Long-Term Ozone Changes Over the Northern Hemisphere Mid-Latitudes for the 1979–2012 Period

Figures & data

Fig. 1 Equivalent effective stratospheric chlorine (EESC) calculated for the mid-latitude stratosphere (solid line). Dotted and dashed lines represent the first and second derivatives of EESC, respectively.

Fig. 2 (left column) Monthly fractional deviations (points) of the 35°–60°N mean ozone for spring (MAM) during the 1979–2012 period. (top panel) ozone content in the troposphere and lower stratosphere; (middle panel) ozone content in the upper stratosphere; (bottom panel) total ozone. The solid and dotted curves show the smoothed (by locally weighted regression – LOWES) pattern of the modelled and original data, respectively. (right column) modelled versus observed monthly fractional deviations of the profile and total ozone corresponding to the panels in the left column.

Fig. 3 The solid curves show the smoothed differences between the observed and modelled fractional deviations of total ozone in (top panels) the troposphere and lower stratosphere, (middle panels) the upper stratosphere, and (bottom panels) the entire atmosphere during the 1979–2012 period for the 35°N–60°N zonal belt in winter (left column) and spring (right column). The dotted curves show the 95% confidence interval for these differences.

Fig. 4 As in Fig. 3 but for the smoothed differences in summer and autumn.

Table 1. Seasonal differences (percentage of the 1979–2012 mean values) in 2010 between the observed and modelled fractional deviations of the amount of ozone in the troposphere and lower stratosphere (Tr-LSt), the upper stratosphere (USt), and in the entire atmospheric column (Column) for various northern hemisphere mid-latitude regions and the 35°N–60°N zone. The 95% confidence intervals for the differences are in parentheses and statistically significant results are in bold.

Season	Layer	Central Europe	Continental Europe	North America	East Asia	Zone 35°–60°N
Winter	Tr-LSt	−1.1 (−3.6, 1.2)	−0.6 (−2.5, 1.2)	1.3 (−0.6, 3.2)	−0.1 (−1.8, 1.2)	−0.5 (−1.7, 0.6)
	USt	0.4 (−1.8, 2.1)	0.4 (−1.5, 2.1)	1.4 (−0.1, 2.8)	1.4 (−0.5, 3.2)	1.0 (−0.5, 2.3)
	Column	−1.4 (−3.3, 0.5)	−1.3 (−2.8, 0.3)	0.7 (−0.8, 2.0)	−0.7 (−1.9, 0.3)	−0.8 (−1.9, 0.2)
Spring	Tr-LSt	−2.8 (−4.5,−0.8)	−2.3 (−3.8,−0.7)	−1.5 (−3.4, 0.4)	−1.4 (−3.0, 0.4)	−2.0 (−3.2,−0.5)
	USt	0.5 (−0.7, 1.4)	0.4 (−0.7, 1.3)	−0.2 (−1.2, 1.0)	−0.8 (−2.0, 0.2)	−0.6 (−1.5, 0.2)
	Column	−1.6 (−3.1,−0.3)	−1.2 (−2.5,−0.1)	−0.7 (−2.0, 0.5)	−1.0 (−2.2, 0.2)	−1.0 (−2.0,−0.1)
Summer	Tr-LSt	−2.2 (−3.4,−1.1)	−2.0 (−2.8,−1.0)	−1.5 (−2.6,−0.6)	−1.1 (−2.4, 0.7)	−1.2 (−1.9,−0.1)
	USt	−0.2 (−1.0, 0.6)	−0.1 (−0.9, 0.6)	−0.1 (−1.0, 0.7)	0.0 (−0.8, 0.7)	−0.3 (−1.0, 0.4)
	Column	−1.3 (−1.9,−0.6)	−1.2 (−1.6,−0.6)	−0.8 (−1.3,−0.3)	−0.6 (−1.3, 0.4)	−0.7 (−1.2, 0.1)
Autumn	Tr-LSt	−0.9 (−2.0, 0.6)	−0.6 (−1.4, 0.6)	−0.2 (−1.1, 0.8)	−0.4 (−1.6, 0.7)	−0.1 (−0.8, 0.9)
	USt	−0.5 (−1.2, 0.3)	−0.6 (−1.2, 0.3)	−0.3 (−0.9, 0.6)	−0.3 (−1.1, 0.5)	−0.3 (−1.0, 0.5)
	Column	−0.8 (−1.5, 0.2)	−0.7 (−1.2, 0.3)	−0.4 (−1.0, 0.2)	−0.5 (−1.2, 0.2)	−0.6 (−1.1, 0.1)