Long-term validation of ESA operational retrieval (version 6.0) of MIPAS  Envisat vertical profiles of methane, nitrous oxide, CFC11, and CFC12 using  balloon-borne observations and trajectory matching

Engel, Andreas; Bönisch, Harald; Schwarzenberger, Tim; Haase, H. P.; Grunow, K.; Abalichin, Janna; Sala, S.

doi:10.5194/amt-9-1051-2016

Cited by 17 publications

(20 citation statements)

References 26 publications

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“…The deviation between AirCore and sampler results is on average 0.84 ppm for CO 2 , a result that is comparable in mag-nitude to AirCore inter-comparisons (e.g. Engel et al, 2017;Membrive et al, 2017). For methane, we find a mean deviation of 1.8 ppb, within the uncertainties of both AirCore and LISA (see Sect.…”

Section: Lisa Sampler Comparison With Aircore Measurementssupporting

confidence: 78%

LISA: a lightweight stratospheric air sampler

et al. 2018

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We developed a new lightweight stratospheric air sampler (LISA). The LISA sampler is designed to collect four bag samples in the stratosphere during a balloon flight for CO 2 , CH 4 and CO mole fraction measurements. It consists of four multi-layer foil (MLF) sampling bags, a custommade manifold, and a diaphragm pump, with a total weight of ∼ 2.5 kg.A series of laboratory storage tests were performed to assess the stability of CO 2 , CH 4 and CO mole fractions in both MLF and Tedlar bags. The MLF bag was chosen due to its better overall performance than the Tedlar bag for the three species CO 2 , CH 4 and CO. Furthermore, we evaluated the performance of the pump under low pressure conditions to optimize a trade-off between the vertical resolution and the sample size.The LISA sampler was flown on the same balloon flight with an AirCore in Sodankylä, Finland (67.368 • N, 26.633 • E, 179 m a.s.l.), on 26 April and 4-7 September 2017. A total of 15 stratospheric air samples were obtained during the ascent of four flights. The sample size ranges between 800 and 180 mL for the altitude between 12 and 25 km, with the corresponding vertical resolution ranging from 0.5 to 1.5 km. The collected air samples were analysed for CO 2 , CH 4 and CO mole fractions, and evaluated against AirCore retrieved profiles, showing mean differences of 0.84 ppm for CO 2 , 1.8 ppb for CH 4 and 6.3 ppb for CO, respectively.High-accuracy stratospheric measurements of greenhouse gas mole fractions are useful to validate remote sensing measurements from ground and from space, which has been performed primarily by comparison with collocated aircraft measurements (0.15-13 km), and more recently with Air-Core observations (0-30 km). While AirCore is capable of achieving high-accuracy greenhouse gas mole fraction measurements, it is challenging to obtain accurate altitude registration for AirCore measurements. The LISA sampler provides a viable low-cost tool for retrieving stratospheric air samples for greenhouse gas measurements that is complementary to AirCore. Furthermore, the LISA sampler is advantageous in both the vertical resolution and sample size for performing routine stratospheric measurements of the isotopic composition of trace gases.

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Section: Lisa Sampler Comparison With Aircore Measurementssupporting

confidence: 78%

LISA: a lightweight stratospheric air sampler

et al. 2018

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“…They found good agreement with a 5 % positive bias in the lower stratosphere and upper troposphere. ML2PP v6 CH 4 was compared with BONBON air sampling measurements by Engel et al (2016). The reduced-resolution CH 4 measurements (2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012) agree with in situ data within 5-10 %.…”

Section: Esa Mipassupporting

confidence: 49%

Comparison of the GOSAT TANSO-FTS TIR CH<sub>4</sub> volume mixing ratio vertical profiles with those measured by ACE-FTS, ESA MIPAS, IMK-IAA MIPAS, and 16 NDACC stations

et al. 2017

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Abstract. The primary instrument on the Greenhouse gases Observing SATellite (GOSAT) is the Thermal And Near infrared Sensor for carbon Observations (TANSO) Fourier transform spectrometer (FTS). TANSO-FTS uses three shortwave infrared (SWIR) bands to retrieve total columns of CO 2 and CH 4 along its optical line of sight and one thermal infrared (TIR) channel to retrieve vertical profiles of CO 2 and CH 4 volume mixing ratios (VMRs) in the troposphere. We examine version 1 of the TANSO-FTS TIR CH 4 product by comparing co-located CH 4 VMR vertical profiles from two other remote-sensing FTS systems: the Canadian Space Agency's Atmospheric Chemistry Experiment FTS (ACE-FTS) on SCISAT (version 3.5) and the European Space Smoothing is needed to account for differences between the vertical resolution of each instrument and differences in the dependence on a priori profiles. The smoothing operators use the TANSO-FTS a priori and averaging kernels in all cases. We present zonally averaged mean CH 4 differences between each instrument and TANSO-FTS with and without smoothing, and we examine their information content, their sensitive altitude range, their correlation, their a priori dependence, and the variability within each data set. Partial columns are calculated from the VMR vertical profiles, and their correlations are examined. We find that the TANSO-FTS vertiPublished by Copernicus Publications on behalf of the European Geosciences Union. K. S. Olsen et al.: TANSO-FTS TIR CH 4 vertical profilescal profiles agree with the ACE-FTS and both MIPAS retrievals' vertical profiles within 4 % (± ∼ 40 ppbv) below 15 km when smoothing is applied to the profiles from instruments with finer vertical resolution but that the relative differences can increase to on the order of 25 % when no smoothing is applied. Computed partial columns are tightly correlated for each pair of data sets. We investigate whether the difference between TANSO-FTS and other CH 4 VMR data products varies with latitude. Our study reveals a small dependence of around 0.1 % per 10 degrees latitude, with smaller differences over the tropics and greater differences towards the poles.

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“…In the validation phase of Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) version 6 products, obtained with the ESA level 2 processor, positive biases were found in the CFC-11 VMR profiles. In particular, CFC-11 profiles were found to be affected by a significant bias at all altitudes and latitudes with respect to MIPAS balloon measurements (ML2PP, 2012;Wetzel et al, 2014) and Bonbon (Schmidt et al, 1987) measurements (Engel et al, 2016). While below 19 km this bias was still within the combined systematic and total errors, above this altitude it clearly exceeded this error margin.…”

Section: Introductionmentioning

confidence: 84%

Phosgene in the UTLS: seasonal and latitudinal variations from MIPAS observations

et al. 2016

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Abstract. The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) is a Fourier transform spectrometer that measured mid-infrared atmospheric limb emission spectra from July 2002 to April 2012 on board the polarorbiting satellite ENVISAT. We have used MIPAS data to study the latitudinal variations of phosgene (COCl 2 or carbonyl chloride) and, for the first time, its seasonal variation in the upper troposphere/lower stratosphere region (UTLS). Retrievals of phosgene were made using the 830-860 cm −1 region, corresponding to the ν 5 bands of COCl 2 . Unfortunately, in that region, the ν 4 band of CFC-11, which is much stronger than COCl 2 ν 5 , hides the phosgene emission. In order to evaluate seasonality and latitudinal distribution of phosgene we have analysed all the measurements made by MIPAS on days 18 and 20 of each month of 2008 with the optimized retrieval model (ORM) recently upgraded with the multi-target retrieval technique and with the optimal estimation functionality to apply external constraints to the state vector. Average seasonal profiles of phosgene show an evident latitudinal variability with the largest values observed in the tropical regions (maximum ≈ 35 parts per trillion by volume (pptv) at about 300 hPa). In the midlatitude and polar regions, the volume mixing ratio (VMR) values do not exceed 30 pptv and the vertical distributions are less peaked. Our analysis highlights that COCl 2 seasonal variability is fairly low, apart from the polar regions.

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Long-term validation of ESA operational retrieval (version 6.0) of MIPAS Envisat vertical profiles of methane, nitrous oxide, CFC11, and CFC12 using balloon-borne observations and trajectory matching

Cited by 17 publications

References 26 publications

LISA: a lightweight stratospheric air sampler

LISA: a lightweight stratospheric air sampler

Comparison of the GOSAT TANSO-FTS TIR CH<sub>4</sub> volume mixing ratio vertical profiles with those measured by ACE-FTS, ESA MIPAS, IMK-IAA MIPAS, and 16 NDACC stations

Phosgene in the UTLS: seasonal and latitudinal variations from MIPAS observations

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Long-term validation of ESA operational retrieval (version 6.0) of MIPAS Envisat vertical profiles of methane, nitrous oxide, CFC11, and CFC12 using balloon-borne observations and trajectory matching

Cited by 17 publications

References 26 publications

LISA: a lightweight stratospheric air sampler

LISA: a lightweight stratospheric air sampler

Comparison of the GOSAT TANSO-FTS TIR CH&lt;sub&gt;4&lt;/sub&gt; volume mixing ratio vertical profiles with those measured by ACE-FTS, ESA MIPAS, IMK-IAA MIPAS, and 16 NDACC stations

Phosgene in the UTLS: seasonal and latitudinal variations from MIPAS observations

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Comparison of the GOSAT TANSO-FTS TIR CH<sub>4</sub> volume mixing ratio vertical profiles with those measured by ACE-FTS, ESA MIPAS, IMK-IAA MIPAS, and 16 NDACC stations