Abstract
Abstract. The paper describes the association between high long-lasting solar/geomagnetic activity and geopotential height (GPH) changes in the winter lower atmosphere, based on their development in the Northern Hemisphere in the winter periods (December–March) of 1950–1969 and 1970–2002. Solar/geomagnetic activity is characterised by the 60-day mean of the sunspot number R/by the 60-day mean of the daily sum of the Kp index. The GPH distributions in the lower atmosphere are described by 60-day anomalies from their long-term daily average at 20 hPa/850 hPa. The data have been adopted from the NCEP/NCAR reanalysis. The 60-day mean values of solar/geomagnetic activity and GPH anomalies were calculated in five-day steps over the whole winter period. The analysis was carried out using composite maps which represent their distribution of the GPH anomalies during high solar activity (R ≥ 100) and high geomagnetic activity (ΣKp ≥ 20). Analysis has shown that the distribution of GPH anomalies depends on solar activity, geomagnetic activity and the phase of winter period (early or late winter). The nature of this relationship then depends on the time interval involved, i.e. 1950–1969 or 1970–2002. Positive anomalies in the polar stratosphere (20 hPa) were detected during the whole winter periods of the years 1950–1969. Significant anomalies were detected in the lower troposphere (850 hPa) during the second half of the winter period. The distribution of GPH anomalies on the maps compiled with regard to solar activity was similar to the distribution on maps compiled with regard to geomagnetic activity. In the interval 1970–2002, significant negative GPH anomalies were detected in the stratosphere at high latitudes, and positive anomalies were detected in the region of low latitudes. The distribution of GPH anomalies in the lower troposphere was substantially affected by situations in which, together with high solar activity, also high geomagnetic activity occurred.
Highlights
The composite maps, constructed with regard to the situations in which, together with high solar activity, high geomagnetic activity (R ≥ 100; Kp ≥ 20) was observed, displayed the occurrence of pronounced anomalies; negative anomalies observed at high latitudes in the intervals 1 December–29 January, 16 December–13 February and 31 December–28 February, and positive anomalies observed at low latitudes in all intervals analysed
In the second half of the winter period, high values of both activities were associated with the occurrence of pronounced geopotential height (GPH) anomalies, the distribution of which resembled the negative phase of the North Atlantic Oscillation (NAO)
In the lower troposphere in the second half of the winter period, these values of solar activity were associated with the occurrence of negative GPH anomalies over the Pacific
Summary
A number of papers have dealt with the connection between the distribution of pressure and temperature fields in the winter atmosphere and solar activity (Labitzke and van Loon, 1988; van Loon and Labitzke, 1988; Barnston and Livezey, 1989, 1991; Kodera, 1991, 2003; Balachandran and Rind, 1995; Rind and Balachandran, 1995; Balachandran et al, 1999; Haigh, 1994, 1996, 2003; Gleisner and Thejll, 2003; Gimeno et al, 2003; Kodera and Kuroda, 2005; Gray et al, 2010; and Marchand et al, 2012). J. Bochnıcek et al.: Circulation changes in the winter lower atmosphere time scale shorter (60-days) than used in the previous studies. In view of the number of papers, in which the authors pointed out the change in the nature of the relationship between solar activity, or the parameters related to solar activity, and the distribution of the GPH anomalies in the northern winter lower atmosphere around the year 1970 (Thompson et al, 2000, 2010; Boberg and Lundstedt, 2002; Thejll et al, 2003; Li et al, 2011), we divided the interval 1950–2002 and we investigated, as in Thejll et al (2003), the two parts: 1950– 1969 and 1970–2002. The effect of the quasi-biennial oscillation (QBO) was not studied
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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.
