Sensitivity of Regional Radiative Forcing and Temperature Response to Aviation-induced Ozone

Abstract:

Aviation emissions affect the atmosphere and climate through a number of mechanisms. One important mechanism is the change in ozone budged resulting from emissions of nitrogen oxides (NO_x) and other precursor gases. Significant spatial heterogeneity exists in the aviation-induced ozone changes and consequent climate impact, which may have important implications for the design and evaluation of mitigation strategies for the sector. However, further studies are needed to increase the knowledge of regional impacts.

This study investigates spatial variability – from emissions to temperature response – of aviation ozone perturbations. Using the AEDT year 2006 and 2050 aviation emission inventory in the chemistry-transport model OsloCTM3, we quantify the radiative forcing (RF) due to regional aviation NO_x emissions. In addition to the information provided by RF, there is an increasing need to also quantify the temperature impacts. In order to examine the sensitivity of regional temperature response to aviation-induced ozone perturbations, we perform simulations with the Community Earth System model (CESM). Results are compared to estimates of temperature response calculated using the Regional Temperature change Potential (RTP) metric with aviation RF results from the Aviation Climate Change Research Initiative (ACCRI). Furthermore, we focus in particular on the vertical sensitivity in the ozone forcing-response relationship, especially at higher latitudes where the short-wave component of the ozone RF becomes more important than globally. This also allows for an investigation of potential differences between the temperature response sensitivity to ozone changes caused by aviation emissions and by lower-altitude emissions from other sectors.