Abstract
Abstract. We have estimated changes in surface solar ultraviolet (UV) radiation under cloud free conditions in the 21st century based on simulations of 11 coupled Chemistry-Climate Models (CCMs). The total ozone columns and vertical profiles of ozone and temperature projected from CCMs were used as input to a radiative transfer model in order to calculate the corresponding erythemal irradiance levels. Time series of monthly erythemal irradiance received at the surface during local noon are presented for the period 1960 to 2100. Starting from the first decade of the 21st century, the surface erythemal irradiance decreases globally as a result of the projected stratospheric ozone recovery at rates that are larger in the first half of the 21st century and smaller towards its end. This decreasing tendency varies with latitude, being more pronounced over areas where stratospheric ozone has been depleted the most after 1980. Between 2000 and 2100 surface erythemal irradiance is projected to decrease over midlatitudes by 5 to 15%, while at the southern high latitudes the decrease is twice as much. In this study we have not included effects from changes in cloudiness, surface reflectivity and tropospheric aerosol loading, which will likely be affected in the future due to climate change. Consequently, over some areas the actual changes in future UV radiation may be different depending on the evolution of these parameters.
Highlights
In the past three decades, stratospheric ozone depletion has been a high priority environmental concern, due to the consequent increase in solar ultraviolet radiation reaching the earth’s surface (e.g., Herman et al, 1999; Kerr et al, 2003), and related skin cancer risks (e.g., Slaper et al, 1996)
In this study we focus on future surface UV irradiance as a relative rather than absolute change, since the absolute total ozone is slightly different for each Chemistry-Climate Models (CCMs)
The negative relative changes of irradiance during the 1980s and early 1990s suggest that total ozone, as simulated by the CCMs, had not reached its minimum until early 2000s
Summary
In the past three decades, stratospheric ozone depletion has been a high priority environmental concern, due to the consequent increase in solar ultraviolet radiation reaching the earth’s surface (e.g., Herman et al, 1999; Kerr et al, 2003), and related skin cancer risks (e.g., Slaper et al, 1996). Future levels of surface UV radiation will depend on the evolution of various factors, known to influence the propagation of solar UV radiation in the atmosphere. Some of these factors, such as ozone, clouds, and surface reflectivity are included in standard output products of coupled Chemistry-Climate Models (CCMs) (e.g., Eyring et al, 2006, 2007). The quantity depends on irradiance over a broad spectral region in the ultraviolet and provides a direct link to the harmful biological effects of UV radiation
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
