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Two ground-based Fourier-Transform Infrared Spectrometers (FTIR) are operated in the framework of the NDSC (Network for the Detection of Stratospheric Change) to record long-term trends, to obtain annual cycles, to observe polar processes, and to validate satellite data: one at Kiruna (North of Sweden) and the other one at Izaña, Tenerife Island.

IRF Kiruna (67.8 N, 20.4 E, 420 m a.s.l.):

Figs. 1: Roof of the optical lab at IRF Kiruna.

One FTIR is operated at Kiruna (Sweden), because Kiruna

is frequently inside the polar vortex or at its edge to study polar processes
has a short polar night giving a rather long solar observation period
is rather cold and dry for better quality of the infrared spectra
is easy to access and offers a good infrastructure
is a major location of European campaigns (due to the reasons mentioned above).

Figs. 2+3: Solar tracker and its new cover on the roof of IRF Kiruna. New cover closed and opened.

Next (small) dome includes camera for cloud observation.

Since winter 1989/90 ground-based FTIR measurements were performed during each winter. Since March 1996 a BRUKER^® 120 HR is operated continuously at the Swedish Institute of Space Physics (Institutet foer Rymdfysik, IRF, Dr. Uwe Raffalski) at Kiruna (67.8 N, 20.4 E, 420 m a.s.l.). This is a joint project of the IRF in Kiruna, the Solar Terrestrial Environmental Laboratory (STEL, Prof. Yutaka Kondo) at the University of Nagoya (J) and the IMK at the FZK Karlsruhe (D).

In summer 2004 a remote control of the instrument was established. It includes

MasterSwitch^® to switch on and off all instruments.

Remote access with PCAnywhere^® to both PCs: 1st: Spectrometer, 2nd: All other equippment as solar tracker, cover, camera etc.

Camera for cloud detection.

Remote controlled cover of the solar tracker.

Remote controlled filling of liquid N2.

Camera on the entrance aperture.

This setup allows us to conduct measurements at Kiruna from Karlsruhe and to download data.

Izaña Observatory, Tenerife Island (28.3 N, 16.5 W, 2367 m a.s.l.):

Since February 1999 a Bruker 120M is operated in collaboration with INM at Izaña Observatory (IZO) on Tenerife Island.

Figs. 5+6: Izaña Observatory as reconstructed in 2002; container in front of the building (April 2003).

A FTIR is operated at Izaña Meteorological Observatory, Tenerife Island, because it

is a high-altitude station with excellent conditions for FTIR spectroscopy:
low humidity, clear sky on nearly 80% of all days
is close to the subtropical barrier and allows to study exchange processes between tropics and mid-latitudes
is easy to access and offers a good infrastructure as meteorological and astronomical observation site
is located in the free troposphere and is rather isolated in the Atlantic Ocean: local pollutions do not interfere significantly.

Figs. 7+8: FTIR container and solar tracker on top of it at Izaña Observatory (Feb. 1999).

Atmospheric Trace Constituents and Remote Sensing
Atmosphärische Spurenstoffe und Fernerkundung