scholarly journals MIPAS IMK/IAA CFC-11 (CCl<sub>3</sub>F) and CFC-12 (CCl<sub>2</sub>F<sub>2</sub>) measurements: accuracy, precision and long-term stability

2016 ◽  
Vol 9 (7) ◽  
pp. 3355-3389 ◽  
Author(s):  
E. Eckert ◽  
A. Laeng ◽  
S. Lossow ◽  
S. Kellmann ◽  
G. Stiller ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Atmospheric Chemistry ◽  
Michelson Interferometer ◽  
Temporal Stability ◽  
High Spectral Resolution ◽  
Long Term Stability ◽  
Full Resolution ◽  
Trace Species ◽  
Institute Of Technology ◽  
Relative Differences

Abstract. Profiles of CFC-11 (CCl3F) and CFC-12 (CCl2F2) of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) aboard the European satellite Envisat have been retrieved from versions MIPAS/4.61 to MIPAS/4.62 and MIPAS/5.02 to MIPAS/5.06 level-1b data using the scientific level-2 processor run by Karlsruhe Institute of Technology (KIT), Institute of Meteorology and Climate Research (IMK) and Consejo Superior de Investigaciones Científicas (CSIC), Instituto de Astrofísica de Andalucía (IAA). These profiles have been compared to measurements taken by the balloon-borne cryosampler, Mark IV (MkIV) and MIPAS-Balloon (MIPAS-B), the airborne MIPAS-STRatospheric aircraft (MIPAS-STR), the satellite-borne Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) and the High Resolution Dynamic Limb Sounder (HIRDLS), as well as the ground-based Halocarbon and other Atmospheric Trace Species (HATS) network for the reduced spectral resolution period (RR: January 2005–April 2012) of MIPAS. ACE-FTS, MkIV and HATS also provide measurements during the high spectral resolution period (full resolution, FR: July 2002–March 2004) and were used to validate MIPAS CFC-11 and CFC-12 products during that time, as well as profiles from the Improved Limb Atmospheric Spectrometer, ILAS-II. In general, we find that MIPAS shows slightly higher values for CFC-11 at the lower end of the profiles (below  ∼  15 km) and in a comparison of HATS ground-based data and MIPAS measurements at 3 km below the tropopause. Differences range from approximately 10 to 50 pptv ( ∼  5–20 %) during the RR period. In general, differences are slightly smaller for the FR period. An indication of a slight high bias at the lower end of the profile exists for CFC-12 as well, but this bias is far less pronounced than for CFC-11 and is not as obvious in the relative differences between MIPAS and any of the comparison instruments. Differences at the lower end of the profile (below  ∼  15 km) and in the comparison of HATS and MIPAS measurements taken at 3 km below the tropopause mainly stay within 10–50 pptv (corresponding to  ∼  2–10 % for CFC-12) for the RR and the FR period. Between  ∼  15 and 30 km, most comparisons agree within 10–20 pptv (10–20 %), apart from ILAS-II, which shows large differences above  ∼  17 km. Overall, relative differences are usually smaller for CFC-12 than for CFC-11. For both species – CFC-11 and CFC-12 – we find that differences at the lower end of the profile tend to be larger at higher latitudes than in tropical and subtropical regions. In addition, MIPAS profiles have a maximum in their mixing ratio around the tropopause, which is most obvious in tropical mean profiles. Comparisons of the standard deviation in a quiescent atmosphere (polar summer) show that only the CFC-12 FR error budget can fully explain the observed variability, while for the other products (CFC-11 FR and RR and CFC-12 RR) only two-thirds to three-quarters can be explained. Investigations regarding the temporal stability show very small negative drifts in MIPAS CFC-11 measurements. These instrument drifts vary between  ∼  1 and 3 % decade−1. For CFC-12, the drifts are also negative and close to zero up to  ∼  30 km. Above that altitude, larger drifts of up to  ∼  50 % decade−1 appear which are negative up to  ∼  35 km and positive, but of a similar magnitude, above.

scholarly journals MIPAS IMK/IAA CFC-11 (CCl<sub>3</sub>F) and CFC-12 (CCl<sub>2</sub>F<sub>2</sub>) measurements: accuracy, precision and long-term stability

2015 ◽  
Vol 8 (7) ◽  
pp. 7573-7662 ◽  
Author(s):  
E. Eckert ◽  
A. Laeng ◽  
S. Lossow ◽  
S. Kellmann ◽  
G. Stiller ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Atmospheric Chemistry ◽  
Michelson Interferometer ◽  
Temporal Stability ◽  
High Spectral Resolution ◽  
Long Term Stability ◽  
Trace Species ◽  
High Bias ◽  
Institute Of Technology

Abstract. Profiles of CFC-11 (CCl3F) and CFC-12 (CCl2F2) of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) abord the European satellite Envisat have been retrieved from versions MIPAS/4.61–MIPAS/4.62 and MIPAS/5.02–MIPAS/5.06 level-1b data using the scientific level-2 processor run by Karlsruhe Institute of Technology (KIT), Institute of Meteorology and Climate Research (IMK) and Consejo Superior de Investigaciones Científicas (CSIC), Instituto de Astrofísica de Andalucía (IAA). These profiles have been compared to measurements taken by the balloon borne Cryosampler, Mark IV (MkIV) and MIPAS-Balloon (MIPAS-B), the airborne MIPAS stratospheric aircraft (MIPAS-STR), the satellite borne Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) and the High Resolution Dynamic Limb Sounder (HIRDLS) as well as the ground based Halocarbon and other Atmospheric Trace Species (HATS) network for the reduced spectral resolution period (RR: January 2005–April 2012) of MIPAS Envisat. ACE-FTS, MkIV and HATS also provide measurements during the high spectral resolution period (FR: July 2002–March 2004) and were used to validate MIPAS Envisat CFC-11 and CFC-12 products during that time, as well as ILAS-II profiles. In general, we find that MIPAS Envisat shows slightly higher values for CFC-11 at the lower end of the profiles (below ~ 15 km) and in a comparison of HATS ground-based data and MIPAS Envisat measurements at 3 km below the tropopause. Differences range from approximately 10–50 pptv (~ 5–20 %) during the RR period. In general, differences are slightly smaller for the FR period. An indication of a slight high-bias at the lower end of the profile exists for CFC-12 as well, but this bias is far less pronounced than for CFC-11, so that differences at the lower end of the profile (below ~ 15 km) and in the comparison of HATS and MIPAS Envisat measurements taken at 3 km below the tropopause mainly stay within 10–50 pptv (~ 2–10 %) for the RR and the FR period. Above approximately 15 km, most comparisons are close to excellent, apart from ILAS-II, which shows large differences above ~ 17 km. Overall, percentage differences are usually smaller for CFC-12 than for CFC-11. For both species – CFC-11 and CFC-12 – we find that differences at the lower end of the profile tend to be larger at higher latitudes than in tropical and subtropical regions. In addition, MIPAS Envisat profiles have a maximum in the mixing ratio around the tropopause, which is most obvious in tropical mean profiles. Estimated measurement noise alone can, in most cases, not explain the standard deviation of the differences. This is attributed to error components not considered in the error estimate and also to natural variability which always plays a role when the compared instruments do not measure exactly the same air mass. Investigations concerning the temporal stability show very small negative drifts in MIPAS Envisat CFC-11 measurements. These drifts vary between ~ 1–3 % decade−1. For CFC-12, the drifts are also negative and close to zero up to ~ 30 km. Above that altitude larger drifts of up to ~ 50 % decade−1 appear which are negative up to ~ 35 km and positive, but of a similar magnitude, above.

scholarly journals Validation of revised methane and nitrous oxide profiles from MIPAS-ENVISAT

2015 ◽  
Vol 8 (11) ◽  
pp. 12105-12153
Author(s):  
J. Plieninger ◽  
A. Laeng ◽  
S. Lossow ◽  
T. von Clarmann ◽  
G. P. Stiller ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Michelson Interferometer ◽  
Species Group ◽  
Mixing Ratios ◽  
Full Resolution ◽  
Trace Species ◽  
Surface Data ◽  
Ch4 And N2o ◽  
Scanning Imaging ◽  
The Fourier Transform

Abstract. Improved versions of CH4 and N2O profiles derived at the Institute of Meteorology and Climate Research and Instituto de Astrofísica de Andalucía (CSIC) from spectra measured by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) have become available. For the MIPAS full resolution period (2002–2004) these are V5H_CH4_21 and V5H_N2O_21 and for the reduced resolution period (2005–2012) these are V5R_CH4_224, V5R_CH4_225, V5R_N2O_224 and V5R_N2O_225. Here, we compare CH4 profiles to those measured by the Fourier Transform Spectrometer on board of the Atmospheric Chemistry Experiment (ACE-FTS), the HALogen Occultation Experiment (HALOE) and the Scanning Imaging Absorption Spectrometer for Atmospheric CHartographY (SCIAMACHY) and to the Global Cooperative Air Sampling Network (GCASN) surface data. We find the MIPAS CH4 profiles below 25 km to be typically higher in the order of 0.1 ppmv for both measurement periods. N2O profiles are compared to those measured by ACE-FTS, the Microwave Limb Sounder on board of the Aura satellite (Aura-MLS) and the Sub-millimetre Radiometer on board of the Odin satellite (Odin-SMR) as well as to the Halocarbons and other Atmospheric Trace Species Group (HATS) surface data. The mixing ratios from the satellite instruments agree well for the full resolution period. For the reduced resolution period, MIPAS produces similar values as Odin-SMR, but higher values than ACE-FTS and HATS. Below 27 km, the MIPAS profiles show higher mixing ratios than Aura-MLS, and lower values between 27 and 41 km. Cross comparisons between the two MIPAS measurement periods show that they generally agree quite well, but, especially for CH4, the reduced resolution period seems to produce slightly higher mixing ratios than the full resolution data.

scholarly journals Validation of revised methane and nitrous oxide profiles from MIPAS–ENVISAT

2016 ◽  
Vol 9 (2) ◽  
pp. 765-779 ◽  
Author(s):  
Johannes Plieninger ◽  
Alexandra Laeng ◽  
Stefan Lossow ◽  
Thomas von Clarmann ◽  
Gabriele P. Stiller ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Michelson Interferometer ◽  
Species Group ◽  
Mixing Ratios ◽  
Full Resolution ◽  
Trace Species ◽  
Surface Data ◽  
Ch4 And N2o ◽  
Scanning Imaging ◽  
The Fourier Transform

Abstract. Improved versions of CH4 and N2O profiles derived at the Institute of Meteorology and Climate Research and Instituto de Astrofísica de Andalucía (CSIC) from spectra measured by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) have become available. For the MIPAS full-resolution period (2002–2004) these are V5H_CH4_21 and V5H_N2O_21 and for the reduced-resolution period (2005–2012) these are V5R_CH4_224, V5R_CH4_225, V5R_N2O_224 and V5R_N2O_225. Here, we compare CH4 profiles to those measured by the Fourier Transform Spectrometer on board of the Atmospheric Chemistry Experiment (ACE-FTS), the HALogen Occultation Experiment (HALOE) and the Scanning Imaging Absorption Spectrometer for Atmospheric CHartographY (SCIAMACHY), to the Global Cooperative Air Sampling Network (GCASN) surface data. We find the MIPAS CH4 profiles below 25 km to be typically higher of the order of 0.1 ppmv for both measurement periods. N2O profiles are compared to those measured by ACE-FTS, the Microwave Limb Sounder on board of the Aura satellite (Aura-MLS) and the Sub-millimetre Radiometer on board of the Odin satellite (Odin-SMR) as well as to the Halocarbons and other Atmospheric Trace Species Group (HATS) surface data. The mixing ratios of the satellite instruments agree well with each other for the full-resolution period. For the reduced-resolution period, MIPAS produces similar values as Odin-SMR, but higher values than ACE-FTS and HATS. Below 27 km, the MIPAS profiles show higher mixing ratios than Aura-MLS, and lower values between 27 and 41 km. Cross-comparisons between the two MIPAS measurement periods show that they generally agree quite well, but, especially for CH4, the reduced-resolution period seems to produce slightly higher mixing ratios than the full-resolution data.

Polarized high-spectral-resolution lidar based on field-widened Michelson interferometer

2016 ◽  
Author(s):  
Dong Liu ◽  
Zhongtao Cheng ◽  
Jing Luo ◽  
Yongying Yang ◽  
Yupeng Zhang ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Michelson Interferometer ◽  
High Spectral Resolution ◽  
High Spectral Resolution Lidar

Design of the High Spectral Resolution Lidar Filter Based on a Field-Widened Michelson Interferometer

2014 ◽  
Vol 41 (9) ◽  
pp. 0913003 ◽  
Author(s):  
黄寒璐 Huang Hanlu ◽  
刘东 Liu Dong ◽  
杨甬英 Yang Yongying ◽  
成中涛 Cheng Zhongtao ◽  
罗敬 Luo Jing ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Michelson Interferometer ◽  
High Spectral Resolution ◽  
High Spectral Resolution Lidar

scholarly journals Drift-corrected trends and periodic variations in MIPAS IMK/IAA ozone measurements

2014 ◽  
Vol 14 (5) ◽  
pp. 2571-2589 ◽  
Author(s):  
E. Eckert ◽  
T. von Clarmann ◽  
M. Kiefer ◽  
G. P. Stiller ◽  
S. Lossow ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Recent Literature ◽  
Michelson Interferometer ◽  
Quasi Biennial Oscillation ◽  
Significance Level ◽  
Tropical Tropopause ◽  
Time Period ◽  
Ozone Trends ◽  
Institute Of Technology ◽  
Good Agreement

Abstract. Drifts, trends and periodic variations were calculated from monthly zonally averaged ozone profiles. The ozone profiles were derived from level-1b data of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) by means of the scientific level-2 processor run by the Karlsruhe Institute of Technology (KIT), Institute for Meteorology and Climate Research (IMK). All trend and drift analyses were performed using a multilinear parametric trend model which includes a linear term, several harmonics with period lengths from 3 to 24 months and the quasi-biennial oscillation (QBO). Drifts at 2-sigma significance level were mainly negative for ozone relative to Aura MLS and Odin OSIRIS and negative or near zero for most of the comparisons to lidar measurements. Lidar stations used here include those at Hohenpeissenberg (47.8° N, 11.0° E), Lauder (45.0° S, 169.7° E), Mauna Loa (19.5° N, 155.6° W), Observatoire Haute Provence (43.9° N, 5.7° E) and Table Mountain (34.4° N, 117.7° W). Drifts against the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) were found to be mostly insignificant. The assessed MIPAS ozone trends cover the time period of July 2002 to April 2012 and range from −0.56 ppmv decade−1 to +0.48 ppmv decade−1 (−0.52 ppmv decade−1 to +0.47 ppmv decade−1 when displayed on pressure coordinates) depending on altitude/pressure and latitude. From the empirical drift analyses we conclude that the real ozone trends might be slightly more positive/less negative than those calculated from the MIPAS data, by conceding the possibility of MIPAS having a very small (approximately within −0.3 ppmv decade−1) negative drift for ozone. This leads to drift-corrected trends of −0.41 ppmv decade−1 to +0.55 ppmv decade−1 (−0.38 ppmv decade−1 to +0.53 ppmv decade−1 when displayed on pressure coordinates) for the time period covered by MIPAS Envisat measurements, with very few negative and large areas of positive trends at mid-latitudes for both hemispheres around and above 30 km (~10 hPa). Negative trends are found in the tropics around 25 and 35 km (~25 and 5 hPa), while an area of positive trends is located right above the tropical tropopause. These findings are in good agreement with the recent literature. Differences of the trends compared with the recent literature could be explained by a possible shift of the subtropical mixing barriers. Results for the altitude–latitude distribution of amplitudes of the quasi-biennial, annual and the semi-annual oscillation are overall in very good agreement with recent findings.

scholarly journals Development of a 355-nm high-spectral-resolution lidar using a scanning Michelson interferometer for aerosol profile measurement

2020 ◽  
Vol 28 (16) ◽  
pp. 23209 ◽  
Author(s):  
Yoshitaka Jin ◽  
Tomoaki Nishizawa ◽  
Nobuo Sugimoto ◽  
Shoken Ishii ◽  
Makoto Aoki ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Michelson Interferometer ◽  
High Spectral Resolution ◽  
Profile Measurement ◽  
High Spectral Resolution Lidar

scholarly journals IMK/IAA MIPAS temperature retrieval version 8: nominal measurements

2020 ◽  
Author(s):  
Michael Kiefer ◽  
Thomas von Clarmann ◽  
Bernd Funke ◽  
Maya García-Comas ◽  
Norbert Glatthor ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Spectral Resolution ◽  
Spectroscopic Data ◽  
A Priori ◽  
Michelson Interferometer ◽  
High Spectral Resolution ◽  
Transfer Model ◽  
Random Component ◽  
Horizontal Structure ◽  
Total Uncertainty

Abstract. 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 non-linearity, 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 temperature a priori below 43 km. Above, a priori data is 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 micron region are used in the radiative transfer modelling 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 0.8 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 24 km altitude for northern midlatitude nighttime conditions to 2.3 K at 12 km for tropical nighttime conditions. The estimated total uncertainty amounts to values between 0.5 K at 24 km and northern polar winter conditions to 2.3 K at 12 km and northern midlatitude day 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 2002–2004 and the reduced spectral resolution results from 2005–2012 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.

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