Fossil and Nonfossil Sources of Organic and Elemental Carbon Aerosols in the Outflow from Northeast China

Source quantification of carbonaceous aerosols in the Chinese outflow regions still remains uncertain despite their high mass concentrations. Here, we unambiguously quantified fossil and nonfossil contributions to elemental carbon (EC) and organic carbon (OC) of total suspended particles (TSP) from a regional receptor site in the outflow of Northeast China using radiocarbon measurement. OC and EC concentrations were lower in summer, representing mainly marine air, than in other seasons, when air masses mostly traveled over continental regions in Mongolia and northeast China. The annual-mean contribution from fossil-fuel combustion to EC was 76 ± 11% (0.1−1.3 μg m−3). The remaining 24 ± 11% (0.03−0.42 μg m−3) was attributed to biomass burning, with slightly higher contribution in the cold period (∼31%) compared to the warm period (∼21%) because of enhanced emissions from regional biomass combustion sources in China. OC was generally dominated by nonfossil sources, with an annual average of 66 ± 11% (0.5−2.8 μg m−3), approximately half of which was apportioned to primary biomass burning sources (34 ± 6%). In winter, OC almost equally originated from primary OC (POC) emissions and secondary OC (SOC) formation from fossil fuel and biomass-burning sources. In contrast, summertime OC was dominated by primary biogenic emissions as well as secondary production from biogenic and biomass-burning sources, but fossil-derived SOC was the smallest contributor. Distinction of POC and SOC was performed using primary POC-to-EC emission ratios separated for fossil and nonfossil emissions.

Drift distances, times and primary grain sources of the Arctic Ocean, Exp302 (ACEX)

Knowledge of the long-term history of the perennial ice is an important issue that has eluded study because the Cenozoic core material needed has been unavailable until the recent Arctic Coring Expedition (ACEX). Detrital Fe oxide mineral grains analyzed by microprobe from the last 14 Ma (164 m) of the ACEX composite core on the Lomonosov Ridge were matched to circum-Arctic sources with the same mineral and 12-element composition. These precise source determinations and estimates of drift rates were used to determine that these sand grains could not be rafted to the ACEX core site in less than a year. Thus the perennial ice cover has existed since 14 Ma except for the unlikely rapid return to seasonal ice between the average sampling interval of about 0.17 Ma. Both North America and Russia contributed significant Fe grains to the ACEX core during the last 14 Ma.

Multinational corporations in Brazil and Mexico : structural sources of economic and noneconomic power : report to the Subcommittee on Multinational Corporations of the Committee on Foreign Relations, United States Senate /

Mode of access: Internet.

Desert tortoise habitat conservation : hearing before the Subcommittee on Forests and Public Land Management of the Committee on Energy and Natural Resources, United States Senate, One Hundred Seventh Congress, first session, on H.R. 880, to provide for the acquisition of property in Washington County, Utah, for implementation of a desert tortoise habitat conservation plan, May 10, 2001.

Shipping list no.: 2001-0272-P.

Status of mineral resource information for assorted Indian lands in Nevada /

Bibliography: p. 123-135.

History of the public information program.

"Operational history paper."

A source book in theatrical history (Sources of theatrical history)

Bibliography: p.593-601.

Sources of hydrographic and meteorological data on the Great Lakes /

Cover title.

Effectiveness of a pilot information service for educational research materials.

Mode of access: Internet.

Perronik, the 'innocent'; or, The quest of the golden basin and diamond lance; one of the sources of stories about the Holy Grail, a Breton legend, after Souvestre,

Mode of access: Internet.