Gridded Daily Sea Ice Velocity in the Northern Hemisphere

The sea ice velocity is derived from AMSR-E and AMSR2 brightness temperature data:
36 GHz channels for January–April and December
18 GHz channels for May–November
The velocity fields are computed using the maximum cross-correlation method.
The size of the template window used in the calculation is 60 × 60 km (6 × 6 pixels).

File Naming

YYMMDD.amsr36i (January–April, December)
YYMMDD.amsr18i (May–November)
Here, YYMMDD indicates the year, month, and day.

Format

Plain binary

Ice velocity is stored on a 145 × 145 grid with a 60 km spacing.
The grid origin (point 1,1) is located at the upper-left, and point 145,145 is the lower-right.

For each grid cell, two variables are stored in the following order:
u(1,1), v(1,1), u(2,1), v(2,1), ..., u(145,145), v(145,145)

u: ice speed in the x-direction (not the east–west direction)
v: ice speed in the y-direction (not the north–south direction)

Each value is stored as a 4-byte real in units of cm/s.

Latitude and longitude for each grid point are provided latlon_amsr_ads145.txt in the format:
i, j, latitude(i,j), longitude(i,j)

Coverage

2003-01-01 to 2011-09-27
2012-07-03 to 2025-07-01