Technical Note: New ground-based FTIR measurements at Ile de La Réunion: observations, error analysis, and comparisons with independent data

[摘要] Ground-based high spectral resolution Fourier-transform infrared (FTIR)solar absorption spectroscopy is a powerful remote sensing technique toobtain information on the total column abundances and on the verticaldistribution of various constituents in the atmosphere. This work presentsresults from two FTIR measurement campaigns in 2002 and 2004, held at Ile deLa Réunion (21° S, 55° E). These campaigns represent the firstFTIR observations carried out at a southern (sub)tropical site. They servethe initiation of regular, long-term FTIR monitoring at this site in thenear future. To demonstrate the capabilities of the FTIR measurements atthis location for tropospheric and stratospheric monitoring, a detailedreport is given on the retrieval strategy, information content andcorresponding full error budget evaluation for ozone (O₃), methane(CH₄), nitrous oxide (N₂O), carbon monoxide (CO), ethane(C₂H₆), hydrogen chloride (HCl), hydrogen fluoride (HF) and nitricacid (HNO₃) total and partial column retrievals. Moreover, we have madea thorough comparison of the capabilities at sea level altitude (St.-Denis)and at 2200 m a.s.l. (Maïdo). It is proved that the performances of thetechnique are such that the atmospheric variability can be observed, at bothlocations and in distinct altitude layers. Comparisons with literature andwith correlative data from ozone sonde and satellite (i.e., ACE-FTS, HALOEand MOPITT) measurements are given to confirm the results. Despite the shorttime series available at present, we have been able to detect the seasonalvariation of CO in the biomass burning season, as well as the impact ofparticular biomass burning events in Africa and Madagascar on theatmospheric composition above Ile de La Réunion. We also show thatdifferential measurements between St.-Denis and Maïdo provide usefulinformation about the concentrations in the boundary layer.

[学科分类] 大气科学