Wednesday, July 25, 2018
¡Tanta nieve! So much snow! [updated x2]
The snowy dry season of 2018 continues in the Cordillera Vilcanota. Yesterday's Sentinel-2 image (above) reveals a landscape blanketed by snow above 4500-4700 m. Quelccaya Ice Cap (lower right) is difficult to delineate, suggesting substantial accumulation at the margin. Hopefully our instrumentation continues to record hourly snowfall at the summit.
Note the variation in color of lakes just west of the glacier, surrounding the area of our camp (labeled). This reflects varying suspended sediment input, with relatively high concentrations apparently flowing into the Qori Kalis proglacial lake (north of camp); snow is accumulating, while also melting and delivering sediment to the lakes. The 'double' lake to the northwest of camp (and Sibinacocha) appear dark blue, as upstream wetlands (bofedales) filter sediment from freshly-exposed areas proximal to the glaciers.
We will be in the area during the second half of August, measuring snow and recovering weather station data. Fieldwork will occur later than normal, allowing an assessment of what appears to be an anomalous year. Although this snow will be beneficial to glacier mass balance, the toll on camelids (llama, alpaca) could be severe - without warming solar radiation typical of the dry season.
[UPDATE 7/26: A press release from SENAMHI* earlier this week (23 July) describes snowfall in the preceding 72 hours above 3,800 m in the Andes, accumulating to 20 cm. In conjunction with clouds, they warn of low temperatures and prolonged snowcover reducing food for livestock.
Gustavo Valdivia wrote yesterday learning details of the situation in the Cordillera Vilcanota. He received a call from the Phinaya community president, who described the situation as critical, because a lot of alpacas died in recent days. The local people agree that the weather is very unusual.
Press releases from SENAMHI can be found here (in Spanish), with a machine translation here.
*SENAMHI is The National Meteorology and Hydrology Service of Peru or El Servicio Nacional de Meteorología e Hidrología del Perú]
[UPDATE 7/27: Today I learned from Bronwen Konecky (Washington University) that SENAMHI is making daily meteorological summaries available on their website. The closest station to Quelccaya - and one of their highest - is Sibinacocha, at ~4890 m (labeled on map above). These data show 11 mm of water equivalent precipitation on 21 July, followed by 5.9 on the 22nd. Since this automated station is located at the southern end of the lake, the image above suggests that considerably more snow fell at higher elevations. The regional nature of this event is demonstrated by daily totals from Sicuani (~3600 m, 45 km to the SW); very similar daily totals were recorded.
To access any SENAMHI data in Peru, go here, then use the "Seleccionar" button to select a District; zoom in on the map. Thanks, SENAMHI.]