Accurate and Consistent Microwave Observations of Venus and Their Implications

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

doi:10.1006/icar.2001.6710

Cited by 58 publications

(51 citation statements)

References 48 publications

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“…Figure 3 and Table 4 compile all available measurements of brightness temperature of Venus in the wavelength range from 0.013 m (22.46 GHz) to 1.25 m (239.3 MHz), including the ones obtained by us. Figure 3 also includes the model by Butler et al (2001). Our observations clearly indicate that T b,cor decreases with increasing wavelength beyond ∼ 0.5 m, in contrast to the model which remains practically flat beyond ∼0.06 m.…”

Section: Resultsmentioning

confidence: 70%

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Radio observation of Venus at meter wavelengths using the GMRT

Mohan

Roy

Swarup

et al. 2017

Icarus

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The Venusian surface has been studied by measuring radar reflections and thermal radio emission over a wide spectral region of several centimeters to meter wavelengths from the Earth-based as well as orbiter platforms. The radiometric observations, in the decimeter (dcm) wavelength regime showed a decreasing trend in the observed brightness temperature (T b ) with increasing wavelength. The thermal emission models available at present have not been able to explain the radiometric observations at longer wavelength (dcm) to a satisfactory level. This paper reports the first interferometric imaging observations of Venus below 620 MHz. They were carried out at 606, 332.9 and 239.9 MHz using the Giant Meterwave Radio Telescope (GMRT). The T b values derived at the respective frequencies are 526 K, 409 K and < 426 K, with errors of ∼7% which are generally consistent with the reported T b values at 608 MHz and 430 MHz by previous investigators, but are much lower than those derived from high-frequency observations at 1.38-22.46 GHz using the VLA.

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Section: Resultsmentioning

confidence: 70%

“…Magellan (Pettengill et al, 1991); Venus Express (Markiewicz et al, 2007) (ii) Venera and Vegas Landers (Vinogradov et al, 1976;Florenskii et al, 1982;Basilevsky et al, 1986), and (iii) radar and radio observations made from the Earth (Campbell et al, 1989;Condon et al, 1973;Muhleman et al, 1973;Butler et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Radio observation of Venus at meter wavelengths using the GMRT

Mohan

Roy

Swarup

et al. 2017

Icarus

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“…Laboratory measurements in 14 a CO₂ atmosphere with 300 ppm SO₂ at 435 K and up to 92 bars (Steffes et al 2015), observations 15 of Venus atmospheric opacity at wavelengths of 3·1 cm, 10·6 cm and longer (Muhleman 1969), 16 and more recent observational data at wavelengths between 1·3 and 22·6 cm (Butler 2001), lead 17 to a reasonable approximation to the expected one-way atmospheric losses in dB as simply onetenth of the square of the frequency in GHz ( Figure 5). For InSAR, relative phase shifts caused by 19 variability in the concentration of sulphuric acid droplets in the clouds are more severe at shorter 20 wavelengths.…”

Section: Magellan Sar Image With False Colour Metre-scale Slope As a mentioning

confidence: 80%

VenSAR on EnVision: Taking earth observation radar to Venus

Ghail

Hall

Mason

et al. 2018

International Journal of Applied Earth Observation and Geoinfor

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“…The few existing measurements of gaseous H 2 SO 4 below the clouds show great spatial and temporal variability [Butler et al, 2001]. There is a net transport of H 2 SO 4 from the cloud-tops, where it is formed by the action of solar UV photons on gaseous SO 2, CO 2 and H 2 O, to the sub-cloud atmosphere where it dissociates at altitudes of 35-45 km due to the high temperatures to form H 2 O and SO 3 [Krasnopolsky and Pollack, 1994].…”

Section: Discussionmentioning

confidence: 99%

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

Tsang¹,

Wilson

Barstow

et al. 2010

Geophysical Research Letters

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[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:

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Accurate and Consistent Microwave Observations of Venus and Their Implications

Cited by 58 publications

References 48 publications

Radio observation of Venus at meter wavelengths using the GMRT

Radio observation of Venus at meter wavelengths using the GMRT

VenSAR on EnVision: Taking earth observation radar to Venus

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

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