scholarly journals Airborne limb-imaging measurements of temperature, HNO<sub>3</sub>, O<sub>3</sub>, ClONO<sub>2</sub>, H<sub>2</sub>O and CFC-12 during the Arctic winter 2015/16: characterization, in-situ validation and comparison to Aura/MLS

Author(s):  
Sören Johansson ◽  
Wolfgang Woiwode ◽  
Michael Höpfner ◽  
Felix Friedl-Vallon ◽  
Anne Kleinert ◽  
...  

Abstract. The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) was operated on board the German High Altitude and LOng range (HALO) research aircraft during the PGS (POLSTRACC/GW-LCYCLE/SALSA) aircraft campaigns in the Arctic winter 2015/2016. Research flights were conducted from 17 December 2015 until 18 March 2016 between 80° W–30° E longitude and 25° N–87° N latitude. From the GLORIA infrared limb emission measurements, two dimensional cross sections of temperature, HNO3, O3, ClONO2, H2O and CFC-12 are retrieved. During 15 scientific flights of the PGS campaigns the GLORIA instrument measured more than 15 000 atmospheric profiles at high spectral resolution. Dependent on flight altitude and tropospheric cloud cover, the profiles retrieved from the measurements typically range between 5 and 14 km, and vertical resolutions between 400 m and 1000 m are achieved. The estimated total (random and systematic) 1σ errors are in the range of 1 to 2 K for temperature and 10 % to 20 % relative error for the discussed trace gases. Comparisons to in-situ instruments deployed on board HALO have been performed. Over all flights of this campaign the median differences and median absolute deviations between in-situ and GLORIA observations are −0.75 K ± 0.88 K for temperature, −0.03 ppbv ± 0.85 ppbv for HNO3, −3.5 ppbv ± 116.8 ppbv for O3, −15.4 pptv ± 102.8 pptv for ClONO2, −0.13 ppmv ± 0.63 ppmv for H2O and −19.8 pptv ± 46.9 pptv for CFC-12. These differences are mainly within the expected performances of the cross-compared instruments. Events with stronger deviations are explained by atmospheric variability and different sampling characteristics of the instruments. Additionally comparisons of GLORIA HNO3 and O3 with measurements of the Aura Microwave Limb Sounder (MLS) instrument show highly consistent structures in trace gas distributions and illustrate the potential of the high spectral resolution limb-imaging GLORIA observations for resolving narrow mesoscale structures in the UTLS.

2018 ◽  
Vol 11 (8) ◽  
pp. 4737-4756 ◽  
Author(s):  
Sören Johansson ◽  
Wolfgang Woiwode ◽  
Michael Höpfner ◽  
Felix Friedl-Vallon ◽  
Anne Kleinert ◽  
...  

Abstract. The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) was operated on board the German High Altitude and Long Range Research Aircraft (HALO) during the PGS (POLSTRACC/GW-LCYCLE/SALSA) aircraft campaigns in the Arctic winter 2015/2016. Research flights were conducted from 17 December 2015 until 18 March 2016 within 25–87∘ N, 80∘ W–30∘ E. From the GLORIA infrared limb-emission measurements, two-dimensional cross sections of temperature, HNO3, O3, ClONO2, H2O and CFC-12 are retrieved. During 15 scientific flights of the PGS campaigns the GLORIA instrument measured more than 15 000 atmospheric profiles at high spectral resolution. Dependent on flight altitude and tropospheric cloud cover, the profiles retrieved from the measurements typically range between 5 and 14 km, and vertical resolutions between 400 and 1000 m are achieved. The estimated total (random and systematic) 1σ errors are in the range of 1 to 2 K for temperature and 10 % to 20 % relative error for the discussed trace gases. Comparisons to in situ instruments deployed on board HALO have been performed. Over all flights of this campaign the median differences and median absolute deviations between in situ and GLORIA observations are -0.75K±0.88 K for temperature, -0.03ppbv±0.85 ppbv for HNO3, -3.5ppbv±116.8 ppbv for O3, -15.4pptv±102.8 pptv for ClONO2, -0.13ppmv±0.63 ppmv for H2O and -19.8pptv±46.9 pptv for CFC-12. Seventy-three percent of these differences are within twice the combined estimated errors of the cross-compared instruments. Events with larger deviations are explained by atmospheric variability and different sampling characteristics of the instruments. Additionally, comparisons of GLORIA HNO3 and O3 with measurements of the Aura Microwave Limb Sounder (MLS) instrument show highly consistent structures in trace gas distributions and illustrate the potential of the high-spectral-resolution limb-imaging GLORIA observations for resolving narrow mesoscale structures in the upper troposphere and lower stratosphere (UTLS).


2012 ◽  
Vol 5 (5) ◽  
pp. 1173-1191 ◽  
Author(s):  
J. Ungermann ◽  
C. Kalicinsky ◽  
F. Olschewski ◽  
P. Knieling ◽  
L. Hoffmann ◽  
...  

Abstract. The Cryogenic Infrared Spectrometers and Telescope for the Atmosphere – New Frontiers (CRISTA-NF), an airborne infrared limb-sounder, was operated aboard the high-flying Russian research aircraft M55-Geophysica during the Arctic RECONCILE campaign from January to March 2010. This paper describes the calibration process of the instrument and the retrieval algorithm employed and then proceeds to present retrieved trace gas volume mixing ratio cross-sections for one specific flight in this campaign. We are able to resolve the uppermost troposphere/lower stratosphere for several trace gas species for several kilometres below the flight altitude (16 to 19 km) with an unprecedented vertical resolution of 400 to 500 m for the limb-sounding technique. The instrument points sideways with respect to the flight direction. Therefore, the observations are also characterised by a rather high horizontal sampling along the flight track, which provides a full vertical profile every ≈15 km. Assembling the vertical trace gas profiles derived from CRISTA-NF measurements to cross-sections shows filaments of vortex and extra-vortex air masses in the vicinity of the polar vortex. During this campaign, the M55-Geophysica carried further instruments enabling trace gas volume mixing ratios derived from CRISTA-NF to be validated by comparing them with measurements by the in situ instruments HAGAR and FOZAN and observations by MIPAS-STR. This validation suggests that the retrieved trace gas volume mixing ratios are both qualitatively and quantitatively reliable.


2012 ◽  
Vol 5 (6) ◽  
pp. 1205-1228 ◽  
Author(s):  
W. Woiwode ◽  
H. Oelhaf ◽  
T. Gulde ◽  
C. Piesch ◽  
G. Maucher ◽  
...  

Abstract. The mid-infrared FTIR-limb-sounder Michelson Interferometer for Passive Atmospheric Sounding–STRatospheric aircraft (MIPAS-STR) was deployed onboard the research aircraft M55 Geophysica during the RECONCILE campaign (Reconciliation of Essential Process Parameters for an Enhanced Predictability of Arctic Stratospheric Ozone Loss and its Climate Interactions) in the Arctic winter/spring 2010. From the MIPAS-STR measurements, vertical profiles and 2-dimensional vertical cross-sections of temperature and trace gases are retrieved. Detailed mesoscale structures of polar vortex air, extra vortex air and vortex filaments are identified in the results at typical vertical resolutions of 1 to 2 km and typical horizontal sampling densities of 45 or 25 km, depending on the sampling programme. Results are shown for the RECONCILE flight 11 on 2 March 2010 and are validated with collocated in-situ measurements of temperature, O3, CFC-11, CFC-12 and H2O. Exceptional agreement is found for the in-situ comparisons of temperature and O3, with mean differences (vertical profile/along flight track) of 0.2/−0.2 K for temperature and −0.01/0.05 ppmv for O3 and corresponding sample standard deviations of the mean differences of 0.7/0.6 K and 0.1/0.3 ppmv. The comparison of the retrieved vertical cross-sections of HNO3 from MIPAS-STR and the infrared limb-sounder Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere–New Frontiers (CRISTA–NF) indicates a high degree of agreement. We discuss MIPAS-STR in its current configuration, the spectral and radiometric calibration of the measurements and the retrieval of atmospheric parameters from the spectra. The MIPAS-STR measurements are significantly affected by continuum-like contributions, which are attributed to background aerosol and broad spectral signatures from interfering trace gases, and are important for mid-infrared limb-sounding in the Upper Troposphere/Lower Stratosphere (UTLS) region. Taking into consideration continuum-like effects, we present a scheme suitable for accurate retrievals of temperature and an extended set of trace gases, including the correction of a systematic line-of-sight offset.


2011 ◽  
Vol 4 (6) ◽  
pp. 6915-6967 ◽  
Author(s):  
J. Ungermann ◽  
C. Kalicinsky ◽  
F. Olschewski ◽  
P. Knieling ◽  
L. Hoffmann ◽  
...  

Abstract. The Cryogenic Infrared Spectrometers and Telescope for the Atmosphere – New Frontiers (CRISTA-NF), an airborne infrared limb-sounder, was operated aboard the high-flying Russian research aircraft M55-Geophysica during the Arctic RECONCILE campaign from January to March 2011. This paper describes the calibration process of the instrument and the employed retrieval algorithm and then proceeds to present retrieved trace gas mixing ratio cross-sections for one specific flight of this campaign. We are able to resolve the uppermost troposphere/lower stratosphere for several trace gas species for several kilometres below the flight altitude (16 to 19 km) with an unprecedented vertical resolution of 400 to 500 m for the limb-sounding technique. The observations are also characterised by a rather high horizontal sampling along the flight track that provides a full vertical profile every ≈15 km. Assembling the vertical trace gas profiles derived from CRISTA-NF measurements to cross-sections depicts filaments of vortex and extra-vortex air masses in the vicinity of the polar vortex. During this campaign, the M55-Geophysica carried further instruments, which allows for a validation of trace gas mixing ratios derived from CRISTA-NF against measurements by the in situ instruments HAGAR and FOZAN and observations by MIPAS-STR. This validation suggests that the retrieved trace gas mixing ratios are both qualitatively and quantitatively reliable.


2011 ◽  
Vol 4 (6) ◽  
pp. 7035-7108 ◽  
Author(s):  
W. Woiwode ◽  
H. Oelhaf ◽  
T. Gulde ◽  
C. Piesch ◽  
G. Maucher ◽  
...  

Abstract. The mid-infrared FTIR-limb-sounder Michelson Interferometer for Passive Atmospheric Sounding – STRatospheric aircraft (MIPAS-STR) was deployed onboard the stratospheric aircraft M55 Geophysica during the RECONCILE campaign in the arctic winter/spring 2010. From the MIPAS-STR measurements, vertical profiles and 2-dimensional vertical cross-sections of temperature and trace gases are retrieved. Detailed mesoscale structures of polar vortex air, extra vortex air and vortex filaments are identified in the results at a typical vertical resolution of 1 to 2 km and typical horizontal sampling density of 45 or 25 km, depending on the sampling programme. Results are shown for the RECONCILE flight 11 on 2 March 2010 and are validated with collocated in-situ measurements of temperature, O3, CFC-11, CFC-12 and H2O. Exceptional agreement is found for the in-situ comparisons of temperature and O3, with mean differences (vertical profile/along flight track) of 0.2/−0.2 K for temperature and −0.01/0.05 ppmv for O3 and corresponding sample standard deviations of the mean differences of 0.7/0.6 K and 0.1/0.3 ppmv. The comparison of the retrieved vertical cross-sections of HNO3 from MIPAS-STR and the infrared limb-sounder Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere – New Frontiers (CRISTA-NF) indicates comprehensive agreement. We discuss MIPAS-STR in its current configuration, the spectral and radiometric calibration of the measurements and the retrieval of atmospheric parameters from the spectra. The MIPAS-STR measurements are significantly affected by continuum-like contributions, which are attributed to background aerosol and broad spectral signatures from interfering trace gases and are important for mid-infrared limb-sounding measurements in the Upper Troposphere/Lower Stratosphere (UTLS) region. Considering for continuum-like effects, we present a scheme suitable for accurate retrievals of temperature and an extended set of trace gases, including the correction of a systematic line-of-sight offset.


2013 ◽  
Vol 13 (5) ◽  
pp. 2487-2505 ◽  
Author(s):  
S. Groß ◽  
M. Esselborn ◽  
B. Weinzierl ◽  
M. Wirth ◽  
A. Fix ◽  
...  

Abstract. During four aircraft field experiments with the DLR research aircraft Falcon in 1998 (LACE), 2006 (SAMUM-1) and 2008 (SAMUM-2 and EUCAARI), airborne High Spectral Resolution Lidar (HSRL) and in situ measurements of aerosol microphysical and optical properties were performed. Altogether, the properties of six different aerosol types and aerosol mixtures – Saharan mineral dust, Saharan dust mixtures, Canadian biomass burning aerosol, African biomass burning mixture, anthropogenic pollution aerosol, and marine aerosol have been studied. On the basis of this extensive HSRL data set, we present an aerosol classification scheme which is also capable to identify mixtures of different aerosol types. We calculated mixing lines that allowed us to determine the contributing aerosol types. The aerosol classification scheme was supported by backward trajectory analysis and validated with in-situ measurements. Our results demonstrate that the developed aerosol mask is capable to identify complex stratifications with different aerosol types throughout the atmosphere.


2020 ◽  
Author(s):  
Marianna Linz ◽  
Benjamin Birner ◽  
Alan Plumb ◽  
Edwin Gerber ◽  
Florian Haenel ◽  
...  

&lt;p&gt;Age of air is an idealized tracer often used as a measure of the stratospheric circulation. We will show how to quantitatively relate age to the diabatic circulation and the adiabatic mixing. As it is an idealized tracer, age cannot be measured itself and must be inferred from other tracers. Typically, the two primary trace gases used are sulfur hexafluoride and carbon dioxide. Other tracers have a compact relationship with age, however, and can also be used to calculate age. We will discuss a range of tracer measurements from both satellites and in situ, including sulfur hexafluoride, carbon dioxide, nitrous oxide, methane, and the ratio of argon to nitrogen. We will compare the age derived from these different species, including different calculation methods and caveats, and compare with modeled ideal age and trace gas concentrations. We conclude by showing the strength of the diabatic circulation and the adiabatic mixing calculated from these trace gas calculations.&lt;/p&gt;


2020 ◽  
Author(s):  
Hans-Christoph Lachnitt ◽  
Peter Hoor ◽  
Daniel Kunkel ◽  
Stafan Hofmann ◽  
Martina Bramberger ◽  
...  

&lt;p&gt;The tropopause acts as a transport barrier between the upper troposphere and the lower stratosphere. Non-conservative (i.e. PV changing) processes are required to overcome this barrier. Orographically generated gravity waves (i.e. mountain waves) can potentially lead to cross-isentropic fluxes of trace gases via the generation of turbulence. Thus they may alter the isentropic gradient of these trace species across the tropopause.&lt;br&gt;The specific goal of this study is to identify cross-isentropic mixing processes at the tropopause based on the distribution of trace gases (i.e. tracer-tracer correlations). Based on airborne in-situ trace gas measurements of CO and N&lt;sub&gt;2&lt;/sub&gt;O during the DEEPWAVE (Deep Propagating Gravity Wave Experiment) campaign in July 2014 we identified mixing regions above the Southern Alps during periods of gravity wave activity. These in-situ data show that the composition of the air above the Southern Alps change from the upstream to the leeward side of the mountains indicating cross isentropic mixing of trace gases in the region of gravity wave activity.&lt;br&gt;We complement our analysis of the measurement data with high resolution operational analysis data from the ECMWF (European Centre for Medium-Range Weather Forecasts). Furthermore, using potential vorticity and stability parameters.&lt;br&gt;Using 3D wind fields, data form Graphical Turbulence Guidance (GTG) system and in-situ measurements of the vertical wind we identify occurrence of turbulence in the region of mixing events. Using wavelet analysis, we could identify the spatial and temporal scales of local trace gas fluxes. We also give estimates of cross-isentropic flux, i.e. we want to quantify the mixing in terms of exchange.&lt;/p&gt;


2016 ◽  
Vol 41 (5) ◽  
pp. 365-372
Author(s):  
A. S. Kuz’michev ◽  
T. I. Babukhina ◽  
A. V. Gan’shin ◽  
A. N. Luk’yanov ◽  
R. M. Markov ◽  
...  

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