 |
| Titel |
Cloud-resolving chemistry simulation of a Hector thunderstorm |
| VerfasserIn |
K. A. Cummings, T. L. Huntemann, K. E. Pickering, M. C. Barth, W. C. Skamarock, H. Höller, H.-D. Betz, A. Volz-Thomas, H. Schlager |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 5 ; Nr. 13, no. 5 (2013-03-08), S.2757-2777 |
| Datensatznummer |
250018482
|
| Publikation (Nr.) |
 copernicus.org/acp-13-2757-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| Cloud chemistry simulations were performed for a Hector thunderstorm
observed on 16 November 2005 during the SCOUT-O3/ACTIVE campaigns based in
Darwin, Australia, with the primary objective of estimating the average NO
production per lightning flash in this unique storm type which occurred in a
tropical island environment. The 3-D WRF-Aqueous Chemistry (WRF-AqChem)
model is used for these calculations and contains the WRF nonhydrostatic
cloud-resolving model with online gas- and aqueous-phase chemistry and a
lightning-NOx (LNOx) production algorithm. The model was
initialized by inducing convection with an idealized morning sounding and
sensible heat source, and initial condition chemical profiles from merged
aircraft observations in undisturbed air. Many features of the idealized
model storm, such as storm size and peak radar reflectivity, were similar to
the observed storm. Tracer species, such as CO, used to evaluate convective
transport in the simulated storm found vertical motion from the boundary
layer to the anvil region was well represented in the model, with a small
overestimate of enhanced CO at anvil altitudes. The lightning detection
network (LINET) provided lightning flash data for the model and a lightning
placement scheme injected the resulting NO into the simulated cloud. A
lightning NO production scenario of 500 moles flash−1 for both CG and
IC flashes yielded anvil NOx mixing ratios that compared well with
aircraft observations and were also similar to those deduced for several
convective modeling analyses in the midlatitudes and subtropics. However,
these NO production values were larger than most estimates for tropical
thunderstorms and given several uncertainties, LNOx production may have
been as large as 600 moles flash−1. Approximately 85% of the
simulated LNOx mass was located above 7 km in the later stages of the
storm, which was greater than amounts found for subtropical and midlatitude
convection. Modeled upper tropospheric NO2 partial columns were also
considerably greater than most satellite observations of tropical marine
convective events, as tropical island convection, such as Hector, is more
vigorous and more productive of LNOx. Additional research is needed to
investigate whether LNOx production per flash increases in storms with
greater wind shear, such as this Hector storm, which showed significant
variation in wind direction with altitude. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|