부산대학교 도서관

In this paper we describe the stratospheric and mesospheric ozone (version V5r_O3_m22) distributions retrieved from MIPAS observations in the three middle atmosphere modes (MA, NLC, and UA) taken with an unapodized spectral resolution of 0.0625cm-1 from 2005 until April 2012. O3 is retrieved from microwindows in the 14.8 and 10µm spectral regions and requires non-local thermodynamic equilibrium (non-LTE) modelling of the O3 v1 and v3 vibrational levels. Ozone is reliably retrieved from 20km in the MA mode (40km for UA and NLC) up to ~105km during dark conditions and up to ~95km during illuminated conditions. Daytime MIPAS O3 has an average vertical resolution of 3-4km below 70km, 6-8km at 70-80km, 8-10km at 80-90, and 5-7km at the secondary maximum (90-100km). For nighttime conditions, the vertical resolution is similar below 70km and better in the upper mesosphere and lower thermosphere: 4-6km at 70-100km, 4-5km at the secondary maximum, and 6-8km at 100-105km. The noise error for daytime conditions is typically smaller than 2% below 50km, 2-10% between 50 and 70km, 10-20% at 70-90km, and ~30% above 95km. For nighttime, the noise errors are very similar below around 70km but significantly smaller above, being 10-20% at 75-95km, 20-30% at 95-100km, and larger than 30% above 100km. The additional major O3 errors are the spectroscopic data uncertainties below 50km (10-12%) and the non-LTE and temperature errors above 70km. The validation performed suggests that the spectroscopic errors below 50km, mainly caused by the O3 air-broadened half-widths of the v2 band, are overestimated. The non-LTE error (including the uncertainty of atomic oxygen in nighttime) is relevant only above ~85km with values of 15-20%. The temperature error varies from ~3% up to 80km to 15-20% near 100km. Between 50 and 70km, the pointing and spectroscopic errors are the dominant uncertainties. The validation performed in comparisons with SABER, GOMOS, MLS, SMILES, and ACE-FTS shows that MIPAS O3 has an accuracy better than 5% at and below 50km, with a positive bias of a few percent. In the 50-75km region, MIPAS O3 has a positive bias of 10%, which is possibly caused in part by O3 spectroscopic errors in the 10µm region. Between 75 and 90km, MIPAS nighttime O3 is in agreement with other instruments by 10%, but for daytime the agreement is slightly larger, ~10-20%. Above 90km, MIPAS daytime O3 is in agreement with other instruments by 10%. At night, however, it shows a positive bias increasing from 10% at 90km to 20% at 95-100km, the latter of which is attributed to the large atomic oxygen abundance used. We also present MIPAS O3 distributions as function of altitude, latitude, and time, showing the major O3 features in the middle and upper mesosphere. In addition to the rapid diurnal variation due to photochemistry, the data also show apparent signatures of the diurnal migrating tide during both day- and nighttime, as well as the effects of the semi-annual oscillation above ~70km in the tropics and mid-latitudes. The tropical daytime O3 at 90km shows a solar signature in phase with the solar cycle. [ABSTRACT FROM AUTHOR]