Climate change has already had an impact on the environment; this impact is expected to increase in the future. The Polar Regions are highly vulnerable to climate change because of polar amplification. Large amounts of carbon are stored in permafrost in the form of organic matter. Climate change and changes in land-use can destabilize these carbon reservoirs. This can lead to large emissions of greenhouse gasses to the atmosphere, and with that, increase the rate of climate change. It is crucial to know the effects of climate change on permafrost. This thesis uses the CoupModel5 to model the effects of climate change on the permafrost at the UNISCALM site, Adventdalen, Svalbard. Next to that, the effect of the presence of organic matter in relationship to climate change is investigated. High-resolution hydro-climatic data from the UNISCALM site is used as boundary conditions in the model set-up. The model is run for the period 1976-2013. The results are validated with sub-surface temperature data. After that, the same model set-up is used and the temperature is increased according to the temperature data from the Representative Concentration Pathways (RCPs) scenarios: RCP2.6,RCP4.5, RCP6.0, and RCP8.5, for the period 2014-2100. It is investigated how the thermal state of the permafrost and the active layer thickness (ALT) will be affected. Two alternate scenarios areinvestigated; (S2) 10 cm organic matter layer, and (S3) 50 cm organic matter layer. All RCPs show an increase in sub-surface temperature. For S1, until 2050 the RCPs follow a similar pattern, after that they start to diverge. RCP2.6 experiences only a slight increase until 2100. RCP4.5 and RCP6.0 are relatively similar until approximately 2080, from that point on the ALT from RCP6.0 plots consistently below RCP4.5. RCP8.5 shows a steady increase in temperature from 2050-2080. Around 2080 the permafrost starts to collapse and the permafrost degradation occurs rapidly. The different organic matter scenarios follow roughly the same pattern, but differ in magnitude and timing. When more organic material is present, the ALT varies less over time. Next to that, the response time is slower if organic material is present. The mean annual temperature for RCP8.5 is above 0 °C from2080. This indicates that the mean annual temperature plays a significant role in permafrost degradation. The projected temperatures for RCP4.5 and RCP6.0 are expected to be above 0 °C in the 22nd century, indicating that the permafrost will collapse under every climate change scenario, apartfrom RCP2.6. The different reactions to change in climate for the organic matter scenarios can be attributed to the difference in thermal conductivity between organic matter (low thermal conductivity) and mineral soils (high thermal conductivity). This indicates that permafrost areas where organicmaterial is present will react less to fluctuations in temperatures than when no organic material is present. Overall, it can be concluded that climate change will have an enormous impact on permafrost and that it is crucial to include it in the global climate models.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:su-147526 |
| Date | January 2017 |
| Creators | op den Kelder, Antonia |
| Publisher | Stockholms universitet, Institutionen för naturgeografi |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
Page generated in 0.0016 seconds