The Microwave Absorption and Abundance of Sulfuric Acid Vapor in the Venus Atmosphere Based on New Laboratory Measurements

Kolodner, Marc A.; Steffes, Paul G.

doi:10.1006/icar.1997.5887

Cited by 77 publications

(74 citation statements)

References 20 publications

(11 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unfortunately, at the altitude of the cloud base of Venus, the measurement errors in radio occultation profile analysis are beginning to become quite large. Previous studies by Kolodner and Steffes (1998) indicate large vertical and meridional variations, and even significant inversions in the sulfuric acid vapor mixing ratio below cloud base. Such strong observed variations must be indicative either of a tremendous amount of vertical overturning in the subcloud region, or of significant measurement uncertainties.…”

Section: Reduced Acid Vapor Boundary Conditionmentioning

confidence: 84%

“…In all simulations presented here, I define a water vapor boundary condition of 30 ppmv at 40 km altitude (Pollack et al 1993). Similarly, a sulfuric acid boundary condition of 10 ppmv is set at 40 km altitude Kolodner and Steffes (1998), except in a subset of simulations in which this boundary condition is reduced to 5 ppmv. The top boundary condition for vapors assumes a constant mixing ratio above the top boundary.…”

Section: Vapor Boundary and Initial Conditionsmentioning

confidence: 99%

“…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%

See 2 more Smart Citations

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

McGouldrick

2017

Earth Planets Space

View full text Add to dashboard Cite

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).

show abstract

Section: Reduced Acid Vapor Boundary Conditionmentioning

confidence: 84%

Section: Vapor Boundary and Initial Conditionsmentioning

confidence: 99%

Section: Reduced Acid Vapor Boundary Conditionmentioning

confidence: 99%

See 1 more Smart Citation

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

McGouldrick

2017

Earth Planets Space

View full text Add to dashboard Cite

show abstract

“…[12] Turning from infrared to radio frequencies, radio occultation can be used to measure vertical profiles of gaseous H 2 SO 4 at altitudes down to $35 km; a recent reanalysis of six individual occultations from the Magellan and Mariner 10 orbiters found H 2 SO 4 abundances at 41 km s ranging from 0 ppm to 8 ppm [Kolodner and Steffes, 1998], and it certainly seems reasonable to suggest that a larger range of variation might be found if more occultations were analysed. The decomposition of each H 2 SO 4 molecule would yield a molecule of H 2 O, so this range of >8 ppm of H 2 SO 4 at 41 km would be expected to yield a variation of >8 ppm in water vapour abundance at this altitude, and thus is entirely consistent with the present results from VIRTIS.…”

Section: Discussionmentioning

confidence: 99%

Correlations between cloud thickness and sub‐cloud water abundance on Venus

Tsang¹,

Wilson

Barstow

et al. 2010

Geophysical Research Letters

View full text Add to dashboard Cite

[1] Past spacecraft observations of Venus have found considerable spatial and temporal variations of water vapour abundance above the clouds. Previous searches for variability below the clouds at 30-45 km altitude found no large scale latitudinal gradients, but lacked the spatial resolution to detect smaller scale variations. Here we interpret results from the VIRTIS imaging spectrometer on Venus Express, remotely sounding at near-infrared 'spectral window' wavelengths, as indicating that the water vapour abundance at 30-40 km altitude varies from 22 to 35 ppmv (±4 ppmv). Furthermore, this variability is correlated with cloud opacity, supporting the hypothesis that its genesis is linked to cloud convection. It is also possible to fit the observations without requiring spatial variation of water abundance, but this places a strong constraint on the spectral dependence of the refractive index data assumed for the lower cloud particles, for which there is as yet no supporting evidence. Citation:

show abstract

“…This expression is slightly modified from that given in Kolodner and Steffes (1998) as per M. A. Kolodner (personal communication).…”

Section: Radiative Transfer Modelingmentioning

confidence: 98%

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

Jenkins

Kolodner

Butler

et al. 2002

Icarus

View full text Add to dashboard Cite

The Microwave Absorption and Abundance of Sulfuric Acid Vapor in the Venus Atmosphere Based on New Laboratory Measurements

Cited by 77 publications

References 20 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

Correlations between cloud thickness and sub‐cloud water abundance on Venus

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

Contact Info

Product

Resources

About