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Titel |
Measurements of light-absorbing particles on the glaciers in the Cordillera Blanca, Peru |
VerfasserIn |
C. G. Schmitt, J. D. All, J. P. Schwarz, W. P. Arnott, R. J. Cole, E. Lapham, A. Celestian |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1994-0416
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Digitales Dokument |
URL |
Erschienen |
In: The Cryosphere ; 9, no. 1 ; Nr. 9, no. 1 (2015-02-12), S.331-340 |
Datensatznummer |
250116753
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Publikation (Nr.) |
copernicus.org/tc-9-331-2015.pdf |
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Zusammenfassung |
Glaciers in the tropical Andes have been rapidly losing mass since the 1970s.
In addition to the documented increase in temperature, increases in light-absorbing particles deposited on glaciers could be contributing to the
observed glacier loss. Here we report on measurements of light-absorbing
particles sampled from glaciers during three surveys in the Cordillera Blanca
Mountains in Peru. During three research expeditions in the dry seasons
(May–August) of 2011, 2012 and 2013, 240 snow samples were
collected from 15 mountain peaks over altitudes ranging from 4800 to
nearly 6800 m. Several mountains were sampled each of the 3 years and
some mountains were sampled multiple times during the same year. Collected
snow samples were melted and filtered in the field then later analyzed using
the Light Absorption Heating Method (LAHM), a new technique that measures the
ability of particles on filters to absorb visible light. LAHM results have
been calibrated using filters with known amounts of fullerene soot, a common
industrial surrogate for black carbon (BC). As sample filters often contain
dust in addition to BC, results are presented in terms of effective black
carbon (eBC). During the 2013 survey, snow samples were collected and kept
frozen for analysis with a Single Particle Soot Photometer (SP2). Calculated
eBC mass from the LAHM analysis and the SP2 refractory black carbon (rBC)
results were well correlated (r2 = 0.92). These results indicate that a
substantial portion of the light-absorbing particles in the more polluted
regions were likely BC. The 3 years of data show that glaciers in the
Cordillera Blanca Mountains close to human population centers have
substantially higher levels of eBC (as high as 70 ng g−1) than remote
glaciers (as low as 2.0 ng g−1 eBC), indicating that population
centers can influence local glaciers by sourcing BC. |
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