Ozone and Spectroradiometric UV Changes in the Past 20 Years over High Latitudes

Figures & data

Table 1. Stations with long time series of accessible UV data analyzed in this study. Stations are listed from northern to southern high latitudes.

	Latitude	Longitude	Data used	Instruments	Data source
55°–70°N
Barrow	71.19	−156.41	1991–2010	SUV-100	NSF^1
Sodankylä	67.36	26.63	1990–2011	Brewer MKII	FMI^2
Jokioinen	60.81	23.49	1996–2011	Brewer MKIII	FMI^2
Churchill	58.75	−94.07	1992–2011	Brewer MKII	WOUDC^3
55°–70°S
Ushuaia	−54.49	−68.19	1990–2008	SUV-100	NSF^1
Palmer	−64.46	−64.03	1990–2010	SUV-100	NSF^2
Syowa	−69.00	39.58	1993–2011	Brewer MKII, MKIII	WOUDC^3

¹ National Science Foundation.

² Finnish Meteorological Institute.

³ World Ozone and Ultraviolet Radiation Data Centre.

Fig. 1 Changes in total ozone over (a) 55°–70°N and (b) 55°–70°S. Long-term changes are given as a percentage per decade.

Fig. 2 Changes in AOD at 550 nm over (a) 55°–70°N and (b) 55°–70°S. For the overlapping period 2000–2006, the zonal mean AODs are 0.21 (GACP) and 0.14 (MODIS) for northern high latitudes; 0.20 (GACP) and 0.13 (MODIS) for southern high latitudes.

Fig. 3 Changes in cloud fraction over (a) 55°–70°N and (b) 55°–70°S. For the overlapping period 2000–2006, the stations mean cloud fractions are 0.65 (ISCCP) and 0.70 (MODIS) for northern high latitudes; 0.74 (ISCCP) and 0.79 (MODIS) for southern high latitudes.

Fig. 4 Changes in UV irradiances at 305 and 325 nm averaged over (a) four stations located between 55° and 70°N and (b) three stations located between 55° and 70°S.

Table 2. Long-term changes in UV irradiance and total ozone (in percent per decade) averaged over four stations between 55° and 70°N and three stations between 55° and 70°S. Values in parentheses refer to the statistical significance of each trend. Dashes in parentheses indicate a confidence level less than 90%.

Long-term changes (% per decade)	55°–70°N	55°–70°S
Ozone	+1.5 ± 0.4 (99%)	−0.2 ± 0.5 (–)
305 nm	−3.9 ± 2.1 (90%)	−2.7 ± 2.0 (–)
325 nm	−0.4 ± 1.0 (–)	−0.7 ± 0.9 (–)
[305–325] nm	−3.5 ± 1.6 (95%)	−2.0 ± 1.7 (–)

Table 3. Long-term changes and their standard errors (in percent per decade) of deseasonalized monthly mean UV irradiances at 305 and 325 nm and of their differences [305 nm–325 nm] at different stations. The last column shows the respective trends in satellite-derived total ozone.

	Latitude	Period	305 nm	325 nm	[305–325] nm	Total ozone
55°–70°N
Barrow	71.19	08/1994–08/2010	−6.9 ± 3.4	−2.9 ± 1.6	−4.0 ± 2.9	2.7 ± 0.8
Sodankylä	67.36	08/1994–08/2011	−8.7 ± 3.9	−2.3 ± 1.9	−6.4 ± 2.9	1.2 ± 0.8
Jokioinen	60.81	08/1996–08/2011	−0.5 ± 3.8	0.7 ± 2.1	−1.2 ± 2.7	0.4 ± 0.8
Churchill	58.75	08/1994–08/2011	0.4 ± 2.7	2.8 ± 1.5	−2.4 ± 2.1	1.7 ± 0.6
Mean of the 4 stations		08/1994–08/2011	−3.9 ± 2.1	−0.4 ± 1.0	−3.5 ± 1.6	1.5 ± 0.4
55°–70°S
Ushuaia	−54.49	02/1994–02/2008	0.4 ± 2.5	1.6 ± 1.1	−1.2 ± 2.0	0.5 ± 0.8
Palmer	−64.46	02/1994–02/2010	−8.3 ± 3.5	−6.1 ± 1.9	−2.2 ± 2.7	−0.2 ± 0.7
Syowa	−69.00	02/1994–02/2011	−0.3 ± 3.2	2.4 ± 1.4	−2.7 ± 2.6	−0.7 ± 0.8
Mean of the 3 stations		02/1994–02/2010	−2.7 ± 2.0	−0.7 ± 0.9	−2.0 ± 1.7	−0.2 ± 0.5