The importance of plant-water stress for predictions of ground-level ozone in a warm world

Emmerichs, Tamara; Lu, Yen-Sen; Taraborrelli, Domenico

ltrpresentationEvapotranspiration is important for Earth’s water and energy cycles as it strongly affects air temperature, cloud
presentation
ltrpresentationcover and precipitation. Leaf stomata are the conduit of transpiration and thus their opening is sensitive to weather and climate
presentation
ltrpresentationconditions. This feedback can exacerbate heat waves and droughts and can play a role in their spatio-temporal propagation.
presentation
ltrpresentationTherefore, the plant response to available water is a key element mediating vegetation-atmosphere interactions. Sustained high
presentation
ltrpresentationtemperatures strongly favor high ozone levels with significant negative effects on air quality and thus human health. Our study
presentation
ltrpresentationassesses the process representation of evapotranspiration in the atmospheric chemistry model ECHAM/MESSy. Diverse water
presentation
ltrpresentationstress parametrizations are implemented in a stomatal model based onltrpresentationCOltrpresentation2ltrpresentationassimilation. The stress factors depend on either
presentation
ltrpresentationsoil moisture or leaf water potential and act directly on photosynthetic activity, mesophyll and stomatal conductance. Overall,
presentation
ltrpresentationthe new functionalities reduce the initial overestimation of evapotranspiration in the model globally by more than one order
presentation
ltrpresentationof magnitude which is most important in the Southern Hemisphere. The intensity of simulated warm spells over continents
presentation
ltrpresentationis significantly enhanced. With respect to ozone, we find that a realistic model representation of plant-water stress depresses
presentation
ltrpresentationuptake by vegetation and enhances its photochemical production in the troposphere. These effects lead to a general increases
presentation
ltrpresentationin simulated ground-level ozone which is most pronounced in the Southern Hemisphere over the continents. The uncertainties
presentation
ltrpresentationfor plant dynamics representation due to too shallow roots can be addressed by more sophisticated land surface models with
presentation
ltrpresentationmulti-layer soil schemes. In regions with low evaporative loss, however, the representation of precipitation remains the largest
presentation
ltrpresentationuncertainty.

Zitieren

Zitierform:

Emmerichs, Tamara / Lu, Yen-Sen / Taraborrelli, Domenico: The importance of plant-water stress for predictions of ground-level ozone in a warm world. 2023. Copernicus Publications.

Zugriffsstatistik

Gesamt:
Volltextzugriffe:
Metadatenansicht:
12 Monate:
Volltextzugriffe:
Metadatenansicht:

Grafik öffnen

Rechte

Rechteinhaber: Tamara Emmerichs et al.

Nutzung und Vervielfältigung:

Export