The relationships between air temperature and rockfalls at high-elevation sites are very important to know, but are also very difficult to study. This difficulty is mainly due to the lack of meteorological stations positioned at the altitudes of the rock detachments. Air temperature decrease with height approximates 0.6 °C/100 m in the free atmosphere (environmental lapse rate), but this lapse rate may differ from the one on a mountain slope according to the time of day because it is modulated by local climate conditions. A reliable method to estimate air temperatures at high elevation sites is to use the altitudinal temperature lapse rate (ATLR) and to apply this to estimate temperatures at high-elevation sites for rockfalls studies. To calculate ATLR before rockfall events, we used data acquired from automatic weather stations that are located at an elevation above 2500 m (Centro Funzionale Regione Autonoma Valle d'Aosta). The main results are reported in the highlights. This work has highlighted that it is not enough to improve the knowledge on air temperature, but it is necessary to develop an integrated knowledge of the thermal conditions of different lithotypes involved in these processes. More info at https://cnrirpicervinia.panomax.com/plateaurosa This contribution is dedicated to the Professor Simona Fratianni.
Le relazioni tra la temperatura dell'aria e le frane in alta quota sono importanti da conoscere, ma sono molto difficili da studiare. Questa difficoltà è causata principalmente dalla mancanza di stazioni meteorologiche posizionate alle quote dei distacchi. La diminuzione della temperatura dell'aria con la quota in atmosfera libera è di circa 0,6 °C /100 m, ma sui versanti montuosi questa diminuzione varia in relazione a diversi fattori locali, sia geografici e sia climatici. Un metodo affidabile per stimare la temperatura dell'aria a quote elevate consiste nell'utilizzare il gradiente altitudinale di temperatura calcolato localmente (ATLR) e applicarlo in alta quota. Per calcolare l'ATLR, abbiamo utilizzato i dati acquisiti dalle stazioni meteorologiche automatiche ubicate ad un'altitudine superiore a 2500 m (Centro Funzionale Regione Autonoma Valle d'Aosta). I principali risultati sono riportati negli Highlights. Questo lavoro ha messo in luce che non è sufficiente migliorare le conoscenze sulla temperatura dell'aria, ma è anche necessario conoscere le condizioni termiche dei diversi litotipi coinvolti in questi processi. Per ulteriori informazioni: https://cnrirpicervinia.panomax.com/plateaurosa Questo contributo è dedicato alla professoressa Simona Fratianni.
Gradiente termico verticale e processi di instabilità naturale in alta quota: il caso di studio del Cervino
Nigrelli G;Chiarle M;
2021
Abstract
The relationships between air temperature and rockfalls at high-elevation sites are very important to know, but are also very difficult to study. This difficulty is mainly due to the lack of meteorological stations positioned at the altitudes of the rock detachments. Air temperature decrease with height approximates 0.6 °C/100 m in the free atmosphere (environmental lapse rate), but this lapse rate may differ from the one on a mountain slope according to the time of day because it is modulated by local climate conditions. A reliable method to estimate air temperatures at high elevation sites is to use the altitudinal temperature lapse rate (ATLR) and to apply this to estimate temperatures at high-elevation sites for rockfalls studies. To calculate ATLR before rockfall events, we used data acquired from automatic weather stations that are located at an elevation above 2500 m (Centro Funzionale Regione Autonoma Valle d'Aosta). The main results are reported in the highlights. This work has highlighted that it is not enough to improve the knowledge on air temperature, but it is necessary to develop an integrated knowledge of the thermal conditions of different lithotypes involved in these processes. More info at https://cnrirpicervinia.panomax.com/plateaurosa This contribution is dedicated to the Professor Simona Fratianni.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
