Level-3 12.5 km Sea Ice Data Fields

The following notations are used throughout this document:

Int8 8-bit (1-byte) signed integer
Int16 16-bit (2-byte) signed integer
NT2 Enhanced NASA Team algorithm
BBA Bootstrap Basic Algorithm

North polar grids are 608 pixels by 896 pixels.
South polar grids are 632 pixels by 664 pixels.

North Polar Grids
Field Name
Data Type
Description
Scale Factor
SI_12km_NH_18V_ASC Int16 18.7 GHz horizontal daily average Brightness Temperatures (Tbs) (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_18V_DSC Int16 18.7 GHz vertical daily average descending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_18V_DAY Int16 18.7 GHz vertical daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_18H_ASC Int16 18.7 GHz horizontal daily average ascending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_18H_DSC Int16 18.7 GHz horizontal daily average descending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_18H_DAY Int16 18.7 GHz horizontal daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_23V_ASC Int16 23.8 GHz vertical daily average ascending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_23V_DSC Int16 23.8 GHz vertical daily average descending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_23V_DAY Int16 23.8 GHz vertical daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_23H_ASC Int16 23.8 GHz horizontal daily average ascending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_23H_DSC Int16 23.8 GHz horizontal daily average descending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_23H_DAY Int16 23.8 GHz horizontal daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_36V_ASC Int16 36.5 GHz vertical daily average ascending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_36V_DSC Int16 36.5 GHz vertical daily average descending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_36V_DAY Int16 36.5 GHz vertical daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_36H_ASC Int16 36.5 GHz horizonta daily average ascending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_36H_DSC Int16 36.5 GHz horizontal daily average descending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_36H_DAY Int16 36.5 GHz horizontal daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_89V_ASC Int16 89.0 GHz vertical daily average ascending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_89V_DSC Int16 89.0 GHz vertical daily average descending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_89V_DAY Int16 89.0 GHz vertical daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_89H_ASC Int16 89.0 GHz horizontal daily average ascending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_89H_DSC Int16 89.0 GHz horizontal daily average descending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_89H_DAY Int16 89.0 GHz horizontal daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_NH_ICECON_ASC Int16 Sea ice concentration daily ascending average

Value
Description
0 Open Water
120 Land Mask
1 to 100 Percent Ice Concentration
Not Applicable (N/A)
SI_12km_NH_ICECON_DSC Int16 Sea ice concentration daily descending average

Value
Description
0 Open Water
120 Land Mask
1 to 100 Percent Ice Concentration
N/A
SI_12km_NH_ICECON_DAY Int16 Sea ice concentration daily average

Value
Description
0 Open Water
120 Land Mask
1 to 100 Percent Ice Concentration
N/A
SI_12km_NH_ICEDIFF_ASC Int16 Sea ice concentration daily ascending average using the difference between NT2 and BBA algorithms

Value
Description
0 Open Water
120 Land Mask
1 to 100 or -1 to -100 Percent difference between algorithms1
N/A
SI_12km_NH_ICEDIFF_DSC Int16 Sea ice concentration daily descending average using the difference between NT2 and BBA algorithms

Value
Description
0 Open Water
120 Land Mask
1 to 100 or -1 to -100 Percent difference between algorithms1
N/A
SI_12km_NH_ICEDIFF_DAY Int16 Sea ice concentration daily average using the difference between NT2 and BBA algorithms

Value
Description
0 Open Water
120 Land Mask
1 to 100 or -1 to -100 Percent difference between algorithms1
N/A
SI_12km_NH_SNOWDEPTH_5DAY Int16 Five-day snow depth (cm)

Value
Description
110 Missing Data
120 Land Mask
130 Open Water
140 Multiyear Sea Ice
150 Variability in Snow Depth
160 Snow Melt
N/A
1 Positive values 1 to 100% represent the difference in concentration where NT2 is greater than BBA and negative values -1 to -100% represent the difference in concentration where BBA is greter than NT2.

South Polar Grids
Field Name
Data Type
Description
Scale Factor
SI_12km_SH_18V_ASC Int16 18.7 GHz horizontal daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_18V_DSC Int16 18.7 GHz vertical daily average descending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_18V_DAY Int16 18.7 GHz vertical daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_18H_ASC Int16 18.7 GHz horizontal daily average ascending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_18H_DSC Int16 18.7 GHz horizontal daily average descending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_18H_DAY Int16 18.7 GHz horizontal daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_23V_ASC Int16 23.8 GHz vertical daily average ascending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_23V_DSC Int16 23.8 GHz vertical daily average descending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_23V_DAY Int16 23.8 GHz vertical daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_23H_ASC Int16 23.8 GHz horizontal daily average ascending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_23H_DSC Int16 23.8 GHz horizontal daily average descending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_23H_DAY Int16 23.8 GHz horizontal daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_36V_ASC Int16 36.5 GHz vertical daily average ascending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_36V_DSC Int16 36.5 GHz vertical daily average descending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_36V_DAY Int16 36.5 GHz vertical daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_36H_ASC Int16 36.5 GHz horizontal daily average ascending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_36H_DSC Int16 36.5 GHz horizontal daily average descending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_36H_DAY Int16 36.5 GHz horizontal daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_89V_ASC Int16 89.0 GHz vertical daily average ascending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_89V_DSC Int16 89.0 GHz vertical daily average descending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_89V_DAY Int16 89.0 GHz vertical daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_89H_ASC Int16 89.0 GHz horizontal daily average ascending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_89H_DSC Int16 89.0 GHz horizontal daily average descending Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_89H_DAY Int16 89.0 GHz horizontal daily average Tbs (K)
Valid range: approximately 50 to 300 K		 Multiply data values by 0.1 to obtain units in K
SI_12km_SH_ICECON_ASC Int16 Sea ice concentration daily ascending average

Value
Description
0 Open Water
120 Land Mask
1 to 100 Percent Ice Concentration
N/A
SI_12km_SH_ICECON_DSC Int16 Sea ice concentration daily descending average

Value
Description
0 Open Water
120 Land Mask
1 to 100 Percent Ice Concentration
N/A
SI_12km_SH_ICECON_DAY Int16 Sea ice concentration daily average

Value
Description
0 Open Water
120 Land Mask
1 to 100 Percent Ice Concentration
N/A
SI_12km_SH_ICEDIFF_ASC Int16 Sea ice concentration daily ascending average using the difference between NT2 and BBA algorithms

Value
Description
0 Open Water
120 Land Mask
1 to 100 or -1 to -100 Percent difference between algorithms1
N/A
SI_12km_SH_ICEDIFF_DSC Int16 Sea ice concentration daily descending average using the difference between NT2 and BBA algorithms

Value
Description
0 Open Water
120 Land Mask
1 to 100 or -1 to -100 Percent difference between algorithms1
N/A
SI_12km_SH_ICEDIFF_DAY Int16 Sea ice concentration daily average using the difference between NT2 and BBA algorithms

Value
Description
0 Open Water
120 Land Mask
1 to 100 or -1 to -100 Percent difference between algorithms1
N/A
SI_12km_NH_SNOWDEPTH_5DAY Int16 Five-day snow depth (cm)

Value
Description
110 Missing Data
120 Land Mask
130 Open Water
140 Multiyear Sea Ice
150 Variability in Snow Depth
160 Snow Melt
N/A
1 Positive values 1 to 100% represent the difference in concentration where NT2 is greater than BBA and negative values -1 to -100% represent the difference in concentration where BBA is greter than NT2.