In:
The Holocene, SAGE Publications, Vol. 25, No. 4 ( 2015-04), p. 569-582
Abstract:
We present a Holocene summer air temperature reconstruction based on fossil chironomids from Lake Brazi (1740 m.a.s.l.), a shallow mountain lake in the South Carpathians. Summer air temperature reconstruction was performed using transfer functions based on the Swiss (Sw-TF) and the merged Norwegian–Swiss calibration data set (NS-TF). Our results suggest that summer air temperatures increased rapidly from the onset of the early Holocene onwards ( ca. 11,500–10,200 cal. yr BP), reaching close to present July air temperatures (~11.2°C). Between ca. 10,200 and 8500 cal. yr BP mean reconstructed temperatures increased further by 1.5–2.0°C. Later on, from ca. 8500 cal. yr BP, chironomid-based summer temperatures started to decrease, although mean values were still above present-day temperatures. The next time period ( ca. 6000–3000 cal. yr BP) was cooler and with less variable temperature conditions than earlier. Afterwards ( ca. 3000–2000 cal. yr BP), a sharp decrease occurred in inferred temperatures with values under present-day conditions by 1.8°C. Finally, in the last 2000 years, reconstructed temperatures showed again an increasing trend at Lake Brazi. Short-term temperature declines of 0.6–1.2°C were observed between ca. 10,350–10,190, 9750–9500, 8700–8500, 7600–7300, 7100–6900 and 4400–4000 cal. yr BP. These temperature declines are, however, within the estimated error of prediction of the chironomid-based inferences. Generally, our reconstructed temperatures complied with the summer insolation curve at 45°N, with other proxy-records (i.e. pollen and diatoms) from the same sediment and with other records from the Carpathians and from Western Europe.
Type of Medium:
Online Resource
ISSN:
0959-6836
,
1477-0911
DOI:
10.1177/0959683614565953
Language:
English
Publisher:
SAGE Publications
Publication Date:
2015
detail.hit.zdb_id:
2027956-5
SSG:
14
SSG:
3,4
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