Monday, December 22, 2008

Last days on ice and the storm that wasn’t


Friday 19 December 2008

Beautiful, the ascent of Utsteinen nunatak after dinner last night. No wind, clear skies and a panoramic view that stretches for hundreds of kilometres. And a neat view of the station, actually.

For days now, the radar team is working on data analysis, getting the GPS and radar data together. Kenny is processing the radar data, doing the necessary filtering etc. As we mentioned before in the blog, the collected field that the data was promising. However, now that we completed the analysis it is clear that we have more than decent data (and this collected only during a couple of days). With the radar you emit an electromagnetic signal from the surface through the ice. This signal will reflect when reaching the bedrock on which the ice rest, or when it hits water (like the ocean). So, we can use the radargrams to detect the underbelly of the ice sheet, or whether the ice floats or not. So we can easily detect grounding lines, where the ice starts to get into contact with the ocean. Moreover, from the GPS data is also possible to detect the hinge line, the line from where tidal motion influences the ice. But, more interesting, it also shows isochrones within the ice as the signal is influenced by dust etc. And these are quite interesting to study as they may tell us about the present and past accumulation rates (how much snow actually falls on the surface), ice flow and ice flow changes. Moreover, we can use these lines to improve ice sheet models, because the internal layers are very good markers. Especially the area around the grounding line is a challenge, because the ice that by motion crosses this line is ‘added’ to the ocean volume and thus raises the sea level. Understanding the dynamics of grounding lines is a thus an important part of the interaction between the ice sheet and climate.

But, back to the shear reality of everyday station life. A storm was announced, but then again it never came. Well, it was announced, but not by the forecasting crew of Neumeyer. I don’t mind that information can be interpreted or maybe ‘misused’, but if afterwards people start to say that the meteorological forecasting is not correct, then I start to feel itchy. Anyway, we all enjoyed that anti-storm with clear skies, superb visibility and lack of wind. Summer, finally after all we had endured before. A second supply of new people arrived today on base, which means that tomorrow, we pull out. The BELISSSIMA adventure is almost over, but not merely the end of ULBonIce. We still have our bloguette around. We’ll put posts some pictures on the blog, from the moment we are back in civilisation.

-F

2 comments:

Louis-Philippe Loncke said...

Fantastic Photo. What altitude is that ? and at what altitude is the base below ?

Pablo (yo) said...

Hello,
I have a blog about stamps at http://albumdeestampillas.blogspot.com
I try to receive at least a visit from each country. So far, I had no visits from Antarctica. (In my flagcounter, it is listed as a separate country) So if you are in Antarctica (or are in contact with someone there), I would really apreciate if you could visit me and leave me a comment.
Thanks,
Pablo from Argentina

Bonjour,
J'ai un blog sur les timbres à http://albumdeestampillas.blogspot.com
J'essaie de recevoir au moins une visite de chaque pays. Jusqu'ici, je n'avais pas de visite de l'Antarctique. (Dans mon Flagcounter, il est répertorié comme un pays distinct) Donc si vous êtes dans l'Antarctique (ou sont en contact avec quelqu'un), je voudrais vraiment apprécierez si vous pouviez me voir et me laisser un commentaire.
Merci,
Pablo de l'Argentine