Sunphotometric observations of the 2001 Asian dust storm over Canada and the U.S.

Thulasiraman, S.; O’Neill, Norman T.; Royer, A.; Holben, B. N.; Westphal, Douglas L.; McArthur, L. J. B.

doi:10.1029/2001gl014188

Cited by 55 publications

(51 citation statements)

References 11 publications

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“…This could be because the particle vertical distribution in the spring is generally different from those in the other seasons. During the spring, for example, long-range transport of Asian dust can significantly increase the particle concentrations in the free troposphere (25), resulting in a larger proportion of particles above the boundary layer as compared to those of the other seasons. Because the particle mass loading below the boundary layer determines the surface PM2.5 concentration, similar AOT levels will predict a lower surface PM2.5 concentration in the spring as compared to the other seasons.…”

Section: Resultsmentioning

confidence: 99%

Estimating Ground-Level PM_2.5 in the Eastern United States Using Satellite Remote Sensing

Liu

Sarnat

Kilaru

et al. 2005

Environ. Sci. Technol.

429

283

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An empirical model based on the regression between daily PM 2.5 (particles with aerodynamic diameters of less than 2.5 µm) concentrations and aerosol optical thickness (AOT) measurements from the multiangle imaging spectroradiometer (MISR) was developed and tested using data from the eastern United States during the period of 2001. Overall, the empirical model explained 48% of the variability in PM 2.5 concentrations. The root-meansquare error of the model was 6.2 µg/m 3 with a corresponding average PM 2.5 concentration of 13.8 µg/m 3 . When PM 2.5 concentrations greater than 40 µg/m 3 were removed, model results were shown to be unbiased estimators of observations. Several factors, such as planetary boundary layer height, relative humidity, season, and other geographical attributes of monitoring sites, were found to influence the association between PM 2.5 and AOT. The findings of this study illustrate the strong potential of satellite remote sensing in regional ambient air quality monitoring as an extension to ground networks. With the continual advancement of remote sensing technology and global data assimilation systems, AOT measurements derived from satellite remote sensors may provide a cost-effective approach as a supplemental source of information for determining ground-level particle concentrations.

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Section: Resultsmentioning

confidence: 99%

Estimating Ground-Level PM_2.5 in the Eastern United States Using Satellite Remote Sensing

Liu

Sarnat

Kilaru

et al. 2005

Environ. Sci. Technol.

429

283

View full text Add to dashboard Cite

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“…The Gobi Deserts in Mongolia and northern China, and the Taklimakan Desert in western China, are the two dominant source regions of dust in east Asia. Once lofted to high altitudes, dust can then become entrained in the jet stream and may be transported long distances over the Pacific Ocean to North America (Cahill, 2003;Duce et al, 1980;Jaffe et al, 1999;Thulasiraman et al, 2002). The Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) in 2001 was designed to study the impact these spring dust events have on the physical, chemical and radiative properties of the Asian aerosol as it is transported over the mainland and the Pacific Ocean (Huebert et al, 2003;Seinfeld et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Direct observations of the atmospheric processing of Asian mineral dust

et al. 2007

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Abstract. The accumulation of secondary acids and ammonium on individual mineral dust particles during ACEAsia has been measured with an online single-particle mass spectrometer, the ATOFMS. Changes in the amounts of sulphate, nitrate, and chloride mixed with dust particles correlate with air masses from different source regions. The uptake of secondary acids depended on the individual dust particle mineralogy; high amounts of nitrate accumulated on calcium-rich dust while high amounts of sulphate accumulated on aluminosilicate-rich dust. Oxidation of S(IV) to S(VI) by iron in the aluminosilicate dust is a possible explanation for this enrichment of sulphate, which has important consequences for the fertilization of remote oceans by soluble iron. This study shows the segregation of sulphate from nitrate and chloride in individual aged dust particles for the first time. A transport and aging timeline provides an explanation for the observed segregation. Our data suggests that sulphate became mixed with the dust first. This implies that the transport pathway is more important than the reaction kinetics in determining which species accumulate on mineral dust. Early in the study, dust particles in volcanically influenced air masses were mixed predominately with sulphate. Dust mixed with chloride then dominated over sulphate and nitrate when a major dust front reached the R. V. Ronald Brown. We hypothesize that the rapid increase in chloride on dust was due to mixing with HCl(g) released from acidified sea salt particles induced by heterogeneous reaction with volcanic SO 2 (g), prior to the arrival of the dust front. The amount of ammonium mixed with dust correlated strongly with the total amount of secondary acid reaction products in the dust. Submicron dust and ammonium sulphate were internally mixed, contrary to frequent reports that they exist as external mixtures. The size distribution of the mixing Correspondence to: K. Prather (kprather@ucsd.edu) state of dust with these secondary species validates previous mechanisms of the atmospheric processing of dust and generally agrees with simulated aerosol chemistry from the STEM-2K3 model. This series of novel results has important implications for improving the treatment of dust in global chemistry models and highlights a number of key processes that merit further investigation through laboratory and field studies.

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“…Most of these events have involved sources in the Gobi and Takla Makan deserts Asia (Husar et al, 2001;, Thulasiraman, 2002, although recently, a case of Saharan dust transport across Asia and the Pacific to North America has been documented . In addition, modelling studies have identified many aspects of the climatology, interannual variability and pathways of dust transport and deposition (Holzer et al, 2003Chin et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Trans-Pacific dust events observed at Whistler, British Columbia during INTEX-B

et al. 2008

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Abstract. The meteorology and physico-chemical characteristics of aerosol associated with two new cases of long range dust transport affecting western Canada during spring 2006 are described. Each event showed enhancements of both sulfate aerosol and crustal material of Asian origin. However, the events were of quite different character and demonstrate the highly variable nature of such events. The April event was a significant dust event with considerable enhancement of fine particle sulfate while the May event was a weaker dust event, also with significant fine particle sulfate enhancement. The latter event was notable in the sense that it was of short duration and was quickly followed by a large increase of organic material likely of regional origin. Comparison of these two events with other documented cases extending back to 1993, suggests that all dust events show coincident enhancements of sulfate and crustal aerosol. However, events vary across a wide continuum based on the magnitude of aerosol enhancements and their sulfate to calcium ratios. At one extreme, events are dominated by highly significant crustal enhancements (e.g. the well-documented 1998 and 2001 "dust" events) while at the other are events with some dust transport, but where sulfate enhancements are of very high magnitude (e.g. the 1993 event at Crater Lake and the 15 May 2006 event at Whistler). Other events represent a "mix". It is likely that this variability is a function of the comparative strengths of the dust and anthropogenic SO2 sources, the transport pathway and in particular the extent to which dust is transported across industrial SO2 sources, and finally, meteorological and chemical processes.

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Sunphotometric observations of the 2001 Asian dust storm over Canada and the U.S.

Cited by 55 publications

References 11 publications

Estimating Ground-Level PM_2.5 in the Eastern United States Using Satellite Remote Sensing

Estimating Ground-Level PM_2.5 in the Eastern United States Using Satellite Remote Sensing

Direct observations of the atmospheric processing of Asian mineral dust

Trans-Pacific dust events observed at Whistler, British Columbia during INTEX-B

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Sunphotometric observations of the 2001 Asian dust storm over Canada and the U.S.

Cited by 55 publications

References 11 publications

Estimating Ground-Level PM2.5 in the Eastern United States Using Satellite Remote Sensing

Estimating Ground-Level PM2.5 in the Eastern United States Using Satellite Remote Sensing

Direct observations of the atmospheric processing of Asian mineral dust

Trans-Pacific dust events observed at Whistler, British Columbia during INTEX-B

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Estimating Ground-Level PM_2.5 in the Eastern United States Using Satellite Remote Sensing

Estimating Ground-Level PM_2.5 in the Eastern United States Using Satellite Remote Sensing