Sentences with phrase «gem atmospheric levels»
Consequently, rapid industrial development in the Northern Hemisphere may have caused the significant two-fold rise in boreal GEM atmospheric levels reported after World War II.
http://www.pnas.org/ Not exact matches
From 1990 to 1996, a decrease in atmospheric GEM concentrations was observed at both the Wank and Lista stations, with higher levels at Wank (Fig. 3).
The firn air at Summit Station (72.6 ° N, 38.5 ° W) in central Greenland allowed us to reconstruct the decadal - average atmospheric history of GEM levels during the last ≈ 70 years.
While atmospheric GEM concentrations reconstructed from Summit firn air are higher than mean hemispheric values, they reproduce GEM levels observed shipboard between 40 ° and 50 ° N (see Fig.