Supraglacial debris temperatures, near-surface temperatures and on-glacier air temperatures measured during the 2014, 2015 and 2016 monsoon seasons at Khumbu Glacier, Nepal

• Main Authors: Rowan, Ann V, Quincey, Duncan J, Gibson, Morgan J, Irvine-Fynn, Tristram D L
• Format: Dataset
• Language: English
• Published: PANGAEA 2017
• Subjects: Gemini; Journal of Glaciology
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.883071; https://doi.org/10.1594/PANGAEA.883071

On-glacier air temperature (Ta), near-surface debris temperature (Ts), and temperatures within the debris layer (Td) down to the debris-ice interface (Ti) were measured at five sites (KH1-5) at Khumbu Glacier in Nepal. At each site, a vertical section was excavated and thermistors were placed within the exposed section at measured intervals between the debris surface and the debris-ice interface. The excavated debris was then replaced as close to the original condition as possible. Rather than measuring surface temperature unshielded from incoming solar radiation, Ts is near-surface debris temperature as the thermistors were covered with a thin layer of debris; the measurement depth of Ts was therefore 0.02 m. Ta was measured using thermistors mounted in naturally ventilated radiation shields 1 m above the debris surface. All thermistors were connected to Gemini Tiny Tag Plus2 TGP-4520 dataloggers that have a stated accuracy of ±0.4°C, and temperature was sampled every 30 minutes in local (Nepal) time = GMT + 4.5 hours. The manufacturer calibrated the equipment before use, and at the end of the data collection measurements at room temperature agreed within the stated accuracy. The location and elevation of each site were measured using a Garmin GPSmap 62s handheld unit, which has a stated accuracy of ±5 m in the horizontal plane and ±3 m in the vertical plane. At KH3 in summer 2014 and KH2 in summer 2016, movement of the debris and collapse of the underlying ice at the start of the monsoon season caused thermistors to migrate, and anomalous Td values were recorded from early June onwards. All files have the column format: line number, date/time, Ta, Ts (where measured, as indicated below), Td and Ti (where it was possible to access the debris-ice interface, as indicated below). The depths of measurements below the debris surface were: KH1 (05/2014-11/2014); 0.1, 0.25, 0.4, 0.55, 0.7 0.8, 0.9 1.0 m (Ts and Ti were not measured) KH1 (11/2014-11/2015); 0.02, 0.1, 0.25, 0.4, 0.55, 0.7 0.8, 0.9 1.0 m (Ti was not ...