Atmospheric aerosol trace element chemistry at Mauna Loa Observatory: 1. 1979–1985

Abstract

Aerosol samples were collected at the Mauna Loa Observatory in Hawaii from February 1979 to May 1985. The samples were analyzed via instrumental neutron activation analysis (INAA) for up to 47 elements and via ion chromatography for sulfate. The data are dominated by crustal dust that arrives via long‐range transport from Asia each spring, thus creating a “dust season.” Of the 47 elements detected, 37 have a notably higher mass average during the dust season. The data record is explored using enrichment factors, principal component analysis, and chemical mass balances (receptor modeling). The crustal material accounts for 60–70% of the overall aerosol mass during dust seasons, yet only 15–20% during nondust seasons. It is by far the largest contributor to the natural variation dominating the principal component analysis by describing greater than 60% of the overall variance. Particulate sulfate is another major component accounting for 10–40% of the aerosol mass during dust seasons and 60–75% of the mass during nondust seasons. Particulate sulfate can be derived from crustal material and sea salt. Anthropogenic activity also can produce particulate sulfate or its precursors that can adhere to the surface of crustal material that travels over a polluted area. Minor components in the downslope winds are marine sea‐salt aerosol contributing less than 3% of the aerosol mass during the dust season and 5–6% during the nondust season. Local basalt is considered to contribute less than 2% during the dust season and 3–4% during the nondust season. (Carbon mass is not determined and therefore no carbon‐based aerosols such as soot or organic aerosols are considered in the total aerosol mass.)

Metal Compositions of PM10 and PM2.5 Aerosols in Taipei during Spring, 2002

“…Apparently, dust from long-range transport and scavenging by precipitation caused large variations in Al concentration. Large temporal variability for mineral-derived elements was consistent with other observations in remote areas downwind and big desert countries, such as northeastern China , Hong Kong , and Hawaii (Zieman et al 1995). In an usual case observed by Kim and Park (2001), a sharp decrease in total PM concentration by one order of magnitude (from approx.…”

A review of atmospheric chemistry observations at mountain sites

“…Weak dust layers occur in the FT over Japan during periods with no evident dust outbreaks or even in seasons other than spring (e.g., Iwasaka et al 1983). Asian dust events have been observed at FWS (Suzuki et al 2008(Suzuki et al , 2010, MLO (Bodhaine 1995;Clarke and Charlson 1985;Darzi and Winchester 1982;Holmes and Zoller 1996;Hyslop et al 2013;Parrington et al 1983;Parrington and Zoller 1984;Perry et al 1999;VanCuren and Cahill 2002;Zieman et al 1995), LAV (Jaffe et al 2003b;VanCuren 2003;VanCuren and Cahill 2002;VanCuren et al 2005), and WHI (Leaitch et al 2009;McKendry et al 2008). A distinct seasonal cycle with a spring maximum of Ca 2+ concentration can be seen at HPO (~0.25 μg m −3 ; Fig.…”

“…Other studies have reported that in January or February, many elements associated with continental crust experienced an increase in the mass of samples. The aerosol concentration of crustal elements remained elevated until June or July, suggesting that the dust season is from late winter to mid-summer (Parrington et al 1983;Zieman et al 1995). VanCuren et al (2005) concluded that Asian aerosols influence LAV throughout spring, summer, and fall.…”

Impact of Asian dust and continental pollutants on cloud chemistry observed in northern Taiwan during the experimental period of ABC/EAREX 2005

“…[3] Aerosol transport, including dust from Asia, across the Pacific Ocean, is well documented from low-lying groundbased observations [e.g., Prospero et al, 1985Prospero et al, , 2003Zieman et al, 1995;Arimoto et al, 1996;Huebert et al, 2001;Liu et al, 2006] and elevated mountain sites [Wai et al, 2008]. Asian mineral dust can be transported by the prevailing westerlies in the spring [e.g., Zhang et al, 1997], increasing particulate matter concentrations [e.g., Liu et al, 2006;Park et al, 2008] and pH values of rainwater [Wang et al, 2002] and cloud water in downwind areas.…”