MyOcean Arctic MFC: V1 Validation of sea ice drift

Validation results

Results by bulletin date
November 2010
11-03
11-10
11-17
11-24

December 2010
12-01
12-08
12-15
12-22
12-29

January 2011
01-05
01-12
01-19
01-26

February 2011
02-02
02-09
02-16
02-23

March 2011
03-02
03-09
03-16
03-23
03-30

April 2011
04-06
04-13
04-20
04-27

May 2011
05-04
05-11
05-18
05-25

June 2011
06-01
06-08
06-15
06-22
06-29

July 2011
07-06
07-13
07-20
07-27

August 2011
08-03
08-10
08-17
08-24
08-31

September 2011
09-07
09-14
09-21
09-28

October 2011
10-05
10-12
10-19
10-26

November 2011
11-02
11-09
11-16
11-23
11-30

December 2011
12-07
12-14
12-21
12-28

January 2012
01-04
01-11
01-18
01-25

February 2012
02-01

Documentation

This web page contains information about the validation algorithm, the observational data, and the model results.

The validation results are produce for one-day ice drift by comparing drift distances from observations and model reults. The observations are available for periods that span 23-25 hours, sampled irregularly during each day. The model results are available as daily averages for each calendar day (UTC time). Note that tidal motion is not included in the model.

The observations are mapped onto the grid of the model results, which is on a polar stereographic projection, and drift distances in the model results are produced by integration of sea ice drift velocities.

Validation sectors

In order to take into account the differences in sampling, the drift distances from the observational product is scaled (linearly) to a 24 hour period. The validation algorithm then assigns weights according to the temporal distribution between the two calendar dates that are spanned by the observations. The model velocities are then integrated in two Eulerian steps: initially, the drift distance in the model is computed for the day fraction of the first calendar date, then, the subsequent drift during the second calendar date is found by integration of drift velocities at the end point of the trajectory from the initial step.

Validation data

Validation of the MyOcean Arctic MFC results for sea ice drift is performed using the observational product from the Division of Microwaves and Remote Sensing at the Technical University of Denmark. The data are available from the MyOcean Sea Icea and Wind Thematic Assembly Center (SIW TAC), and can be downloaded from the THREDDS server at this location.

These SIW TAC sea ice drift data are based on a pattern recognition algorithm which is applied to observations from Synthetic Aperture Radar (SAR) imagery.

The validation of sea ice drift is carried out for the full domain (i.e., the Arctic Basin and adjacent seas), and also for a sub-division into three sectors, as displayed in the figure on the right.

  • 65°W - 55°E (green sector)
  • 55°E - 175°E (blue sector)
  • 175°E - 65°W (red sector)

TOPAZ

The model results are produced with the TOPAZ ocean data assimilation model system. Presently, TOPAZ is run weekly with data assimillation one week prior to the bulletin date, followed by a one-week 100 member ensemble simulation ending on the bulletin date, and finally a 10 day deterministic forecast. TOPAZ was developed and is maintained by the Nansen Center.

TOPAZ results are available as aggregated, best estimates, and as a list of Bulletin dates with separate forecasts.