Can we model Puspa?

About precipitation events in August called Puspa

Posted by Wolfgang Gurgiser on September 1, 2018


  • described as light rainfall or drizzle events that wetten the soil towards the beginning of the new agricultural year at the end of the dry season in August Gurgiser et al. 2016 - important for traditional farming since long as deducible from the existence of an own (Quechua) term for these precipitation events
  • not well known from a scientific viewpoint due to missing local experiences (of the scientists) and missing observations with high enough resolution

As data availability has increased in recent years and luckily, we could observe an event classified as Puspa by our local partners on August 17th (hitting also the area of our newly installed weather station), we are curious to learn more about such events, especially if atmospheric models are able to reproduce them in a realistic way.

Images of our automatic camera in Huaraz captured on August 17th 2018 from 0800-1830 (10min capture interval).

On the eastern slopes above Huaraz, the event was characterized by slow but continuous cloud development from around 1000 on. Precipitation around Nevado Churup started at 1310 and the area with the presumably highest precipitation rates (as visible from the webcam) was surprisingly stable until 1600. In between this period, some showers also hit the surroundings of Nevado Churup and our weather station in Llupa measured ~2mm of total precipitation. Around 1700, another, more wide-spread precipitation event started with weak rainfall (<0.5mm) also hitting the city of Huaraz.

Within upcoming research activities we hope to have the chance to thoroughly investigate this and other Puspa events to know whether present day atmospheric models can reproduce these events and if yes, to analyze potential trends in the frequency of Puspa in the Huaraz region in the last decades.