scholarly journals Enhancement of odd nitrogen modifies mesospheric ozone chemistry during polar winter

2015 ◽  
Vol 42 (23) ◽  
Author(s):  
P. T. Verronen ◽  
R. Lehmann
Keyword(s):  
Mesospheric Ozone ◽  
Odd Nitrogen

HOx, NOx, and ClOx: Their Role in Atmospheric Photochemistry

1974 ◽  
Vol 52 (8) ◽  
pp. 1582-1591 ◽  
Author(s):  
Steven C. Wofsy ◽  
Michael B. McElroy
Keyword(s):  
Gas Phase ◽  
Phase Reaction ◽  
Dominant Form ◽  
Supersonic Aircraft ◽  
Mesospheric Ozone ◽  
Ozone Photochemistry ◽  
Odd Nitrogen ◽  
Good Agreement ◽  
Odd Oxygen

Sources of atmospheric odd nitrogen and hydrogen are reviewed and their role m ozone photochemistry is discussed. A model, containing few adjustable parameters, gives good agreement with observed distributions of stratospheric and mesospheric ozone. Nitric oxide emitted by supersonic aircraft would lead to a significant reduction in the concentration of atmospheric ozone if the globally averaged source of NO should exceed 2 × 107 molecules cm−2 s−1. A traffic model projected by Broderick etal. for 1990 could lead to a reduction of about 2% in the column density of O3.Sources of atmospheric chlorine are discussed. It is argued that HCl should be the dominant form of atmospheric chlorine and that it is produced mainly from aerosols of marine origin. The atmospheric source strength is about 2 × 108 tons per year according to Chesselet etal. and HCl may be removed by gas phase reaction with NH3. The role of chlorine compounds as a catalyst for recombination of odd oxygen is discussed and shown to play no major role in the normal atmosphere. Reactions of OH and HO2 with O3 may provide an important sink for tropospheric odd oxygen such that O3 may not be a passive tracer for tropospheric motions.

scholarly journals Penetration of MeV electrons into the mesosphere accompanying pulsating aurorae

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Y. Miyoshi ◽  
K. Hosokawa ◽  
S. Kurita ◽  
S.-I. Oyama ◽  
Y. Ogawa ◽  
...  
Keyword(s):  
High Energy ◽  
Daily Basis ◽  
Maximum Energy ◽  
Energy Electron ◽  
High Energy Electron ◽  
Whistler Mode ◽  
Chorus Waves ◽  
Mesospheric Ozone ◽  
Field Lines ◽  
Eiscat Radar

AbstractPulsating aurorae (PsA) are caused by the intermittent precipitations of magnetospheric electrons (energies of a few keV to a few tens of keV) through wave-particle interactions, thereby depositing most of their energy at altitudes ~ 100 km. However, the maximum energy of precipitated electrons and its impacts on the atmosphere are unknown. Herein, we report unique observations by the European Incoherent Scatter (EISCAT) radar showing electron precipitations ranging from a few hundred keV to a few MeV during a PsA associated with a weak geomagnetic storm. Simultaneously, the Arase spacecraft has observed intense whistler-mode chorus waves at the conjugate location along magnetic field lines. A computer simulation based on the EISCAT observations shows immediate catalytic ozone depletion at the mesospheric altitudes. Since PsA occurs frequently, often in daily basis, and extends its impact over large MLT areas, we anticipate that the PsA possesses a significant forcing to the mesospheric ozone chemistry in high latitudes through high energy electron precipitations. Therefore, the generation of PsA results in the depletion of mesospheric ozone through high-energy electron precipitations caused by whistler-mode chorus waves, which are similar to the well-known effect due to solar energetic protons triggered by solar flares.

scholarly journals Comparison of ozone profiles and influences from the tertiary ozone maximum in the night-to-day ratio above Switzerland

2017 ◽  
Vol 17 (17) ◽  
pp. 10259-10268 ◽  
Author(s):  
Lorena Moreira ◽  
Klemens Hocke ◽  
Niklaus Kämpfer
Keyword(s):  
Annual Variation ◽  
Lower Stratosphere ◽  
Microwave Radiometer ◽  
Relative Difference ◽  
Atmospheric Composition ◽  
Composition Change ◽  
Ozone Maximum ◽  
Ozone Profile ◽  
Mesospheric Ozone ◽  
The Mean

Abstract. Stratospheric and middle-mesospheric ozone profiles above Bern, Switzerland (46.95° N, 7.44° E; 577 m) have been continually measured by the GROMOS (GROund-based Millimeter-wave Ozone Spectrometer) microwave radiometer since 1994. GROMOS is part of the Network for the Detection of Atmospheric Composition Change (NDACC). A new version of the ozone profile retrievals has been developed with the aim of improving the altitude range of retrieval profiles. GROMOS profiles from this new retrieval version have been compared to coincident ozone profiles obtained by the satellite limb sounder Aura Microwave Limb Sounder (MLS). The study covers the stratosphere and middle mesosphere from 50 to 0.05 hPa (from 21 to 70 km) and extends over the period from July 2009 to November 2016, which results in more than 2800 coincident profiles available for the comparison. On average, GROMOS and MLS comparisons show agreement generally over 20 % in the lower stratosphere and within 2 % in the middle and upper stratosphere for both daytime and nighttime, whereas in the mesosphere the mean relative difference is below 40 % during the daytime and below 15 % during the nighttime. In addition, we have observed the annual variation in nighttime ozone in the middle mesosphere, at 0.05 hPa (70 km), characterized by the enhancement of ozone during wintertime for both ground-based and space-based measurements. This behaviour is related to the middle-mesospheric maximum in ozone (MMM).

Losses and transport of odd nitrogen species(NOy) over the western Atlantic Ocean during GCE/CASE/WATOX

1990 ◽  
Vol 4 (3) ◽  
pp. 279-295 ◽  
Author(s):  
John D. Ray ◽  
Menachem Luria ◽  
Donald R. Hastie ◽  
Sue Malle ◽  
William C. Keene ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Nitrogen Species ◽  
Western Atlantic ◽  
Western Atlantic Ocean ◽  
Odd Nitrogen

scholarly journals Ground-Based Millimeterwave Measurements of Strato-Mesospheric Ozone.

1996 ◽  
Vol 48 (3) ◽  
pp. 353-360 ◽  
Author(s):  
Kin-aki Kawabata ◽  
Hideo Ogawa ◽  
Yoshinori Yonekura
Keyword(s):  
Mesospheric Ozone

scholarly journals Mesospheric Ozone Density Profile in the Polar Region.

1997 ◽  
Vol 49 (5) ◽  
pp. 675-688 ◽  
Author(s):  
Hiromasa Yamamoto ◽  
Ken-ichi Yajima ◽  
Hiroyuki Sekiguchi ◽  
Tadao Makino
Keyword(s):  
Density Profile ◽  
Polar Region ◽  
Mesospheric Ozone

A mid-latitude balloon-borne observation of total odd nitrogen

1990 ◽  
Vol 17 (1) ◽  
pp. 73-76 ◽  
Author(s):  
Y. Kondo ◽  
P. Aimedieu ◽  
W. A. Matthews ◽  
W. R. Sheldon ◽  
J. R. Benbrook
Keyword(s):  
Odd Nitrogen

The Oxides of Nitrogen: Their Relation to Tropospheric Ozone

2015 ◽  
Author(s):  
Jack G. Calvert ◽  
John J. Orlando ◽  
William R. Stockwell ◽  
Timothy J. Wallington
Keyword(s):  
Tropospheric Ozone ◽  
Anthropogenic Activity ◽  
N2o Emissions ◽  
Nox Emissions ◽  
Oxides Of Nitrogen ◽  
Assessment Report ◽  
Natural Emissions ◽  
Gas Phase Oxidation ◽  
Odd Nitrogen

Reactive (or “odd”) nitrogen is emitted into the atmosphere in a variety of forms, with the most important being NOx (NO and NO2), ammonia (NH3), and nitrous oxide (N2O). Emissions of these species into the atmosphere have been summarized, for example, by the IPCC Fourth Assessment Report (the AR4; IPCC, 2007). Some discussion of NOx emissions and trends has also been presented in Chapter I. Emissions of NOx are mainly the result of anthropogenic activity associated with fossil fuel combustion and industrial activity. For the 1990s, the AR4 estimates total anthropogenic NOx emissions of 33.4 TgN yr−1, with natural emissions (mostly from soil and lightning) accounting for an additional 8.4–13.7 TgN yr−1. Ammonia emissions are comparable in magnitude to those for NOx, with anthropogenic emissions (45.5 TgN yr−1) again exceeding natural emissions (10.6 TgN yr−1). Although the majority of the ammonia produces aerosols or is scavenged by aerosol and is subsequently lost from the atmosphere, some gas phase oxidation does occur, which can in part lead to NOx production. The N2O source strength is about 17.7 TgN yr−1, with natural sources outweighing anthropogenic ones (IPCC, 2007). However, N2O is essentially inert in the troposphere, and thus the vast majority of its photooxidation and concomitant NOx release occurs in the stratosphere. The major NOx − related reactions occurring in the Earth’s troposphere are summarized in Figure III-A-1. As just alluded to, the species NO and NO2 are jointly referred to as NOx and are often treated collectively. This is because, under daytime conditions, these two species are rapidly interconverted, with the interconversion occurring on a much shorter timescale than the loss of either species.

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