气候变化领域集成服务门户(CCPortal): Using daily air temperature thresholds to evaluate snow melting occurrence and amount on Alpine glaciers by T-index models: The case study of the Forni Glacier (Italy)

CCPortal

DOI	10.5194/tc-8-1921-2014
	Using daily air temperature thresholds to evaluate snow melting occurrence and amount on Alpine glaciers by T-index models: The case study of the Forni Glacier (Italy)
	Senese A.; Maugeri M.; Vuillermoz E.; Smiraglia C.; Diolaiuti G.
发表日期	2014
ISSN	19940416
卷号	8 期号:5
英文摘要	Glacier melt conditions (i.e., null surface temperature and positive energy budget) can be assessed by analyzing data acquired by a supraglacial automatic weather station (AWS), such as the station installed on the surface of Forni Glacier (Italian Alps). When an AWS is not present, the assessment of actual melt conditions and the evaluation of the melt amount is more difficult and simple methods based on T-index (or degree days) models are generally applied. These models require the choice of a correct temperature threshold. In fact, melt does not necessarily occur at daily air temperatures higher than 0 °C. In this paper, we applied both energy budget and T-index approaches with the aim of solving this issue. We start by distinguishing between the occurrence of snowmelt and the reduction in snow depth due to actual ablation (from snow depth data recorded by a sonic ranger). Then we find the daily average temperature thresholds (by analyzing temperature data acquired by an AWS on Forni Glacier) which, on the one hand, best capture the occurrence of significant snowmelt conditions and, on the other, make it possible, using the T-index, to quantify the actual snow ablation amount. Finally we investigated the applicability of the mean tropospheric lapse rate to reproduce air temperature conditions at the glacier surface starting from data acquired by weather stations located outside the glacier area. We found that the mean tropospheric lapse rate allows for a good and reliable reconstruction of glacier air temperatures and that the choice of an appropriate temperature threshold in T-index models is a very important issue. From our study, the application of the +0.5 °C temperature threshold allows for a consistent quantification of snow ablation while, instead, for detecting the beginning of the snow melting processes a suitable threshold has proven to be at least-4.6 °C.
学科领域	ablation; air temperature; cryosphere; energy budget; glaciology; snowmelt; threshold; troposphere; Alps; Forni Valley; Italy; Lombardy; Sondrio; Valtellina
语种	英语
scopus关键词	ablation; air temperature; cryosphere; energy budget; glaciology; snowmelt; threshold; troposphere; Alps; Forni Valley; Italy; Lombardy; Sondrio; Valtellina
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/120042
作者单位	Università Degli Studi di Milano, Department of Earth Sciences, via Mangiagalli 34, Milan, 20131, Italy; Università Degli Studi di Milano, Department of Physics, via Celoria 16, Milan, 20133, Italy; Ev-K2-CNR, via San Bernardino 145, Bergamo, 24126, Italy
推荐引用方式 GB/T 7714	Senese A.,Maugeri M.,Vuillermoz E.,et al. Using daily air temperature thresholds to evaluate snow melting occurrence and amount on Alpine glaciers by T-index models: The case study of the Forni Glacier (Italy)[J],2014,8(5).
APA	Senese A.,Maugeri M.,Vuillermoz E.,Smiraglia C.,&Diolaiuti G..(2014).Using daily air temperature thresholds to evaluate snow melting occurrence and amount on Alpine glaciers by T-index models: The case study of the Forni Glacier (Italy).Cryosphere,8(5).
MLA	Senese A.,et al."Using daily air temperature thresholds to evaluate snow melting occurrence and amount on Alpine glaciers by T-index models: The case study of the Forni Glacier (Italy)".Cryosphere 8.5(2014).