TY  - JOUR
A1  - Eghdami, Hanieh
A1  - Werner, Willy
A1  - Büker, Patrick
T1  - Spatio-Temporal Variation of Ozone Concentrations and Ozone Uptake Conditions in Forests in Western Germany
T2  - Atmosphere
N2  - The study analyzes the long-term trends (1998–2019) of concentrations of the air pollutants ozone (O3) and nitrogen oxides (NOx) as well as meteorological conditions at forest sites in German midrange mountains to evaluate changes in O3 uptake conditions for trees over time at a plot scale. O3 concentrations did not show significant trends over the course of 22 years, unlike NO2 and NO, whose concentrations decreased significantly since the end of the 1990s. Temporal analyses of meteorological parameters found increasing global radiation at all sites and decreasing precipitation, vapor pressure deficit (VPD), and wind speed at most sites (temperature did not show any trend). A principal component analysis revealed strong correlations between O3 concentrations and global radiation, VPD, and temperature. Examination of the atmospheric water balance, a key parameter for O3 uptake, identified some unusually hot and dry years (2003, 2011, 2018, and 2019). With the help of a soil water model, periods of plant water stress were detected. These periods were often in synchrony with periods of elevated daytime O3 concentrations and usually occurred in mid and late summer, but occasionally also in spring and early summer. This suggests that drought protects forests against O3 uptake and that, in humid years with moderate O3 concentrations, the O3 flux was higher than in dry years with higher O3 concentrations.
KW  - forests
KW  - ozone
KW  - nitrogen oxides
KW  - meteorology
KW  - atmospheric water balance
KW  - Rheinland-Pfalz
KW  - Mittelgebirge
KW  - Wald
KW  - Ozon
KW  - Stickstoffoxide
KW  - Bodennahe Luftschicht
KW  - Einstrahlung
KW  - Niederschlag
KW  - Wasserbilanz
Y1  - 2020
UR  - https://ubt.opus.hbz-nrw.de/frontdoor/index/index/docId/1662
UR  - https://nbn-resolving.org/urn:nbn:de:hbz:385-1-16625
IS  - 11/11
PB  - MDPI
CY  - Basel
ER  -