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Earlier onset of the spring fine dust season in the southwestern United States
Author(s) -
Hand J. L.,
White W. H.,
Gebhart K. A.,
Hyslop N. P.,
Gill T. E.,
Schichtel B. A.
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl068519
Subject(s) - particulates , spring (device) , environmental science , mineral dust , atmospheric sciences , climatology , asian dust , aerodynamic diameter , aerosol , geology , geography , meteorology , chemistry , mechanical engineering , organic chemistry , engineering
Particulate matter (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 to 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 1 to 2 weeks over the 20 year time period. March dust concentrations were strongly correlated with the Pacific Decadal Oscillation index ( r = −0.65, p < 0.01), which was mostly in its negative phase from 2007 to 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.