Cristin-resultat-ID: 1940816
Sist endret: 29. september 2021, 16:44
Resultat
Vitenskapelig foredrag
2021

Workshop on downscaling with TopoSCALE for cryospheric applications

Bidragsytere:
  • Kristoffer Aalstad
  • Joel Fiddes
  • Leo Celestin Paul Martin
  • Esteban Alonso-Gonzalez
  • Yeliz A. Yilmaz
  • Norbert Pirk
  • mfl.

Presentasjon

Navn på arrangementet: ICIMOD Cryosphere Forum 2021 - Status of research on changing permafrost and associated impacts in the Hindu Kush Himalaya
Sted: Online
Dato fra: 20. september 2021
Dato til: 23. september 2021

Arrangør:

Arrangørnavn: ICIMOD

Om resultatet

Vitenskapelig foredrag
Publiseringsår: 2021

Klassifisering

Vitenskapsdisipliner

Meteorologi

Emneord

Permafrost • Snø

Beskrivelse Beskrivelse

Tittel

Workshop on downscaling with TopoSCALE for cryospheric applications

Sammendrag

Meteorological forcing data is a crucial ingredient when modeling the past, present, and future state of the cryosphere. At the same time, cold regions (i.e. the high elevations and/or latitudes of our planet) where most of the cryosphere is found are typically remote with a very low density of in-situ observations. The few meteorological stations that do exist are typically quite unrepresentative due to the often extreme surface heterogeneity and complex terrain in these regions. This makes empirical-statistical and geostatistical downscaling techniques that rely heavily on station data somewhat impractical for cryospheric applications. On the other side of the scale, we have dynamical downscaling techniques that rely on using sophisticated regional climate models to downscale historical global reanalysis data or projections from global climate models. Although these are not as dependent on local observations in that they are able to mechanistically model the state of the atmosphere, they are prohibitively expensive to run at the decadal timescales and hillslope (1 km - 100 m) spatial scale that is often sought in cryospheric applications. In this workshop, we will provide an overview of various downscaling techniques and introduce the topography-based downscaling routine TopoSCALE as well as its many applications and downstream methods listed below. TopoSCALE was developed to provide a computationally feasible technique for generating hourly hillslope scale atmospheric forcing for cryospheric modeling from global reanalysis data or other atmospheric model outputs, without the need for in-situ data. It relies heavily on topographic parameters derived from digital elevation models to be able to scale the input atmospheric forcing to the local topography. It has been tested quite extensively in a variety of environments, including: the Swiss Alps, Svalbard, the California Sierra Nevada, and High Mountain Asia. TopoSCALE is also being used as part of ongoing permafrost reanalysis efforts in the ESA Permafrost_CCI project. The scheme can be coupled to a clustering framework (TopoSUB) which can speed up distributed simulations by orders of magnitude compared to the more traditional gridded approach to land surface modeling. TopoSCALE can also be used together with bias-correction techniques to help downscale future regional climate projections to the hillslope scale with applications to cryospheric climate impact studies. Recent and ongoing applications of TopoSCALE together with snow data assimilation have been particularly fruitful in being able to handle biases in solid precipitation, which has been one of the most challenging problems for downscaling in cryospheric applications. Importantly, TopoSCALE lets modellers shift limited computational resources away from the downscaling exercise to probing uncertainties through ensemble simulations and constraining these with Earth observations.

Bidragsytere

Kristoffer Aalstad

  • Tilknyttet:
    Forfatter
    ved Seksjon for naturgeografi og hydrologi ved Universitetet i Oslo

Joel Fiddes

  • Tilknyttet:
    Forfatter

Leo Celestin Paul Martin

  • Tilknyttet:
    Forfatter

Esteban Alonso-Gonzalez

  • Tilknyttet:
    Forfatter

Yeliz Yilmaz

Bidragsyterens navn vises på dette resultatet som Yeliz A. Yilmaz
  • Tilknyttet:
    Forfatter
    ved Seksjon for naturgeografi og hydrologi ved Universitetet i Oslo
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