1 / 23

Joshua King and Chris Derksen Climate Research Division Environment Canada

SnowSAR in Canada: An evaluation of basin scale dual-frequency (17.2 and 9.6 GHz) snow property retrieval in a tundra environment. Joshua King and Chris Derksen Climate Research Division Environment Canada Toronto, Ontario, Canada.

lacey-roberson
Download Presentation

Joshua King and Chris Derksen Climate Research Division Environment Canada

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SnowSAR in Canada: An evaluation of basin scale dual-frequency (17.2 and 9.6 GHz) snow property retrieval in a tundra environment Joshua King and Chris Derksen Climate Research Division Environment Canada Toronto, Ontario, Canada Thanks to: Nick Rutter, Tom Watts and all participants in the field campaign

  2. Motivation • Radar as an emerging technology for observation of snow properties • ESA Earth Explorer CoReH2O • Dual frequency 17.2 and 9.6 GHz (Ku- and X-band) synthetic aperture radar (SAR) • Few studies have investigated seasonal/spatial Ku- and X-band radar response and no previous study in a tundra environments VV Ku VH

  3. Research Gaps • Soil/Vegetation properties • Uncertainties related to variation in soil and vegetation dielectrics • Snow grain properties • Unbiased measurements may allow the role of large depth hoar to be evaluated • Scaling of observations • Are small scale variations in snow and soil properties influential at the airborne and/or satellite level?

  4. SnowSAR in Canada • Airborne radar operating at the proposed CoReH2O frequencies • 17.2 and 9.6 GHz • Dual-polarization (VV, VH) • 2 x 2 m spatial resolution • Three observation campaigns in Trail Valley Creek near Inuvik, NWT (December 2012 , March 2013, April 2013) • Trench stratigraphy experiments • Improved snow grain characterization (IRIS) • Seasonal soil permittivity in multiple locations

  5. Study area and plan

  6. Flight data summary December - 0/27 March – 24/27 April - 23/27 Incidence angles between 38 and 55 degrees Local incidence angles between 26 and 62 degrees Swath generally < 400 m All 4 channels (Ku and X VV, VH) available with all completed flight lines

  7. Snow Measurement Campaign Snow Pit (< 1 m) Snow Trench (5 to 50 m) Snow Transect (> 100 m) Lidar (Basin scale)

  8. Sic Sic Creek Basin

  9. Sic SicCreek - Snow Pit Locations Pit Locations Upland Tundra River Valley Forest Transition

  10. December Sic Sic Creek - Seasonal Pit Locations March Upland Plateau Valley April Forest transition March

  11. Sic Sic Creek - Backscatter April 2013, 50 m, 45-50 deg elevation Upland Plateau Valley Forest transition

  12. MEMLS Workflow – Pit Snow Pits MET Tower Data Mironov (2010) 2-Layer Snowpack SSA to Pc From IRIS Surface Roughness Wegmüller & Mätzler(1999) Snow Input 1 M = 0.05 Q = 0.1 Sccho = 13 MEMLS Active Derived Data Simulated Data Observed Data

  13. Sic Sic Creek - MEMLS Active • 10 m average of observed radar backscatter • Small range of depth suggest grains may be an important in sic sic creek • Can we compare single pits against radar pixels?

  14. Sic SicValley - 5 m Trench • IR photography completed in 5 to 50 m trench excavations by Watts & Rutter • Stratigraphy extracted from stitched IR imagery to create 2D map

  15. Sic SicValley - 5 m Trench • Topography produces a range of depth over short distances • Also tends to drive DH fraction • Distribution of grain properties built from snow pits within +-3 days • Due to the nature of tundra snow, the slab distribution includes solid facets

  16. MEMLS Workflow – Distribution Snow Pits MET Tower Data Trench Excavation Mironov(2010) 2-Layer Snowpack Grain Distribution Stratigraphy Distribution Surface Roughness Snow Input 1 Wegmüller & Mätzler(1999 Snow Input 2 Snow Input n MEMLS Active Derived Data Simulated Data Field Data

  17. Valley Trench – MEMLS Active

  18. Summary/Moving forward • Relating backscatter to physical snow properties is a complex process • Improved understanding of horizontal variation in grain properties and stratigraphy is needed • Model advancement and inversion possible but requires community effort to assist in validation • Physically based justification for tuning possible with known distributions • Additional uncertainties including soil contribution must be resolved in the near future

  19. Snow texture

  20. Vegetation • Backscatter appears influenced by local vegetation • Methods needed to decompose contributions from vegetation and snow to develop retrieval

  21. Upland Tundra – Soil Permittivity

  22. Snow Measurement Campaign Snow Pit (< 1 m) Snow Trench (5 to 50 m) • Manual Stratigraphy • Density (100 cc cutter) • Temperature Profile (4 cm) • IRIS SSA (5 cm) • IR Stratigraphy • Multiple snow pits • IRIS SSA (5 cm)

  23. Snow pits in local context

More Related