Observations on the state of mountain glacier science

Transcription

1 Georg Kaser Observations on the state of mountain glacier science Cordillera Blanca, Peru swiss polar day zurich

2 The Third Pole(s) App. 200,000 glaciers 726,258 km 2 38,5 % TW 412 mm SLE The Randolph Glacier Inventory IPCC AR5 WG1 Ch.4 (2013) Pfeffer et al JoG swiss polar day zurich 2/27

3 The Third Pole(s) Pfeffer et al. JoG swiss polar day zurich 3/27

4 Building knowledge using knowledge Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe. Hypothesis driven curiosity W. Tad Pfeffer, AGU Nye Lecture 2011 We Are All Engineers Now: Delivering Useful Projections of Sea Level Rise 1. We use knowledge to produce information! 2. Do we also build new knowledge? Engineering Monitoring Science swiss polar day zurich 4/27

5 Minimal models Marzeion et al. TC (2012) Positive Degreday (PDD) Models Degre Day Factor (DDF) Finsterwalder, S., Schunk, H., Der Suldenferner. Zeitschrift des DOeAV 18, Hoinkes, H.C., Steinacker, R., Hydrometeorological implications of the mass balance of Hintereisferner, to , Proceedings of the snow and ice symposium, Moscow IAHS Publ. no. 104, pp swiss polar day zurich 5/27

6 Air temperature ice melt Location Air Temperature Observation Site Altitude (m a.s.l.) Distance (km) Correlation Coefficient DDF Melt Fact (mm C 1 da Mountain (54 C +) 3 Slope (17 C +) 4 Glacier (18 C +) 7 Valley ( 43 C +) 5 DDF as obtained for the runoff of a snow free microcatchment on the Aletsch Glacier during the melt period from 31 July to 27 August 1965, using the air temperature from various stations with different site characteristics. (Lang, 1976, 1978, Lang&Braun 1990) Mario Rohrer (2016) swiss polar day zurich 6/27

7 Seasonal fresh water reservoirs Monthly maxiumum glacier vs rainfall runoff contribution Kaser et al. PNAS (2010) swiss polar day zurich 7/27

8 Attributing Glaciers mass loss to drivers 1850 to 2010 natural natural + anthropogenic observed Marzeion et al. Science (2014) Alps (small glaciers) at present: 100 % from anthropogenic forcing. Global (large glaciers) at present.: 70 % from anthropogenic forcing, 30 % relaxation from LIA swiss polar day zurich 8/27

9 W. Gurgiser et al. (2014) swiss polar day zurich 9/27

10 Climate change commitment due to slow processes in the cryosphere Marzeion et al. Nature CC ( ) swiss polar day zurich 10/27

11 Climate change commitment due to slow processes in the cryosphere Marzeion et al. Nature CC ( ) swiss polar day zurich 11/27

12 Observed contributions explain observed Global Mean Sea Level Rise Data from Table 13.1 IPCC AR5 WG1 Ch.13 (2013) swiss polar day zurich 12/27

13 Hintereisferner: glaciological vs ALS geodetic mass balance 0 mass balance [10 3 kg m 2 ] Klug et al. TC swiss polar day zurich 13/27

14 Langenferner mass balance reanalysis Galos et al. TC 2017 Modeled point mass balances = pseudo observations swiss polar day zurich 14/27

15 Process resolving (?) mass balance model sublimation, melt energy balance SW SW LW LW QS, QL + / + + GLACIER + / QG (20 30 levels) SNOW snowfall energy fluxes mass fluxes Th. Mölg swiss polar day zurich 15/27

16 Model parameter fitting SH11 SH22 Component resolving mass balance model! Gurgiser et al. JoG swiss polar day zurich 16/27

17 Parameter transfer Glaciar Shallap Gurgiser et al. JoG (2013) swiss polar day zurich 17/27

18 2 m wind fields from Large Eddy Simulations Resulting in ± 16 W m 2 deviations from conventionally extrapolated valeus of sensible heat flux Sauter & Galos TC swiss polar day zurich 18/27

19 Snow cover dynamics Kaser et al. (2017) swiss polar day zurich 19/27

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21 The climate signal Vernagtferner, Ötztal Alps; AD 1601 Nicolussi, K. (1993) ZGG Glaciers are low pass filters, but these filters come without a manual B. Marzeion (Marzeion et al, TC 2012) machines that turn weather into climate signals swiss polar day zurich 21/27

22 The long term climate signal Roe and Baker (2014) Synthetic lenght variations stochast. climate

23 The climate signal Mass balance components and reasons (point) Monsoon onset Mölg et al., TC (2012) swiss polar day zurich 23/27

24 The climate signal Past glacier extent and potential reasons Prinz et al., TC (2016) swiss polar day zurich 24/27

25 Atmospheric circulation modes and glacier mass balance Glaciar Shallap CB Energy Balance at < 4,700 masl Niño Niña Maussion et al. TC swiss polar day zurich 25/27

26 Glaciers and atmospheric circulation modes NAO + Alps Asian Monsoon ENSO Mt. Kenya + + Cordillera Blanca Rwenzori + + Kilimanjaro IOZM ENSO Irian Jaya + ENSO hygric seasonality circulation patterns (modes) swiss polar day zurich 26/27

27 Résumé ENGINEERING We are pritty good MONITORING Improve monitoring techniques/reanalyses; Reorganize monitoring network; SCIENCE Go beyond component analysis; (Nearby) Lab conditions; Atmospheric physics in complex terrain; clear hypotheses (clever questions); Cordillera Blanca, Peru swiss polar day zurich