acos_l2_filter_b7
bias_correct_acos_b7
acos_warn_levels_b7
XCO2_Bias_Corrected = XCO2_Raw + 0.300*(dp + 0.0) + 8.60*(sqrt_alb_3 - 0.500) + 0.0160*(co2_grad_del - 25.0) + 14.5*(DWS - 0.0200) +0.15 ppm
XCO2_Bias_Corrected = XCO2_Raw + 0.290*(dp + 1.20) + 4.10*(alb_3 - 0.400) + 0.0150*(co2_grad_del - 20.0) + 7.50*(aod_du - 0.0100) -0.20 ppm
XCO2_Bias_Corrected = XCO2_Raw - 42.4*(s32 - 0.610) - 0.0930*(co2_grad_del + 3.00) + 1.80*(aodheight_ic - 0.180) + 0.325*(logDust + 0.0) +0.90 ppm
Bias correction parameter uncertainties are given in the data users guide.
There is some uncertainty in not only the bias correction coefficients but in the chosen parameters themselves. This release bias correction may be slightly different that of previous releases, and also somewhat different from those of previous ACOS algorithm versions. This has to do with details of the particular retrieval algorithm version and is considered normal (though not ideal).
GOSAT
TANSO-FTS
ACOS L2 Lite Output
B7.3.10A
Filtered with acos_b7_prefilter
Dec 2016
Chris O'Dell: odell@atmos.colostate.edu
ppm
A priori XCO2 Value
-999999.0000
xco2_apriori
/xco2_apriori
none
L2 File Index
-1
1-Based Index of L2 File for each sounding
file_index
/file_index
hPa
Pressure_Levels
-999999.0000
Pressure at each level; Defined on layer boundaries. These are oriented space-to-surface, so the first element defines the TOA, the last element defines the surface.
pressure_levels
/pressure_levels
ppm
XCO2
-999999.0000
Column-averaged dry-air mole fraction of CO2 (includes bias correction)
xco2
/xco2
seconds since 1970-01-01 00:00:00
time
-999999.00000000000
time
/time
none
Pressure Weighting Function
-999999.0000
Pressure weighting function for each level; Defined on layer boundaries. These are oriented space-to-surface, so the first element defines the TOA, the last element defines the surface.
pressure_weight
/pressure_weight
dimensionless
CO2 Ratio
-999999.0000
Band 3 / Band 2 Ratio of retrieved Single-band XCO2 using IMAP-DOAS algorithm
co2_ratio
/Preprocessors/co2_ratio
dimensionless
H2O Ratio
-999999.0000
Band 3 / Band 2 Ratio of retrieved Single-band XH2O using IMAP-DOAS algorithm
h2o_ratio
/Preprocessors/h2o_ratio
ppm
xco2_strong
-999999.0000
XCO2 from Strong CO2 Band only, IMAP-DOAS algorithm
xco2_strong_idp
/Preprocessors/xco2_strong_idp
ppm
xco2_weak
-999999.0000
XCO2 from Weak CO2 Band only, IMAP-DOAS algorithm
xco2_weak_idp
/Preprocessors/xco2_weak_idp
none
o2_ratio_p_idp
-999999.0000
O2 Ratio (nonscattering retrieval) from IMAP-DOAS algorithm, GOSAT P Polarization
o2_ratio_p_idp
/Preprocessors/o2_ratio_p_idp
hPa
delta_surface_pressure_abp
-999999.0000
Retrieved-Prior Pressure from the fast O2A-band only preprocessor retrieval
dp_abp
/Preprocessors/dp_abp
none
o2_ratio_s_idp
-999999.0000
O2 Ratio (nonscattering retrieval) from IMAP-DOAS algorithm, GOSAT S Polarization
o2_ratio_s_idp
/Preprocessors/o2_ratio_s_idp
degrees
sounding_solar_zenith
-999999.0000
solar zenith angle at the time of the measurement
solar_zenith_angle
/solar_zenith_angle
degrees_east
longitude
-999999.0000
center longitude of the measurement
longitude
/longitude
degrees_north
latitude
-999999.0000
center latitude of the measurement
latitude
/latitude
degrees
sounding_zenith
-999999.0000
zenith angle of the satellite at the time of the measurement
sensor_zenith_angle
/sensor_zenith_angle
none
XCO2_Quality_Flag
127
0=Good, 1=Bad
xco2_quality_flag
/xco2_quality_flag
none
XCO2 Column Averaging Kernel
-999999.0000
Normalized XCO2 averaging kernel; Defined on layer boundaries. These are oriented space-to-surface, so the first element defines the TOA, the last element defines the surface.
xco2_averaging_kernel
/xco2_averaging_kernel
none
Observation date and time matching sounding_id
-9999
Year, month (1-12), day (1-31), hour (0-23), minute (0-59), second (0-59).
date
/date
dimensionless
Water Cloud Optical Depth
-999999.0000
Retrieved Water Cloud Optical Depth at 0.755 microns
aod_water
/Retrieval/aod_water
none
Signal_band3/Signal_band2
-999999.0000
Ratio of Band 3 to Band 2 signal level
s32
/Retrieval/s32
dimensionless
Dust Aerosol Optical Depth
-999999.0000
Retrieved Dust Aerosol Optical Depth at 0.755 microns
aod_dust
/Retrieval/aod_dust
per wn
Retrieved Band 3 albedo slope
-999999.0000
albedo_slope_3
/Retrieval/albedo_slope_3
dimensionless
Black Carbon Optical Depth
-999999.0000
Retrieved Black Carbon Optical Depth at 0.755 microns
aod_bc
/Retrieval/aod_bc
dimensionless
Sea Salt Optical Depth
-999999.0000
Retrieved Sea Salt Carbon Optical Depth at 0.755 microns
aod_seasalt
/Retrieval/aod_seasalt
m/s
Prior Surface Wind Speed
-999999.0000
Surface wind speed retrieved by the Level-2 retrieval
windspeed_apriori
/Retrieval/windspeed_apriori
kg/m^2
Total Column Water Vapor A Priori
-999999.0000
Prior TCWV (from ECMWF prior profile)
tcwv_apriori
/Retrieval/tcwv_apriori
ppm
Change in CO2 vertical gradient (surface minus level 13), retrieved-apriori
-999999.0000
level 13 is at P/Psurf=0.631579
co2_grad_del
/Retrieval/co2_grad_del
W/m^2/um/sr
Retrieved Fluorescence at 757 nm
-999999.0000
Simultaneous Fluorescence retrieval (at 757 nm) by L2 code; note this is different than the dedicated retrieval using only solar lines
fs
/Retrieval/fs
hPa
Prior Surface Pressure
-999999.0000
Prior surface pressure used in the retrieval, as determined by ECMWF short-term (0-9 hour) forecast
psurf_apriori
/Retrieval/psurf_apriori
dimensionless
SigmaB_Coefficient
-999999.0000
Multiply Psurf by these values to get the pressure layer boundaries (= pressure levels)
SigmaB
/Retrieval/SigmaB
none
Band 2 Albedo
-999999.0000
Retrieved Band 2 (1.6 micron) surface albedo
albedo_2
/Retrieval/albedo_2
K
Temperature_at_700hPa
-999999.0000
Temperature at 700 hPa (from ECMWF)
T700
/Retrieval/T700
none
Band 1 Albedo
-999999.0000
Retrieved Band 1 (0.76 micron) surface albedo
albedo_1
/Retrieval/albedo_1
dimensionless
Reduced Chi-Squared of L2 Fit per band
-999999.0000
Reduced Chi-Squared for each band (1,2,3) of L2 spectral fit
reduced_chi_squared_per_band
/Retrieval/reduced_chi_squared_per_band
kg/m^2
Total Column Water Vapor
-999999.0000
Retrieved TCWV obtained by multiplying retrieved h2o_scale factor to prior (ECMWF) TCWV
tcwv
/Retrieval/tcwv
kg/m^2
Total Column Water Vapor Uncertainty
-999999.0000
Retrieved TCWV Posterior Uncertainty
tcwv_uncertainty
/Retrieval/tcwv_uncertainty
per wn
Retrieved Band 2 albedo slope
-999999.0000
albedo_slope_2
/Retrieval/albedo_slope_2
Kelvin
Retrieved Offset to Prior Temperature Profile in Kelvin
-999999.0000
deltaT
/Retrieval/deltaT
GOSAT radiance units * 1e7
Band 1 Radiance Offset
-999999.0000
Retrieved Band 1 (0.76 micron) radiance offset
b1offset
/Retrieval/b1offset
dimensionless
Retrieved scale factor to Prior Water Vapor Profile
-999999.0000
h2o_scale
/Retrieval/h2o_scale
dimensionless
log(dust+water+salt)
-999999.0000
Retrieved max(log(aod_dust+aod_sulfate+aod_ss),-5), at 0.755 microns
logDWS
/Retrieval/logDWS
hPa
Delta Psurf from L2
-999999.0000
Retrieved-Prior Pressure from the L2 Full-Physics retrieval
dp
/Retrieval/dp
none
Levenberg-Marquardt Parameter
-999999.0000
Value of Levenberg-Marquardt Parameter on final iteration
lm_param
/Retrieval/lm_param
m/s
Retrieved Surface Wind Speed
-999999.0000
Surface wind speed retrieved by the Level-2 retrieval
windspeed
/Retrieval/windspeed
dimensionless
Ice Cloud Optical Depth
-999999.0000
Retrieved Ice Cloud Optical Depth at 0.755 microns
aod_ice
/Retrieval/aod_ice
none
Iterations
127
No. of iterations used in retrieval
iterations
/Retrieval/iterations
none
Band 3 Albedo
-999999.0000
Retrieved Band 1 (2.04 micron) surface albedo
albedo_3
/Retrieval/albedo_3
dimensionless
Sulfate Aerosol Optical Depth
-999999.0000
Retrieved Sulfate Aerosol Optical Depth at 0.755 microns
aod_sulfate
/Retrieval/aod_sulfate
per wn
Retrieved Band 1 albedo slope
-999999.0000
albedo_slope_1
/Retrieval/albedo_slope_1
none
Strong_CO2 SNR Clipped
-999999.0000
Band 3 SNR clipped at 600
snr_strong_clip
/Retrieval/snr_strong_clip
none
diverging_steps
127
No. of diverging steps taken in retrieval
diverging_steps
/Retrieval/diverging_steps
ppm
Retrieved CO2 vertical gradient (surface minus level 13) in ppm
-999999.0000
level 13 is at P/Psurf=0.631579
grad_co2
/Retrieval/grad_co2
0=ocean;1=land
Surface Type
127
Surface type used in the retrieval: 0=ocean and corresponds to a Coxmunk+Lambertian surface; 1=land and corresponds to a pure Lambertian surface
surface_type
/Retrieval/surface_type
none
Signal_band3/Signal_band1
-999999.0000
Ratio of Band 3 to Band 1 signal level
s31
/Retrieval/s31
hPa
Retrieved Surface Pressure
-999999.0000
Surface pressure retrieved by the Level-2 retrieval
psurf
/Retrieval/psurf
dimensionless
Total Cloud+Aerosol Optical Depth
-999999.0000
Retrieved Total Cloud+Aerosol Optical Depth at 0.755 microns
aod_total
/Retrieval/aod_total
dimensionless
Organic Carbon Optical Depth
-999999.0000
Retrieved Organic Carbon Optical Depth at 0.755 microns
aod_oc
/Retrieval/aod_oc
ppm
Raw value of Retrieved XCO2
-999999.0000
xco2_raw
/Retrieval/xco2_raw
degrees
sounding_glint_angle
-999999.0000
Angular distance from viewing along the perfect glint direction
glint_angle
/Sounding/glint_angle
degrees East of North
sounding_azimuth
-999999.0000
azimuth angle of the satellite at the time of the measurement
sensor_azimuth_angle
/Sounding/sensor_azimuth_angle
none
snr_O2_L1b
-999999.0000
O2A-Band Continuum Signal-to-Noise Ratio
snr_o2
/Sounding/snr_o2
degrees
relative_airmass
-999999.0000
Airmass, computed as 1/cos(solar_zenith_angle) + 1/cos(sensor_zenith_angle)
airmass
/Sounding/airmass
degrees East of North
sounding_solar_azimuth
-999999.0000
solar azimuth angle at the time of the measurement
solar_azimuth_angle
/Sounding/solar_azimuth_angle
none
GOSAT orbit path number
-1
GOSAT fixed orbit path number ranging from 1-45
path
/Sounding/path
none
snr_weak_CO2_L1b
-999999.0000
Weak CO2-Band Continuum Signal-to-Noise Ratio
snr_weak_co2
/Sounding/snr_weak_co2
meters
Altitude
-999999.0000
Surface Altitude in meters above sea level
altitude
/Sounding/altitude
none
JAXA L1B Processing Version
-9999
l1b_type
/Sounding/l1b_type
none
snr_strong_CO2_L1b
-999999.0000
Strong CO2-Band Continuum Signal-to-Noise Ratio
snr_strong_co2
/Sounding/snr_strong_co2
percent
Land Fraction
127
Fraction of the footprint that contains land in percent
land_fraction
/Sounding/land_fraction
none
Gain
-1
TANSO-FTS gain mode: H is the high-gain mode (used over most of the planet); M is the medium gain mode (used over very bright surfaces)
gain
/Sounding/gain
ppm
XCO2_Posterior_Error
-999999.0000
xco2_uncertainty
/xco2_uncertainty
none
L2 Warn Level
127
Data Quality Indicator.0=Most likely good; 19=least likely good
warn_level
/warn_level
ppm
CO2 Apriori Profile
-999999.0000
Prior CO2 Prior assumed by L2 code; Defined on layer boundaries. These are oriented space-to-surface, so the first element defines the TOA, the last element defines the surface.
co2_profile_apriori
/co2_profile_apriori
bands
/bands
levels
/levels
none
L2 Source File
Missing
Source L2 File Names for these soundings
source_files
/source_files