Abstract. Version 8 infrared limb emission spectra provided by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on Envisat were used to infer global distributions of HNO3, ClONO2, HNO4, and N2O5 in the altitude range from about 6 to 80 km. Here we describe in detail the analysis of the spectral data by means of constrained non-linear least-squares fitting, and provide information about the averaging kernels, the vertical and horizontal resolutions, and the error budgets of the derived trace gas profiles. For HNO3 and N2O5, the error budgets are dominated by systematic errors, mainly spectroscopic uncertainties, in the relevant altitude range, while for HNO4 and ClONO2 they are dominated by spectral noise. This implies that systematic biases of up to 20% and <10% cannot be excluded for HNO3 and N2O5, respectively, while the information about spatial and temporal variability is quite certain. Random uncertainties of HNO4 and ClONO2 can be favourably reduced by averaging, while systematic uncertainties in the order of 3% (ClONO2) and 20% (HNO4) will remain. The vertical resolution is in the order of 2 to 6 km in the lower and middle stratosphere, depending on the species and the atmospheric situation. Besides the four nitrogen reservoir species, we also present NOyas a derived data product. It is constructed from [HNO3] + [ClONO2] + [HNO4] + 2 x [N2O5] + [NO] + [NO2] and characterised in terms of its random and systematic error budget. Along with the regular data product of the four nitrogen reservoir species, an additional representation of the data on a coarser vertical grid is offered. These data can be used without consideration of the averaging kernels. The new trace gas distributions are compared to the previous data version, and they are discussed along the most relevant signatures of processes to be observed. We find that the new data products provide improved consistency between the full- and reduced-resolution mission periods of MIPAS, as well as between the observation modes covering different altitude ranges, and they exhibit all the analysed features caused by known atmospheric processes.

Global distributions of chlorine monoxide (ClO) were retrieved from infrared limb emission spectra recorded with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), covering the time period from July 2002 to April 2012. The retrieval was performed by constrained non-linear least squares fitting using spectral lines in the fundamental band of ClO around 844 cm-1. The vertical resolution of V8 ClO is 4 km at 18-20 km and 7.5-9.5 km at 40 km altitude. The considerable improvement at 40 km with respect to the previous V5 data version is achieved by extension of the spectral range for retrieval of upper stratospheric ClO. Errors are by far dominated by measurement noise and increase from 0.4-0.5 ppbv at 20 km to 0.8 ppbv at 50 km altitude. Thus, in general, individual ClO profiles are noisy, and profile averaging has to be performed for, e.g., analysis of the upper stratospheric maximum. However, strongly enhanced lower stratospheric ClO amounts of more than 1.5 ppbv during polar winter are well detected in single measurements. Along with the standard representation of the data, an alternative coarse grid representation that obviates the need to apply averaging kernels in certain situations is also provided. Due to improved modeling of the atmospheric continuum and the instrumental offset, the high bias in upper stratospheric ClO that had particularly affected the previous V5 data over the period 2005-2012 has been removed. A comparison with ClO measurements of the Microwave Limb Sounder (MLS) on the Aura satellite shows good agreement between the lower stratospheric enhancements observed by the two instruments in polar winter. There is also good agreement between the upper stratospheric ClO amounts observed in the northern hemisphere and at southern hemispheric low latitudes. With the support of simulations from the Earth system model ECHAM/MESSy Atmospheric Chemistry (EMAC), deviations between the ClO amounts of MIPAS and MLS in the Antarctic lower stratosphere during July and in the upper stratosphere, especially at southern mid- and high latitudes during winter, are attributed to the different local solar times of the measurements.

We present a global climatology of upper-tropospheric hydrogen cyanide (HCN), carbon monoxide (CO), acetylene (C2H2), ethane (C2H6), peroxyacetyl nitrate (PAN), and formic acid (HCOOH) obtained from observations of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on board the Environmental Satellite (Envisat) between 2002 and 2012. At northern midlatitudes and high latitudes, the biomass burning tracer HCN, but also CO, PAN, and HCOOH, exhibit maxima during spring and/or summer and minima during winter. On the contrary, maximum northern extratropical C2H2 and C2H6 amounts were measured during winter and spring, and minimum values were measured during summer and fall. In the tropics and subtropics, enhanced amounts of all pollutants were observed during all seasons, especially widespread and up to southern midlatitudes during austral spring. Other characteristic features are eastward transport of anthropogenic C2H6 and of biogenic HCOOH from Central and North America in boreal summer, accumulation of pollutants in the Asian monsoon anticyclone (AMA), and enhanced C2H2 over southeastern Asia in boreal winter. Clear indication of biogenic release of HCOOH was also found above tropical South America and Africa. A global correlation analysis of the other pollutants with HCN corroborates common release by biomass burning as a source of the widespread southern hemispheric pollution during austral spring. Furthermore, high correlation with HCN points to biomass burning as a major source of tropical and subtropical C2H2 and PAN during most of the year. In the northern extratropics, there are generally low correlations with HCN during spring and early summer, indicating the influence of anthropogenic and biogenic sources. However, in August, there are stronger correlations above Siberia and boreal North America, which points to common release by boreal fires. This is confirmed by the respective enhancement ratios (ERs). The ERs measured above northeastern Africa fit well to the emission ratios of the dominant local fire type (savanna burning) for C2H2, while those for CO, C2H6, and HCOOH rather indicate tropical forest fires or additional anthropogenic or biogenic sources. The southern hemispheric ΔC2H6/ΔHCN ERs obtained during August to October are in good agreement with the emission ratio for savanna fires. The same applies for ΔC2H2/ΔHCN in August and for ΔHCN/ΔCO and ΔHCOOH/ΔHCN in October.

Using the IMK–IAA data processor, methane and nitrous oxide distributions were retrieved from version-8 limb emission spectra recorded with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). The dataset includes measurements from the nominal, upper troposphere–lower stratosphere, middle-atmosphere, upper-atmosphere and noctilucent-cloud observation modes. The processing differs from the previous version-5 data with respect to the atmospheric state variables that are jointly retrieved along with the target gases CH4 and N2O, the treatment of the radiance offset, the selection of microwindows, the regularization, the spectroscopic data used and the treatment of horizontal variability of the atmospheric state. Besides the regular data product, a coarse-grid representation of the profiles with unity averaging kernels is available, as well as a specific research product for middle-atmosphere measurements resulting from a slightly different retrieval approach. The CH4 errors are dominated by the large spectroscopic uncertainty for line intensities, which probably is too pessimistic, and estimated to be 21 %–34 % in the altitude range 6–68 km for northern midlatitude summer day conditions. The N2O errors are 7 %–17 % below 45 km. At higher altitudes they increase strongly due to nearly vanishing N2O amounts. Analysis of the horizontal averaging kernels reveals that for both gases the horizontal resolution is sampling-limited; i.e., information is not smeared over consecutive limb scans. Zonal-mean seasonal composites of both CH4 and N2O exhibit the typical distribution of source gases with strong upwelling in the tropics and subsidence above the winter poles. Comparison with the previous data version shows several improvements: first, the vertical resolution of the retrieved CH4 (N2O) profiles has generally been significantly enhanced and varies between 2.5 (2.5) and 4 (5) km at altitudes between 10 and 60 km, with the best resolution around 30 km for both species. Secondly, the number of non-converged retrievals has been clearly reduced, and thirdly, formerly strongly oscillating profiles are now considerably smoother.

The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on Envisat provided infrared limb emission spectra, which were used to infer global distributions of CFC-11, CFC-12, and HCFC-22. Spectra were analysed using constrained non-linear least-squares fitting. Changes with respect to earlier data versions refer to the use of version 8 spectra, the altitude range where the background continuum is considered, details of the regularization and microwindow selection, and the occasional joint fitting of interfering species, the use of new spectroscopic data, the joint fit of a tangent-height-dependent spectral offset, and the use of 2D temperature fields. In the lower stratosphere the error budget is dominated by uncertainties in spectroscopic data, while above this measurement noise is the leading error source. The vertical resolution of CFC-11 and CFC-12 is 2–3 km near the tropopause, about 4 km at 30 km altitude, and 6–10 km at 50 km. The vertical resolution of HCFC-22 is somewhat coarser, 3–4 km at the tropopause and 10–12 km at 35 km altitude. In the altitude range of interest, the horizontal resolution is typically limited by the horizontal sampling of the measurements, not by the smearing of the retrievals. Horizontal information displacement does not exceed 150 km, which can become an issue only for comparisons with model simulations with high horizontal resolution or localized in situ observations. Along with the regular data product, an alternative representation of the data on a coarser vertical grid is offered. These data can be used without consideration of the averaging kernels. The new data version provides improvement with respect to reduction of biases and improved consistency between the full- and reduced-resolution mission period of MIPAS.

New global nitric oxide (NO) volume mixing ratio and lower-thermospheric temperature data products, retrieved from Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) spectra with the Institute of Meteorology and Climate Research and Instituto de Astrofisica de Andalucia (IMK-IAA) MIPAS data processor, have been released. The dataset covers the entire Envisat mission lifetime and includes retrieval results from all MIPAS observation modes. The data are based on European Space Agency (ESA) version 8 calibration and were processed using an improved retrieval approach compared to previous versions, specifically regarding the choice and construction of the a priori and atmospheric parameter profiles, the treatment of horizontal inhomogeneities, the treatment of the radiance offset correction, and the selection of optimized numerical settings. NO retrieval errors in individual observations are dominated by measurement noise and range from 5 % to 50 % in the stratosphere and thermosphere and reach 40 % to 90 % in the mesosphere. Systematic errors are typically within 10 %-30 %. Lower-thermospheric temperature errors are 5 to 50 K with a systematic component of around 20 K, the latter being dominated by non-thermodynamic equilibrium (non-LTE)-related uncertainties. NO data from different observation modes are consistent within 5 %-10 %. MIPAS version 8 temperatures have a better representation of the diurnal tide in the lower thermosphere compared to previous data versions. The new MIPAS temperatures are systematically warmer than results from the empirical US Naval Research Laboratory Mass Spectrometer Incoherent Scatter Radar (NRLMSIS) version 2.0 model by 30 to 80 K in the 100-120 km region and are colder above.

We present a new version of O3 data retrieved from the three Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) observation modes that we refer to for simplicity as the modes of the middle atmosphere (middle atmosphere, MA; upper atmosphere, UA; and noctilucent cloud, NLC). The O3 profiles cover altitudes from 20 up to 100 km for the daytime and up to 105 km at nighttime, for all latitudes, and the period 2005 until 2012. The data have been obtained with the IMK–IAA (Institute of Meteorology and Climate Research and Instituto de Astrofísica de Andalucía) MIPAS level-2 data processor and are based on ESA version-8 re-calibrated radiance spectra with improved temporal stability. The processing included several improvements with respect to the previous version, such as the consistency of the microwindows and spectroscopic data with those used in the nominal-mode V8R data, the O3 a priori profiles, and updates of the non-local thermodynamic equilibrium (non-LTE) parameters and the nighttime atomic oxygen. In particular, the collisional relaxation of O3(v1,v3) by the atomic oxygen was reduced by a factor of 2 in order to obtain a better agreement of nighttime mesospheric O3 with “non-LTE-free” measurements. Random errors are dominated by the measurement noise with 1σ values for single profiles for the daytime of < 5 % below ∼ 60 km, 5 %–10 % between 60 and 70 km, 10 %–20 % at 70–90 km, and about 30 % at 95 km. For nighttime, they are very similar below 70 km but smaller above (10 %–20 % at 75–95 km, 20 %–30 % at 95–100 km and larger than 30 % above 100 km). The systematic error is ∼ 6 % below ∼ 60 km (dominated by uncertainties in spectroscopic data) and 8 %–12 % above ∼ 60 km, mainly caused by non-LTE uncertainties. The systematic errors in the 80–100 km range are significantly smaller than in the previous version. The major differences with respect to the previous version are as follows: (1) the new retrievals provide O3 abundances in the 20–50 km altitude range that are larger by about 2 %–5 % (0.2–0.5 ppmv); (2) O3 abundances were reduced by ∼ 2 %–4 % between 50 and 60 km in the tropics and mid-latitudes; (3) O3 abundances in the nighttime O3 minimum just below 80 km were reduced, leading to a more realistic diurnal variation; (4) daytime O3 concentrations in the secondary maximum at the tropical and middle latitudes (∼ 40 %, 0.2–0.3 ppmv) were larger; and (5) nighttime O3 abundances in the secondary maximum were reduced by 10 %–30 %. The O3 profiles retrieved from the nominal mode (NOM) and the middle-atmosphere modes are fully consistent in their common altitude range (20–70 km). Only at 60–70 km does daytime O3 of NOM seem to be larger than that of MA/UA by 2 %–10 %. Compared to other satellite instruments, MIPAS seems to have a positive bias of 5 %–8 % below 70 km. Noticeably, the new version of MIPAS data agrees much better than before with all instruments in the upper mesosphere–lower thermosphere, reducing the differences from ∼± 20 % to ∼± 10 %. Further, the diurnal variation in O3 in the upper mesosphere (near 80 km) has been significantly improved.

A new global O3 data product retrieved from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) spectra with the IMK–IAA MIPAS data processor has been released. These data are based on ESA version 8 recalibrated radiance spectra with improved temporal stability. Changes in the level-2 processing with respect to previous data versions include the following: (1) the retrievals use improved temperature data and thus suffer less from the propagation of related errors. (2) The background continuum is now considered up to 58 km. (3) A priori information is now used to constrain the retrieval of the radiance offset. (4) Water vapour is fitted jointly with ozone to minimize the impact of interfering water lines. (5) A more adequate regularization has been chosen. (6) Ozone absorption lines in the MIPAS A band (685–980 cm−1) are used almost exclusively because of inconsistencies in spectroscopic data in the MIPAS AB band (1010–1180 cm−1). Only at altitudes above 50 km, where A-band ozone lines do not provide sufficient information, are ozone lines in the MIPAS AB band used. (7) Temperature-adjusted climatologies of vibrational temperatures of O3 and CO2 are considered to account for non-local thermodynamic equilibrium radiation. Ozone errors are estimated to be less than 10 % in the altitude range 20–50 km. The error budget is dominated by the spectroscopic errors, followed by the uncertainty of the instrumental line shape function, the gain calibration error, and the spectral noise. The error contribution of interfering gases is almost negligible. The vertical resolution depends on altitude and atmospheric conditions. In 2002–2004 it varies between 2.5 km at the lowest altitudes and 6 km at 70 km, while in 2005–2012 it covers 2 to 5.5 km in the same altitude range. The horizontal smearing in terms of the full width at half maximum of the horizontal component of the two-dimensional averaging kernel matrix is smaller than, or approximately equal to, the distance between two subsequent limb scans at all altitudes. This implies that the horizontal resolution is sampling-limited or optimal, respectively. An additional data version is made available that is free of the formal a priori information and thus more user-friendly for certain applications. Version 8 ozone results show a better consistency between the two MIPAS measurement periods. They seem to be more realistic than preceding data versions in terms of long-term stability, as at least a part of the drift is corrected. Further, the representation of elevated stratopause situations is improved.

Supplement to IMK/IAA MIPAS V8 methane & nitrous oxide Contents S1 Overview 3 S2 Methane error contribution profile plots and tabulated values for FR NOM data (V8H_CH4_61) 5 S3 Methane error contribution profile plots and tabulated values for RR NOM data (V8R_CH4_261) 40 S4 Methane error contribution profile plots and tabulated values for RR MA data (V8R_CH4_561) 75 S5 Methane error contribution profile plots and tabulated values for RR UA data (V8R_CH4_662) 110 S6 Nitrous oxide error contribution profile plots and tabulated values for FR NOM data (V8H_N2O_61) 145 S7 Nitrous oxide error contribution profile plots and tabulated values for RR NOM data (V8R_N2O_261) 180 S8 Nitrous oxide error contribution profile plots and tabulated values for RR MA data (V8R_N2O_561) 215 N. Glatthor et al.: Supplement to IMK/IAA MIPAS V8 methane & nitrous oxide Table S0.Labels and definitions of the representative atmospheric conditions which were used to calculate the error budget.Daytime atmospheres are defined by solar zenith angles < 90 • .Nighttime atmospheres are defined by solar zenith angles > 95 • for NOM observations, > 98 • for MA observations, and > 100 • for UA observations.representative atmosphere label month(s) used latitude range Northern polar winter day Jan, Feb 65 • N -90 • N Northern polar winter night Jan, Feb 65 • N -90 • N Northern polar spring day Apr 65 • N -90 • N Northern polar spring night Apr 65 • N -90 • N Northern polar summer day Jul,

Motivated by an improved European Space Agency (ESA) version of calibrated Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) spectra (version 8.03), we have released version 8 of MIPAS temperatures and pointing information retrieved from 2005-2012 MIPAS measurements at 12-15 mu m in the Middle Atmosphere (MA), Upper Atmosphere (UA) and Noctilucent Cloud (NLC) measurement modes. The Institute of Meteorology and Climate Research-Instituto de Astrofisica de Andalucia (IMK-IAA) retrieval processor in use considers non-local thermodynamic equilibrium (non-LTE) emission explicitly for each limb scan. This non-LTE treatment is essential to obtain accurate temperatures above the mid-mesosphere because at the altitudes covered, up to 115 km, the simplified climatology-based non-LTE treatment employed for the Nominal (NOM) measurements is insufficient. Other updates in MA/UA/NLC version 8 non-LTE temperature retrievals from previous data releases include more realistic atomic oxygen and carbon dioxide abundances, an updated set of spectroscopic data, an improved spectral shift retrieval, a continuum retrieval extended to altitudes up to 58 km, consideration of an altitude-dependent radiance offset retrieval, the use of wider microwindows above 85 km to capture the offset, an improved accuracy in forward model calculations, new a priori temperature information, improved temperature horizontal gradient retrievals and the use of MIPAS version 5 interfering species where available. The resulting MIPAS MA/UA/NLC IMK-IAA temperature dataset is reliable for scientific analysis in the full measurement vertical range for the MA (18-102 km) and the NLC (39-102 km) observations and from 42 to 115 km for the UA observations. The random temperature errors, dominated by the instrumental noise, are typically less than 1 K below 60 km, 1-3 K at 60-70 km, 3-5 K at 70-90 km, 6-8 K at 90-100 km, 8-12 K at 100-105 km and 12-20 K at 105-115 km. Random pointing correction errors, also mainly arising from instrumental noise, are on average 50 m for tangent altitudes up to 60 km and decrease linearly to values smaller than 20 m for altitudes above 95 km. The vertical resolution is 3 km at altitudes below 50 km, 3-5 km at 50-70 km, 4-6 km at 70-90 km, 6-10 km at 90-100 km and 8-11 km at 100-115 km. The systematic errors in retrieved temperatures below 75 km are driven by uncertainties in the CO2 spectroscopic data and, above 80 km, by uncertainties in the non-LTE model parameters (including collisional rates and atomic oxygen abundance) and the CO2 abundance. These lead to systematic temperature errors of less than 0.7 K below 55 km, 1 K at 60-80 km, 1-2 K at 80-90 km, 3 K at 95 km, 6-8 K at 100 km, 10-20 K at 105 km and 20-30 K at 115 km. Systematic errors in the tangent altitude correction, mainly arising from CO2 spectroscopic uncertainties, are 250 m at 20 km, 200 m at 40-60 km, 100 m at 80 km and smaller than 50 m above 90 km. The consistency between the MA/UA/NLC and the NOM IMK-IAA datasets is excellent below 70 km (typical 0.5-1 K differences). The comparison of this temperature dataset with co-located Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) temperature measurements shows excellent agreement, with differences typically within 1.5 K below 90 km, 1-3 K at 90-95 km, 1-5 K at 95-100 km, 1-8 K at 100-105 km and 1-10 K above. The agreement with SABER improves with respect to previous MIPAS IMK-IAA data versions.

Abstract. Motivated by an improved ESA version of MIPAS calibrated spectra (version 8.03), we have released version 8 of MIPAS temperatures and pointing information retrieved from 2005–2012 MIPAS measurements at 12–15 μm in the Middle Atmosphere (MA), Upper Atmosphere (UA) and Noctilucent Cloud (NLC) measurement modes. The IMK/IAA retrieval processor in use considers non-local thermodynamic equilibrium (non-LTE) emission explicitly for each limb scan. This non-LTE treatment is essential to obtain accurate temperatures above the mid-mesosphere, because at the altitudes covered, up to 115 km, the simplified climatology-based non-LTE treatment employed for the nominal (NOM) measurements is insufficient. Other updates in MA/UA/NLC V8 non-LTE temperature retrievals from previous data releases include: more realistic atomic oxygen and carbon dioxide abundances; an updated set of spectroscopic data; an improved spectral shift retrieval; a continuum retrieval extended to altitudes up to 58 km; consideration of an altitude-dependent radiance offset retrieval; the use of wider microwindows above 85 km to capture the offset; an improved accuracy in forward model calculations; new temperature a priori information; improved temperature horizontal gradient retrievals; and, the use of MIPAS version 5 interfering species, where available. The resulting MIPAS MA/UA/NLC IMK/IAA temperature dataset is reliable for scientific analysis in the full measurement vertical range for the MA (18–102 km) and the NLC (39–102 km) observations, and from 42 to 115 km for the UA observations. The random temperature errors, dominated by the instrumental noise, are typically less than 1 K below 60 km, 1–3 K at 60–70 km, 3–5 K at 70–90 km, 6–8 K at 90–100 km, 8–12 K at 100–105 km and 12–20 K at 105–115 km. Pointing correction random errors, also mainly arising from instrumental noise, are on average 50 m for tangent altitudes up to 60 km and decrease linearly to values smaller than 20 m for altitudes above 95 km. The vertical resolution is 3 km at altitudes below 50 km, 3–5 km at 50–70 km, 4–6 km at 70–90 km, 6–10 km at 90–100 km and 8–11 km at 100–115 km. The systematic errors of retrieved temperatures below 75 km are driven by uncertainties in the CO2 spectroscopic data and, above 80 km, by uncertainties in the non-LTE model parameters (including collisional rates and atomic oxygen abundance) and the CO2 abundance. These lead to systematic temperature errors of less than 0.7 K below 55 km, 1 K at 60–80 km, 1–2 K at 80–90 km, 3 K at 95 km, 6–8 K at 100 km, 10–20 K at 105 km and 20–30 K at 115 km. Systematic errors in the tangent altitude correction, mainly arising from CO2 spectroscopic uncertainties, are 250 m at 20 km and 200 m at 40–60 km, 100 m at 80 km and smaller than 50 m above 90 km. The consistency between the MA/UA/NLC and the NOM IMK/IAA datasets is excellent below 70 km (tyical 0.5–1 K differences). The comparison of this V8 temperature dataset with co-located SABER temperature measurements shows an excellent agreement, even better than in previous MIPAS IMK/IAA versions.

Table S0.Labels and definitions of the representative atmospheric conditions used to estimate MIPAS temperature errors.

Abstract. New global nitric oxide (NO) volume mixing ratio and lower thermospheric temperature data products, retrieved from Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) spectra with the IMK-IAA MIPAS data processor, have been released. The dataset covers the entire Envisat mission lifetime and includes retrieval results from all MIPAS observation modes. The data are based on ESA version 8 calibration and were processed using an improved retrieval approach compared to previous versions, specifically regarding the choice and construction of the a priori and atmospheric parameter profiles, the treatment of horizontal inhomogeneities, the treatment of the radiance offset correction, and the selection of optimized numerical settings. NO retrieval errors of individual observations are dominated by measurement noise and range from 5 % to 50 % in the stratosphere and thermosphere, and reach 40 % to 90 % in the mesosphere. Systematic errors are typically within 10–30 %. Lower thermospheric temperature errors are 5 K to 50 K with a systematic component of around 10K, the latter being dominated by non-LTE related uncertainties. NO data from different observation modes are consistent within 5–10 %. MIPAS version 8 temperatures have a better representation of the diurnal tide in the lower thermosphere compared to previous data versions. The new MIPAS temperatures are systematically warmer than results from the empirical NLRMSIS2.0 model by 30 K to 80 K in the 100–120 km region, and are colder above.

This document serves as reference for the definitions of the representative atmospheres used for the calculation of ozone error budgets, as listed in Tab.S1, and as collection of the respective error budgets for FR data (2002)(2003)(2004), which are listed in tables S2-S35 and depicted in figures S1-S34, and the respective error budgets for RR data (2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012), which are listed in tables S36-S69 and depicted in figures S35-S68.The errors are presented as relative errors in percent, even if they are of additive nature, i.e., do not scale with the retrieved volume mixing ratio.They were calculated with respect to the average ozone profile that was calculated from the single geolocations which contribute to the respective representative atmospheres.

This paper describes the error estimation for temperature and trace gas mixing ratios retrieved from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) limb emission spectra. The following error sources are taken into account: measurement noise, propagated temperature and pointing noise, uncertainties in the abundances of spectrally interfering species, instrument line shape errors, and spectroscopic data uncertainties in terms of line intensities and broadening coefficients. Furthermore, both the direct impact of volatile and persistent gain calibration uncertainties, offset calibration, and spectral calibration uncertainties, as well as their impact through propagated calibration-related temperature and pointing uncertainties, are considered. An error source specific to the MIPAS upper atmospheric observation mode is the propagation of the smoothing error crosstalk of the combined NO and temperature retrieval. Whenever non-local thermodynamic equilibrium modelling is used in the retrieval, related kinetic constants and mixing ratios of species involved in the modelling of populations of excitational states also contribute to the error budget. Both generalized Gaussian error propagation and perturbation studies are used to estimate the error components. Error correlations are taken into account. Estimated uncertainties are provided for a multitude of atmospheric conditions. Some error sources were found to contribute both to the random and the systematic component of the total estimated error. The sequential nature of the MIPAS retrievals gives rise to entangled errors. These are caused by error sources that affect the uncertainty in the final data product via multiple pathways, i.e., on the one hand, directly, and, on the other hand, via errors caused in a preceding retrieval step. These errors tend to partly compensate for each other. The hard-to-quantify effect of the horizontally non-homogeneous atmosphere and unknown error correlations of spectroscopic data are considered to be the major limitations of the MIPAS error estimation.

A new global set of atmospheric temperature profiles is retrieved from recalibrated radiance spectra recorded with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). Changes with respect to previous data versions include a new radiometric calibration considering the time dependency of the detector nonlinearity and a more robust frequency calibration scheme. Temperature is retrieved using a smoothing constraint, while tangent altitude pointing information is constrained using optimal estimation. ECMWF ERA-Interim is used as a priori temperature below 43 km. Above, a priori data are based on data from the Whole Atmosphere Community Climate Model Version 4 (WACCM4). Bias-corrected fields from specified dynamics runs, sampled at the MIPAS times and locations, are used, blended with ERA-Interim between 43 and 53 km. Horizontal variability of temperature is considered by scaling an a priori 3D temperature field in the orbit plane in a way that the horizontal structure is provided by the a priori while the vertical structure comes from the measurements. Additional microwindows with better sensitivity at higher altitudes are used. The background continuum is jointly fitted with the target parameters up to 58 km altitude. The radiance offset correction is strongly regularized towards an empirically determined vertical offset profile. In order to avoid the propagation of uncertainties of O3 and H2O a priori assumptions, the abundances of these species are retrieved jointly with temperature. The retrieval is based on HITRAN 2016 spectroscopic data, with a few amendments. Temperature-adjusted climatologies of vibrational populations of CO2 states emitting in the 15 µm region are used in the radiative transfer modeling in order to account for non-local thermodynamic equilibrium. Numerical integration in the radiative transfer model is now performed at higher accuracy. The random component of the temperature uncertainty typically varies between 0.4 and 1 K, with occasional excursions up to 1.3 K above 60 km altitude. The leading sources of the random component of the temperature error are measurement noise, gain calibration uncertainty, spectral shift, and uncertain CO2 mixing ratios. The systematic error is caused by uncertainties in spectroscopic data and line shape uncertainties. It ranges from 0.2 K at 20 km altitude for northern midlatitude summer conditions to 2.3 K at 12 km for tropical conditions. The estimated total uncertainty amounts to values between 0.6 K at 20 km for midlatitude summer conditions to 2.5 K at 12–15 km for tropical conditions. The vertical resolution varies around 3 km for altitudes below 50 km. The long-term drift encountered in the previous temperature product has been largely reduced. The consistency between high spectral resolution results from 2002 to 2004 and the reduced spectral resolution results from 2005 to 2012 has been largely improved. As expected, most pronounced temperature differences between version 8 and previous data versions are found in elevated stratopause situations. The fact that the phase of temperature waves seen by MIPAS is not locked to the wave phase found in ECMWF analyses demonstrates that our retrieval provides independent information and does not merely reproduce the prior information.

Measurements of long-lived trace gases (SF6, CFC-11, CFC-12, HCFC-22, CCl4, N2O, CH4, H2O, and CO) performed with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) have been used to infer the stratospheric and mesospheric meridional circulation. The MIPAS data set covers the time period from July 2002 to April 2012. The method used for this purpose was the direct inversion of the two-dimensional continuity equation for the concentrations of trace gases and air density. This inversion predicts an “effective velocity” that gives the best fit for the evolution of the concentrations on the assumption that an explicit treatment of Fickian diffusion can be neglected. These effective velocity fields are used to characterize the mean meridional circulation. Multiannual monthly mean effective velocity fields are presented, along with their variabilities. According to this measure, the stratospheric circulation is found to be highly variable over the year, with a quite robust annual cycle. The new method allows us to track the evolution of various circulation patterns over the year in more detail than before. According to the effective velocity characterization of the circulation, the deep branch of the Brewer–Dobson circulation and the mesospheric overturning pole-to-pole circulation are not separate but intertwined phenomena. The latitude of stratospheric uplift in the middle and upper stratosphere is found to be quite variable and is not always found at equatorial latitudes. The usual schematic of stratospheric circulation with the deep and the shallow branch of the Brewer–Dobson circulation and the mesospheric overturning circulation is an idealization which best describes the observed atmosphere around equinox. Sudden stratospheric warmings and the quasi-biennial oscillation cause a pronounced year-to-year variability of the meridional circulation.

The annual variation of δD in the tropical lower stratosphere is a critical indicator for the relative importance of different processes contributing to the transport of water vapour through the cold tropical tropopause region into the stratosphere. Distinct observational discrepancies of the δD annual variation were visible in the works of Steinwagner et al. (2010) and Randel et al. (2012). Steinwagner et al. (2010) analysed MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) observations retrieved with the IMK/IAA (Institut für Meteorologie und Klimaforschung in Karlsruhe, Germany, in collaboration with the Instituto de Astrofísica de Andalucía in Granada, Spain) processor, while Randel et al. (2012) focused on ACE-FTS (Atmospheric Chemistry Experiment Fourier Transform Spectrometer) observations. Here we reassess the discrepancies based on newer MIPAS (IMK/IAA) and ACE-FTS data sets, also showing for completeness results from SMR (Sub-Millimetre Radiometer) observations and a ECHAM/MESSy (European Centre for Medium-Range Weather Forecasts Hamburg and Modular Earth Submodel System) Atmospheric Chemistry (EMAC) simulation (Eichinger et al., 2015b). Similar to the old analyses, the MIPAS data set yields a pronounced annual variation (maximum about 75 ‰), while that derived from the ACE-FTS data set is rather weak (maximum about 25 ‰). While all data sets exhibit the phase progression typical for the tape recorder, the annual maximum in the ACE-FTS data set precedes that in the MIPAS data set by 2 to 3 months. We critically consider several possible reasons for the observed discrepancies, focusing primarily on the MIPAS data set. We show that the δD annual variation in the MIPAS data up to an altitude of 40 hPa is substantially impacted by a “start altitude effect”, i.e. dependency between the lowermost altitude where MIPAS retrievals are possible and retrieved data at higher altitudes. In itself this effect does not explain the differences with the ACE-FTS data. In addition, there is a mismatch in the vertical resolution of the MIPAS HDO and H2O data (being consistently better for HDO), which actually results in an artificial tape-recorder-like signal in δD. Considering these MIPAS characteristics largely removes any discrepancies between the MIPAS and ACE-FTS data sets and shows that the MIPAS data are consistent with a δD tape recorder signal with an amplitude of about 25 ‰ in the lowermost stratosphere.