Maybe that you wonder what are the Open Top Chambers, that Zorigto is placing at different locations in the region of the Station?
For the projects ITEX (http://www.cevl.msu.edu/ael/projects/tempmanip.html) and Tarantella (http://www.ipy.org/projects/item/410-tarantella-terrestrial-ecosystems-in-and-Arctic-Antarctic), the Open Top Chambers (OTC) were developed to simulate the impact of climate change on terrestrial ecosystems in the short and long term in polar regions (Arctic and Antarctica). OTC are small greenhouses that increase the temperature (average of 2 ° C) and humidity, and decrease the wind strength.
The establishment of a long-term experiment in polar regions request a simple, strong experimental procedure, that does not depend on a energy source because of harsh climatic conditions. For example, at Signy Island (Sub-Antarctic Island), a OTC was blown away by the wind. The choice of the structure and especially its fixation on the rock surface are very important because, during the austral winter, the station is closed and nobody can repair damages.
Thus, the selected OTCs have the form of a hexagonal pyramid with an open top allowing exchanges with the outside and a limited temperature increase.
Microprobes measuring temperature and humidity are placed in these structures in order to monitor these parameters during time in the OTC. Controls sites are also selected with similar initial conditions to assess the modifications due to natural environmental changes. This allows to distinguish between natural variations and those due to conditions present in the OTC. Annual monitoring of diversity and coverage of communities will be carried out.
Our OTC have been built by the technicians of the General Workshop of Mechanics of the Faculty of Sciences, Michel Leroy et Michel Colin, that we thank for their helpfulness and efficiency!
Here, you see Zorigto placing two OTCs on the Teltet nunatak.
While building them, we were dreaming about the possible effects of the OTCs on the Antarctic biodiversity!
Marie-José Mano (PhD student)