Open AccessEvaluation of GOME satellite measurements of tropospheric NO 2 and HCHO using regional data from aircraft campaigns in the southeastern United States
Author(s) -
Martin R. V.,
Parrish D. D.,
Ryerson T. B.,
Nicks D. K.,
Chance K.,
Kurosu T. P.,
Jacob D. J.,
Sturges E. D.,
Fried A.,
Wert B. P.
Publication year - 2004
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2004jd004869
Subject(s) - troposphere , environmental science , atmospheric sciences , tropospheric ozone , satellite , ozone , formaldehyde , nitrogen dioxide , sampling (signal processing) , in situ , meteorology , climatology , geography , chemistry , geology , physics , organic chemistry , astronomy , detector , optics
We compare tropospheric measurements of nitrogen dioxide (NO 2 ) and formaldehyde (HCHO) from the Global Ozone Monitoring Experiment (GOME) satellite instrument with in situ measurements over eastern Texas and the southeast United States. On average, the GOME and in situ measurements of tropospheric NO 2 and HCHO columns are consistent despite pronounced sampling differences. The geometric mean in situ to GOME ratios over the campaign are 1.08 for NO 2 and 0.84 for HCHO, with corresponding geometric standard deviations of 1.27 and 1.38. The correlation of the observed column spatial variability between the two NO 2 measurement sets is encouraging before (r 2 = 0.54, n = 18) and after (r 2 = 0.67, n = 18) correcting for a sampling bias. Mean relative vertical profiles of HCHO and NO 2 calculated with a global three‐dimensional model (GEOS‐CHEM) and used in the GOME retrieval are highly consistent with in situ measurements; differences would affect the retrieved NO 2 and HCHO columns by a few percent. GOME HCHO columns over eastern Texas include contributions from anthropogenic volatile organic compound (VOC) emissions but are dominated by biogenic VOC emissions at the regional scale in August–September when HCHO columns are within 20% of those over the southeastern United States. In situ measurements show that during summer the lowest 1500 m (the lower mixed layer) contains 75% of the tropospheric NO 2 column over Houston and Nashville, and 60% of the HCHO column over Houston. Future validation of space‐based measurements of tropospheric NO 2 and HCHO columns over polluted regions should include coincident in situ measurements that span the entire satellite footprint, especially in the heterogeneous mixed layer.