Ground truth measurements in the form of snow/ice cores were obtained from three sites in 2006: Rothschild Island, Latady Island and Smyley Island. The sites selected corresponded to the position of Automatic Weather Stations (AWS) deployed during the previous season. At both the Rothschild Island and Smyley Island sites the AWS - due to an unprecedented amount of snowfall - had been buried. Therefore, two cores, 8m and 12m in length, were obtained from the approximate position of the AWS, in addition to the sampling of a snow pit. At the Latady Island site, the top 60cm of the 5m AWS was protruding above the surface - again, due to an unprecedented amount of snowfall. A diagonally descending trench was dug to recover the AWS and two cores were collected at this site. This work was carried out as part of a project to understand how air mass origin and meteorology affect the mass accumulation of snow in areas of the Antarctic Peninsula, and how the atmosphere''s properties are preserved in the snow, Photographs of the expedition showing the ground layout, the situation of the cores and what was done when they were gathered are available and stored with the data.

Three micro-power Automatic Weather Stations (AWS) with two sonic ranging sensors were deployed at field-sites situated at Rothschild Island, Latady Island and Smyley Island in January 2005. The AWS instruments included a wind vane and two humicaps on the mast and two sonic ranging sensors mounted on separate horizontal scaffold poles. The AWS data collected contributed to a project concerned with understanding how air mass origin and meteorology affect the mass accumulation of snow in areas of the Antarctic Peninsula, and how the atmosphere''s properties are preserved in the snow.

The Weather Research and Forecasting (WRF) model output over the whole of Peru at 12 km horizontal resolution and 3 hourly output (domain 1, d01), the Rio Santa River Basin (in the Cordillera Blanca) at 4 km horizontal resolution and hourly output (domain 2, d02), the Vilcanota-Urubamba region at 4 km horizontal resolution and hourly output (domain 3, d03) and the upper region of the Rio Santa River Basin at 800 m horizontal resolution and hourly output (domain 4, d04). Domains 1 to 3 cover the period from 1980 to 2018, domain 4 covers from 2009 to 2018. Full details of the WRF model setup can be found in Fyffe et al., (2021). These data were corrected as part of the PEGASUS (Producing EnerGy and preventing hAzards from SUrface water Storage in Peru) and Peru GROWS (Peruvian Glacier Retreat and its Impact on Water Security) projects. The datasets were created to assess past climate in the Peruvian Andes, as a basis to determine future climate in the region, and as an input for glaciological and hydrological models. The data were created using the British Antarctic Survey high performance computer. The creation of this data was conducted under the Peru GROWS and PEGASUS projects, which were both funded by NERC (grants NE/S013296/1 and NE/S013318/1, respectively) and CONCYTEC through the Newton-Paulet Fund. The Peruvian part of the Peru GROWS project was conducted within the framework of the call E031-2018-01-NERC "Glacier Research Circles", through its executing unit FONDECYT (Contract No. 08-2019-FONDECYT).