Although this report is intended to be a comprehensive assessment of anthropogenic77 sources and sinks of greenhouse gas emissions for the United States, certain sources have been identified yet excluded from the estimates presented for various reasons. Before discussing these sources, however, it is important to note that processes or activities that are not anthropogenic in origin or do not r...

Although this report is intended to be a comprehensive assessment of anthropogenic77 sources and sinks of greenhouse gas emissions for the United States, certain sources have been identified yet excluded from the estimates presented for various reasons. Before discussing these sources, however, it is important to note that processes or activities that are not anthropogenic in origin or do not r...

Measurement of the levels of ozone and carbon monoxide (a tracer of anthropogenic pollution) at three surface sites on the Atlantic coast of Canada allow the estimation of the amount of ozone photochemically produced from anthropogenic precursors over North America and transported to the lower troposphere over the temperate North Atlantic Ocean. This amount is greater than that injected from th...

measurements of pb, cu, zn, as, ni, hg, and fe heavy metals and major elements and components such as ca, hco3, so4, na, k, mg and cl in soluble rain fractions were performed on rainwater collected at arak plain during the rainy seasons of 2012. concentrations of the heavy metals in the soluble fractions decreased for fe, pb, zn, ni, cu, as and hg, respectively and the major elements and compon...

We apply a full year of continuous atmospheric acetone measurements from the University of Minnesota tall tower Trace Gas Observatory (KCMP tall tower; 244 m a.g.l.), with a 0.5× 0.667 GEOS-Chem nested grid simulation to develop quantitative new constraints on seasonal acetone sources over North America. Biogenic acetone emissions in the model are computed based on the MEGANv2.1 inventory. An i...

Aircraft observations of Asian outflow from the TRACE-P aircraft mission over the NW Pacific (March-April 2001) show large CH4 enhancements relative to background, as well as strong CH4-C2H6-CO correlations that provide signatures of regional sources. We apply a global chemical transport model simulation of the CH4-C2H6-CO system for the TRACE-P period to interpret these observations in terms o...

[1] Methyl bromide (CH3Br) constitutes the largest source of bromine atoms to the stratosphere and plays an important role in stratospheric ozone depletion. However, the CH3Br atmospheric budget remains uncertain. We report the first measurements of stable carbon isotope ratios for atmospheric CH3Br and explore the constraints they provide for the atmospheric budget. The measured dC of CH3Br ra...

Heavy metal contamination around the National Iranian Lead and Zinc Company (NILZ) in Zanjan province was evaluated in this paper. Collected data were used to appraise the degree of soil contamination and also the source of pollution in the study area based on geoaccumulation index (Igeo), and enrichment factor (EF). The levels of Fe, Zn, Cd and Pb in the samples exceed those reported in litera...

Background and Purpose: The contamination by potentially toxic element (PTE) is a common environmental issue in worldwide rivers. The present study examined PTEs concentration in sediments of Talar River which is one of the main rivers in the Sothern Caspian Basin. Materials and Methods: The sediment samples (n= 44) were collected from top 0–5 cm of surface sediment in the main channel and flo...