EO Products / Link to pagePicture Ice Thickness

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Source: https://www.copernicus.eu/en/access-data/copernicus-services-catalogue/satellite-sea-ice-thickness

Business Process

Product Description

Description

Sea ice thickness combined with sea ice concentration provides an estimate of ice volume (described as the amount of space occupied by ice in a three-dimensional unit). Although sea ice floats over the ocean, part of the sea ice can be found under the water. The depth of sea ice below the surface of the ocean is known as the 'draft', while the depth of ice above the waterline is known as the 'freeboard'. On average approximately 1/9th of the sea ice is above the waterline and 8/9ths below although the exact amount depends on the buoyancy of the ocean below (Metoffice, 2023). The sea ice thickness is the sum of the freeboard and the draft. Only the freeboard ice may be measured by several platforms (e.g., airborne, satellite) and the draft from submersible and sonar, therefore the sea ice thickness derived by satellite altimeters refers to measurements of the sea ice freeboard, which is the difference between the height of the surface of sea ice and the surface of water in open leads (areas of open water within the sea ice).

The snow on top of sea ice changes this ratio and complicates the estimation of the ice thickness, requiring the use of auxiliary information about snow depth and density.

The requirement to correct measurements for the snow depth introduces uncertainty into the measurement of sea ice freeboard. As freeboard is approximately 1/9th of the total sea ice thickness (freeboard plus draft), the described uncertainty can lead to larger impacts to navigation, as sea ice with a thickness of 2-3 m can only be penetrated by ice-strengthened vessels or icebreakers with a sufficient ice class. Most ships and fishing vessels are not ice-strengthened and must therefore avoid all ice areas.

Product Specification

BUSINESS PROCESS

SD, SC, SCE, IN, SO

(see Annex)

DESCRIPTION

OF GEOINFORMATION

	Ice thickness refers to the distance between the top surface of a body of ice and the underlying water
EO INFORMATION OF INTEREST	Sea Ice Thickness (SIT)

Available from 1981 to ongoing at a variety of spatial and temporal resolution

MAIN PROCESS STEPS	Satellites equipped with altimeters use laser beams to measure the height of the ice surface above the underlying surface. By subtracting the known elevation of the land or water beneath the ice, ice thickness is retrieved. Assumptions are made to remove influence of snow cover.
INPUT DATA SOURCE	Altimeter data, snow cover thickness and density information
SPATIAL RESOLUTION AND COVERAGE	25-111km
ACCURACY / CONSTRAINS	The requirement to correct measurements for the snow depth introduces uncertainty into the measurement of sea ice freeboard.
LIMITATIONS	The snow on top of sea ice complicates the estimation of the ice thickness, requiring the use of auxiliary information about snow depth and density.

FORMEIf known

Once retrieved the emerged portion of ice

that has emerged because if this information is known, the volume of the portion of ice that is submerged can also be estimated

and assuming that is 1/9th of the submerged part, it can be estimated the total volume of the ice. The interpretation of data can indeed be challenging, especially when handled by personnel without extensive experience in the field.

TEMPORAL RESOLUTION

/Weekly

	Available from 1981 to ongoing at a variety of spatial and temporal resolution (weekly mean, monthly mean).
FREQUENCY UPDATE

FREQUENCY

	Daily, yearly
DELIVERY / OUTPUT FORMAT	NetCDF, PNG, ASCII, XML
ACCESSIBILITY	Copernicus

CMEMS

Marine Service, Artic hub, NSIDC DAAC

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Business Process Challenges

Ship Design (SD) Challenges

• SD-1 Environmental Conditions
• SD-2 Defining Ice Class for Vessels
• SD-3 Vessel Concept, dimensions, and design
• SD-4 Material Selection in Ship Design Phase
• SD-5 Deciding design temperature (based on intended operations)

Ship Construction Challenges

Ship Construction (SC) Challenges

• SC-
• SC-1 Lifting Operations 
• SC-2 Tow Operations
• SC-3 Planning of Sea Trials Outside of Ice Season
• SC-4 Avoiding Ice During Sea Trials
• SC-5 Planning of Sea Ice Trials
• SC-6 Finding Suitable Ice During Sea Trials
• SC-7 Ship Operation in Ice During Sea Trials

Ship Certification

(SCE) Challenges

• SCE-2 Icing Prediction for Vessel CertificationSCE-3 Risk Assessment for Operations in Ice
• SCE-4 Strategic Planning using PolarisSCE-5 Monitoring Ship Icing Conditions During Voyage
• SCE-6 Monitoring Sea Ice Conditions During Voyage
• SCE-7 Defining Design Parameters for Ship Class Rules
• SCE-8 Ship Emission Monitoring
• SCE-9 Ship Monitoring, Location and Operation
• SCE-10 Oil and Substance Spill Monitoring

Insurance (IN) Challenges

• IN-1 Incident Investigation
• IN-2 Understanding the Current and Future Expected Conditions
• IN-3 Ensure compliance of portfolio with Poseidon Principles
• IN-4 Risk evaluating vessels according to POLARIS

Ship Operation (SO) Challenges

• SO-1 Navigating Through Ice
• SO-2 Avoiding Ice Edge 
• SO-3 Navigating Along (or just inside) the Ice Edge
• SO-4 Avoiding Ship Icing Conditions
• SO-5 Avoiding Sea Ice
• SO-6 Oil Spill Monitoring
• SO-7 Avoiding Snow Cover on IceSO-8 Strategic Planning
• SO-9 Risk Analysis According to POLARIS
• SO-10 Search & Rescue Operations
• SO-11 Monitoring Vessels Without AIS Transponder
• SO-12 Navigating Waters with Poor Charting

End of Life Vessel Disposal

• ELD-1 Weather condition monitoring
• ELD-2 Environmental impact monitoring of operations impact to local nature
• ELD-3 Authority monitoring of vessels on their way for scrapping