Microwave Remote Sensing of the Temperature and Distribution of Sulfur Compounds in the Lower Atmosphere of Venus

Jenkins, Jon M.; Kolodner, Marc A.; Butler, B. J.; Suleiman, S. H.; Steffes, Paul G.

doi:10.1006/icar.2002.6894

Cited by 51 publications

(28 citation statements)

References 38 publications

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“…The polar profiles tend to achieve somewhat larger integrated cloud mass than LCPS, but only by a few percent. Note, however, that observations by Jenkins et al (2002) suggest a decrease in sulfuric acid mixing ratio at the cloud base from polar to equatorial latitudes. Changing this boundary condition also might significantly affect the total mass of the simulated condensational cloud in the polar latitudes.…”

Section: Nominalmentioning

confidence: 89%

“…The reason for testing this is that the true value of the acid vapor boundary condition below the cloud base has proven rather difficult to constrain. The value of the sulfuric acid vapor mixing ratio has been most extensively measured by means of radio occultations, taking advantage of the fact that sulfuric acid absorbs radio emission at frequencies within the S-band and X-band (Kolodner and Steffes 1998;Jenkins et al 2002). Unfortunately, at the altitude of the cloud base of Venus, the measurement errors in radio occultation profile analysis are beginning to become quite large.…”

Section: Reduced Acid Vapor Boundary Conditionmentioning

confidence: 99%

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Effects of variation in coagulation and photochemistry parameters on the particle size distributions in the Venus clouds

McGouldrick

2017

Earth Planets Space

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This paper explores the effects that variation in the coalescence efficiency of the Venus cloud particles can have on the structure of the Venus cloud. It is motivated by the acknowledgment of uncertainties in the measured parameters-and the assumptions made to account for them-that define our present knowledge of the particle characteristics. Specifically, we explore the consequence of allowing the coalescence efficiency of supercooled sulfuric acid in the upper clouds to tend to zero. This produces a cloud that occasionally exhibits an enhancement of small particles at altitude (similar to the upper hazes observed by Pioneer Venus and subsequently shown to be somewhat transient). This simulated cloud occasionally exhibits a rapid growth of particle size near cloud base, exhibiting characteristics similar to those seen in the controversial Mode 3 particles. These results demonstrate that a subset of the variations observed as near-infrared opacity variations in the lower and middle clouds of Venus can be explained by microphysical, in addition to dynamical, variations. Furthermore, the existence of a population of particles exhibiting less efficient coalescence efficiencies would support the likelihood of conditions suitable for charge exchange, hence lightning, in the Venus clouds. We recommend future laboratory studies on the coalescence properties of sulfuric acid under the range of conditions experienced in the Venus clouds. We also recommend future in situ measurements to better characterize the properties of the cloud particles themselves, especially composition and particle habits (shapes).

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Section: Nominalmentioning

confidence: 89%

Section: Reduced Acid Vapor Boundary Conditionmentioning

confidence: 99%

Effects of variation in coagulation and photochemistry parameters on the particle size distributions in the Venus clouds

McGouldrick

2017

Earth Planets Space

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“…Vertical profiles of SO 2 determined by the ISAV experiment aboard Vega 1 and 2 [ Bertaux et al , 1996]. The circles indicate the Pioneer Venus and Venera 12 GC measurements, the square indicates the 2.3‐ μ m nightside observations [ Bézard et al , 1993], and the triangle indicates the upper limit from microwave flux measurements [ Jenkins et al , 2002]. …”

Section: Sulfur Dioxidementioning

confidence: 99%

“…Remote sensing of the deep atmosphere is possible at centimeter wavelengths either from ground‐based radio telescopes or from radio occultation experiments aboard spacecraft. Multifrequency measurements with the Very Large Array (VLA) have provided constraints on sulfuric acid vapor (H 2 SO 4 ), the dominant microwave absorber, between approximately 35 and 55 km [ Jenkins et al , 2002]. The Mariner 10 and Magellan radio occultation experiments yielded vertical profiles of H 2 SO 4 in about the same altitude range but with a much better vertical resolution [ Jenkins et al , 1994; Kolodner and Steffes , 1998].…”

Section: Introductionmentioning

confidence: 99%

Composition of the atmosphere of Venus below the clouds

Bézard

Bérgh

2007

J. Geophys. Res.

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[1] The composition of Venus' lower atmosphere, beneath the clouds, has been investigated through both in situ measurements and remote-sensing observations. In 1978 the mass spectrometers and gas chromatographs aboard the Venera 11-12 landers and Pioneer Venus Large probe returned unique information on the abundances of carbon dioxide, nitrogen, noble gases, and other minor species. Radio occultations from the Pioneer and Magellan spacecraft provided measurements of the vertical profile of sulfuric acid vapor. In the 1980s and 1990s the discovery of near-infrared emission from the night side of Venus, through narrow spectral windows in the 0.9-2.5 micron region, opened a new opportunity of probing the lower atmosphere and surface. The abundances of water vapor, halides, carbon monoxide, sulfur dioxide, and carbonyl sulfide were determined, as well as the deuterium-to-hydrogen ratio. The vertical profile of water vapor in the 0-to 45-km-altitude range and the CO and OCS mean vertical gradients in the 30-to 40-km region have been determined from various analyses. In addition, evidence for latitudinal variations of these two species was found from Galileo and recent ground-based nightside observations. Conflicting results have been reported on the SO 2 abundance below 35 km and on the H 2 O profile below 20 km. The whole set of available measurements provides important constraints on the chemistry and dynamics of Venus' lower atmosphere. However, key information is still missing, including the abundances of CO and sulfur compounds near the surface, composition maps at high latitudes, and possible small-scale and temporal variability of trace compounds.

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“…The cloud properties (∼40 km to 60 km) are based on the Pioneer Venus project observations [ Knollenberg and Hunten , 1980; James et al , 1997]. Information on Venusian atmospheric composition under the cloud is contributed by Magellan radio occultations [ Kolodner and Steffes , 1998] and ground‐based microwave observations [ Jenkins et al , 2002], in addition to the missions mentioned above [ de Bergh et al , 2006]. The gaseous mixing ratios in Venus' mesosphere were recently updated by results delivered from the Venus Express project [ Fedorova et al , 2008; Vandaele et al , 2008], which also provides the most recent distribution of the ionosphere [ Pätzold et al , 2007].…”

Section: Introductionmentioning

confidence: 99%

X band model of Venus atmosphere permittivity

et al. 2010

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[1] A model of Venus' atmosphere permittivity profile up to 300 km is developed in this paper for X band. The model includes both the real and imaginary parts of the atmospheric permittivity, derived using data sets inferred or directly measured from past exploration missions to Venus: the real part is obtained by calculating the total polarization of the mixture of the atmospheric components including CO 2 , N 2 , H 2 O, SO 2 , H 2 SO 4 , CO, etc.; the imaginary part is derived using the superposition of the absorption of each component. The properties of the atmospheric components such as polarization and absorption are modeled with respect to frequency, temperature, and pressure. The validity of this model is verified by comparing simulation results with available measurements of Venus' atmosphere. This permittivity model is intended as a critical tool for the design of next-generation orbiting radar systems, in particular interferometric radars.

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Microwave Remote Sensing of the Temperature and Distribution of Sulfur Compounds in the Lower Atmosphere of Venus

Cited by 51 publications

References 38 publications

Effects of variation in coagulation and photochemistry parameters on the particle size distributions in the Venus clouds

Effects of variation in coagulation and photochemistry parameters on the particle size distributions in the Venus clouds

Composition of the atmosphere of Venus below the clouds

X band model of Venus atmosphere permittivity

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