  We report the latest results of 225 GHz atmospheric opacity measurements from
two arctic sites; one on high coastal terrain near the Eureka weather station,
on Ellesmere Island, Canada, and the other at the Summit Station near the peak
of the Greenland icecap. This is a campaign to search for a site to deploy a
new telescope for submillimeter Very Long Baseline Interferometry and THz
astronomy in the northern hemisphere. Since 2011, we have obtained 3 months of
winter data near Eureka, and about one year of data at the Summit Station. The
results indicate that these sites offer a highly transparent atmosphere for
observations in submillimeter wavelengths. The Summit Station is particularly
excellent, and its zenith opacity at 225 GHz is statistically similar to the
Atacama Large Milllimeter/submillimeter Array in Chile. In winter, the opacity
at the Summit Station is even comparable to that observed at the South Pole.
