 |
| Titel |
Representativeness and seasonality of major ion records derived from NEEM firn cores |
| VerfasserIn |
G. Gfeller, H. Fischer, M. Bigler, S. Schüpbach, D. Leuenberger, O. Mini |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1994-0416
|
| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 8, no. 5 ; Nr. 8, no. 5 (2014-10-16), S.1855-1870 |
| Datensatznummer |
250116324
|
| Publikation (Nr.) |
 copernicus.org/tc-8-1855-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
The seasonal and annual representativeness of ionic aerosol proxies
(among others, calcium, sodium, ammonium and nitrate) in various
firn cores in the vicinity of the NEEM drill site in northwest
Greenland have been assessed. Seasonal representativeness is very
high as one core explains more than 60% of the variability
within the area. The inter-annual representativeness, however, can
be substantially lower (depending on the species) making replicate
coring indispensable to derive the atmospheric variability of
aerosol species. A single core at the NEEM site records only
30% of the inter-annual atmospheric variability in some
species, while five replicate cores are already needed to cover
approximately 70% of the inter-annual atmospheric variability
in all species.
The spatial representativeness is very high within 60 cm,
rapidly decorrelates within 10 m but does not diminish
further within 3 km. We attribute this to wind reworking
of the snow pack leading to sastrugi formation.
Due to the high resolution and seasonal representativeness of the
records we can derive accurate seasonalities of the measured species
for modern (AD 1990–2010) times as well as for pre-industrial (AD 1623–1750) times.
Sodium and calcium show similar seasonality (peaking in February and March
respectively) for modern and pre-industrial times, whereas ammonium
and nitrate are influenced by anthropogenic activities. Nitrate and
ammonium both peak in May during modern times, whereas during
pre-industrial times ammonium peaked during July–August and nitrate
during June–July. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|