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Titolo:
HIGH-RESOLUTION AMMONIUM ICE CORE RECORD COVERING A COMPLETE GLACIAL-INTERGLACIAL CYCLE
Autore:
FUHRER K; NEFTEL A; ANKLIN M; STAFFELBACH T; LEGRAND M;
Indirizzi:
UNIV BERN,INST PHYS,SIDLERSTR 5 CH-3012 BERN SWITZERLAND LAB GLACIOL & GEOPHYS ENVIRONM,CNRS F-38402 ST MARTIN DHERES FRANCE FED RES INST AGR CHEM CH-3097 LIEBEFELD BERN SWITZERLAND
Titolo Testata:
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
fascicolo: D2, volume: 101, anno: 1996,
pagine: 4147 - 4164
Fonte:
ISI
Lingua:
ENG
Soggetto:
YOUNGER DRYAS EVENT; NITRATE CONCENTRATIONS; GREENLAND; ATMOSPHERE; SULFATE; SHEET; SNOW; INCREASE; CLIMATE; EUROPE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
83
Recensione:
Indirizzi per estratti:
Citazione:
K. Fuhrer et al., "HIGH-RESOLUTION AMMONIUM ICE CORE RECORD COVERING A COMPLETE GLACIAL-INTERGLACIAL CYCLE", JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 101(D2), 1996, pp. 4147-4164

Abstract

High-resolution ammonium measurements were performed along the Greenland Ice Core Program (GRIP) deep ice core, covering a complete climatic cycle. No overall anthropogenic increase is observed over the last 300 years; however, springtime concentrations have roughly doubled since 1950. Biomass burning is estimated to be a major source for ammonia emissions for preindustrial times. It contributes between 10% to 40% to the total ammonium deposited on the central Greenland ice sheet during the Holocene. No correlation is found between the ammonium summer concentrations recorded over the last 100 years and the area burned in northern North America, which is considered to be the main source areafor ammonium deposited on the central Greenland ice sheet. This suggests that the meteorological factor is predominant for the pattern of ammonium spikes observed in the ice core. If unchanged meteorological conditions are assumed for the Holocene, as indicated by the delta(18)Oice record, a decreasing biomass burning activity toward present timecan be derived from the ammonium ice record. Soil and vegetation emissions are responsible for the ammonium background concentrations in the ice. The record therefore may be used to trace back the biomass history of the North American continent. A pronounced decreasing trend in background ammonium is found during the Holocene, reflecting decreasing temperature and therefore lower NH3 emissions in the source region. Variations in the ammonium concentration during the glacial age are discussed in terms of changes in transport and deposition mechanisms andchanges in source strength, which can be related to the extent of theLaurentide ice sheet. The data suggest that the Laurentide ice sheet was built up immediately after the last interglacial and went through several large fluctuations during the last ice age.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 02/04/20 alle ore 00:15:12