scholarly journals In-Situ Chemical and Isotopic Measurements of the Atmosphere of Jupiter

1998 ◽  
Vol 11 (2) ◽  
pp. 1057-1064
Author(s):  
P.R. Mahaffy ◽  
S.K. Atreya ◽  
H.B. Niemann ◽  
T.C. Owen
Keyword(s):  
Mass Spectrometer ◽  
Atmospheric Composition ◽  
Mixing Ratios ◽  
Major Species ◽  
Lateral Mixing ◽  
Detailed Composition ◽  
Different Depths ◽  
Galileo Probe ◽  
Spectrometer Data

AbstractInsights into both the detailed composition of Jupiter’s atmosphere and unexpected local meteorological phenomena were revealed by in-situ measurements from the Galileo Probe Neutral Mass Spectrometer taken on December 7, 1995. Measurements of the neutral atmospheric composition from a pressure of 0.5 bar to approximately 21 bar revealed the mixing ratios of the major species helium and hydrogen as well as numerous minor constituents including methane, water, ammonia, ethane, ethylene, propane, hydrogen sulfide, neon, argon, krypton, and xenon. This instrument measured the isotope ratios3He/4He, D/H, and13C/12C as well as the isotopes of neon, argon, krypton, and xenon. A summary is given of progress that has been made in refining preliminary estimates of the abundances of condensable volatiles and noble gases as a result of an ongoing laboratory study using a nearly identical engineering unit. The depletion of simple condensable species to depths well below their expected condensation levels is explained by a local downdraft in the region of the probe entry. The mass spectrometer data suggests that different species may recover at different depths and this may be due to lateral mixing of Jovian air.

scholarly journals In Situ exploration of the giant planets

2021 ◽  
Author(s):  
O. Mousis ◽  
D. H. Atkinson ◽  
R. Ambrosi ◽  
S. Atreya ◽  
D. Banfield ◽  
...  
Keyword(s):  
Solar System ◽  
Giant Planets ◽  
Atmospheric Composition ◽  
Formation History ◽  
History Of ◽  
Composition Structure ◽  
Galileo Probe ◽  
Probe Measurements

AbstractRemote sensing observations suffer significant limitations when used to study the bulk atmospheric composition of the giant planets of our Solar System. This impacts our knowledge of the formation of these planets and the physics of their atmospheres. A remarkable example of the superiority of in situ probe measurements was illustrated by the exploration of Jupiter, where key measurements such as the determination of the noble gases’ abundances and the precise measurement of the helium mixing ratio were only made available through in situ measurements by the Galileo probe. Here we describe the main scientific goals to be addressed by the future in situ exploration of Saturn, Uranus, and Neptune, placing the Galileo probe exploration of Jupiter in a broader context. An atmospheric entry probe targeting the 10-bar level would yield insight into two broad themes: i) the formation history of the giant planets and that of the Solar System, and ii) the processes at play in planetary atmospheres. The probe would descend under parachute to measure composition, structure, and dynamics, with data returned to Earth using a Carrier Relay Spacecraft as a relay station. An atmospheric probe could represent a significant ESA contribution to a future NASA New Frontiers or flagship mission to be launched toward Saturn, Uranus, and/or Neptune.

scholarly journals Chemical ionization mass spectrometer (CIMS) for ambient measurements of ammonia

2010 ◽  
Vol 3 (2) ◽  
pp. 1133-1162 ◽  
Author(s):  
D. R. Benson ◽  
M. Al-Refai ◽  
S.-H. Lee
Keyword(s):  
Mass Spectrometer ◽  
Chemical Ionization ◽  
Fast Response ◽  
Ionization Mass ◽  
Experimental Conditions ◽  
Molecule Reaction ◽  
Mixing Ratios ◽  
Ambient Nh3 ◽  
Ambient Measurements

Abstract. This study describes a chemical ionization mass spectrometer (CIMS) for fast response, in-situ measurements for gas phase ammonia. Protonated ethanol ions were used as the ion-molecule reaction reagent. The CIMS sensitivity was estimated to be between 4–25 Hz/pptv with 30% uncertainty. The instrument background was below 1 ppbv and at lowest was 300 pptv. The uncertainty associated with the instrumental background was less than 30 pptv under the optimized experimental conditions. The time response was less than 30 s, and the detection limit was approximately 60 pptv. This CIMS was used to measure the ambient NH3 in Kent, Ohio, for several weeks throughout three seasons. The measured ammonia mixing ratios were usually at the sub-ppbv level, and higher during the spring (200±120 pptv) than in the winter (60±75 pptv) and fall (150±80 pptv).

Results from a comparison of HCN measurements and Lagrangian backtrajectory analyses in the Asian Summer Monsoon Anticyclone

2020 ◽  
Author(s):  
Yun Li ◽  
Bärbel Vogel ◽  
Felix Plöger ◽  
Silvia Bucci ◽  
Bernard Legras ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Lower Stratosphere ◽  
Asian Summer Monsoon ◽  
Atmospheric Composition ◽  
Convective Activity ◽  
Mixing Ratios ◽  
Research Aircraft ◽  
Asian Summer ◽  
Good Tracer

<p>The StratoClim aircraft field campaign took place from Kathmandu, Nepal, in summer 2017 in<br>order to study the atmospheric composition, chemistry, and dynamics in the Asian Summer<br>Monsoon Anticyclone (ASMA) which is known to transport surface emissions to the mid-latitude<br>lower stratosphere and the stratosphere worldwide. Hydrogen cyanide (HCN) which is primarily<br>emitted from biomass burning and has a UTLS lifetime on the order of 1-2 years is a good tracer for<br>biomass burning import into the lower and free stratosphere.<br>HCN in the ASM Upper Troposphere and Lower Stratosphere (UTLS) was measured in-situ<br>employing the Chemical-Ionization Time-of-Flight Mass Spectrometer FUNMASS on board the<br>high-altitude research aircraft M55-Geophysica. The observed HCN mixing ratios in and above the<br>ASMA exhibit interesting vertical and horizontal signatures around the tropopause as well as in the<br>LS probably resulting from convective activity or air mass origin (AMO). We here compare<br>measured HCN to Lagrangian simulations by the ClaMS and TRACZILLA models which employ<br>two different approaches to represent higher-reaching convective events. The simulations succeed to<br>track some of the observed HCN features back to convective activity or AMO. The quality of the<br>reproduction and further outcomes on the atmospheric relevance will be discussed in the<br>presentation.</p>

scholarly journals Ozone and water vapour in the austral polar stratospheric vortex and sub-vortex

2004 ◽  
Vol 22 (12) ◽  
pp. 4035-4041 ◽  
Author(s):  
E. Peet ◽  
V. Rudakov ◽  
V. Yushkov ◽  
G. Redaelli ◽  
A. R. MacKenzie
Keyword(s):  
Water Vapour ◽  
Middle Atmosphere ◽  
Weather Forecasting ◽  
Potential Temperature ◽  
Atmospheric Composition ◽  
Meridional Transport ◽  
Ozone Loss ◽  
Mixing Ratios ◽  
Chemical Destruction

Abstract. In-situ measurements of ozone and water vapour, in the Antarctic lower stratosphere, were made as part of the APE-GAIA mission in September and October 1999. The measurements show a distinct difference above and below the 415K isentrope. Above 415K, the chemically perturbed region of low ozone and water vapour is clearly evident. Below 415K, but still above the tropopause, no sharp meridional gradients in ozone and water vapour were observed. The observations are consistent with analyses of potential vorticity from the European Centre for Medium Range Weather Forecasting, which show smaller radial gradients at 380K than at 450K potential temperature. Ozone loss in the chemically perturbed region above 415K averages 5ppbv per day for mid-September to mid-October. Apparent ozone loss rates in the sub-vortex region are greater, at 7ppbv per day. The data support, therefore, the existence of a sub-vortex region in which meridional transport is more efficient than in the vortex above. The low ozone mixing ratios in the sub-vortex region may be due to in-situ chemical destruction of ozone or transport of ozone-poor air out of the bottom of the vortex. The aircraft data we use cannot distinguish between these two processes. Key words. Meteorology and atmospheric dynamics polar meteorology) – Atmospheric composition and structure (middle atmosphere–composition and chemistry)

scholarly journals Using in situ GC-MS for analysis of C<sub>2</sub>–C<sub>7</sub> volatile organic acids in ambient air of a boreal forest site

2017 ◽  
Vol 10 (1) ◽  
pp. 281-289 ◽  
Author(s):  
Heidi Hellén ◽  
Simon Schallhart ◽  
Arnaud P. Praplan ◽  
Tuukka Petäjä ◽  
Hannele Hakola
Keyword(s):  
Organic Acids ◽  
Boreal Forest ◽  
Mass Spectrometer ◽  
Detection Limits ◽  
Ambient Air ◽  
Cold Trap ◽  
Mixing Ratios ◽  
Volatile Organic ◽  
Volatile Organic Acids

Abstract. An in situ method for studying gas-phase C2–C7 monocarboxylic volatile organic acids (VOAs) in ambient air was developed and evaluated. Samples were collected directly into the cold trap of the thermal desorption unit (TD) and analysed in situ using a gas chromatograph (GC) coupled to a mass spectrometer (MS). A polyethylene glycol column was used for separating the acids. The method was validated in the laboratory and tested on the ambient air of a boreal forest in June 2015. Recoveries of VOAs from fluorinated ethylene propylene (FEP) and heated stainless steel inlets ranged from 83 to 123 %. Different VOAs were fully desorbed from the cold trap and well separated in the chromatograms. Detection limits varied between 1 and 130 pptv and total uncertainty of the method at mean ambient mixing ratios was between 16 and 76 %. All straight chain VOAs except heptanoic acid in the ambient air measurements were found with mixing ratios above the detection limits. The highest mixing ratios were found for acetic acid and the highest relative variations for hexanoic acid. In addition, mixing ratios of acetic and propanoic acids measured by the novel GC-MS method were compared with proton-mass-transfer time-of-flight mass spectrometer (PTR-TOFMS) data. Both instruments showed similar variations, but differences in the mixing ratio levels were significant.

scholarly journals Retrieval of Metop-A/IASI N2O Profiles and Validation with NDACC FTIR Data

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 219
Author(s):  
Brice Barret ◽  
Yvan Gouzenes ◽  
Eric Le Flochmoen ◽  
Sylvain Ferrant
Keyword(s):  
Vertical Profile ◽  
Correlation Coefficients ◽  
Atmospheric Composition ◽  
Spectral Window ◽  
Mixing Ratios ◽  
Geographical Variability ◽  
Composition Changes ◽  
Better Than ◽  
Good Agreement

This paper reports atmospheric profiles of N2O retrieved from Metop/IASI with the Software for the Retrieval of IASI Data (SOFRID) for the 2008–2018 period and their validation with FTIR data from 12 stations of the Network for the Detection of Atmospheric Composition Changes (NDACC). SOFRID retrievals performed in the 2160–2218 cm−1 spectral window provide 3 independent pieces of information about the vertical profile of N2O. The FTIR versus SOFRID comparisons display a better agreement in the mid-troposphere (MT, 700–350 hPa) than in the lower (LT, Surface–700 hPa) and upper (UT, 350–110 hPa) troposphere with correlation coefficients (R) in the 0.49–0.83 range and comparable variabilities (3–5 ppbv). The agreement for oceanic and coastal stations (R > 0.77) is better than for continental ones (R < 0.72). The SOFRID MT N2O mixing ratios are significantly biased high (up to 16.8 ppbv) relative to FTIR at continental stations while the biases remain below 4.2 ppbv and mostly unsignificant when oceanic data are considered. The average MT decadal trends derived from SOFRID at the 8 NDACC stations with continuous observations during the 2008–2018 period (1.05 ± 0.1 ppbv·yr−1) is in good agreement with the corresponding FTIR trends (1.08 ± 0.1 ppbv·yr−1) and the NOAA-ESRL trends from surface in-situ measurements (0.95 ± 0.02 ppbv·yr−1). In the Northern Hemisphere where they are clearly detected, the N2O MT seasonal variations from SOFRID and FTIR are phased (summer minima) and have similar amplitudes. SOFRID also detects the UT summer maxima indicating independent MT and UT information. The global MT N2O oceanic distributions from SOFRID display low geographical variability and are mainly characterized by enhanced tropical mixing ratios relative to mid and high latitudes.

scholarly journals Global sensitivity analysis of GEOS-Chem modeled ozone and hydrogen oxides during the INTEX campaigns

2017 ◽  
Author(s):  
Kenneth E. Christian ◽  
William H. Brune ◽  
Jingqiu Mao ◽  
Xinrong Ren
Keyword(s):  
Transport Model ◽  
Specific Model ◽  
Atmospheric Composition ◽  
Chemical Transport Model ◽  
Global Sensitivity ◽  
Mixing Ratios ◽  
Making Sense ◽  
Sensitivity Method ◽  
Lightning Nox

Abstract. Making sense of modeled atmospheric composition requires not just comparison to in situ measurements, but also knowing and quantifying the sensitivity of the model to its input factors. Using a global sensitivity method involving the simultaneous perturbation of many chemical transport model input factors, we find the model uncertainty for ozone (O3), hydroxyl radical (OH), and hydroperoxyl radical (HO2) mixing ratios and apportion this uncertainty to specific model inputs for the DC-8 flight tracks corresponding to the NASA INTEX campaigns of 2004 and 2006. In general, when uncertainties in modeled and measured quantities are accounted for, we find agreement between modeled and measured oxidant mixing ratios with the exception of ozone during the Houston flights of the INTEX-B campaign and HO2 for the flights over the northernmost Pacific Ocean during INTEX-B. For ozone and OH, modeled mixing ratios were most sensitive to a bevy of emissions, notably lightning NOx, various surface NOx sources, and isoprene. HO2 mixing ratios were most sensitive to CO and isoprene emissions as well as the aerosol uptake of HO2. With ozone and OH being generally over predicted by the model, we find better agreement between modeled and measured vertical profiles when reducing NOx emissions from surface as well as lightning sources.

Synergistic Probe-Orbiter Science and Measurements for Understanding the Formation and Evolution of the Icy Giant Planets

2020 ◽  
Author(s):  
Sushil K. Atreya ◽  
Olivier Mousis ◽  
Kim R. Reh
Keyword(s):  
Noble Gases ◽  
Giant Planets ◽  
Heavy Elements ◽  
Critical Set ◽  
Mixing Ratios ◽  
Formation And Evolution ◽  
Galileo Probe ◽  
The Magnetic Field

&lt;p&gt;The Galileo Probe was designed to measure the abundances of the heavy elements (mass &gt;helium) and helium in Jupiter since they are key to understanding the planet&amp;#8217;s formation and heat balance. Broadly speaking, the same formation scenarios presumably apply also to the Icy Giant Planets (IGP), Uranus and Neptune, so the determination of their heavy elements and He is equally important. We will show that the bulk of C, N, S, and O are sequestered in condensible volatiles whose well-mixed regions in the atmospheres of the IGP&amp;#8217;s are extremely deep compared to Jupiter. That poses formidable challenges to their direct in situ measurements. On the other hand, being non-condensible and chemically inert, the noble gases &amp;#8722; He, Ne, Ar, Kr and Xe &amp;#8211; are expected to be uniformly mixed all over the planet, unlike the condensibles whose distribution is governed by dynamics, convection and purported deep oceans. Thus the noble gases would provide the most critical set of data for constraining the IGP formation models. Although the noble gases should be well-mixed everywhere below the homopause, measurements at and below the 1-bar level are needed considering their low mixing ratios, except for He. That depth also gets around any potential cold trapping of the heavy noble gases at the tropopause or adsorption on methane ice aerosols. Entry probes deployed to relatively shallow pressure levels of 5-10 bars would allow a robust determination of the abundances and isotopic ratios of the noble gases, amongst other things. A measurement of CO from orbit, along with other disequilibrium species has the potential of estimating the O/H ratio.&amp;#160;Microwave radiometry from orbiter and the Earth have the potential of measuring the depth profiles of NH&lt;sub&gt;3&lt;/sub&gt; and H&lt;sub&gt;2&lt;/sub&gt;O, which would be important for understanding the atmospheric dynamics and weather in the deep atmosphere. Combined with the above data and the data on the interior and the magnetic field, the probe results on the noble gases would provide essential constraints to the formation, migration and evolution models of the Icy Giant Planets.&amp;#160;&lt;/p&gt;

scholarly journals Using in situ GC-MS for analysis of C<sub>2</sub>-C<sub>7</sub> volatile organic acids in ambient air of a boreal forest site

2016 ◽  
Author(s):  
Heidi Hellén ◽  
Simon Schallhart ◽  
Arnaud P. Praplan ◽  
Tuukka Petäjä ◽  
Hannele Hakola
Keyword(s):  
Organic Acids ◽  
Boreal Forest ◽  
Mass Spectrometer ◽  
Detection Limits ◽  
Ambient Air ◽  
Cold Trap ◽  
Mixing Ratios ◽  
Volatile Organic ◽  
Volatile Organic Acids

Abstract. Abstract. An in situ method for studying C2-C7 monocarboxylic volatile organic acids (VOAs) in ambient air was developed and evaluated. Samples were collected directly into the cold trap of the thermal desorption unit (TD) and analysed in situ using a gas chromatograph (GC) coupled to a mass spectrometer (MS). A polyethylene glycol column was used for separating the acids. The method was validated in the laboratory and tested on the ambient air of a boreal forest in June 2015. Recoveries of VOAs from fluorinated ethylene propylene (FEP) and heated stainless steel inlets were acceptable. Different VOAs were fully desorbed from the cold trap and well separated in the chromatograms. Detection limits varied between 1 and 130 pptv and total uncertainty of the method at mean ambient mixing ratios ranged between 16–76 %. All straight chain VOAs except heptanoic acid in the ambient air measurement were found with mixing ratios above the detection limits. The highest mixing ratios were found for acetic acid and the highest relative variations for hexanoic acid. In addition, mixing ratios of acetic and propanoic acids measured by the novel GC-MS method were compared with proton-mass-transfer time-of-flight mass spectrometer (PTR-TOFMS) data. Both instruments showed similar variations, but differences in the mixing ratio levels were significant.

scholarly journals CASPA-ADM: a mission concept for observing thermospheric mass density

2022 ◽  
Author(s):  
Christian Siemes ◽  
Stephen Maddox ◽  
Olivier Carraz ◽  
Trevor Cross ◽  
Steven George ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Mass Density ◽  
Rapid Development ◽  
European Space Agency ◽  
Cold Atom ◽  
Atmospheric Composition ◽  
Sensor Technology ◽  
Space Agency ◽  
Gas Surface Interactions ◽  
Spectrometer Data

AbstractCold Atom technology has undergone rapid development in recent years and has been demonstrated in space in the form of cold atom scientific experiments and technology demonstrators, but has so far not been used as the fundamental sensor technology in a science mission. The European Space Agency therefore funded a 7-month project to define the CASPA-ADM mission concept, which serves to demonstrate cold-atom interferometer (CAI) accelerometer technology in space. To make the mission concept useful beyond the technology demonstration, it aims at providing observations of thermosphere mass density in the altitude region of 300–400 km, which is presently not well covered with observations by other missions. The goal for the accuracy of the thermosphere density observations is 1% of the signal, which will enable the study of gas–surface interactions as well as the observation of atmospheric waves. To reach this accuracy, the CAI accelerometer is complemented with a neutral mass spectrometer, ram wind sensor, and a star sensor. The neutral mass spectrometer data is considered valuable on its own since the last measurements of atmospheric composition and temperature in the targeted altitude range date back to 1980s. A multi-frequency GNSS receiver provides not only precise positions, but also thermosphere density observations with a lower resolution along the orbit, which can be used to validate the CAI accelerometer measurements. In this paper, we provide an overview of the mission concept and its objectives, the orbit selection, and derive first requirements for the scientific payload.

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