Energy Transfer Processes in the Stratosphere

Taylor, Raymond L.

doi:10.1139/v74-216

Cited by 77 publications

(29 citation statements)

References 21 publications

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“…The concentrations used in the calculation are only estimates and no attempt was made to differentiate between day and night concentrations at low levels. The vibrational excitation rates used in the calculations are taken fro'm Taylor's (1974Taylor's ( , 1975 compilations, except for the use of GllInzer and Troe's (1975) and Quack and Troe's (1975) rates for excitation of nitric oxide by atomic oxygen. The results using these rates appear to confirm the suggestion made by Degges (1971) that atomic oxygen should be an important collision partner above the mesopause.…”

Section: Vibrational Temperaturesmentioning

confidence: 99%

A High Altitude Infrared Radiance Model

Degges¹,

Smith²

1974

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Approved for public release; distribution unlimited. C-- LUJ LL.AIR ii boo;=*m V 0. Abstv'act continued computes infrared radiances for an earth's limb viewing geometry. The nominal spectral region of this study lies between 2.7 and 25 -,irometers and emphasis is placed on radiation originating at alt.tudes between 70 and 500 kin. The physical model is described, with emphasis on the changes required in extending its usefulness, Application of the computer program is described. Model predictions are comp,-(.d with radiance data obtained in the ICECAP auro-al studies program.i'nis comparison is used to illustrate uncertainties in results due to ds't-mptions made in the model and lack of data on actual atmospheric cr,ý)iposition., INTRODUCTIONThe research reported here has had as its major objective the development and improvement of infrared radiance and transmission models of the atmosphere. These models are designed to simulate the radiative properties of the atmosphere to provide predictions for Air Force and other Department of Defense design and surveillance programs. Comparison with available exoerimental measurements provides greater understanding ot the atmosphere and serves to check the adequacy of the models.The main areas of effort have been 1. Extension of the applicability of a current model on non-equilibrium atmospheric infrared radiance between 2.5 and 25 microns.2. Development and improvement of thermal equilibrium models of the infrared transmission and radiance for the earth's lower atmosphere.The goal of the first area has been the further development of a computer program to simulate the natural infrared radiance background of the earth's upper atmosphere. The nominal spectral region under study lie" between 2.7 and 25 micrometerJ a4nd emphasis is placed on radiation originatinq at altitudes between 7t) and 500 kilometers, The general problem area is of interest for systems design, military surveillance and the advancement of knowledge about physical processes in the upper atmosphcre. The immediate application of this work is to aid in developin9 optimum infrared background measurements programs and in interpreting the results of su,.h measurements..This work is an extension of the study of Corbin, et al (1969) and Degges (1972Degges ( , 1974. The fomner investigated the natural infrared backqround of the earth in 5 to 25 micrometer' spectral reqion, with the goal of estimating earth 1imb viewingi radiances for tangent heights from the surface to 500 kti altitude. For convenience, their study divided the atmosphere into two regions with a division at 70 km. Below 70 km the atmosphere was assumed to be in thermal equilibrium. Above 70 km explicit calculations were made of processes which excite and de-excite mullectia vibrational and rotational levels which are the sou.-ce )f infrared radiation, Their study concentrated on radiation from water vapor, carbon dioxide, ozone, nitric oxide and nitrous oxide, which are principal radiating species in the spectral region considered. In addition, ni...

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Section: Vibrational Temperaturesmentioning

confidence: 99%

A High Altitude Infrared Radiance Model

Degges¹,

Smith²

1974

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“…The room temperature value of the rate coefficient k ATM for the exothermic process derived by modeling the 15 µm emission, observed by the Spectral Infrared Rocket Experiment (SPIRE) (Stair et al, 1985) from the MLT region of the atmosphere, is 5×10 −13 cm 3 s −1 (Sharma and Nadile, 1981), 5.2 × 10 −12 cm 3 s −1 (Stair et al, 1985), 3.5 × 10 −12 cm 3 s −1 (Sharma, 1987), and (3 − 9) × 10 −12 cm 3 s −1 (Sharma and Wintersteiner, 1990). These studies gave values of k ATM that are 1-2 orders of magnitude greater than values recommend earlier (Crutzen, 1970;Taylor, 1974). Later analyses of space-based observations have given values around 6×10 −12 (cm 3 s −1 ) Ratkowski et al, 1994;Gusev et al, 2006;Feofilov et al, 2012, and references therein), except for the Vollmann and Grossmann (1997) study giving a value of 1.5 × 10 −12 (cm 3 s −1 ).…”

Section: Introductionmentioning

confidence: 80%

Technical Note: On the possibly missing mechanism of 15 μm emission in the mesosphere–lower thermosphere (MLT)

Sharma

2015

Atmos. Chem. Phys.

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Abstract. Accurate knowledge of the rate as well as the mechanism of excitation of the bending mode of CO 2 is necessary for reliable modeling of the mesosphere-lower thermosphere (MLT) region of the atmosphere. Assuming the excitation mechanism to be thermal collisions with atomic oxygen, the rate coefficient derived from the observed 15 µm emission by space-based experiments (k ATM = 6.0 × 10 −12 cm 3 s −1 ) differs from the laboratory measurements (k LAB = (1.5−2.5)×10−12 cm 3 s −1 ) by a factor of 2-4. The general circulation models (GCMs) of Earth, Venus, and Mars have chosen to use a median value of k GCM = 3.0 × 10 −12 cm 3 s −1 for this rate coefficient. As a first step to resolve the discrepancies between the three rate coefficients, we attempt to find the source of disagreement between the first two. It is pointed out that a large magnitude of the difference between these two rate coefficients (k x ≡ k ATM − k LAB ) requires that the unknown mechanism involve one or both major species: N 2 , O. Because of the rapidly decreasing volume mixing ratio (VMR) of CO 2 with altitude, the exciting partner must be long lived and transfer energy efficiently. It is shown that thermal collisions with N 2 , mediated by a near-resonant rotation-to-vibration (RV) energy transfer process, while giving a reasonable rate coefficient k VR for deexcitation of the bending mode of CO 2 , lead to vibration-totranslation k VT rate coefficients in the terrestrial atmosphere that are 1-2 orders of magnitude larger than those observed in the laboratory. It is pointed out that the efficient nearresonant rotation-to-vibration (RV) energy transfer process has a chance of being the unknown mechanism if very high rotational levels of N 2 , produced by the reaction of N and NO and other collisional processes, have a super-thermal population and are long lived. Since atomic oxygen plays a critical role in the mechanisms discussed here, it suggested that its density be determined experimentally by ground-and spacebased Raman lidars proposed earlier.

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“…vv u vv nY r k n m g À1 Y h is the di usion coe cient of the vibrationally excited nitrogen molecules, m denotes the mass of N 2 , g is the acceleration due to gravity, i 1 3353 K, the rate coe cients of the vibrational-translational energy exchange N 2 j 1 ±O is measured by McNeal et al (1974) and can be approximated as u 1 vt 1X07 Á 10 À10 exp À69X9 À1a3 n cm 3 s À1 by use of the theory of this energy exchange, the rate coe cients of the vibrational-translational energy exchange N 2 j 1 ±O 2 is given by Gilmore et al (1969) as u 2 vt 3X6 Á 10 À12 0X5 n exp À110 À1a3 n cm 3 s À1 , for the vibrational-vibrational energy exchange of x 2 j 1 with CO 2 Taylor (1974) presented u m 1X7 Á 10 À6 exp À175 À1a3 n 6X2 Á 10 À14 exp À15X13 À1a3 n cm 3 s À1 , the rate coe cients of the vibrational-vibrational energy exchange of N 2 j 1 with x 2 j 0 is measured by Suchkov and Schebeko (1981) as u vv 5X2 Á 10 À10 À3a2 n cm 3 s À1 X It is required to know the value of n 6 to calculate the value of n 5 from Eqs. (A19, A20), and the condition n 6 0 was assumed.…”

Section: Energy Balance Equations For Ions and Electronsmentioning

confidence: 99%

Subauroral red arcs as a conjugate phenomenon: comparison of OV1-10 satellite data with numerical calculations

Павлов

1997

Ann. Geophys.

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Abstract. This study compares the OV1-10 satellite measurements of the integral airglow intensities at 630 nm in the SAR arc regions observed in the northern and southern hemisphere as a conjugate phenomenon, with the model results obtained using the time-dependent one-dimensional mathematical model of the Earth ionosphere and plasmasphere (the IZMIRAN model) during the geomagnetic storm of the period 15±17 February 1967. The major enhancements to the IZ-MIRAN model developed in this study are the inclusion of He ions (three major ions: O , H , and He , and three ion temperatures), the updated photochemistry and energy balance equations for ions and electrons, the di usion of NO and O 2 ions and O 1 D and the revised electron cooling rates arising from their collisions with unexcited N 2 Y O 2 molecules and N 2 molecules at the ®rst vibrational level. The updated model includes the option to use the models of the Boltzmann or nonBoltzmann distributions of vibrationally excited molecular nitrogen. Deviations from the Boltzmann distribution for the ®rst ®ve vibrational levels of N 2 were calculated. The calculated distribution is highly nonBoltzmann at vibrational levels v b 2 and leads to a decrease in the calculated electron density and integral intensity at 630 nm in the northern and southern hemispheres in comparison with the electron density and integral intensity calculated using the Boltzmann vibrational distribution of N 2 . It is found that the intensity at 630 nm is very sensitive to the oxygen number densities. Good agreement between the modeled and measured intensities is obtained provided that at all altitudes of the southern hemisphere a reduction of about factor 1.35 in MSIS-86 atomic oxygen densities is included in the IZMIRAN model with the non-Boltzmann vibrational distribution of N 2 . The e ect of using of the O 1 D di usion results in the decrease of 4±6% in the calculated integral intensity of the northern hemisphere and 7±13% in the calculated integral intensity of the southern hemisphere. It is found that the modeled intensities of the southern hemisphere are more sensitive to the assumed values of the rate coe cients of O 4 S ions with the vibrationally excited nitrogen molecules and quenching of O 2 D by atomic oxygen than the modeled intensities of the northern hemisphere.

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Energy Transfer Processes in the Stratosphere

Cited by 77 publications

References 21 publications

A High Altitude Infrared Radiance Model

A High Altitude Infrared Radiance Model

Technical Note: On the possibly missing mechanism of 15 μm emission in the mesosphere–lower thermosphere (MLT)

Subauroral red arcs as a conjugate phenomenon: comparison of OV1-10 satellite data with numerical calculations

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