Investigating Seasonal Snow in Northern Sweden – a Multi-Layer Snow Pack Model and Observations from Abisko Scientific Research Station Provide Clues

• Main Author: Staffansdotter, Anna
• Format: Bachelor Thesis
• Language: English
• Published: Uppsala universitet, Institutionen för geovetenskaper 2017
• Subjects: Snow characteristics; snow layer development; snow pack modelling; climate change; Abisko Scientific Research Station; Snöegenskaper; snöskiktutveckling; snöpackmodell; klimatförändringar; Abisko naturvetenskapliga station; Physical Geography; Naturgeografi; Abisko; Arctic; Arktis; Arktis*; Climate change; Norra Sverige; Northern Sweden
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-326019

Meteorological parameters determine the physical properties of snow precipitating from the atmosphere, but snow layers also continue to develop within the snow pack after the precipitation event. New characteristics form depending on temperature fluctuations, interaction with the soil, overburden compression, rain-on-snow events and more. As climate change is evidenced across the globe and particularly in the Arctic, understanding the relationship between snow and climate is important. In this project, a set of observed data of snow layer characteristics, collected every two weeks each winter over a 50+ year period at Abisko Scientific Research Station, northern Sweden, is co-studied with a multi-layer snow pack model which is able to reproduce additional snow properties. Data is presented in long time series as well as in high resolution to capture both trends and details. Comparison between modelled and observed data is made where possible. Physical processes are discussed and potential trends in the data are evaluated. Results show good agreement for snow pack depth between model and observations, while modelled snow density is largely confirmed by comparison with other records of density measured at Abisko. Modelled outputs illustrate snow pack temperature fluctuations, percolation of melt water and densification of snow layers within the profiles; observed data show variations in snow layer hardness, grain compactness, grain size and dryness. Long-term trends indicate an increase in snow layer hardness and a decrease in snow grain size since the beginning of the record. Förhållanden i atmosfären bestämmer vilken sorts snö som fälls ut som nederbörd, men de snöskikt som bildas i säsongspackad snö fortsätter även att utvecklas genom hela vintern. Snölagrens egenskaper förändras beroende på temperaturvariationer, termodynamisk växelverkan med markytan, belastning från ovanliggande snö, regn, med mera. Med accelererande klimatförändringar – särskilt i Arktis – är det viktigt att förstå hur snö och klimat ...