Tropical tropospheric ozone columns from nadir retrievals of GOME-1/ERS-2, SCIAMACHY/Envisat, and GOME-2/MetOp-A (1996–2012)
Tropical tropospheric ozone columns are retrieved with the convective cloud differential (CCD) technique using total ozone columns and cloud parameters from different European satellite instruments. Monthly-mean tropospheric column amounts [DU] are calculated by subtracting the above-cloud ozone col...
Main Authors: | , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2016-07-01
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Series: | Atmospheric Measurement Techniques |
Online Access: | http://www.atmos-meas-tech.net/9/3407/2016/amt-9-3407-2016.pdf |
Summary: | Tropical tropospheric ozone columns are retrieved with the convective cloud
differential (CCD) technique using total ozone columns and cloud parameters
from different European satellite instruments. Monthly-mean tropospheric
column amounts [DU] are calculated by subtracting the above-cloud
ozone column from the total column. A CCD algorithm (CCD_IUP) has been
developed as part of the verification algorithm developed for TROPOspheric
Monitoring Instrument (TROPOMI) on Sentinel 5-precursor (S5p) mission, which
was applied to GOME/ERS-2 (1995–2003), SCIAMACHY/Envisat (2002–2012), and
GOME-2/MetOp-A (2007–2012) measurements. Thus a unique long-term record of
monthly-mean tropical tropospheric ozone columns (20° S–20° N)
from 1996 to 2012 is now available. An uncertainty estimation has been
performed, resulting in a tropospheric ozone column uncertainty less than 2 DU ( < 10 %) for all instruments. The dataset has not been yet
harmonised into one consistent; however, comparison between the three
separate datasets (GOME/SCIAMACHY/GOME-2) shows that GOME-2 overestimates the
tropical tropospheric ozone columns by about 8 DU, while SCIAMACHY and
GOME are in good agreement. Validation with Southern Hemisphere ADditional
OZonesondes (SHADOZ) data shows that tropospheric ozone columns from the
CCD_IUP technique and collocated integrated ozonesonde profiles from the
surface up to 200 hPa are in good agreement with respect to range,
interannual variations, and variances. Biases within ±5 DU and
root-mean-square (RMS) deviation of less than 10 DU are found for all
instruments. CCD comparisons using SCIAMACHY data with tropospheric ozone
columns derived from limb/nadir matching have shown that the bias and RMS deviation are
within the range of the CCD_IUP comparison with the ozonesondes. The 17-year
dataset can be helpful for evaluating chemistry models and performing climate
change studies. |
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ISSN: | 1867-1381 1867-8548 |