scholarly journals Validation of first chemistry mode retrieval results from the new limb-imaging FTS GLORIA with correlative MIPAS-STR observations

2015 ◽  
Vol 8 (6) ◽  
pp. 2509-2520 ◽  
Author(s):  
W. Woiwode ◽  
O. Sumińska-Ebersoldt ◽  
H. Oelhaf ◽  
M. Höpfner ◽  
G. V. Belyaev ◽  
...  
Keyword(s):  
Michelson Interferometer ◽  
Polar Vortex ◽  
Vertical Resolution ◽  
Ongoing Work ◽  
First Results ◽  
Research Aircraft ◽  
Order Of Magnitude ◽  
Field Deployment ◽  
Cross Track ◽  
Stratospheric Clouds

Abstract. We report first chemistry mode retrieval results from the new airborne limb-imaging infrared FTS (Fourier transform spectrometer) GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) and comparisons with observations by the conventional airborne limb-scanning infrared FTS MIPAS-STR (Michelson Interferometer for Passive Atmospheric Sounding – STRatospheric aircraft). For GLORIA, the flights aboard the high-altitude research aircraft M55 Geophysica during the ESSenCe campaign (ESa Sounder Campaign 2011) were the very first in field deployment after several years of development. The simultaneous observations of GLORIA and MIPAS-STR during the flight on 16 December 2011 inside the polar vortex and under conditions of optically partially transparent polar stratospheric clouds (PSCs) provided us the first opportunity to compare the observations by two different infrared FTS generations directly. We validate the GLORIA results with MIPAS-STR based on the lower vertical resolution of MIPAS-STR and compare the vertical resolutions of the instruments derived from their averaging kernels. The retrieval results of temperature, HNO3, O3, H2O, CFC-11 and CFC-12 show reasonable agreement of GLORIA with MIPAS-STR and collocated in situ observations. For the horizontally binned hyperspectral limb images, the GLORIA sampling outnumbered the horizontal cross-track sampling of MIPAS-STR by up to 1 order of magnitude. Depending on the target parameter, typical vertical resolutions of 0.5 to 2.0 km were obtained for GLORIA and are typically a factor of 2 to 4 better compared to MIPAS-STR. While the improvement of the performance, characterization and data processing of GLORIA are the subject of ongoing work, the presented first results already demonstrate the considerable gain in sampling and vertical resolution achieved with GLORIA.

scholarly journals Validation of first chemistry mode retrieval results from new limb-<i>imaging</i> FTS GLORIA with correlative MIPAS-STR observations

2014 ◽  
Vol 7 (12) ◽  
pp. 12691-12717 ◽  
Author(s):  
W. Woiwode ◽  
O. Suminska-Ebersoldt ◽  
H. Oelhaf ◽  
M. Höpfner ◽  
G. V. Belyaev ◽  
...  
Keyword(s):  
Polar Vortex ◽  
Ongoing Work ◽  
First Results ◽  
Research Aircraft ◽  
Order Of Magnitude ◽  
In Situ Observations ◽  
Field Deployment ◽  
Cross Track ◽  
Stratospheric Clouds

Abstract. We report first chemistry mode retrieval results from the new airborne limb-imaging infrared FTS (Fourier transform spectrometer) GLORIA and comparisons with observations by the conventional airborne limb-scanning infrared FTS MIPAS-STR. For GLORIA, the flights aboard the high-altitude research aircraft M55 Geophysica during the ESSenCe campaign (ESa Sounder Campaign 2011) were the very first in field deployment after several years of development. The simultaneous observations of GLORIA and MIPAS-STR during the flight on 16 December 2011 inside the polar vortex and under the conditions of optically partially transparent polar stratospheric clouds (PSCs) provided us the unique opportunity to compare the observations by two different infrared FTS generations directly. The retrieval results of temperature, HNO3, O3, H2O, CFC-11 and CFC-12 show reasonable agreement of GLORIA with MIPAS-STR and collocated in-situ observations. For the horizontally binned hyperspectral limb-images, the GLORIA sampling outnumbered the horizontal cross-track sampling of MIPAS-STR by up to one order of magnitude. Depending on the target parameter, typical vertical resolutions of 0.5 to 2.0 km were obtained for GLORIA and are typically by factors of 2 to 4 better compared to MIPAS-STR. While the improvement of the performance, characterisation and data processing of GLORIA are subject of ongoing work, the presented first results already demonstrate the considerable gain in sampling and vertical resolution achieved with GLORIA.

scholarly journals CRISTA-NF measurements with unprecedented vertical resolution during the RECONCILE aircraft campaign

2012 ◽  
Vol 5 (5) ◽  
pp. 1173-1191 ◽  
Author(s):  
J. Ungermann ◽  
C. Kalicinsky ◽  
F. Olschewski ◽  
P. Knieling ◽  
L. Hoffmann ◽  
...  
Keyword(s):  
Cross Sections ◽  
Polar Vortex ◽  
The Arctic ◽  
Trace Gas ◽  
Retrieval Algorithm ◽  
Vertical Resolution ◽  
Mixing Ratios ◽  
Flight Direction ◽  
Research Aircraft ◽  
Gas Volume

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.

scholarly journals HOCl chemistry in the Antarctic stratospheric vortex 2002, as observed with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS)

2008 ◽  
Vol 8 (6) ◽  
pp. 18967-18992
Author(s):  
T. von Clarmann ◽  
N. Glatthor ◽  
R. Ruhnke ◽  
G. P. Stiller ◽  
O. Kirner ◽  
...  
Keyword(s):  
Heterogeneous Reaction ◽  
Michelson Interferometer ◽  
Polar Vortex ◽  
Heterogeneous Chemistry ◽  
Polar Stratospheric Clouds ◽  
Mean Values ◽  
Mixing Ratios ◽  
Atmospheric Sounding ◽  
Antarctic Polar Vortex ◽  
Stratospheric Clouds

Abstract. In the 2002 Antarctic polar vortex enhanced HOCl mixing ratios were detected by the Michelson Interferometer for Passive Atmospheric Sounding both at altitudes of around 35 km, where HOCl abundances are ruled by gas phase chemistry and at around 24 km, which belongs to the altitude domain where heterogeneous chlorine chemistry is relevant. At altitudes of 33 to 40 km, where in midlatitudinal and tropical atmospheres peak HOCl mixing ratios significantly above 0.2 ppbv (in terms of daily mean values) are observed, polar vortex HOCl mixing ratios were found to be around 0.14 ppbv as long as the polar vortex was intact, centered at the pole, and thus received relatively little sunlight. After deformation and displacement of the polar vortex in the course of a major warming, ClO rich vortex air was more exposed to sunlight, where enhanced HOx abundances led to largely increased HOCl mixing ratios (up to 0.3 ppbv), exceeding typical midlatitudinal and tropical amounts significantly. The HOCl increase was preceded by an increase of ClO. Model runs could reproduce these measurements only when the Stimpfle et al. (1979) rate constant for the reaction ClO+HO2→HOCl+O2 was used but not with the current JPL recommendation. At an altitude of 24 km, HOCl mixing ratios of up to 0.15 ppbv were detected. This HOCl enhancement, which is already visible in 18 September data, is attributed to heterogeneous chemistry, which is in agreement with observations of polar stratospheric clouds. Comparison with a model run where no polar stratospheric clouds appeared during the observation period suggests that a significant part of HOCl was generated from ClO rather than directly via heterogeneous reaction. Excess ClO and HOCl in the measurements is attributed to ongoing heterogeneous chemistry which is not reproduced by the model. In the following days, a decay of HOCl abundances was observed and on 11 October, polar vortex mean daytime mixing ratios were only 0.03 ppbv.

scholarly journals CRISTA-NF measurements with unprecedented vertical resolution during the RECONCILE aircraft campaign

2011 ◽  
Vol 4 (6) ◽  
pp. 6915-6967 ◽  
Author(s):  
J. Ungermann ◽  
C. Kalicinsky ◽  
F. Olschewski ◽  
P. Knieling ◽  
L. Hoffmann ◽  
...  
Keyword(s):  
Cross Sections ◽  
Polar Vortex ◽  
The Arctic ◽  
Trace Gas ◽  
Retrieval Algorithm ◽  
Vertical Resolution ◽  
Gas Mixing ◽  
Air Masses ◽  
Mixing Ratios ◽  
Research Aircraft

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.

scholarly journals HOCl chemistry in the Antarctic Stratospheric Vortex 2002, as observed with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS)

2009 ◽  
Vol 9 (5) ◽  
pp. 1817-1829 ◽  
Author(s):  
T. von Clarmann ◽  
N. Glatthor ◽  
R. Ruhnke ◽  
G. P. Stiller ◽  
O. Kirner ◽  
...  
Keyword(s):  
Heterogeneous Reaction ◽  
Potential Temperature ◽  
Michelson Interferometer ◽  
Polar Vortex ◽  
Heterogeneous Chemistry ◽  
Polar Stratospheric Clouds ◽  
Mean Values ◽  
Mixing Ratios ◽  
Atmospheric Sounding ◽  
Stratospheric Clouds

Abstract. In the 2002 Antarctic polar vortex enhanced HOCl mixing ratios were detected by the Michelson Interferometer for Passive Atmospheric Sounding both at altitudes of around 35 km (1000 K potential temperature), where HOCl abundances are ruled by gas phase chemistry and at around 18–24 km (475–625 K), which belongs to the altitude domain where heterogeneous chlorine chemistry is relevant. At altitudes of 33 to 40 km polar vortex HOCl mixing ratios were found to be around 0.14 ppbv as long as the polar vortex was intact, centered at the pole, and thus received relatively little sunlight. This is the altitude region where in midlatitudinal and tropic atmospheres peak HOCl mixing ratios significantly above 0.2 ppbv (in terms of daily mean values) are observed. After deformation and displacement of the polar vortex in the course of a major warming, ClO-rich vortex air was more exposed to sunlight, where enhanced HOx abundances led to largely increased HOCl mixing ratios (up to 0.3 ppbv), exceeding typical midlatitudinal and tropical amounts significantly. The HOCl increase was preceded by an increase of ClO. Model runs could reproduce these measurements only when the Stimpfle et al. (1979) rate constant for the reaction ClO+HO2→HOCl+O2 was used but not with the current JPL recommendation. At an altitude of 24 km, HOCl mixing ratios of up to 0.15 ppbv were detected. This HOCl enhancement, which is already visible in 18 September data, is attributed to heterogeneous chemistry, which is in agreement with observations of polar stratospheric clouds. The measurements were compared to a model run where no polar stratospheric clouds appeared during the observation period. The fact that HOCl still was produced in the model run suggests that a significant part of HOCl was generated from ClO rather than directly via heterogeneous reaction. Excess ClO, lower ClONO2 and earlier loss of HOCl in the measurements are attributed to ongoing heterogeneous chemistry which is not reproduced by the model. On 11 October, polar vortex mean daytime mixing ratios were only 0.03 ppbv.

scholarly journals The red sky enigma over Svalbard in December 2002: a model using polar stratospheric clouds

2005 ◽  
Vol 23 (5) ◽  
pp. 1603-1610
Author(s):  
N. D. Lloyd ◽  
D. A. Degenstein ◽  
F. Sigernes ◽  
E. J. Llewellyn ◽  
D. A. Lorentzen
Keyword(s):  
Spatial Distribution ◽  
Zenith Angle ◽  
Solar Zenith Angle ◽  
Polar Vortex ◽  
Polar Stratospheric Clouds ◽  
Infra Red ◽  
Order Of Magnitude ◽  
Stage Process ◽  
Polar Meteorology ◽  
Stratospheric Clouds

Abstract. An anomalous red glow due to scattered sunlight was observed at Longyearbyen (78° N, 15° E) on 6 December 2002 from 07:30 UT to 13:30 UT when the solar zenith angle varied between 100.7° and 104°. A model for this red sky event using sunlight scattered in a two stage process by Polar Stratospheric Clouds (PSC) at 25km is presented and demonstrated to be feasible. The model requires a significant fraction of the polar vortex, which is cold enough for the formation of ice PSC, to be occupied with PSC with an integrated vertical extinction of approximately 0.037 at 845nm. Given these conditions, the model is able to predict, within an order of magnitude, the spatial distribution of intensities measured by meridional scanning photometers located at Longyearbyen across the visible and near infra-red spectrum. Keywords. Aerosols and particles; Transmission and scattering of radiation; Polar Meteorology

Record springtime stratospheric ozone depletion at 80°N in 2020

2021 ◽  
Author(s):  
Ramina Alwarda ◽  
Kristof Bognar ◽  
Kimberly Strong ◽  
Martyn Chipperfield ◽  
Sandip Dhomse ◽  
...  
Keyword(s):  
Ozone Depletion ◽  
Transport Model ◽  
Stratospheric Ozone ◽  
Polar Vortex ◽  
The Arctic ◽  
Optical Absorption Spectroscopy ◽  
Chemical Transport Model ◽  
Polar Stratospheric Clouds ◽  
Ozone Loss ◽  
Stratospheric Clouds

&lt;p&gt;The Arctic winter of 2019-2020 was characterized by an unusually persistent polar vortex and temperatures in the lower stratosphere that were consistently below the threshold for the formation of polar stratospheric clouds (PSCs). These conditions led to ozone loss that is comparable to the Antarctic ozone hole. Ground-based measurements from a suite of instruments at the Polar Environment Atmospheric Research Laboratory (PEARL) in Eureka, Canada (80.05&amp;#176;N, 86.42&amp;#176;W) were used to investigate chemical ozone depletion. The vortex was located above Eureka longer than in any previous year in the 20-year dataset and lidar measurements provided evidence of polar stratospheric clouds (PSCs) above Eureka. Additionally, UV-visible zenith-sky Differential Optical Absorption Spectroscopy (DOAS) measurements showed record ozone loss in the 20-year dataset, evidence of denitrification along with the slowest increase of NO&lt;sub&gt;2&lt;/sub&gt; during spring, as well as enhanced reactive halogen species (OClO and BrO). Complementary measurements of HCl and ClONO&lt;sub&gt;2&lt;/sub&gt; (chlorine reservoir species) from a Fourier transform infrared (FTIR) spectrometer showed unusually low columns that were comparable to 2011, the previous year with significant chemical ozone depletion. Record low values of HNO&lt;sub&gt;3&lt;/sub&gt; in the FTIR dataset are in accordance with the evidence of PSCs and a denitrified atmosphere. Estimates of chemical ozone loss were derived using passive ozone from the SLIMCAT offline chemical transport model to account for dynamical contributions to the stratospheric ozone budget.&lt;/p&gt;

scholarly journals First results of the PML monitor of atmospheric turbulence profile with high vertical resolution

2013 ◽  
Vol 559 ◽  
pp. L6 ◽  
Author(s):  
A. Ziad ◽  
F. Blary ◽  
J. Borgnino ◽  
Y. Fanteï-Caujolle ◽  
E. Aristidi ◽  
...  
Keyword(s):  
Atmospheric Turbulence ◽  
Vertical Resolution ◽  
First Results ◽  
High Vertical Resolution

scholarly journals Comparison of SMILES ClO profiles with other satellite and balloon-based measurements

2013 ◽  
Vol 6 (1) ◽  
pp. 613-663 ◽  
Author(s):  
H. Sagawa ◽  
T. O. Sato ◽  
P. Baron ◽  
E. Dupuy ◽  
N. Livesey ◽  
...  
Keyword(s):  
Systematic Error ◽  
Michelson Interferometer ◽  
Space Station ◽  
Polar Vortex ◽  
Middle Latitude ◽  
Information And Communications Technology ◽  
Polar Regions ◽  
Systematic Bias ◽  
Spectral Bandwidth ◽  
Level 2

Abstract. We evaluate the quality of ClO profiles derived from the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the International Space Station (ISS). Version 2.1.5 of the level-2 product generated by the National Institute of Information and Communications Technology (NICT) is the subject of this study. Based on error analysis simulations the systematic error was estimated as 5–10 pptv at the pressure range of 80–20 hPa, 35 pptv at the ClO peak altitude (~ 4 hPa), and 5–10 pptv at pressures &amp;leq; 0.5 hPa for daytime mid-latitude conditions. For nighttime measurements, a systematic error of 8 pptv was estimated for the ClO peak altitude (~ 2 hPa). The SMILES NICT v2.1.5 ClO profiles agree with those derived from another level-2 processor developed by JAXA within of the bias uncertainties, except for the nighttime measurements in the low and middle latitude region where the SMILES NICT v2.1.5 profiles have a negative bias of ~ 30 pptv in the lower stratosphere. This bias is considered to be due to the use of a limited spectral bandwidth in the retrieval process, which makes it difficult to distinguish between the ClO signal and wing contributions of spectral features outside the bandwidth. In the middle and upper stratosphere outside the polar regions, no significant systematic bias was found for the SMILES NICT ClO profile with respect to datasets from other instruments such as the Aura Microwave Limb Sounder (MLS), the Odin Sub-Millimetre Radiometer (SMR), and the Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), which demonstrates the scientific usability of the SMILES ClO data including the diurnal variations. Inside the chlorine-activated polar vortex the SMILES NICT v2.1.5 ClO profiles show larger volume mixing ratios by 0.3 ppbv (30%) at 50 hPa compared to those of the JAXA processed profiles. This discrepancy is also considered to be an effect of the limited spectral bandwidth in the retrieval processing. We also compared the SMILES NICT ClO profiles of chlorine-activated polar vortex conditions with those measured by the balloon-borne instruments Terahertz and submillimeter Limb Sounder (TELIS) and the MIPAS-balloon (MIPAS-B).

Charge moderated preplanetary growth from single grains to giant aggregates

2021 ◽  
Author(s):  
Felix Jungmann ◽  
Jens Teiser ◽  
Maximilian Kruss ◽  
Tobias Steinpilz ◽  
Kolja Joeris ◽  
...  
Keyword(s):  
Cross Sections ◽  
Planet Formation ◽  
Dipole Moments ◽  
Copper Plate ◽  
Net Charge ◽  
Electrostatic Charges ◽  
Ongoing Work ◽  
Astrophysical Journal ◽  
Stable Clusters ◽  
Order Of Magnitude

&lt;p&gt;In early phases of planet formation, bouncing and fragmentation barriers still represent major obstacles. Beginning at micrometer, dust can readily grow to sub-millimeter size in collisions due to cohesion before bouncing prevails. Later, streaming instabilities trigger further growth which might finally results into planetesimal formation by gravitational collapse. However, for streaming instabilities sub-millimeter grains might be too small, therefore there is gap of at least 1 order of magnitude in size which needs to be bridged.&lt;/p&gt; &lt;p&gt;Here, we present our ongoing work how to bridge this gap by charge moderated aggregation [1]. When two (dielectric) grains collide they charge. This tribocharging or collisional charging is omnipresent in nature. We designed drop tower experiments in which we generated charges on glass and basalt grains by collisions in a shaker. In microgravity, the particle trajectories and collisions were observed, and charges were measured by applying an electric field.&lt;/p&gt; &lt;p&gt;In early work, we analyzed millimeter-sized glass grain collisions with a copper plate. The coefficient of restitution increased with the charge on a single grain due to mirror charge forces. That means highly charged grains tend to stick more easily to surfaces than uncharged grains. The velocity where sticking is possible was increased by a factor of 100 up to several dm/s [2].&lt;br /&gt;&amp;#160;&lt;br /&gt;More recently, we used half millimeter basalt spheres and observed sticking events at several cm/s among grains themselves [3]. This is also way higher than predicted by adhesion. In a number of cases, we could observe the sequential formation of aggregates of up to ten single grains. During approach the grains are accelerated due to net charge Coulomb forces but likely also due to higher order charges on the surfaces in agreement to earlier measurements of strong permanent dipole moments [4]. Attraction increases collision cross-sections and the growth is sped up. Growth only stopped by the end of microgravity [3].&amp;#160;&lt;/p&gt; &lt;p&gt;To observe the formation of still larger aggregates we developed a new setup, in which a dense cloud of 150 &amp;#181;m diameter basalt grains was continuously agitated slightly under microgravity and in vacuum. Here, the growth of a giant aggregate of centimeter size was observed collecting nearly all material in one cluster [5].&lt;/p&gt; &lt;p&gt;To conclude, in experiments under various conditions, we see strong evidence that electrostatic charges on grains are able to conquer the bouncing barrier. We observed the bottom-up growth tracking individual particles, stable clusters emerging from dense regions and the formation of giant clusters during agitation. These are all bricks in the wall giving evidence that collisional charging might play a crucial role in planet formation.&lt;/p&gt; &lt;p&gt;&lt;strong&gt;References:&lt;/strong&gt;&lt;/p&gt; &lt;p&gt;[1] Steinpilz, T.; Joeris, K.; Jungmann, F.; Wolf, D.; Brendel, L.; Teiser, J.; Shinbrot, T.; Wurm, G. Nature Physics 2020a, 16, 225-229.&lt;/p&gt; &lt;p&gt;[2] Jungmann, F.; Steinpilz, T.; Teiser, J.; Wurm, G. Journal of Physics Communications 2018, 2 095009, 095009.&lt;/p&gt; &lt;p&gt;[3] Jungmann, F.;Wurm, G. Astronomy and Astrophysics 2021, DOI: https://doi.org/10.1051/0004-6361/202039430.&lt;/p&gt; &lt;p&gt;[4] Steinpilz, T.; Jungmann, F.; Joeris, K.; Teiser, J.; Wurm, G. New Journal of Physics 2020b, 22, 093025.&lt;/p&gt; &lt;p&gt;[5] Teiser, J.; Kruss, M.; Jungmann, F.; Wurm, G. The Astrophysical Journal Letters 2021, 908, L22.&lt;/p&gt;

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