Satellite Retrieval of Snow Cover Properties in Satellite Retrieval of Snow Cover Properties in Northern CanadaNorthern Canada

Current Capabilities and Plans for IPY Current Capabilities and Plans for IPY

Anne WalkerClimate Research Division, Science and Technology

Branch

CARMA Meeting, November 28-30, 2006, Vancouver

Climate Processes SectionClimate Processes Section

Research Themes

Cold climate energy and water cycle• RCM application/evaluation• Scaling of atmosphere and surface processes • MAGS – 2 (Mackenzie GEWEX Study)

Land surface processes and models• Developing parameterizations of key processes re: the energy, water and

carbon cycle• CLASS--coupled land surface scheme for CGCM, RCM, GEM, MC2,

WATFLOOD and others• BERMS--Boreal Ecosystem Research and Monitoring Sites

Cryosphere in the climate system• CRYSYS (Cryosphere System in Canada)• remote sensing--development, validation and implementation of new

techniques• spatial and temporal variability of cryospheric elements

Measurement science/climate observation research• accuracy and compatibility of climate observations• automation and new technologies• special field observation programs (e.g. FOPEX)

Satellite Remote Sensing – Snow CoverSatellite Remote Sensing – Snow Cover

Reflection of visible light < 1 km spatial res. Impeded by cloud cover

and lack of sunlight 40+ year record of satellite

sensors (AVHRR, Landsat, MODIS)

Optical -- Snow extent Passive Microwave – Depth/SWE

Microwave emission from earth’s surface

10-25 km spatial res. “All-weather”, independent

of light conditions ~ 30 year record of satellite

sensors (SMMR, SSM/I, AMSR-E)

Passive Microwave Remote Sensing of Snow Passive Microwave Remote Sensing of Snow Cover PropertiesCover Properties

Volume scattering of emitted earth radiation by snow cover provides basis for retrieval of snow cover properties from passive microwave data

Data available in near real time and as historical archive in gridded format Canadian focus on development of regional-based retrieval methods (algorithms)

for dominant landscapes – prairies, boreal forest, tundra

Snow cover snow grains and air

Microwave energy emitted by underlying ground (TBg) is scattered by grains

TB snow surface < TBg

Amount of scattering is a function of snow depth and density SWE

TB = SWE

Regional SWE Products for Research and Operational Regional SWE Products for Research and Operational ApplicationsApplications

Manitoba – Red River watershed- specialized maps sent to provincial water resource agencies focussed on priority river basins for forecasting spring runoff and flood risk

Mackenzie Basin- MAGS research on snow cover variations, RCM evaluation

Snare River Basin – NWT- maps for hydro companies (e.g. NWT Power Corp.) in support of planning hydroelectric power operations

CCanadian Prairies-weekly maps produced and sent to users (federal, provincial agencies, private industry) who have a requirement for regular monitoring of snow cover in western Canada- available to public on www.socc.ca (State of Canadian Cryosphere)

Validation of Satellite Derived SWE InformationValidation of Satellite Derived SWE Information

6.9 GHz

1.4 GHz

19.35 GHz85.5 GHz37 GHz

MSC microwave radiometers on NRC Twin Otter

In-situ measurements

1) Airborne/field validation campaigns1) Airborne/field validation campaigns Acquisition of airborne microwave

radiometer data and ground-based measurements to support:

- validation of satellite retrievals- algorithm refinement/new development

2) Regional snow surveys2) Regional snow surveys

Targetted to specific landscape environments ground-based measurement transects over extensive areas

3) Comparison with snow depth/SWE 3) Comparison with snow depth/SWE available from EC monitoring networks + available from EC monitoring networks + other agenciesother agencies

Current MSC Snow Depth/SWE Network

Improving Passive Microwave SWE Retrievals for Northern Improving Passive Microwave SWE Retrievals for Northern Canada (Canada (EC and Wilfrid Laurier U.)EC and Wilfrid Laurier U.)

Derksen et al., Remote Sensing of Environment, 2005

Tundra Ecosystem Research Station (TERS) located at Daring Lake NWT

Study Objectives: Conduct in-situ snow survey to assess variability

and physical properties of snow cover.

Integrate ground based and airborne radiometer data to investigate snow cover relationships for representative terrain units at a variety of scales (aircraft/field campaigns).

Investigate the influence of lake ice on passive microwave brightness temperatures - existing algorithms do not consider lake covered area and cause SWE underestimations.

Field sampling and aircraft remote sensing data collection during 2004-2006

Variability and Change in the Canadian Cryosphere

Can. contribution to the “State and Fate of the Cryosphere” IPY 105

Photo: Vital Arctic Graphics, UNEP, GRID-Arendal, 2005

Activities

Cryospheric information contributing to the IPY snapshot

Cryosphere-climate variability and feedbacks

Improved representation of Arctic processes in CLASS

Simulation of the cryosphere in climate models

The human dimension

Canadian cryospheric data portal for IPYDIS

Planned IPY snow cover field campaigns in Canadian tundra regions:

April-May 2007 NWTJan-Feb 2008 Northern QuebecApril-June 2008 NWT & Arctic

Islands

What is the spatial/temporal variability in SWE over What is the spatial/temporal variability in SWE over northern Canada?northern Canada?

• Major field activities planned for IPY with airborne over flights and ground surveys in NWT, Nunavut and Québec to address these issues

• Assess transferability of satellite retrieval techniques developed at NWT and N. Manitoba study sites to other tundra regions

IPY Deliverables:• Maps of validated SWE over northern Canada documenting

spatial and temporal variations during IPY time period.• Application of retrieval techniques to passive microwave

satellite time series to generate a 30 year time series of SWE and assess climate-related variability.

• International collaboration Assess transferability of techniques to other circumarctic regions

IPY Field Activities in Support of Validated Satellite IPY Field Activities in Support of Validated Satellite SWE Products (Maps, Data Sets)SWE Products (Maps, Data Sets)

2007

2008

2008

April 2007 Alaska-Canada Barrens Snowmobile Transect

2007 and 2008 Field surveys and aircraft/field campaigns

2007

• Near real-time access to Canadian cryospheric data for cryospheric Near real-time access to Canadian cryospheric data for cryospheric monitoring and decision-makingmonitoring and decision-making ( (www.ccin.cawww.ccin.ca))

Outreach: Canadian Cryospheric Information Outreach: Canadian Cryospheric Information Network (CCIN)Network (CCIN)

State of the Canadian State of the Canadian Cryosphere (SOCC) site Cryosphere (SOCC) site receives ~5000 unique visits per receives ~5000 unique visits per month during winter monthsmonth during winter months