HR: 0800h
AN: A31B-0839 [Abstracts]
TI: Using Isotopes to Track the Passage of a Spring 2002 Dust Storm Over Hefei, China
AU: * Christensen, J N
EM: jnchristensen@lbl.gov
AF: Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., MS 70A4418, Berkeley, CA 94720
AU: Cliff, S S
EM: sscliff@ucdavis.edu
AF: Dept. of Applied Science, UC Davis, One Shields Ave., Davis, 95616
AU: VanCuren, R A
EM: rvancure@arb.ca.gov
AF: Dept. of Applied Science, UC Davis, One Shields Ave., Davis, 95616
AU: VanCuren, R A
EM: rvancure@arb.ca.gov
AF: Research Div., California Air Resources Board, 1001 I St., Sacremento, CA 95812
AU: Tomutsa, L
EM: ltomutsa@lbl.gov
AF: Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., MS 70A4418, Berkeley, CA 94720
AU: Perry, K D
EM: perry@met.utah.edu
AF: Dept. of Meteorology, Univ. of Utah, 135 S 1460 E, Salt Lake City, UT 84112
AU: DePaolo, D J
EM: depaolo@eps.berkeley.edu
AF: Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., MS 70A4418, Berkeley, CA 94720
AU: DePaolo, D J
EM: depaolo@eps.berkeley.edu
AF: Dept. Earth & Planetary Science, UC Berkeley, 307 McCone Hall MC4767, Berkeley, CA 94720
AB:
Research over the past decade has highlighted the importance of intercontinental transport and exchange of atmospheric
aerosols, including soil-derived dust and industrial pollutants. These far-traveled aerosols can affect air quality,
atmospheric radiative forcing and cloud formation and can be an important component in soils. Principal component analysis
of elemental data for aerosols collected over California has identified a persistent Asian soil dust component that peaks
with Asian dust storm events [1]. Isotopic fingerprinting can provide an additional and potentially more discriminating tool
for tracing the sources of dust. A time series of aerosol samples was collected on Teflon filters (PM2.5) near Hefei,
China, during a dust storm in Spring 2002. We analyzed these samples for isotopic composition, including 87Sr/86Sr
and 143Nd/144Nd, and also measured the amounts of K, Rb, Sr, Sm, and Nd by isotope dilution. Samples were
collected on a daily basis between April 6 and May 4, 2002, a period that included the passage of a dust storm and coincided
with the ITCT-2K2. Samples were dissolved off the filters using HF-HNO3-HCl, chemically separated, and analyzed for Sr and
Nd isotopes using thermal ionization mass spectrometry. Total amounts of Sr and Nd were small (5-10 ng Sr in typical samples)
but high-quality isotopic analyses were obtained. A sharp rise in Sr loading and 87Sr/86Sr is observed to coincide
with the dust storm arrival. After the storm's passage, Sr loads fall relatively quickly while 87Sr/86Sr falls
more gradually back to background levels over nearly a week. These results provide a basis for our isotopic study of
California mineral aerosols, including the identification and apportionment of local and far-traveled Asian dust and their
variation in time.
[1] VanCuren et al. (2005) J. Geophys. Res., 110, D09S90, doi: 10.1029/2004JD004973
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0322 Constituent sources and sinks
DE: 0394 Instruments and techniques
DE: 1040 Radiogenic isotope geochemistry
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005