An evaluation of IASI-NH 3 with ground-based Fourier transform infrared spectroscopy measurements

摘要: Global distributions of atmospheric ammonia (NH3) measured with satellite instruments such as the Infrared Atmospheric Sounding Interferometer (IASI) contain valuable information on NH3 concentrations and variability in regions not yet covered by ground-based instruments. Due to their large spatial coverage (bi-)daily overpasses, observations have potential increase our knowledge distribution emissions associated seasonal cycles. However remain poorly validated, only a handful available studies often using surface measurements without any vertical information. In this study, we present first validation IASI-NH3 product Fourier transform infrared spectroscopy (FTIR) observations. Using recently developed consistent retrieval strategy, concentration profiles been retrieved from nine Network for Detection Composition Change (NDACC) stations around world between 2008 2015. We demonstrate importance strict spatio-temporal collocation criteria comparison. Large differences regression results are observed changing intervals criteria, mostly due terrain characteristics short lifetime atmosphere. The variations both datasets most sites. Correlations found be high at sites areas considerable levels, whereas correlations lower low levels close detection limit IASI instrument. A combination all (Nobs Combining double line 547) give mean relative difference g'32.4g€±g€(56.3)g€%, correlation r 0.8 slope 0.73. These an improved estimate performance compared previous upper-bound estimates (-50 +100%). © Author(s) 2016.