  Thanks to the first mm studies on the territory of the former USSR in the
early 1960s and succeeding sub-mm measurements in the 1970s - early 1980s at
wavelengths up to 0.34 mm, a completely unique astroclimate was revealed in the
Eastern Pamirs, only slightly inferior to the available conditions on the
Chajnantor plateau in Chile and Mauna Kea. Due to its high plateau altitude
(4300 - 4500 m)surrounded from all sides by big (\sim7000 m) air-drying icy
mountains and remoteness from oceans this area has the lowest relative humidity
in the former USSR and extremely high atmospheric stability. In particular,
direct measurements of precipitated water vapor in the winter months showed
typical pwv=0.8 - 0.9 mm with sometimes of 0.27 mm. To validate previous
studies and to compare them with results for other similar regions we performed
opacity calculations at mm - sub-mm wavelengths for different sites in the
Eastern Pamirs, Tibet, Indian Himalayas, APEX, ALMA, JCM, LMT and many others.
To do this we integrate radiative transfer equations using the output of NASA
Global Modeling and Assimilation Office model GEOS-FPIT for more than 12 years.
We confirm previous conclusions about exceptionally good astroclimate in the
Eastern Pamirs. Due to its geographical location, small infrastructure and the
absence of any interference in radio and optical bands, this makes the Eastern
Pamirs the best place in the Eastern Hemisphere for both optical and sub-mm
astronomy.
