Titelangaben
Trebs, Ivonne ; Bohn, Birger ; Ammann, Christof ; Rummel, Udo ; Blumthaler, Mario ; Königstedt, Rainer ; Meixner, Franz X. ; Fan, S. ; Andreae, Meinrat O.:
Relationship between the NO2 photolysis frequency and the solar
global irradiance.
In: Atmospheric Measurement Techniques.
Bd. 2
(2009)
Heft 2
.
- S. 725-739.
ISSN 1867-8548
DOI: https://doi.org/10.5194/amt-2-725-2009
Abstract
Representative values of the atmospheric NO2 photolysis frequency j(NO2) are required for the adequate calculation and interpretation of NO and NO2 concentrations and exchange fluxes near the surface. Direct measurements of j(NO2) at ground level are often not availablein field studies. In most cases, modeling approaches involving complex radiative transfer calculations are used to estimate j(NO2) and other photolysis frequencies for air chemistry studies. However, important input parameters for accurate modeling are often missing, most importantlywith regard to the radiative effects of clouds. On the other hand, solar global irradiance (“global radiation”, G) is nowadays measured as a standard parameter in most field experiments and in many meteorological observation networksaround the world. Previous studies mainly reported linear relationships between j(NO2) and G. We have measured j(NO2) using spectro- or filter radiometers and G using pyranometers side-by-side at several field sites. Our results cover a solar zenith angle range of 0–90, and are based on nine field campaigns in temperate, subtropical and tropical environments during the period 1994–2008. We show that a second-order polynomial function (intercept = 0): j(NO2) = (1+)×(B1 ×G+B2 ×G2), with defined as the site-dependent UV-A surface albedo and the polynomial coefficients: B1 =(1.47±0.03)×10−5W−1 m2 s−1and B2 = (−4.84±0.31)×10−9W−2 m4 s−1 can be used to estimate ground-level j(NO2) directly from G, independent of solar zenith angle under all atmospheric conditions. The absolute j(NO2) residual of the empirical function is ±6×10−4 s−1(2). The relationship is valid for sites below 800ma.s.l. and with low surface albedo ( <0.2). It isnot valid in high mountains, above snow or ice and sandy or dry soil surfaces.
Weitere Angaben
Publikationsform: | Artikel in einer Zeitschrift |
---|---|
Begutachteter Beitrag: | Ja |
Zusätzliche Informationen: | BAYCEER78716 |
Institutionen der Universität: | Forschungseinrichtungen > Forschungszentren > Bayreuther Zentrum für Ökologie und Umweltforschung - BayCEER Forschungseinrichtungen Forschungseinrichtungen > Forschungszentren |
Titel an der UBT entstanden: | Ja |
Themengebiete aus DDC: | 500 Naturwissenschaften und Mathematik |
Eingestellt am: | 07 Aug 2015 06:59 |
Letzte Änderung: | 07 Aug 2015 06:59 |
URI: | https://eref.uni-bayreuth.de/id/eprint/17746 |