A presentation by Craig J. Evanego - U.S. National Ice Center Remote Sensing and Monitoring Ice Conditions in the Great Lakes

I. Purpose: Importance of monitoring ice conditions in the Great Lakes II. Present: Existing data sources III. Future: Capabilities/advantages of a new data source Overview: The Use of Remotely Sensed Data for Great Lakes Ice Analysis

North American Ice Service (NAIS)

NAIS Mission Combine strengths of each Ice Center Combine strengths of each Ice Center Offer an integrated ice information service for North America Offer an integrated ice information service for North America High quality and consistency High quality and consistency Single point-of-access for users Single point-of-access for users Optimize resources of both countries & reduce duplication of effort Optimize resources of both countries & reduce duplication of effort Data access, system development, research, etc Data access, system development, research, etc Built around a common “public” suite of products Built around a common “public” suite of products Each center maintains ability to provide service for individual clients independently Each center maintains ability to provide service for individual clients independently

NAIS Ice Analysis of the Great Lakes

Typical Ice Conditions in the Great Lakes

Importance of Monitoring Ice Conditions in the Great Lakes 1)Aid the Safety of Winter Navigation and Coast Guard Operations 2) Monitoring Climate Variability and Change

Monitoring Great Lakes Ice Conditions to Aid Safety of Navigation

Special chart, derived from NAIS ice analysis, designed specifically for Coast Guard operations Shows thickest forms of ice present across the Great Lakes

Monitoring Great Lakes Ice Cover to Monitor Climate Variability & Change from Assel (2003):from Assel et al (2003): Great Lakes ice cover is a sensitive indicator of regional climate and climate change (Assel and Rodionov, 1998)

5. Geostationary Operational Environmental Satellites (GOES) NAIS Ice Analysis of the Great Lakes: Primary Remote Sensing Data Sources 1.Synthetic Aperture Radar (SAR) - RADARSAT - ENVISAT 2. Moderate Resolution Imaging Spectroradiometer (MODIS) 3. DMSP Operational Linescan System (OLS) 4. Advanced Very High Resolution Radiometer (AVHRR)

Great Lakes SAR imagery Primary data source for the NAIS Great Lakes ice analysis Currently using data from Radarsat-1 and Envisat Advantages: SAR imagery is all-weather Excellent spatial resolution (ScanSAR Wide Mode = 100 m) Using ScanSAR Wide mode, can get complete coverage of Lakes 2-3 times per week.

Great Lakes SAR imagery - Annotated

Explanation of the WMO “Egg Code” Fa Fb Fc - Predominant form of ice (i.e. floe size, fast ice) corresponding to Sa, Sb and Sc, respectively. Ct - Total concentration of ice in area, reported in tenths. Ca Cb Cc - Partial concentration (Ca, Cb, Cc) are also reported in tenths. Reported in order of decreasing thickness, Ca is the concentration of the thickest ice and Cc is the concentration of the thinnest ice. Sa Sb Sc - Stage of ice development (Sa, Sb, Sc) is listed in decreasing order of thickness. These codes are directly correlated with the partial concentrations above. That is, Ca is the concentration of stage Sa, and so on.

Explanation of Coding for Lake Ice Ice TypeCode Thickness New Ice cm Thin Lake Ice cm Medium Lake Ice cm Thick Lake Ice cm Very Thick Lake Ice1 >70 cm

Great Lakes SAR imagery - Annotated

Great Lakes MODIS imagery Along with SAR, an important data source for the NAIS Great Lakes ice analysis. Advantages: Good spatial resolution (up to 250 m) Available in ‘true color’ Data available over entire Lakes region each day Available, in GeoTiff format, from sites on WWW

Great Lakes MODIS imagery March 12, 2006

Great Lakes MODIS imagery – NOAA Coastwatch

Great Lakes MODIS imagery ‘True color’ Visible imagery High spatial resolution at 250 m. GeoTiff format ideal for use in NIC analysis.

Great Lakes MODIS imagery Visible MODIS image from December 2, 2005 (Note new ice forming along western shore of southern Green Bay.)

Great Lakes MODIS imagery - Annotated

Great Lakes DMSP OLS imagery Advantages: Good spatial resolution (up to 550 m) Data available over entire Lakes region each day Another commonly used data source, used in conjunction with SAR and MODIS data, for the NAIS Great Lakes ice analysis.

Great Lakes DMSP OLS imagery - Annotated

NAIS Analysis Software Based on ESRI’s ArcGIS software Allows for editing of lines and egg code attributes, as well as chart generation

Ice Analysis in the Future RADARSAT-2 Expected launch in December of RADARSAT-2 will have the capability to send and receive both H and V in four states: HH, HV, VH, and VV 1 st commercial spaceborne SAR to offer quadrature- polarimetry ("quad-pol") capability Polarimetric data – could be used to locate regions of severe ice deformation, which is a primary concern for winter navigation in the Great Lakes

Multiple Polarization: RADARSAT-2 vs. its Predecessors Polarimetric data available on RADARSAT-2 will enable analysts to better interpret regions of ice deformation.

Use of Polarimetric Data to Identify Region of Severe Ice Deformation

Multiple Polarization: Cross-Polarization HH- polarized HV- polarized (from Van der Sanden and Ross, 2001)

Questions / Comments?