On the efficiency of solar heating in the middle atmosphere

Journal Article · Mon Jul 01 04:00:00 EDT 1991 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/91GL01525· OSTI ID:5407290

Mlynczak, M G ^[1]; Solomon, S

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1. NASA Langley Research Center, Langley AFB, VA (United States)

The authors calculate the efficiency at which solar ultraviolet radiation absorbed in the Hartley band of ozone is directly converted to heat in the terrestrial mesosphere and lower thermosphere (50-110 km). The ozone molecule undergoes photolysis to yield the excited species O({sup 1}D) and O{sub 2}({sup 1}{Delta}) with a quantum yield of about 0.9. Spontaneous emission from O{sub 2}({sup 1}{Delta}) and from O{sub 2}({sup 1}{Sigma}) (excited by energy transfer from O({sup 1}D)) significantly decreases the amount of energy available for heat. Similarly, they calculate the efficiency at which solar ultraviolet radiation absorbed by O{sub 2} in the Schumann-Runge continuum is directly converted to heat in the lower thermosphere (95 - 110 km). The O{sub 2} undergoes photolysis and the excited product O({sup 1}D) is generated. Spontaneous emission from O{sub 2}({sup 1}{Sigma}) (excited by energy transfer from O({sup 1}D)) reduces the amount of energy available for heat in the lower thermosphere. The consideration of these energy transfer and loss processes results in significantly reduced heating rates as compared to those conventionally calculated in models of the middle atmosphere.

• OSTI ID: 5407290
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 18:7; ISSN GPRLA; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
ABSORPTION
CHEMICAL REACTIONS
CONVERSION
DECOMPOSITION
EARTH ATMOSPHERE
EFFICIENCY
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY CONVERSION
ENERGY TRANSFER
ENERGY-LEVEL TRANSITIONS
EXCITATION
HEATING
MESOSPHERE
NONMETALS
OXYGEN
OZONE
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
RADIATIONS
SOLAR ENERGY CONVERSION
SOLAR HEATING
SORPTIVE PROPERTIES
SURFACE PROPERTIES
THERMOSPHERE
ULTRAVIOLET RADIATION