Episode of unusual high solar ultraviolet radiation in central Europe due to dynamical reduced stratospheric ozone in May 2005

Abstract. In late May this year unusual high levels of solar ultraviolet radiation were observed in Europe. In Northern Germany the measured irradiance of erythemally effective radiation exceeded the climatological mean by more than about 20%. An extreme low ozone event for the season coincided with the high solar elevation angles during late spring leading to the highest value of erythemal UV-radiation ever observed at this location in May. This ''ozone mini-hole'' was caused by an elevation of tropopause height accompanied with a poleward advection of natural low total ozone from the tropics. The resultant increase in UV-radiation is of particular significance for human health. Dynamically induced low ozone episodes that happen around the summer solstice can considerably enhance the solar UV-radiation in the mid latitudes and therefore contribute to the UV-burden of people living in the mid latitudes.

Download Full-text

Episode of unusual high solar ultraviolet radiation over central Europe due to dynamical reduced total ozone in May 2005

Atmospheric Chemistry and Physics ◽

10.5194/acp-6-1771-2006 ◽

2006 ◽

Vol 6 (7) ◽

pp. 1771-1776 ◽

Cited By ~ 24

Author(s):

C. Stick ◽

K. Krüger ◽

N. H. Schade ◽

H. Sandmann ◽

A. Macke

Keyword(s):

Ultraviolet Radiation ◽

Central Europe ◽

Uv Radiation ◽

Solar Ultraviolet Radiation ◽

Solar Uv ◽

The Tropics ◽

Sky Conditions ◽

Effective Radiation ◽

Ozone Episodes ◽

Solar Ultraviolet

Abstract. In late May 2005 unusual high levels of solar ultraviolet radiation were observed over central Europe. In Northern Germany the measured irradiance of erythemally effective radiation exceeded the climatological mean by more than about 20%. An extreme low ozone event for the season coincided with high solar elevation angles and high pressure induced clear sky conditions leading to the highest value of erythemal UV-radiation ever observed over this location in May since 1994. This hereafter called "ozone mini-hole" was caused by an elevation of tropopause height accompanied with a poleward advection of ozone-poor air from the tropics. The resultant increase in UV-radiation is of particular significance for human health. Dynamically induced low ozone episodes that happen in late spring can considerably enhance the solar UV-radiation in mid latitudes and therefore contribute to the UV-burden of people living in these regions.

Download Full-text

Spring and summer time ozone and solar ultraviolet radiation variations over Cape Point, South Africa

Annales Geophysicae ◽

10.5194/angeo-37-129-2019 ◽

2019 ◽

Vol 37 (2) ◽

pp. 129-141 ◽

Cited By ~ 1

Author(s):

David J. du Preez ◽

Jelena V. Ajtić ◽

Hassan Bencherif ◽

Nelson Bègue ◽

Jean-Maurice Cadet ◽

...

Keyword(s):

South Africa ◽

Ultraviolet Radiation ◽

Uv Radiation ◽

Stratospheric Ozone ◽

Solar Ultraviolet Radiation ◽

Clear Sky ◽

Solar Uv Radiation ◽

Solar Uv ◽

Solar Ultraviolet ◽

Ozone Levels

Abstract. The correlation between solar ultraviolet radiation (UV) and atmospheric ozone is well understood. Decreased stratospheric ozone levels which led to increased solar UV radiation levels at the surface have been recorded. These increased levels of solar UV radiation have potential negative impacts on public health. This study was done to determine whether the break-up of the Antarctic ozone hole has an impact on stratospheric columnar ozone (SCO) and resulting ambient solar UV-B radiation levels at Cape Point, South Africa, over 2007–2016. We investigated the correlations between UV index, calculated from ground-based solar UV-B radiation measurements and satellite-retrieved column ozone data. The strongest anti-correlation on clear-sky days was found at solar zenith angle 25∘ with exponential fit R2 values of 0.45 and 0.53 for total ozone column and SCO, respectively. An average radiation amplification factor of 0.59 across all SZAs was calculated for clear-sky days. The MIMOSA-CHIM model showed that the polar vortex had a limited effect on ozone levels. Tropical air masses more frequently affect the study site, and this requires further investigation.

Download Full-text

Spring and summer time ozone and solar ultraviolet radiation variations over Cape Point, South Africa

10.5194/angeo-2018-56 ◽

2018 ◽

Cited By ~ 1

Author(s):

D. Jean du Preez ◽

Jelena V. Ajtić ◽

Hassan Bencherif ◽

Nelson Bègue ◽

Caradee Y. Wright

Keyword(s):

South Africa ◽

Ultraviolet Radiation ◽

Uv Radiation ◽

Stratospheric Ozone ◽

Polar Vortex ◽

Solar Ultraviolet Radiation ◽

Solar Uv Radiation ◽

Solar Uv ◽

Solar Ultraviolet ◽

Ozone Levels

Abstract. The correlation between solar ultraviolet radiation (UV) and atmospheric ozone is well understood. Decreased stratospheric ozone levels which led to increased solar UV radiation levels at the surface have been recorded. These increased levels of solar UV radiation have potential negative impacts on public health. This study was done to determine whether or not the break-up of the Antarctic ozone hole has an impact on stratospheric columnar ozone (SCO) concentrations and resulting ambient solar UV-B radiation levels at Cape Point, South Africa. At Cape Point, the strongest anti-correlation on clear-sky days was found at solar zenith angle 20° with exponential fit R2 values of 0.71 and 0.66 for total ozone column and SCO, respectively. An average radiation amplification factor of 0.92 was found and the largest decrease in ozone levels occurred during September months. The MIMIOSA-CHIM model showed that the polar vortex had a limited effect on ozone levels at 435–440 K for September and 600 K over Cape Point during November. Tropical air-masses more frequently affect the study site, and this requires further investigation.

Download Full-text

Stratospheric ozone depletion

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2005.1783 ◽

2006 ◽

Vol 361 (1469) ◽

pp. 769-790 ◽

Cited By ~ 98

Author(s):

F. Sherwood Rowland

Keyword(s):

Ultraviolet Radiation ◽

Ozone Depletion ◽

Biological Activities ◽

Stratospheric Ozone ◽

Ozone Layer ◽

Ultraviolet B ◽

Montreal Protocol ◽

Atmospheric Measurements ◽

Solar Ultraviolet Radiation ◽

Solar Ultraviolet

Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within the ozone layer have been shown to include very efficient catalytic chain reactions involving the chemical species HO, HO 2 , NO, NO 2 , Cl and ClO. The NO X and ClO X chains involve the emission at Earth's surface of stable molecules in very low concentration (N 2 O, CCl 2 F 2 , CCl 3 F, etc.) which wander in the atmosphere for as long as a century before absorbing ultraviolet radiation and decomposing to create NO and Cl in the middle of the stratospheric ozone layer. The growing emissions of synthetic chlorofluorocarbon molecules cause a significant diminution in the ozone content of the stratosphere, with the result that more solar ultraviolet-B radiation (290–320 nm wavelength) reaches the surface. This ozone loss occurs in the temperate zone latitudes in all seasons, and especially drastically since the early 1980s in the south polar springtime—the ‘Antarctic ozone hole’. The chemical reactions causing this ozone depletion are primarily based on atomic Cl and ClO, the product of its reaction with ozone. The further manufacture of chlorofluorocarbons has been banned by the 1992 revisions of the 1987 Montreal Protocol of the United Nations. Atmospheric measurements have confirmed that the Protocol has been very successful in reducing further emissions of these molecules. Recovery of the stratosphere to the ozone conditions of the 1950s will occur slowly over the rest of the twenty-first century because of the long lifetime of the precursor molecules.

Download Full-text