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File Format Basics
MODIS Atmosphere L2 Joint Product files are stored in Hierarchical Data Format (HDF).
HDF is a multi-object file format for sharing scientific data in multi-platform distributed environments.
HDF files should only be accessed through HDF library subroutine and function calls,
which can be downloaded from the HDF web site.
Each of the gridded statistical parameters (outlined below) within the HDF file is stored as a Scientific Data Set (SDS).
There are two sets of geolocation arrays in the Joint Atmosphere product.
The first (default) set is for the 5-km resolution parameters,
which are derived from the Water Vapor (05_L2), Cloud (06_L2), Profile (07_L2), and Cloud Mask (35_L2) products.
These 5-km geolocation arrays have the Scientific Data Set (SDS) names: Latitude and Longitude.
The second set is for the 10-km resolution parameters,
which are derived from the Aerosol (04_L2) product.
These 10-km geolocation arrays have the SDS names: Latitude_10km and Longitude_10km.
Users should ensure they are using the correct geolocation array when working with various parameters in the file.
Collection 005 Updates
The next generation of MODIS data products, tagged Collection 005, will begin being produced in May 2005.
Collection 005 MODIS data will be earmarked by significant improvements in almost every key data product (SDS parameter).
The Collection 005 reprocessing effort will begin with reprocessing Terra (AM overpass) MODIS data beginning at the start of the Terra MODIS data stream (2/2000) moving forward.
Soon after that, the Collection 005 reprocessing effort will be doubled when Aqua (PM overpass)
MODIS data is reprocessed beginning at the start of the Aqua MODIS data stream (7/2002) moving forward.
Collection 005 changes to the Joint Atmosphere product are shown in blue text below and, in addition,
are tagged with the blue and green Collection 005 icon, shown to the right.
SDS Parameter List
5-km Geolocation
- Latitude
Description: Latitude for 5-km parameters.
Source product, SDS: 06_L2, Latitude
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, day & night
Notes: For reduced file size, Real*4 source data are repacked as Integer*2.
A precision loss of 1/1000th of a degree results.
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- Longitude
Description: Longitude for 5-km parameters.
Source product, SDS: 06_L2, Longitude
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, day & night
Notes: For reduced file size, Real*4 source data are repacked as Integer*2.
A precision loss of 1/1000th of a degree results.
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Water Vapor (05_L2)
- Precipitable_Water_Near_Infrared_Clear
Description: Total column precipitable water vapor (cm) for clear sky
(bright land and sunglint ocean only) using near infrared retrieval.
Source product, SDS: 05_L2, Water_Vapor_Near_Infrared
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, daytime only
Notes: Source data at 1-km is subsampled at 5-km.
Clear sky data are collected by using the Surface Type Flag in the 05_L2 SDS Quality_Assurance_Near_Infrared.
Flag values of 0 (bright land) and 3 (ocean glint) only are used to pass data through to array.
SDS name changed to clarify aggregation.
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Cloud (06_L2)
Cloud Optical Parameters
- Cloud_Optical_Thickness
Description: Cloud optical thickness at 0.66 µm derived from a two-channel retrieval using MODIS band 7 and either band 1, 2, or 5.
Source product, SDS: 06_L2, Cloud_Optical_Thickness
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, daytime only
Notes: Source data at 1-km is subsampled at 5-km. Note that all cloud phases (liquid water, ice, and undetermined phase) are represented in the parameter; users must read the Cloud Phase (Retrieval Processing Path) Flag in the Cloud_Quality_Assurance SDS to determine the cloud phase represented by each pixel.
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- Cloud_Optical_Thickness_Uncertainty
Description: Cloud Optical Thickness Relative Uncertainty (Percent).
Source product, SDS: 06_L2, Cloud_Optical_Thickness_Uncertainty
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, daytime only
Notes: Source data at 1-km is subsampled at 5-km. Note that all cloud phases (liquid water, ice, and undetermined phase) are represented in the parameter;
users must read the Cloud Phase (Retrieval Processing Path) Flag in the Cloud_Quality_Assurance SDS
to determine the cloud phase represented by each pixel.
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- Cloud_Effective_Radius
Description: Cloud particle effective radius (µm) derived from a two-channel retrieval using MODIS band 7 and either band 1, 2, or 5.
Source product, SDS: 06_L2, Effective_Particle_Radius
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, daytime only
Notes: Source data at 1-km is subsampled at 5-km. Note that all cloud phases (liquid water, ice, and undetermined phase) are represented in the parameter; users must read the Cloud Phase (Retrieval Processing Path) Flag in the Cloud_Quality_Assurance SDS to determine the cloud phase represented by each pixel. SDS name changed to clarify application.
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- Cloud_Effective_Radius_Uncertainty
Description: Cloud Effective Radius Relative Uncertainty (Percent).
Source product, SDS: 06_L2, Cloud_Effective_Radius_Uncertainty
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, daytime only
Notes: Source data at 1-km is subsampled at 5-km. Note that all cloud phases (liquid water, ice, and undetermined phase) are represented in the parameter;
users must read the Cloud Phase (Retrieval Processing Path) Flag in the Cloud_Quality_Assurance SDS
to determine the cloud phase represented by each pixel.
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- Cloud_Effective_Radius_Difference
Description: Cloud Particle Effective Radius two-channel retrieval using MODIS band 6 and band 20
differenced from band 7 retrieval. Note that the band 7 retrieval uses band 7 and either band 1, 2, or 5.
Plane 1 of SDS is band 6 - band 7 retrieval.
Plane 2 of SDS is band 20 - band 7 retrieval.
Source product, SDS: 06_L2, Effective_Radius_Difference
Array type, dimension, size: Int*2, 2x406x270, 438k
Resolution, mode: 5-km, daytime only
Notes: Source data at 1-km is subsampled at 5-km. Note that all cloud phases (liquid water, ice, and undetermined phase) are represented in the parameter;
users must read the Cloud Phase (Retrieval Processing Path) Flag in the Cloud_Quality_Assurance SDS
to determine the cloud phase represented by each pixel. SDS name changed to clarify application.
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- Cloud_Water_Path
Description: Column Cloud Water Path two-band retrieval using band 7 and either band 1, 2, or 5 .
Source product, SDS: 06_L2, Cloud_Water_Path
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, daytime only
Notes: Source data at 1-km is subsampled at 5-km. Note that all cloud phases (liquid water, ice, and undetermined phase) are represented in the parameter;
users must read the Cloud Phase (Retrieval Processing Path) Flag in the Cloud_Quality_Assurance SDS
to determine the cloud phase represented by each pixel.
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- Cloud_Water_Path_Uncertainty
Description: Cloud Water Path Relative Uncertainty (Percent).
Source product, SDS: 06_L2, Cloud_Water_Path_Uncertainty
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, daytime only
Notes: Source data at 1-km is subsampled at 5-km. Note that all cloud phases (liquid water, ice, and undetermined phase) are represented in the parameter;
users must read the Cloud Phase (Retrieval Processing Path) Flag in the Cloud_Quality_Assurance SDS
to determine the cloud phase represented by each pixel.
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- Cloud_Optical_Thickness_1621
Description: Cloud optical thickness two-channel retrieval using band 7 and band 6
Source product, SDS: 06_L2, Cloud_Optical_Thickness_1621
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, daytime only
Notes: Source data at 1-km is subsampled at 5-km.
Note that all cloud phases (liquid water, ice, and undetermined phase) are represented in the parameter;
users must read the Cloud Phase (Retrieval Processing Path) Flag in the Cloud_Quality_Assurance SDS
to determine the cloud phase represented by each pixel.
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- Cloud_Optical_Thickness_Uncertainty_1621
Description: Cloud Optical Thickness Relative Uncertainty (Percent) using band 7 and band 6
Source product, SDS: 06_L2, Cloud_Optical_Thickness_Uncertainty_1621
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, daytime only
Notes: Source data at 1-km is subsampled at 5-km. Note that all cloud phases (liquid water, ice, and undetermined phase) are represented in the parameter;
users must read the Cloud Phase (Retrieval Processing Path) Flag in the Cloud_Quality_Assurance SDS
to determine the cloud phase represented by each pixel.
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- Cloud_Effective_Radius_1621
Description: Cloud Particle Effective Radius two-channel retrieval using band 7 and band 6
Source product, SDS: 06_L2, Effective_Particle_Radius_1621
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, daytime only
Notes: Source data at 1-km is subsampled at 5-km. Note that all cloud phases (liquid water, ice, and undetermined phase) are represented in the parameter; users must read the Cloud Phase (Retrieval Processing Path) Flag in the Cloud_Quality_Assurance SDS to determine the cloud phase represented by each pixel. SDS name changed to clarify application.
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- Cloud_Effective_Radius_Uncertainty_1621
Description: Cloud Effective Particle Radius Relative Uncertainty (Percent) using band 7 and band 6
Source product, SDS: 06_L2, Cloud_Effective_Radius_Uncertainty_1621
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, daytime only
Notes: Source data at 1-km is subsampled at 5-km. Note that all cloud phases (liquid water, ice, and undetermined phase) are represented in the parameter;
users must read the Cloud Phase (Retrieval Processing Path) Flag in the Cloud_Quality_Assurance SDS
to determine the cloud phase represented by each pixel.
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- Cloud_Water_Path_1621
Description: Column Cloud Water Path two-band retrieval using band 7 and band 6.
Source product, SDS: 06_L2, Cloud_Water_Path_1621
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, daytime only
Notes: Source data at 1-km is subsampled at 5-km. Note that all cloud phases (liquid water, ice, and undetermined phase) are represented in the parameter;
users must read the Cloud Phase (Retrieval Processing Path) Flag in the Cloud_Quality_Assurance SDS
to determine the cloud phase represented by each pixel.
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- Cloud_Water_Path_Uncertainty_1621
Description: Cloud Water Path Relative Uncertainty (Percent) using band 7 and band 6
Source product, SDS: 06_L2, Cloud_Water_Path_Uncertainty_1621
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, daytime only
Notes: Source data at 1-km is subsampled at 5-km. Note that all cloud phases (liquid water, ice, and undetermined phase) are represented in the parameter;
users must read the Cloud Phase (Retrieval Processing Path) Flag in the Cloud_Quality_Assurance SDS
to determine the cloud phase represented by each pixel.
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- Cloud_Phase_Optical_Properties
Description: Cloud Phase as determined by the Cloud Optical Property algorithm.
Note that this phase flag is identical for both the primary retrieval and the 1.6/2.1 µm retrieval.
Source product, SDS: 06_L2, Cloud_Phase_Optical_Properties
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, daytime only
Notes: Source data at 1-km is subsampled at 5-km. This information is identical to that stored
in the Cloud Phase (Retrieval Processing Path) Flag in the Cloud_Quality_Assurance SDS; but is stored here to simplify its access by users.
Key:
[ 0 = Fill (Cloud Mask undetermined),
1 = Decision Tree Stop (typically Clear),
2 = Liquid Water Phase Cloud,
3 = Ice Phase Cloud,
4 = Undetermined Phase Cloud ]
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- Cloud_Quality_Assurance
Collection 005 Version Format
QA (Bit) Flag Description Key
All bit and byte numbering starts at 0
Right (least significant bit) to Left (most significant bit)
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Byte #0
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| Bits |
Flag Description |
Flag Interpretation
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| 0 |
Cloud Optical Thickness General QA |
0 = Not Useful
1 = Useful |
| 1-2 |
Cloud Optical Thickness Confidence QA |
0 = No Confidence or Fill
1 = Marginal Confidence
2 = Good Confidence
3 = Very Good Confidence |
| 3-4 |
Cloud Optical Thickness Out-of-Bounds Flag |
0 = Within Bounds (0-100)
1 = Marginally Out of Bounds (100-150)
2 = Greatly Out of Bounds (150+)
3 = Surface reflectance too large for retrieval (LE 0) |
| 5 |
Cloud Effective Radius General QA |
0 = Not Useful
1 = Useful |
| 6-7 |
Cloud Effective Radius Confidence QA |
0 = No Confidence or Fill
1 = Marginal Confidence
2 = Good Confidence
3 = Very Good Confidence |
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Byte #1
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| Bits |
Flag Description |
Flag Interpretation |
| 0 |
Water Path General QA |
0 = Not Useful
1 = Useful |
| 1-2 |
Water Path Confidence QA |
0 = No Confidence or Fill
1 = Marginal Confidence
2 = Good Confidence
3 = Very Good Confidence |
| 3-5 |
1.6/2.1µm Cloud Retrieval Phase |
0 = Fill (Cloud Mask undet. or Non-Snow Land)
1 = Decision Tree Stop (over Ocean, Snow, or Ice)
2 = Cloud, Liquid Water Phase
3 = Cloud, Ice Phase
4 = Cloud, Undetermined Phase |
| 6 |
1.6/2.1µm Cloud Retrieval Outcome |
0 = 1.6/2.1 retrieval not attempted or unsuccessful
1 = 1.6/2.1 retrieval successful |
| 7 |
(Spare) |
Bits not used (set) |
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Byte #2
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| Bits |
Flag Description |
Flag Interpretation |
| 0-2 |
Primary Cloud Retrieval Phase |
0 = Fill (Cloud Mask undetetmined)
1 = Decision Tree Stop (typically Clear)
2 = Cloud, Liquid Water Phase
3 = Cloud, Ice Phase
4 = Cloud, Undetermined Phase |
| 3 |
Primary Cloud Retrieval Outcome |
0 = Retrieval not attempted or unsuccessful
1 = Retrieval successful |
| 4 |
Reyleigh Correction |
0 = No
1 = Yes |
| 5 |
Atmospheric Correction |
0 = No
1 = Yes |
| 6-7 |
Band Used for Primary Optical Thickness Retrieval |
0 = Retrieval not attempted
1 = 0.645µm (land)
2 = 0.858µm (water)
3 = 1.24µm (snow/ice) |
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Byte #3
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| Bits |
Flag Description |
Flag Interpretation |
| 0 |
1.6/2.1µm Optical Thickness General QA |
0 = Not Useful
1 = Useful |
| 1-2 |
1.6/2.1µm Optical Thickness Confidence QA |
0 = No Confidence or Fill
1 = Marginal Confidence
2 = Good Confidence
3 = Very Good Confidence |
| 3 |
1.6/2.1µm Effective Radius General QA |
0 = Not Useful
1 = Useful |
| 4-5 |
1.6/2.1µm Effective Radius Confidence QA |
0 = No Confidence or Fill
1 = Marginal Confidence
2 = Good Confidence
3 = Very Good Confidence |
| 6-7 |
Clear Sky Restoral Flag |
0 = Not Restored
1 = Restored via Edge Detection
2 = Restored via Spatial Variance
3 = Restored vis 250m Tests |
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Byte #4
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| Bits |
Flag Description |
Flag Interpretation |
| 0 |
1.6/2.1µm Water Path General QA |
0 = Not Useful
1 = Useful |
| 1-2 |
1.6/2.1µm Water Path Confidence QA |
0 = No Confidence or Fill
1 = Marginal Confidence
2 = Good Confidence
3 = Very Good Confidence |
| 3-5 |
Multi-Layer Cloud & Phase Flag |
0 = Fill (Cloud Mask undetetmined)
1 = Decision Tree Stop (typically Clear)
2 = Single Layer Liquid Water Cloud
3 = Multi Layer Liquid Water Cloud
4 = Single Layer Ice Cloud
5 = Multi Layer Ice Cloud
6 = Single Layer Undetermined Phase Cloud
7 = Multi Layer Undetermined Phase Cloud |
| 6 |
Primary Cloud Retrieval Outcome
(flag duplicated from byte #2,
necessary for proper computation of
several L3 multi-layer cloud flag statistics)
|
0 = Retrieval not attempted or unsuccessful
1 = Retrieval successful |
| 7 |
(Spare) |
Bits not used (set) |
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Cirrus Parameters
- Cirrus_Reflectance
Description: Cirrus reflectance at 0.66 µm.
Source product, SDS: 06_L2, Cirrus_Reflectance
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, daytime only
Notes: Source data at 1-km is subsampled at 5-km.
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Cloud Top Parameters
- Cloud_Top_Pressure
Description: Cloud top pressure (hPa) at 5x5 1-km pixel resolution using infrared retrieval methods. If less than 4 out of the 25 1-km pixels are cloudy (cloud fraction < 16%), then the 5x5 km area is processed using the "clear" retrieval path and cloud top pressure is set to missing (fill). This is done because CO2-slicing is not sensitive enough to give an accurate cloud top pressure when the cloud fraction is less than around 15%.
Source product, SDS: 06_L2, Cloud_Top_Pressure
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, day & night
Notes: Data duplicated exactly from source file.
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- Cloud_Top_Temperature
Description: Cloud top temperature (K) at 5x5 1-km pixel resolution using infrared retrieval methods. If less than 4 out of the 25 1-km pixels are cloudy (cloud fraction < 16%), then the 5x5 km area is processed using the "clear" retrieval path and cloud top temperature is set to missing (fill). This is done because CO2-slicing is not sensitive enough to give an accurate cloud top pressure, from which temperature is derived, when the cloud fraction is less than around 15%.
Source product, SDS: 06_L2, Cloud_Top_Temperature
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, day & night
Notes: Data duplicated exactly from source file.
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- Cloud_Fraction
Description: Cloud fraction at 5-km derived from 1-km cloud mask (5x5 1-km pixel resolution) using solar and infrared tests. Fractions are computed as: [(count of lowest 2 clear sky confidence levels, cloudy & probably cloudy) / (total count)].
Source product, SDS: 06_L2, Cloud_Fraction
Array type, dimension, size: Int*1, 406x270, 109k
Resolution, mode: 5-km, day & night
Notes: Data duplicated exactly from source file.
Due to computational characteristics, cloud fractions are typically computed in 4% increments [0%, 4%, 8%, ... 96%, 100%], the exceptions are in areas where 1 or more of the 5x5 1-km cloud mask pixels contain missing data or fill (in other words, invalid cloud mask values -- for example in severe sun-glint regions like the Gulf of Mexico in June). Only cloud fractions of 16% and above will have corresponding non-fill cloud top pressure and cloud top temperature data associated with them (see Cloud Top Pressure and Temperature Description fields, above).
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- Cloud_Phase_Infrared
Description: Cloud Phase as determined by the UW Infrared algorithm.
Source product, SDS: 06_L2, Cloud_Phase_Infrared
Array type, dimension, size: Int*1, 406x270, 109k
Resolution, mode: 5-km, day & night
Notes: Data duplicated exactly from source file.
Key:
[ 0 = Clear,
1 = Liquid Water Phase Cloud,
2 = Ice Phase Cloud,
3 = Mixed Phase Cloud,
6 = Undetermined Phase Cloud ]
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Profile (07_L2)
- Precipitable_Water_Infrared_Clear
Description: Total column precipitable water vapor (cm) for clear sky using infrared retrieval.
Source product, SDS: 07_L2, Water_Vapor
Array type, dimension, size: Int*2, 406x270, 219k
Resolution, mode: 5-km, day & night
Notes: Data duplicated exactly from source file. SDS name changed to clarify application.
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Cloud Mask (35_L2)
- Cloud_Mask
Description: Cloud mask information.
Source product, SDS: 35_L2, Cloud_Mask (1st byte only)
Array type, dimension, size: Int*1, 406x270, 109k
Resolution, mode: 5-km, day & night
Notes: Source data at 1-km is subsampled at 5-km. Only the first byte is copied from the source (input) SDS.
The first byte contains six QA flags.
Key: For help reading QA (bit) flag arrays,
review the Bit Interpretation page.
QA (Bit) Flag Description Key
All bit and byte numbering starts at 0
Right (least significant bit) to Left (most significant bit)
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Byte #0
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| Bits |
Flag Description |
Flag Interpretation |
| 0 |
Cloud Mask Status Flag |
0 = Not Determined
1 = Determined |
| 1-2 |
Unobstructed FOV Cloudiness Flag |
0 = Cloudy
1 = Probably Cloudy
2 = Probably Clear
3 = Confident Clear |
| 3 |
Day/Night Flag |
0 = Night
1 = Day |
| 4 |
Sunglint Flag |
0 = Yes
1 = No |
| 5 |
Snow/Ice Background Flag |
0 = Yes
1 = No |
| 6-7 |
Land/Water Flag |
0 = Water
1 = Coastal
2 = Desert
3 = Land |
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10-km Geolocation and Viewing Geometry
- Latitude_10km
Description: Latitude for 10-km parameters.
Source product, SDS: 04_L2, Latitude
Array type, dimension, size: Int*2, 203x135, 54k
Resolution, mode: 10-km, daytime only
Notes: For reduced file size, Real*4 source data are repacked as Integer*2.
A precision loss of 1/1000th of a degree results. SDS name changed to clarify application.
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- Longitude_10km
Description: Longitude for 10-km parameters.
Source product, SDS: 04_L2, Longitude
Array type, dimension, size: Int*2, 203x135, 54k
Resolution, mode: 10-km, daytime only
Notes: For reduced file size, Real*4 source data are repacked as Integer*2.
A precision loss of 1/1000th of a degree results. SDS name changed to clarify application.
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- Solar_Zenith_10km
Description: Solar zenith angle (cell to sun) for 10-km parameters.
Source product, SDS: 04_L2, Solar_Zenith
Array type, dimension, size: Int*2, 203x135, 54k
Resolution, mode: 10-km, daytime only
Notes: Data duplicated exactly from source file. SDS name changed to clarify application.
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- Viewing_Zenith_10km
Description: Sensor zenith angle (cell to sensor) for 10-km parameters.
Source product, SDS: 04_L2, Sensor_Zenith
Array type, dimension, size: Int*2, 203x135, 54k
Resolution, mode: 10-km, daytime only
Notes: Data duplicated exactly from source file. SDS name changed to clarify application.
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- Relative_Azimuth_10km
Description: Relative azimuth angle for 10-km parameters.
Computation equation: if ( abs (sensor_azimuth - solar_azimuth) > 180) then RA = 360 - abs ( sensor_azimuth - solar_azimuth ) else RA = abs ( sensor_azimuth - solar_azimuth )
Array type, dimension, size: Int*2, 203x135, 54k
Resolution, mode: 10-km, daytime only
Notes: New angle parameter computed from input sensor and solar azimuth angle data.
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Aerosol (04_L2)
- Aerosol_Optical_Depth
Description: Aerosol optical depth at 0.55 µm over land (corrected solution) and ocean (best solution).
Source product, SDS: 04_L2, Optical_Depth_Land_And_Ocean
Array type, dimension, size: Int*2, 203x135, 54k
Resolution, mode: 10-km, daytime only
Notes: Data duplicated exactly from source file. SDS name changed to clarify application.
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- Aerosol_Optical_Depth_Ratio_Small
Description: Ratio of small mode optical depth to all modes at 0.55 µm over land and ocean.
Source product, SDS: 04_L2, Optical_Depth_Ratio_Small_Land_And_Ocean
Array type, dimension, size: Int*2, 203x135, 54k
Resolution, mode: 10-km, daytime only
Notes: Data duplicated exactly from source file. SDS name changed to clarify application.
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- Aerosol_Solution_Index_Ocean_Small_Average
Description: Solution number index (1 through 4) for small aerosol particles (average solution only) over ocean.
Indices of ocean models 1 through 4 correspond to accumulation (small) mode models with effective radii 0.10, 0.15, 0.20, 0.25 µm, respectively.
Source product, SDS: 04_L2, Solution_Index _Ocean_Small
Array type, dimension, size: Int*1, 203x135, 27k
Resolution, mode: 10-km, daytime only
Notes: Data packed from Int*2 in source file to Int*1 to save space (causes no data accuracy loss).
Only the 2nd (average) solution is kept. SDS name changed to clarify application.
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- Aerosol_Solution_Index_Ocean_Large_Average
Description: Solution number index (5 through 9) for large aerosol particles (average solution only) over ocean.
Indices of ocean models 5 through 7 correspond to coarse (large) mode models of marine (sea salt) particles with effective radii 1.0, 1.5, 2.0 µm, respectively. Indices of ocean models 8 and 9 correspond to coarse (large) mode models of mineral dust particles with effective radii 1.5 and 2.5 µm, respectively.
Source product, SDS: 04_L2, Solution_Index _Ocean_Large
Array type, dimension, size: Int*1, 203x135, 27k
Resolution, mode: 10-km, daytime only
Notes: Data packed from Int*2 in source file to Int*1 to save space (causes no data accuracy reduction).
Only the 2nd (average) solution is kept. SDS name changed to clarify application.
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- Deep_Blue_Aerosol_Optical_Depth_550_Land
Description: AOT at 0.55 micron for land (corrected) with all quality data (Quality flag=1,2,3).
Source product, SDS: 04_L2, Deep_Blue_Aerosol_Optical_Depth_550_Land
Array type, dimension, size: Int*2, 203x135, 54k
Resolution, mode: 10-km, daytime only
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- Deep_Blue_Angstrom_Exponent_Land
Description: Deep Blue Angstrom Exponent for land (0.412-0.47 micron) with all quality data (Quality flag=1,2,3).
Source product, SDS: 04_L2, Deep_Blue_Angstrom_Exponent_Land
Array type, dimension, size: Int*2, 203x135, 54k
Resolution, mode: 10-km, daytime only
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- Deep_Blue_Single_Scattering_Albedo_412_Land
Description: Deep Blue Single Scattering Albedo at 0.412 micron for land with all quality data (Quality flag=1,2,3).
Source product, SDS: 04_L2, Deep_Blue_Single_Scattering_Albedo_Land
Array type, dimension, size: Int*2, 203x135, 54k
Resolution, mode: 10-km, daytime only
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- Deep_Blue_Aerosol_Quality_Assurance
Description: QA flags for (deep blue) aerosol retrievals over land.
Source product, SDS: 04_L2, Quality_Assurance_Land
Array type, dimension, size: Int*1, 203x135, 27k
Resolution, mode: 10-km, daytime only
Notes: This might be a place holder array for populating in C006. (Status Unknown)
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- Aerosol_Quality_Assurance
Description: QA flags for aerosol retrievals over land and ocean.
Source product, SDS: 04_L2, Quality_Assurance_Land {2 QA flags only} and Quality_Assurance_Ocean {1 QA flag only}
Array type, dimension, size: Int*1, 203x135, 27k
Resolution, mode: 10-km, daytime only
Notes: Only six bits gleaned from two QA arrays in the source (input) 04_L2 HDF file are set.
SDS name changed to clarify application.
Key: For help reading QA (bit) flag arrays,
review the Bit Interpretation page.
QA (Bit) Flag Description Key
All bit and byte numbering starts at 0
Right (least significant bit) to Left (most significant bit)
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Byte #0
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| Bits |
Flag Description |
Flag Interpretation |
| 0-1 |
Aerosol Optical Depth
Land 0.47µm
Confidence Flag |
0 = No Confidence or Fill
1 = Marginal Confidence
2 = Good Confidence
3 = Very Good Confidence |
| 2-3 |
Aerosol Optical Depth
Land 0.66µm
Confidence Flag |
0 = No Confidence or Fill
1 = Marginal Confidence
2 = Good Confidence
3 = Very Good Confidence |
| 4-5 |
Aerosol Optical Depth
Ocean Avg. Solution
Confidence Flag |
0 = No Confidence or Fill
1 = Marginal Confidence
2 = Good Confidence
3 = Very Good Confidence |
| 6-7 |
Spares |
(not set) |
|
|
|
