Abundances of cloud-related gases in the Venus atmosphere as inferred from observed radio opacity

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1982

OSTI ID:6182943

Steffes, P G

Various radio-analytical techniques have detected microwave opacity in the middle atmosphere of Venus, well above the main carbon dioxide opacity of the lower atmosphere. Consideration of the amount, distribution, and effects of the constituents which produce the main cloud layer at about 50 km altitude, indicate that such cloud-related gases, especially sulfuric acid vapor, are the predominant source of the observed opacity of the middle atmosphere. Theoretical and laboratory studies were made of the microwave absorption from three cloud-related gases: sulfur dioxide, sulfur trioxide, and gaseous sulfuric acid. While the measured absorption from sulfur dioxide under conditions for the middle atmosphere of Venus was found to be 50% larger than suggested by theory, the amount of sulfur dioxide required to explain the opacity as measured by radio occulation exceeded the abundance measured in situ by atmospheric probes, suggesting that there must be another important source of opacity. Sulfur trioxide was tested and found to be relatively transparent, but laboratory measurements of the microwave opacity of gaseous sulfuric acid under Venus atmospheric conditions indicate that it is an exceptionally strong absorber with absorptivity that has a surprisingly weak dependence on radio frequency. Initial theoretical studies also indicate a large absorptivity and weak frequency dependence, although the measured opacity is larger than the computed value, presumably due to deviations from Van Vleck-Weisskopf theory.

• Research Organization: Stanford Univ., CA (USA)
• OSTI ID: 6182943
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
ATMOSPHERES
CHALCOGENIDES
ELECTROMAGNETIC RADIATION
FLUIDS
GASES
HYDROGEN COMPOUNDS
INORGANIC ACIDS
OPACITY
OPTICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PLANETARY ATMOSPHERES
PLANETS
RADIATIONS
RADIOWAVE RADIATION
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
SULFUR TRIOXIDE
SULFURIC ACID
VENUS PLANET