Atmospheric and Space Electricity [AE]

AE21A MCC:3020 Tuesday 0800h

Thunderstorms, Lightning, and Atmospheric Chemistry

Presiding:T Fehr, DLR Institut fuer Physik der Atmosphaere; P LaRoche, Office National d'Etudes et de Recherches Aerospatiale (ONERA)

AE21A-01 08:00h

Surface Observation of NO$_{x}$ Produced by Lightning in Qinghai-Tibetan Plateau of China

* Qie, X (qiex@ns.lzb.ac.cn) , Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, w. 260 Donggang Road, Lanzhou, 730000 China
Zhou, Y (zhouyj@ns.lzb.ac.cn) , Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, w. 260 Donggang Road, Lanzhou, 730000 China

The global production of nitrogen oxides are important for understanding many aspects of global atmospheric chemistry and the overall nitrogen cycle of the earth. But the production of NO$_{x}$ by lighting represents the largest uncertainty in the global NO$_{x}$ budget with varying by over two orders of magnitude. The global annual lightning-produced NO$_{x}$ budget is difficult to be estimated accurately without better understanding of the regional production of NO$_{x}$ by lightning and its role in regional atmospheric chemistry because lightning production is non-homogeneous in space and time. Here we present the surface observation of lightning-produced NO$_{x}$ on Qinghai-Tibetan Plateau, where no obvious artificial NO$_{x}$ sources and electromagnetic disturbance. The NOx concentration, average electric field, and types of lightning flashes have been observed in two sites of the Tibetan Plateau, Datong (2600m asl) in northeastern Qinghai province and Naqu (4500m asl) in northern Tibetan, by using NO$_{x}$ analyzer, electric field mill, as well as fast antenna system. In the stable atmospheric stratification of fine day, the values of NO$_{x}$ concentration and average electric field did not show visible variation. During thunderstorms, the peaks on surface NO$_{x}$ concentration are good correlated to lightning flashes, but with a distinct time lag between the NO$_{x}$ peak and the corresponding lightning flash. A linear correlation has been found between the increase of NO$_{x}$ concentration and the number of lightning flashes. The average increase of NO$_{x}$ concentration per lightning flash is 6.01ppbv in Naqu, and 90.6ppbv in Datong. The productions of NO by one lightning flash in Naqu is estimated to be 1.34\times10$^{26}$ molecules, and while that in Datong is 1.23\times10$^{28}$ molecules. Acknowledgement: This work is supported by National Natural Science Foundation of China (40135010).

AE21A-02 INVITED 08:10h

Production of Nitric Oxide in Continental Thunderstorms

* Ridley, B (ridley@ucar.edu) , National Center for Atmospheric Research, PO Box 3000, Boulder, CO 80307 United States

The global production of NO by thunderstorms is uncertain but is likely in the range of 2-20 Tg(N)/yr. Current global Chemistry-Transport models would imply a narrower range of 2-7 Tg(N)/yr or about 10-20 percent of the current annual emissions from fossil fuel burning. Although a number of aircraft studies of continental thunderstorms have been made, they have not been able to really refine the global estimate. They have shown that large mixing ratios of NOx (NO + NO2) are found in the anvil outflow region of active storms due to lightning production and, depending on location, transport of NOx (and other reactive constituents) from near or within the boundary layer. Direct injection to high altitudes has unique chemical consequences compared to near-surface emissions because the lifetime of NOx is several days to a week. The chemical impact on, for example, ozone production or HOx radical partitioning can be much broader than the scale of the original thunderstorm. The aircraft programs combined with model analyses or interferometer observations have also shown that in some storms the NO production by intra-cloud flashes approaches the production by cloud-to-ground flashes. Here, observations of unexpectedly high mixing ratios of NO measured within Florida thunderstorm anvils during the NASA CRYSTAL-FACE study will be discussed and coarse estimates of the production per flash for storms of quite different size and electrical activity will be summarized. Some of the issues for possible future studies of the chemical impact of electrically active deep convection will also be considered.

AE21A-03 08:25h

Spectroscopic Measurements of NO$_{2}$ in a Colorado Thunderstorm: Determination of the Mean Production by Cloud-to-Ground Lightning Flashes

* Langford, A O (andrew.o.langford@noaa.gov) , NOAA Aeronomy Laboratory, 325 S. Broadway, R/AL8, Boulder, CO 80305-3328 United States
Portmann, R W (robert.w.portmann@noaa.gov) , NOAA Aeronomy Laboratory, 325 S. Broadway, R/AL8, Boulder, CO 80305-3328 United States
Daniel, J S (john.s.daniel@noaa.gov) , NOAA Aeronomy Laboratory, 325 S. Broadway, R/AL8, Boulder, CO 80305-3328 United States
Miller, H L (henry.leroy.miller@noaa.gov) , NOAA Aeronomy Laboratory, 325 S. Broadway, R/AL8, Boulder, CO 80305-3328 United States
Miller, H L (henry.leroy.miller@noaa.gov) , Cooperative Institute for Research in Environmental Science, University of Colorado, Box 216, Boulder, CO 80309 United States
Solomon, S (susan.solomon@noaa.gov) , NOAA Aeronomy Laboratory, 325 S. Broadway, R/AL8, Boulder, CO 80305-3328 United States

Ground-based visible absorption spectroscopy of zenith-scattered sky light was used to measure changes in the column abundance of NO$_{2}$ during the passage of a thunderstorm over Boulder, Colorado on September 12, 2002. The measurements showed a 10-fold rise in slant column NO$_{2}$ within the thunderstorm cell, consistent with an increase of about 7 ppbv in the lower core updrafts and main precipitation shaft. Mean mixing ratios of about 3 and 1.5 ppbv were inferred for the upper cell and anvil, respectively. These observations, together with measurements from the Denver NEXRAD and the Colorado State University (CSU) CHILL radars, and cloud-to-ground (CG) lightning flash data from the National Lightning Detection Network (NLDN), are used to estimate the flash mean production of NOx by CG lightning. The measurements suggest a mean production rate of (5.8\pm 2.9) x 10$^{26}$ NO$_{x}$ molecules per CG flash or (2.3\pm 1.4) x 10$^{17}$ NO$_{x}$/J. These results are compared to previous work and the implications for global NO$_{x}$ production discussed.

AE21A-04 INVITED 08:35h

Nitrogen Oxides from Thunderstorms - First Results from TROCCINOX

* Schumann, U (ulrich.schumann@dlr.de) , DLR Institute of Atmospheric Physics, Oberpfaffenhofen, PO Box 1116, Wessling, 82230 Germany
Schlager, H (hans.schlager@dlr.de) , DLR Institute of Atmospheric Physics, Oberpfaffenhofen, PO Box 1116, Wessling, 82230 Germany
Chaboureau, J P (chajp@aero.obs-mip.fr) , Laboratoire d'Aerologie, OMP, 14 Avenue Ed Belin, Toulouse, 31400 France
Fehr, T (thorsten.fehr@dlr.de) , DLR Institute of Atmospheric Physics, Oberpfaffenhofen, PO Box 1116, Wessling, 82230 Germany
Held, G (gerhard@ipmet.unesp.br) , Instituto de Pesquisas Meteorologicas (IPMET), Universidade Estadual Paulista (UNESP), CX Postal, 281 , Bauru, 17001-970 Brazil
Hoeller, H (hartmut.hoeller@dlr.de) , DLR Institute of Atmospheric Physics, Oberpfaffenhofen, PO Box 1116, Wessling, 82230 Germany
Huntrieser, H (heidi.huntrieser@dlr.de) , DLR Institute of Atmospheric Physics, Oberpfaffenhofen, PO Box 1116, Wessling, 82230 Germany
Kurz, C (Christian.Kurz@dlr.de) , DLR Institute of Atmospheric Physics, Oberpfaffenhofen, PO Box 1116, Wessling, 82230 Germany
Lawrence, M G (lawrence@mpch-mainz.mpg.de) , Max Planck Institute of Chemistry, Postfach 3060, Mainz, 55020 Germany
Luo, B (beiping.luo@env.ethz.ch) , ETH Institute for Atmospheric and Climate Science, Hoenggerberg HPP L8.2, Zuerich, 8093 Switzerland
Pommereau, J P (pommereau@aerov.jussieu.fr) , Service d'Aeronomie du CNRS, BP 3, Verrieres le Buisson, 91371 France
Meijer, E (meijere@knmi.nl) , KNMI, P.O. Box 201, De Bilt, 3730 Netherlands

Within the EU-project "Tropical Convection, Cirrus and Nitrogen Oxides Experiment" (TROCCINOX), in cooperation with the Brazilian project TROCCIBRAS, lightning induced NOx has been measured at altitudes up to 12.5 km in the outflow from continental thunderstorms in the tropics in February/March 2004. Thunderstorms in both subtropical and tropical air masses were sampled. In tropical air masses, high NO and CO background mixing ratios were observed. In the anvil outflow, spiky NO structures (maximum 65 nmol/mol) above background were observed. Some of the spikes were notably wide (order several 10 km) indicating outflow from a thunderstorm anvil, others were narrow (order 200 m) clearly originating from fresh lightning events. From the still preliminary analysis of the few cases it appears that the subtropical and tropical TROCCINOX thunderstorms exhibit similarly enhanced nitrogen oxides concentrations (0.5-1.9 nmol/mol) and mass fluxes (1.1-2.0 x 10**8 kg/s) as found in the LINOX/EULINOX thunderstorms. The three TROCCINOX case studies indicate global lightning-NOx production rates between 2 and 9 Tg(N)/yr. These are lower limit estimates because of missing data above 12.5 km altitude. A further campaign with measurements at higher altitudes is under preparation. Preliminary model studies show that matching the measured NOx data is very demanding.

http://www.pa.op.dlr.de/troccinox/

AE21A-05 08:50h

Lightning activity and cloud properties of the convective storm system on 3 March 2004 observed during TROCCINOX/TroCCiBras and implications for lightning NOx production

* Fehr, T (Thorsten.Fehr@dlr.de) , Institut f\"{u}r Physik der Atmosph\"{a}re, DLR, Oberpfaffenhofen, Wessling, 82234 Germany
Gomes Held, A M (ana@ipmet.unesp.br) , Instituto de Pesquisas Meteorol\'{o}gicas, UNESP, CX Postal, 281, Bauru, 17001-970 Brazil
H\"{o}ller, H (Hartmut.Hoeller@dlr.de) , Institut f\"{u}r Physik der Atmosph\"{a}re, DLR, Oberpfaffenhofen, Wessling, 82234 Germany
Schlager, H (Hans.Schlager@dlr.de) , Institut f\"{u}r Physik der Atmosph\"{a}re, DLR, Oberpfaffenhofen, Wessling, 82234 Germany
Pinto, O (osmar@dge.inpe.br) , Grupo de Eletricidade Atmosf\'{e}rica (ELAT), Av. Astronautas 1758, S.J. Campos, 12240-540 Brazil
Kawasaki, Z (zen@comm.eng.osaka-u.ac.jp) , Department of Communications Engineering, Osaka University, Yamada-Oka 2-1, Suita, Osaka, 565-0871 Japan
Huntrieser, H (Heidi.Huntrieser@dlr.de) , Institut f\"{u}r Physik der Atmosph\"{a}re, DLR, Oberpfaffenhofen, Wessling, 82234 Germany
Gatzen, C (christoph.gatzen@dlr.de) , Institut f\"{u}r Physik der Atmosph\"{a}re, DLR, Oberpfaffenhofen, Wessling, 82234 Germany
Held, G (gerhard@ipmet.unesp.br) , Instituto de Pesquisas Meteorol\'{o}gicas, UNESP, CX Postal, 281, Bauru, 17001-970 Brazil
Schumann, U (Ulrich.Schumann@dlr.de) , Institut f\"{u}r Physik der Atmosph\"{a}re, DLR, Oberpfaffenhofen, Wessling, 82234 Germany

In February and March 2004 the first field experiment of the joint EU-Brazilian TROCCINOX/TroCCiBras projects was performed in south-eastern Brazil. One of the major targets of these projects is to reduce the uncertainties in the estimates of the global production of lightning-induced nitrogen oxides by investigating tropical convection. The experimental strategy of TROCCINOX included cloud-scale observations with the DLR research aircraft "Falcon", measuring trace gases (NO$_{x}$, NO$_{y}$, CO and O$_{3}$), meteorological parameters, as well as aerosol and water vapor profiles. In addition, ground-based observations from two Doppler radars were provided by IPMet/UNESP, almost covering the complete Brazilian State of Sa\~{o} Paulo. Measurements from a VLF/LF lightning location network covering Southern and South-Eastern Brazil were assembled by ELAT/INPE. The Osaka University Lightning Research Group installed a regional VHF lightning mapping system, allowing the co-located analysis with radar measurements. Satellite observations (e.g., TRMM, MSG) provide further information on various parameters. In addition, cloud-scale simulations are performed to complement the experimental results. In the afternoon of 3 March 2004 wide spread tropical convection developed in the Bauru area and the aircraft was measuring in and around the thunderstorm anvils. These observations are complemented by the measurements of the Bauru radar and the lightning detection systems. Cloud scale simulations in combination with the radar and satellite observations are used to estimate the transport properties in the observed storms. The combined results are used to estimate the NO$_{x}$ production and transport in the observed cells.

AE21A-06 INVITED 09:00h

Using Models and Observations to Reduce Uncertainties in Lightning NOx Production

* Pickering, K E (pickerin@atmos.umd.edu) , University of Maryland, Department of Meteorology, College Park, MD 20742 United States

Cloud-scale models in conjunction with aircraft measurements of NOx in thunderstorms and ground-based lightning observations have been used to constrain the amount of NO produced per flash. Cloud and chemistry simulations for several case studies of storms in different environments will be presented. Observed lightning flash rates have been incorporated into the model, and several scenarios of NO production per intracloud (IC) and per cloud-to-ground (CG) flash are assumed. The resulting NOx mixing ratios are compared with aircraft measurements taken within the storm (typically the anvil region) to determine the most likely NO production scenario. The range of values of NO production per flash (or per meter of lightning channel length) that have been deduced from the model will be shown and compared with values of production in the literature that have been deduced from observed NO spikes. Results show that on a per flash basis, IC flashes are nearly as productive of NO as CG flashes. Mean estimates of NO production per flash vary by a factor of three from one storm to another. When combined with the global flash rate of 44 flashes per second from Optical Transient Detector (OTD) measurements, these estimates yield global NO production rates of 3-9 TgN/year. This uncertainty is less than the factor of 10 often quoted over the last decade.

AE21A-07 09:15h

Vertical Distribution of Nitrogen Oxides From Lightning Based on ECMWF Convective Mass Fluxes

Olivie, D (olivie@knmi.nl) , Royal Netherlands Meteorological Institute, P.O. Box 201, De Bilt, NL-3730 AE Netherlands
* Meijer, E (meijere@knmi.nl) , Royal Netherlands Meteorological Institute, P.O. Box 201, De Bilt, NL-3730 AE Netherlands
van Velthoven, P (velthove@knmi.nl) , Royal Netherlands Meteorological Institute, P.O. Box 201, De Bilt, NL-3730 AE Netherlands

Most global chemistry transport models (CTMs) apply prescribed vertical profiles of lightning-produced nitrogen oxides (LNOx) based on a study by Pickering et al. (1998). However, these profiles are based on a few storm cases only, so their general applicability is uncertain and the models will likely have too little variability in the vertical distribution of LNOx. Furthermore it is difficult to incorporate these profiles consistently with other cloud parameters. In this study we suggest to vertically distribute LNOx according to the CTMs convective scheme, which is adopted from Tiedtke (1989). This new method involves the rescaling of the convective mass fluxes to the area of the storm, the separation of up- and downdrafts, and dealing with several complexities that arise when meteorological quantities are averaged over space and time. We will show that this convective redestribution of LNOx produces the expected C-shaped profiles, that are similar to those of Pickering, but with much larger variability, consistent with the variability of ECMWF convective vigour. Next we will evaluate these new LNOx profiles with lightning-influenced observations from EULINOX, conducted in Europa, and TROCCINOX, conducted in Brazil. The CTM used in this study is Tracer Model Version 4 (TM4) and is driven by meteorology of the European Centre for Medium-Range Weather Forecasts (ECWMF). The parameterization of LNOx is based on an empirical linear relationship between convective precipitation and flash frequency (Meijer et al., 2001).

AE21A-08 INVITED 09:25h

Numerical Modeling of Nitric Oxide Production by Lightning

* Helsdon, J H (john.helsdon@sdsmt.edu) , Intstitute of Atmospheric Sciences, South Dakota School of Mines and Technology, 501 E. St. Joseph St., Rapid City, SD 57701 United States

The production of nitric oxide (NO) by lightning remains the least well quantified of the various sources of NO in the atmosphere. NO, along with NO$_{2}$, are important in moderating the ozone budget of the troposphere. Since lightning-produced NO is created at mid-tropospheric levels and, subsequently, transported into the upper troposphere by thunderstorm airflows, it is able to interact with ozone directly, rather than having to be brought up from the surface where chemical lifetimes are shorter. Current estimates of the global annual source term for lightning-produced NO span an order of magnitude and need to be refined in order for more accurate incorporation into global chemical transport models. One method of refining these estimates is to better understand the NO production of individual thunderstorms through numerical modeling of the production and distribution of NO within such storms. We have employed our three-dimensional Storm Electrification Model (SEM) to study this problem by simulating the 10 July 1996 storm from the Stratospheric-Tropospheric Experiment: Radiation, Aerosols, and Ozone (STERAO) project. The explicit lightning scheme in the SEM allows the calculation of NO production based on the energy dissipated by each lightning flash, with the NO distributed along the generated lightning channel. Using data on lightning flash production and observed NO mixing ratios obtained during STERAO, we can directly compare the simulated NO concentrations with those observed to determine source amounts and distributions within the storm. In this talk, an overview of the methodology will be presented along with the latest results from this ongoing research.

AE21A-09 09:40h

Satellite Detection of Lightning NO$_2$ and Implications for Lightning Parameterizations

* Boersma, F (boersma@knmi.nl)
Eskes, H (eskes@knmi.nl)
Meijer, E (meijere@knmi.nl)

Nitrogen oxides (NO$_x$ = NO + NO$_2$) from lightning flashes contribute to the formation of ozone in the upper troposphere, and have a strong effect on the oxidizing capacity of the atmosphere. However, recent estimates of annual global lightning NO$_x$ emissions range by one order of magnitude, and this makes it difficult for chemistry-transport models to properly quantify the impact of lightning NO$_x$ on ozone and OH. The uncertainties mostly result from modelling NO$_x$ from lightning in a "bottom-up" way, requiring important assumptions on certain lightning characteristics with limited observational constraints. Here we provide evidence that retrievals of tropospheric NO$_2$ from the Global Ozone Monitoring Experiment (GOME) contain spatially and temporally resolved information on tropical tropospheric distributions of lightning NO$_x$. From comparing modeled lightning, and observed total NO$_2$, we find that the production of lightning NO$_x$ over tropical oceans is significantly overestimated in parameterizations relating convective rainfall, or cloud top heights, to lightning flash frequencies. From a simple, first-order correction for the regionally different oceanic overestimations, it follows that global lightning NO$_x$ emissions amount to ~4.1 Tg [N] for 1997.

AE21A-10 09:50h

The Effects of Lightning-Produced NO$_x$ and its Vertical Distribution on Atmospheric Chemistry: Sensitivity Simulations with the Model of Atmospheric Chemistry and Transport, Max-Planck Institute for chemistry version (MATCH-MPIC)

* Labrador, L J (lorenzo@mpch-mainz.mpg.de) , Max-Planck Institute for Chemistry, P. O. Box 3060, Mainz, D-55020 Germany
von Kuhlmann, R (kuhlmann@mpch-mainz.mpg.de) , Max-Planck Institute for Chemistry, P. O. Box 3060, Mainz, D-55020 Germany
Lawrence, M G (lawrence@mpch-mainz.mpg.de) , Max-Planck Institute for Chemistry, P. O. Box 3060, Mainz, D-55020 Germany

The impact of different assumptions concerning the source magnitude as well as the vertical placement of lightning-produced nitrogen oxides is studied using the global chemistry transport model MATCH-MPIC. The responses of NO$_x$, O$_3$, OH, HNO$_3$ and peroxyacetyl-nitrate (PAN) are investigated. A marked sensitivity to both parameters was found. NO$_x$ burdens globally can be enhanced up to 100% depending on the vertical placement and source magnitude strength. In all cases, the largest enhancements occur in the tropical upper troposphere, where lifetimes of most trace gases are longer and where they thus become more susceptible to long-range transport by long-range circulation patterns. Comparison with observations indicate that the 0 and 20 Tg/yr(N) production rates of NO$_x$ from lightning are too low and too high, respectively. However, no single intermediate production rate or vertical distribution can be singled out as best fitting the observations due to the large scatter in the datasets. This underscores the need for further measurement campaigns in key regions, particularly in the tropics.