts wander. You notice a little head swimming somewhere in the distance. You think “oh look, a polar bear!”.
Can you spot the polar bear?
How about now?
On that cruise we were really lucky – we got to see a couple more polar bears over the next days, and at some point even two at the same time, meeting for the delicious dinner below.
Polar bear dinner.
So yes. Is there any job in the world that could be more awesome?
Movie on how the most important instrument in oceanography works.
On our cruise on the WHOI research vessel Knorr in 2011, Sindre Skrede (find him on twitter or vimeo for many more exciting pictures and movies!) and I made a movie for his blog, describing the most important oceanographic instrument. We recently translated the movie from Norwegian to English and here it is. Enjoy!
Internal waves exist on the interface between fluids of different densities. In the ocean they are mostly observed through their surface imprint. In the tank, we could also observe them by looking in from the side, but this is hardly feasible in the ocean. But luckily vision is easier in the atmosphere than in the ocean.
On our research cruise on the RRS James Clark Ross in August 2012, we were lucky enough to observe atmospheric internal waves, and even breaking ones (see image above). This is quite a rare sight, and a very spectacular one, especially since, due to the low density contrast between the two layers, the waves break extremely slowly.
It is really hard to imagine what it looked like for real. This movie shows the view of Jan Mayen – the volcano, the rest of the island and then the atmospheric waves. Please excuse the wobbly camera – we were after all on a ship and I was too excited to stabilize properly.
Ice formation in the ocean – using my own photos to tell the story.
Recently I talked about using my own photo to explain the generation of wind-generated waves to students. And then I realized that there is another set of photos that I have been using for teaching purposes for years that I could share here, too. Those are photos that I took on my very first “real” (as in “not a student, but participating in real research”) cruise back in 2003. In a time when pictures were still analog and you could take 36 pictures and then you had to change to a new film if you had planned ahead and brought one. I think I brought 6 films on the one-month cruise. It seemed excessive at the time, and today I easily take that amount of pictures in a day, especially when at sea and in the ice.
Anyway, let’s talk about the ice.
Newly forming ice in the front, older ice in the back.
In the picture above you see several different kinds of ice: Older ice that looks like what you would imagine ice to look like in the back towards the horizon, and newly forming ice between the old ice and the ship. The ice has only just started freezing and forms a slush at the ocean’s surface that dampens out wave movement. In places, pancake ice is starting to form.
Pancake ice are almost round pieces of ice that are formed when slush freezes together. Since there is still some wave action in the water, the little ice plates bump into each other, forming a little puffy rim. Pancakes typically have a sizes ranging from the palm of your hand to maybe half a meter.
Several of the pancakes frozen together to form larger ice floes.
If the sea state isn’t too rough and the cooling continues, several of the pancakes freeze together to form larger ice floes.
Pancakes frozen together to form a closed surface.
Eventually, pancakes freeze together to form a closed surface.
Sea ice cover, additionally covered in snow.
If cooling persists, the sea ice cover thickens gradually, and snow falls on the surface.
I was so lucky to see all of these different stages of ice on my very first research cruise! And I was even luckier – in this year’s GEOF332 “field course in oceanography”, I got to show pancake ice to my students, in Hardanger fjord in February! Granted, the pancakes were really thin and we never got to see a closed sea ice cover, but what an awesome first day for a student cruise!
The Hardanger fjord covered in pancake ice on February 1st, 2013.
Using a photo from one of my research cruises to explain the formation of wind waves.
Wind waves are (surprise coming up!) waves generated by wind that blows over the ocean’s surface. The size of those waves depends on several factors: The strength of the wind, the length of time the wind has been blowing over the ocean, and the fetch (hence the “fetching” title of this post).
The bow of the RRS James Clark Ross and wind-generated waves in front of it. Note how the wind direction is indicated by the wind vane, and how parts of the ocean are sheltered by the ice floes.
The image above is really useful to talk about this concept. We see the wind direction indicated by the wind vane at the bow of the RRS James Clark Ross. In the lee of the ice floes, the water surface is smooth because it is sheltered from the wind. As the distance from the ice flow, and hence the fetch, increases, waves start forming again. In addition to the formation of waves, you can see how waves are refracted around the ice floe.
I like teaching using photos that I took myself. Not only do they show exactly what I want to talk about, but they also give me the opportunity to share stories, like in this case of how I took that photo when we were first approaching the ice edge in the Greenland Sea and then the next day there was ice everywhere and we saw polar bears. Not only are students entertained and fascinated hearing personal stories of experiences at sea, I think that those stories are also important for helping students form their self-image as an oceanographer, and for motivating them to stick it out through the tougher spots of their studies. Stories also help students remember content, and story telling is a very useful method in the classroom (but more about that in another post).