Temperature dependence of O(1 D ) rate constants for reactions with O2, N2, CO2, O3, and H2O

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.

Section: Energy Balance Equations For Ions and Electronssupporting

confidence: 79%

“…Streit et al (1976) reported that the measured rate coe cient c j c j . Tully (1974) developed a classic collision complex model to describe production of N 2 j in these reactions.…”

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

“…where is the production rate (Streit et al, 1976), u 3 2X5 Á 10 À12 cm 3 s À1 is the rate coecient for quenching of O 1 D by atomic oxygen (Sobral et al, 1993). In the SAR arc region, O 1 D are produced mainly by excitation of O 3 P by thermal electron impact (Kozyra et al, 1997).…”

Section: Introductionmentioning

confidence: 99%

Correlations between SAR arc intensity and solar and geomagnetic activity

Lobzin

Павлов

1999

Abstract. We present a study of statistical relationships between SAR arc intensities acquired by the Paci®c Northwest Laboratory Photometer Network during 1978±1988 and solar and geomagnetic activity indices hstY p 10X7, and Kp by use of the method of multiple regression analysis. We found signi®cant correlations between intensity and all of the indices involved. In the present work we show for the ®rst time that the partial correlation coecients depend on the time oset, t, between the time of SAR arc intensity observations and the onset of the geomagnetic storm recovery phase, with the largest correlations being observed when 8 h t 16 h. It is also shown that there are signi®cant dierences between partial correlation coecients calculated for SAR arcs associated with strong hst min À100 nT and weak hst min b À100 nT geomagnetic storms. We observe also that the multiple correlation coecients for strong storms are much larger than for weak ones. We found that the variations in the electron temperature, e , in the SAR arc region are not mainly produced by variations in the electron density of the ionosphere but are strongly driven by the additional heating of the electron gas due to an interaction of the ring current ions and the plasmaspheric electrons. As a result, variations of e in the SAR arc region with characteristic time scales from several minutes to several hours are stipulated by time variations of ring current parameters.Key words. Atmospheric composition and structure (airglow and aurora) á Ionosphere (ionosphere± atmosphere interactions; ionosphere±magnetosphere interactions).

“…Besides that, energy transfer from O( 1 D) to O 2 leads to the formation of electronicallyvibrationally excited molecules O 2 (b 1 + g , v) (Streit et al, 1976;Lee and Slanger, 1978). Mlynczak et al (1993) supposed that vibrational kinetics can be neglected, which is possible only if the processes of vibrational-vibrational (V-V) and vibrational-translational (V-T) energy transfer between vibrational sublevels of electronic states are much faster than collisional deactivation of electronically excited states.…”

Section: Introductionmentioning

confidence: 99%

“…O 2 +hν(SRC)→O( 3 P)+O( 1 D) 2.60×10 −6 1.0 Rodrigo et al (1986), DeMore et al (1997) O 2 +hν(Lyman-α)→O( 3 P)+O( 1 D) 3.40×10 −9 0.48-0.58 Rodrigo et al (1986), Reddmann and Uhl (2003) O 3 +hν→O 2 (X, v=0-35 Streit et al (1976), Lee and Slanger (1978), Green et al (2000) O ( …”

Section: Introductionmentioning

confidence: 99%

Model of daytime emissions of electronically-vibrationally excited products of O3 and O2 photolysis: application to ozone retrieval

Yankovsky

Manuilova

2006

(X 3 − g , v). In contrast to the previous models of kinetics of O 2 (a 1 g ) and O 2 (b 1 + g ), our model takes into consideration the following basic facts: first, photolysis of O 3 and O 2 and the processes of energy exchange between the metastable products of photolysis involve generation of oxygen molecules on highly excited vibrational levels in all considered electronic states -b 1 + g , a 1 g and X 3 − g ; second, the absorption of solar radiation not only leads to populating the electronic states on vibrational levels with vibrational quantum number v equal to 0 -O 2 (b 1 + g , v=0) (at 762 nm) and O 2 (a 1 g , v=0) (at 1.27 µm), but also leads to populating the excited electronicvibrational states O 2 (b 1 + g , v=1) and O 2 (b 1 + g , v=2) (at 689 nm and 629 nm). The proposed model allows one to calculate not only the vertical profiles of the O 2 (a 1 g , v=0) and O 2 (b 1 + g , v=0) concentrations, but also the profiles of2)] and O 2 (X 3 − g , v=1-35). In the altitude range 60-125 km, consideration of the electronic-vibrational kinetics significantly changes the calculated concentrations of the metastable oxygen molecules and reduces the discrepancy between the altitude profiles of ozone concentrations retrieved from the 762-nm and 1.27-µm emissions measured simultaneously.