Publication Date:
2016-04-14
Description:
PM 2.5 dust concentrations (mineral particles with aerodynamic diameters less than 2.5 µm) typically peak in spring and early summer at rural and remote sites across the southwestern United States. Trend analyses indicate that springtime regional mean PM 2.5 dust concentrations have increased from 1995 through 2014, especially in March (5.4 % yr -1 , p 〈 0.01). This increase reflects an earlier onset of the spring dust season across the Southwest by one to two weeks over the 20-year time period. March dust concentrations were strongly correlated with the Pacific Decadal Oscillation (PDO) index (r = -0.65, p 〈 0.01), which was mostly in its negative phase from 2007 through 2014, during which the region was drier, windier, and less vegetated. The positive spring trend and its association with large-scale climate variability have several important implications for visibility, particulate matter, health effects, and the hydrologic cycle in the region.
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
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