The logo of Lhasa

(Image above is from the temple Potala in Lhasa.)


We are proud to present the first measurements of UV dose-rates and stratospheric ozone content from Lhasa (29.67 N, 91.13 E, 3648 m above sea level!). A moderate bandwith filter-instrument with 3 channels (NILUV) was first installed at the roof of the 26'th of June 1996 at the Meteorological Bureau of Tibet. UNIS and the University of Bergen support the Meteorological Bureau, which conducts and will continue this program in order to obtain long term measurements. In addition, we have installed two new NILUV's at roof the Department of Math. & Physics, University of Tibet, June 2000. These instruments are well calibrated and the results so far are promising.

The effective biologically UV dose-rates, total ozone abundances and cloud optical depths are obtained by applying a radiative transfer model to the measured irradiances centered at 305 nm, 312 nm, 320 nm, 340 nm and 380 nm. The Bandpass of these UV filters are 10 nm. The instruments also contains a visible channel, but this channel is not absolutely calibrated.

Initial raw data from the 3 Channel NILUV at the Meteorological Bureau (1996)
Results from the 6 ch. NILUVs at Department of Math. & Physics, University of Tibet (2001)

During our first trip to Tibet an automatic weather station was tested. This intrument is installed at 5400m above sea level and supplies the Meteorological Burea with realtime data.


Updated: 06 february 2001 fred@unis.no