Beginning  with defined key test areas that represents different sea ice regimes, SIMRE provides the basis for a formal and transparent inter comparison of Arctic sea ice mass balance derived from available products guided by open source principles.

Contents of the Products

There are three different types of SIMRE products, based on the ice age (Figure 1). . The files contain seven different sea ice related variables. The variables have dimensions: latitude, longitude, with sizes (29,27) for first year ice example region, (36,28) for multi year ice region and (32,33) for mixed ice region. The file format is NetCDF.

Figure 1. Multi-year ice region inside red polygon, mixed ice region inside orange and first year ice region inside yellow polygon.

Grid Definition

The grid used for the reconciled product is the version 2 of the Equal-Area Scalable Earth Grid (EASE2), properties in Table below.

Property Value
Grid name EASE2
Projection Lambert Azimuthal Equal Area
Ellipsoid WGS84
Datum WGS84
Latitude of origin 90.0
Longitude of origin 0.0
Unit Meter
Proj4 string +proj=laea +lon_0=0 +datum=WGS84 +lat_0=90.0
Grid dimensions (432, 432)
Grid cell size 25000.0
Grid size (10800000.0, 10800000.0)

Table 1.

 

Variables

The product files contain seven variables (in addition to latitude, longitude, time and other CF-related information). There are separate files for each ice type region containing the same variables. The individual monthly datasets of cropped SIMRE grid regions are called ensemble members.

Dimensional variables:

Variable name Long name Standard name Units
longitude longitude of grid cell center longitude Degrees east
latitude latitude of grid cell center latitude Degrees north

 

Ensemble variables:

Variable name Long name Units
mean_thickness Mean thickness from ensemble members Meter
gmean_thickness Geometric mean thickness from ensemble members Meter
median_thickness Median thickness from ensemble members Meter
min_thickness Minimum thickness of all ensemble members Meter
max_thickness Maximum thickness of all ensemble members Meter
sdev_thickness Thickness standard deviation from ensemble members Meter
n_points Number of ensemble members 1