Development of a Snow Accumulation and Ablation Model

1. Development of a Snow Accumulation and Ablation Model to Evaluate Potential Impacts of Climate Change on Downhill Ski Conditions in Northern Lower Michigan Peter J. Sousounis, Ph.D. Acton, Massachusetts 30 March 2005

2. Executive Summary snow accumul model used relationship between temp and snow:water ratio. regression analysis performed using 42 years worth of daily climate data from East Jordan, MI, from 1960-2002. snow ablation model accounted for compaction, sublimation, and melting. models combined to form a snow accumulation and ablation model (SAAM) to forecast daily snowfall totals and snow depth on the ground. SAAM tested using East Jordan Climate record SAAM applied to GCM output to evaluate potential impacts of climate change on the downhill ski season in northern lower Michigan. snowmaking effects included mountain slope and ski trail orientation not included

3. Model Info Converting rainfall to snowfall amounts

4. Results Modeled vs observed snowfall at East Jordan, MI 40 yr means 2586 mm 2502 mm

5. Results Modeled vs observed snowfall at East Jordan, MI 40 yr means 2586 mm 2502 mm

6. Results Snowfall days at East Jordan, MI – over 01 inches 40 yr means 38 days 40 days

7. Results Snowcover days at East Jordan, MI – over 01 inches 40 yr means 112 days 109 days

8. Results Snowcover days at East Jordan, MI – over 12 inches 40 yr means 44 days 49 days

9. Results Snowdepth at East Jordan, MI – Christmas Day 40 yr means 221 mm 203 mm

10. Results Last Day of snowcover at East Jordan, MI 40 yr means March 22 March 22

11. Results Modeled vs observed snowfall at East Jordan, MI 40 yr means 2586 mm 2502 mm

12. Results Summary of snowmodel characteristics at East Jordan, MI

13. Results Modeled vs observed snowfall at Ironwood, MI 40 yr means 4273 mm 4290 mm

14. Climate Change Impacts on Alpine Skiing • Four scenarios • CGCM2_A2a • CGCM2_B2a • HadCM3_A2a • HadCM3_B2a • Three Variables • Tmax • Tmin • precip

15. Climate Change Impacts on Alpine Skiing • Ski Day • snowdepth > 300 mm • Tmax < 4 C • Ski season allowed to extend beyond snowmaking season • Snowmaking • Tmin < -4 C • no precip that day • snowdepth < 350 mm that day • snowmaking capacity: 100 mm/day • snowmaking season: Nov 25 – Mar 30

16. Observed and Modeled Ski Days without snowmaking

17. Historical Observed and Modeled Conditions with snowmaking

18. Climate Change Impacts on Alpine Skiing ski days – CGCMa A2a climate change scenario

19. Climate Change Impacts on Alpine Skiing ski days – CGCMa B2a climate change scenario

20. Climate Change Impacts on Alpine Skiing ski days – HadCM3 A2a climate change scenario

21. Climate Change Impacts on Alpine Skiing ski days – HadCM3 A2a climate change scenario

22. Climate Change Impacts on Alpine Skiing an interactive web site Location Climate Scenario East Jordan, MI HadCM3 A2a Begin Winter End Winter 2020-2021 2039-2040 Snow Mak Conditions Snow Mak Capacity Tmin< 26 F & Sd < 12” 100 mm/day Variable Output Format Total Snowfall Mean Snowdepth Maximum Snowdepth Snowdepth on Dec 25th Day of First Snow > 1 in Days w/ Snowc > 1 in Days w/ Snowc > 6 in Snowmaking Days Skiable Days Graph submit reset

23. Climate Change Impacts on Alpine Skiing • Extensions • Evaluate more scenarios • Consider downscaled information as it becomes available • Evaluate impacts with assumed changes in snowmaking technology – e.g. more snow made in warmer conds. • Web page online