نتایج جستجو برای: ground level ozone

تعداد نتایج: 1221724  

Journal: :Environmental pollution 2010
R Matyssek G Wieser R Ceulemans H Rennenberg H Pretzsch K Haberer M Löw A J Nunn H Werner P Wipfler W Osswald P Nikolova D E Hanke H Kraigher M Tausz G Bahnweg M Kitao J Dieler H Sandermann K Herbinger T Grebenc M Blumenröther G Deckmyn T E E Grams C Heerdt M Leuchner P Fabian K-H Häberle

Ground-level ozone (O(3)) has gained awareness as an agent of climate change. In this respect, key results are comprehended from a unique 8-year free-air O(3)-fumigation experiment, conducted on adult beech (Fagus sylvatica) at Kranzberg Forest (Germany). A novel canopy O(3) exposure methodology was employed that allowed whole-tree assessment in situ under twice-ambient O(3) levels. Elevated O(...

2002
Eugene C. Cordero Terrence R. Nathan

[1] Observations from both ground-based and satellite instruments show record low column ozone abundance between 20 S and 40 S during 1997. The 1997 monthly averaged column ozone from the Total Ozone Mapping Spectrometer (TOMS) is up to 25 Dobson units (DU) lower than the TOMS climatological mean (1979–1996) and up to 20 DU below the previous record low values. Observations from the Halogen Occ...

In this work, we report results of calculations based on the density functional theory of different species metal-ozone, containing mercury, silver and gold. The chosen species range from small molecules and large transition-metal containing ozone with mercury, silver and gold complexes. A comparative analysis of the description of the metal-oxygen bond obtained by different methodologies is pr...

2007
A. Fraser P. F. Fogal C. T. McElroy

The MANTRA (Middle Atmosphere Nitrogen TRend Assessment) 2004 campaign took place in Vanscoy, Saskatchewan, Canada (52 N, 107 W) from 3 August to 15 September, 2004. In support of the main balloon launch, a suite of five zenith-sky and direct-Sun-viewing UV-visible ground-based spectrometers was deployed, primarily measuring ozone and NO2 total columns. Three Fourier transform spectrometers (FT...

2011
C. S. Zerefos

This study examines the long-term variability of UV solar irradiances at 305 nm and 325 nm over selected sites in Canada, Europe and Japan. Site selection was restricted to the availability of the most complete UV spectroradiometric datasets during the period 1990–2011. The analysis includes the long-term variability of total ozone, aerosol optical depth and cloud fraction at the sites studied....

2002

Question UCR -Carter GT -Russell MCNC -Arunachulam Reviewer's Comments 1 What is the hypothesis that we want to test? It is possible to develop a means to quantify differences in ozone impacts of the major classes of emitted VOCs sufficiently well that these relative ozone impact quantifications can be effectively used in VOC regulations to reduce ambient ozone levels. For this to be the case, ...

2017
Daniel Tong Li Pan Weiwei Chen Lok Lamsal Pius Lee Youhua Tang Hyuncheol Kim Shobha Kondragunta Ivanka Stajner

Satellite and ground observations detected large variability in nitrogen oxides (NOx) during the 2008 economic recession, but the impact of the recession on air quality has not been quantified. This study combines observed NOx trends and a regional chemical transport model to quantify the impact of the recession on surface ozone (O3) levels over the continental United States. The impact is quan...

Journal: :Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation 2009

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