The global lightning-induced nitrogen oxides source

Abstract

Abstract. The knowledge of the lightning-induced nitrogen oxides (LNO x ) source is important for understanding and predicting the nitrogen oxides and ozone distributions in the troposphere and their trends, the oxidising capacity of the atmosphere, and the lifetime of trace gases destroyed by reactions with OH. This knowledge is further required for the assessment of other important NO x sources, in particular from aviation emissions, the stratosphere, and from surface sources, and for understanding the possible feedback between climate changes and lightning. This paper reviews more than 3 decades of research. The review includes laboratory studies as well as surface, airborne and satellite-based observations of lightning and of NO x and related species in the atmosphere. Relevant data available from measurements in regions with strong LNO x influence are identified, including recent observations at midlatitudes and over tropical continents where most lightning occurs. Various methods to model LNO x at cloud scales or globally are described. Previous estimates are re-evaluated using the global annual mean flash frequency of 44±5 s −1 reported from OTD satellite data. From the review, mainly of airborne measurements near thunderstorms and cloud-resolving models, we conclude that a "typical" thunderstorm flash produces 15 (2-40)×10 25 NO molecules per flash, equivalent to 250 mol NO x or 3.5 kg of N mass per flash with uncertainty factor from 0.13 to 2.7. Mainly as a result of global model studies for various LNO x parameterisations tested with related observations, the best estimate of the annual global LNO x nitrogen mass source and its uncertainty range is (5±3) Tg a −1 in this study. In spite of a smaller global flash rate, the best estimate is essentially the same as in some earlier reviews, implying larger flash-specific NO x emissions. The paper estimates the LNO x accuracy required for various applications and lays out strategies for improving estimates in the future. An accuracy of Correspondence to: U. Schumann (ulrich.schumann@dlr.de) about 1 Tg a −1 or 20%, as necessary in particular for understanding tropical tropospheric chemistry, is still a challenging goal.

Earth System Chemistry integrated Modelling (ESCiMo) with the Modular Earth Submodel System (MESSy) version 2.51

“…Estimates for the annual total emissions of NO x from lightning are in the range of 2-8 Tg (N) a −1 (see Schumann and Huntrieser, 2007). In Fig.…”

Systematic analysis of tropospheric NO<sub>2</sub> long-range transport events detected in GOME-2 satellite data

“…Schumann and Huntrieser (2007) report that approximately 5±3 TgN/a may originate from NO x emitted by lightning (LiNO x ). Ott et al (2010) show that NO x concentrations in thunderstorm clouds may be higher than 10 ppbv.…”

A Review of Low Frequency Electromagnetic Wave Phenomena Related to Tropospheric-Ionospheric Coupling Mechanisms

“…The global lightning average rate is 44±5 s -1 , reaching a maximum of ~200 strokes per square kilometer per year in Central Africa (geographic coordinates 3 S, 28 E). Individual thunderstorms can deliver up to about 6000 strokes per hour (e.g., Rakov and Uman, 2007;Schumann and Huntrieser, 2007). Relevant characteristics of individual lightning involves flash duration, number of return strokes per flash, charge quantity per flash and per stroke, duration and intensity of continuing current, time to peak and return stroke current, etc.…”

“…NO x radicals can be also produced by ionospheric particle precipitation in the stratosphere and mesosphere. Schumann and Huntrieser (2007) Maximum electric fields measured in thunderclouds are 0.1-0.2 MVm -1 , a fraction of the 1 MVm -1 conventional breakdown. To overcome the lack of electric field strength, two mechanisms are usually invoked for lightning initiation: (i) runaway breakdown initiated by cosmic rays (e.g., Gurevich and Zybin, 2001) and (ii) positive streamers triggered by hydrometeors, i.e., products resulting from atmospheric water vapor condensation (e.g., Petersen et al, 2008).…”