Climatology of nitric oxide in the upper stratosphere, mesosphere, and thermosphere: 1979 through 1986

Abstract

Spectral scan data from the solar backscattered ultraviolet (SBUV) instrument on Nimbus 7 for the wavelength range 200–400 nm have been analyzed to determine the strengths of several of the nitric oxide (NO) gamma band fluorescence features as a function of time and of latitude. The integrated column amount of nitric oxide above an altitude of approximately 45–50 km is inferred from analysis of the strengths of the (10), (01), and (02) nitric oxide gamma bands. Analysis shows that there are about 5 – 6 × 1014 molecules cm−2 of nitric oxide cumulative above 48 km over a wide range of latitudes, increasing sharply near the winter terminator by about a factor of 3 to 12 – 15 × 1014 molecules cm−2. Between 1979 and 1986, column NO near the equator decreased by about a factor of 2, from 6.4 × 1014 molecules cm−2 to 3.3 × 1014 molecules cm−2. The time dependence of the decrease correlates well with solar activity, following the decline in solar activity from solar maximum in 1979 to solar minimum in 1985–1986. At middle and high latitudes, NO appears to have reached a maximum in 1982–1983, a few years after the solar cycle maximum, and has decreased since, but the magnitude of the trend is smaller.

Spectral measurements of PMCs from SBUV/2 instruments

“…We have examined the potential impact of NO on our observations using a synthetic spectrum with a NO vertical column abundance of 1 Â 10 15 cm À2 (Stevens et al, 1997) and vibrational g-factors from Stevens (1995). The maximum impact is approximately 4-5% at 255 nm, consistent with the results of McPeters (1989). The magnitude at 252.5 nm is approximately 1-2%, which is within the smallscale noise of the albedo spectrum.…”

“…2 also includes several strong peaks due to nitric oxide (NO) gamma band fluorescence. McPeters (1989) discusses the analysis of Nimbus-7 SBUV continuous scan data to determine an upper atmosphere NO climatology covering the period 1979-1986. The NO g-band spectrum includes the g(1,4) band at 255 nm and a weaker band at 252.5 nm, which could affect the SBUV/2 PMC detection algorithm.…”

Chlorine in the stratosphere

“…Empirical counterevidence does not lead to the rejection of the hard core of the theory, but simply removes this particular application from the list of valid applications. The theory of subsiding NO x -rich air from higher altitudes as postulated by Callis and Natarajan (1986) is a typical example: Mesospheric air is clearly affected by the solar cycle (McPeters, 1989), and there is evidence of subsidence (e.g., Callis et al, 1996). This theory just failed to explain the ozone hole (c.f.…”

Polar thermosphere-stratosphere photochemical coupling experiment: Two rocket measurements in polar winter at 69°N

“…Solomon et al, 1982;Brasseur, 1993). McPeters (1989) investigated the NO column abundance above 1 mb (about 48 km) based on the SBUV data of Nimbus 7, and found a maximum column abundance in winter at high latitude of 2 × 10 15 cm -2 . The NO column abundances above 50 km found by the present two experiments are comparable to this value if densities of 5 × 10 8 cm -3 are assumed between 48 and 70 km.…”