Sea Surface Temperature (SST)

Introduction

SST Def Temperature of sea surface.
Unit deg.C
ATBD Ver.1 (Oct. 2018)
Ver.2 (Jun. 2020)

Update contents of Ver2

  • ・Added auxiliary data (Himawari SST data)
  • ・Added SD array (/Image_data/Cloud_probability)
  • ・Improved the cloud identification (Improved cloud mask of coast and inland water area)
  • ・Modified the probability density function of cloud mask
  • ・Modified QA flag

Stored Physical quantity

Ver.1 Ver.2

Ver1 Description
Line_tai93 TAI93 at each line
QA_flag
SST Sea Surface Temperature[SST]
Ver2 Description
Cloud_probability Cloud Probability
Line_tai93 TAI93 at each line
QA_flag
SST Sea Surface Temperature[SST]

QA_flag information

Ver.1 Ver.2 Ver.1(Sample Image) Ver.2(Sample Image)

Bit ver1 Description SST_L3_mask*
0 No data 1
1 Land 0: water, 1: land 1
2 Rejected by QC Out of the range: [-5 degC, 40 degC] 1
3 Retrieval error SST determination error 1
4 No data (TIR1) 1
5 No data (TIR2) 1
6 no -
7 no -
8 1: daytime, 0: nighttime or no visible data 0
9 no -
10 no -
11 Unknown clear/cloudy Clear/cloudy could not be determined. 1
12 Cloudy Affected by clouds 1
13 Acceptable (possibly cloudy) Probably clear 0
14 Good Clear 0
15 0: unreliable (inland/too close to land), 1: reliable Denotes the reliability of the clear/cloud determination 0

* Bits masked by statistical processing are indicated by 1.

Bit Ver2 description SST_L3_mask*
0 invalid data 1
1 Land 0: water, 1: land 1
2 Rejected by QC SST out of the range: [-5 degC, 40 degC] 1
3 Retrieval error SST determination error 1
4 Invalid data (TIR1) 1
5 Invalid data (TIR2) 1
6 reserved -
7 reserved -
8 1: daytime, 0: nighttime or no visible data 0
9 Near Land one or more land pixels within the 5x5-pixel window 1
10 Cloudy Affected by clouds 1
11 Unknown clear/cloudy Clear/cloudy could not be determined. 1
12 Possibly cloudy Possibly affected by clouds 1
13 Acceptable Probably clear 0
14 Good Clear 0
15 reserved -

* Bits masked by statistical processing are indicated by 1.

*Download:QA_flag(Ver1) Sample Image
*Download:QA_flag(Ver2) Sample Image

Attribute information

Ver.1 Ver.2

Ver1 Attribute Remarks
Attribute of Image_data
Attribute of Image_data Grid_interval 1000 250m, 500m, 1000m
Grid_interval_unit meter
Image_projection L1B reference grid
Number_of_lines 1495 Variable
Number_of_pixels 1250 Variable
Line_tai93
Line_tai93
64-bit floating-point
Data_description TAI93 at each line
Dim0 L1B-lines
Error_value -1
Maximum_valid_value 999999999
Minimum_valid_value 0
Unit second
SST
SST
16-bit unsigned integer
Data_description Sea Surface Temperature[SST]: SST[degree]=DN*Slope+Offset
Dim0 Line grids
Dim1 Pixel grids
Error_DN 65535
Land_DN 65534
Cloud_error_DN 65533
Retrieval_error_DN 65532
Maximum_valid_DN 65531
Minimum_valid_DN 0
Mask_for_statistics 6207 Detail: QA_flag_information(~L3_mask)
Slope 0.0012
Offset -10
Spatial_resolution 1000 250m, 500m, 1000m
Spatial_resolution_unit meter
Unit degree
Ver2 Attribute Remarks
Attribute of Image_data
Attribute of Image_data Grid_interval 1000 250m, 500m, 1000m
Grid_interval_unit meter
Image_projection L1B reference grid
Number_of_lines 1495 Variable
Number_of_pixels 1250 Variable
Cloud_probability
Cloud_probability
8-bit unsigned integer
Data_description Cloud Probability
Dim0 Line grids
Dim1 Pixel grids
Error_DN 255
Maximum_valid_DN 100
Minimum_valid_DN 0
Slope 1
Offset 0
Spatial_resolution 1000 250m, 500m, 1000m
Spatial_resolution_unit meter
Unit %
Line_tai93
Line_tai93
64-bit floating-point
Data_description TAI93 at each line
Dim0 L1B-lines
Error_value -1
Maximum_valid_value 999999999
Minimum_valid_value 0
Unit second
SST
SST
16-bit unsigned integer
Data_description Sea Surface Temperature[SST]: SST[degree]=DN*Slope+Offset
Dim0 Line grids
Dim1 Pixel grids
Error_DN 65535
Land_DN 65534
Cloud_error_DN 65533
Retrieval_error_DN 65532
Maximum_valid_DN 65531
Minimum_valid_DN 0
Mask_for_statistics 7743 Detail: QA_flag_information(~L3_mask)
Slope 0.0012
Offset -10
Spatial_resolution 1000 250m, 500m, 1000m
Spatial_resolution_unit meter
Unit degree

How to use

  • ・Physical quantity=DN*slope + offset
  • ・Valid values are during Minimum_valid_DN~Maximum_valid_DN