Scaling behaviour of the global tropopause

Abstract

Abstract. Detrended fluctuation analysis is applied to the time series of the global tropopause height derived from the 1980-2004 daily radiosonde data, in order to detect longrange correlations in its time evolution.Global tropopause height fluctuations in small timeintervals are found to be positively correlated to those in larger time intervals in a power-law fashion. The exponent of this dependence is larger in the tropics than in the middle and high latitudes in both hemispheres. Greater persistence is observed in the tropopause of the Northern than in the Southern Hemisphere. A plausible physical explanation of the fact that long-range correlations in tropopause variability decreases with increasing latitude is that the column ozone fluctuations (that are closely related with the tropopause ones) exhibit long range correlations, which are larger in tropics than in the middle and high latitudes at long time scales.This finding for the tropopause height variability should reduce the existing uncertainties in assessing the climatic characteristics. More specifically the reliably modelled values of a climatic variable (i.e. past and future simulations) must exhibit the same scaling behaviour with that possibly existing in the real observations of the variable under consideration. An effort has been made to this end by applying the detrended fluctuation analysis to the global mean monthly land and sea surface temperature anomalies during the period January 1850-August 2008. The result obtained supports the findings presented above, notably: the correlations between the fluctuations in the global mean monthly land and sea surface temperature display scaling behaviour which must characterizes any projection.

Scaling regimes and linear/nonlinear responses of last millennium climate to volcanic and solar forcings

“…In contrast, volcanic eruptions cool the surface, but aerosol heating warms the sunlit lower stratosphere (Shindell et al, 2003;Miller et al, 2012). This leads to an increased meridional gradient in the lower stratosphere but a reduced gradient in the tropopause region (Chandra et al, 1996;Varotsos et al, 1994Varotsos et al, , 2009. Vyushin et al (2004) suggested that volcanic forcings improve the low-frequency variability scaling performance of atmosphere-ocean models compared to all other forcings (see, however, the comment by Blender and Fraedrich, 2004, which also discusses earlier papers on the field) and Blender and Fraedrich (2004).…”

On the progress of the 2015–2016 El Niño event

“…El Niño/La Niña Southern Oscillation (ENSO) is an oceanicatmospheric quasi-periodic phenomenon with several impacts on climate and weather not only in the tropical Pacific, but in many regions all over the world (Varotsos and Deligiorgi, 1991;Kondratyev and Varotsos, 1995a, b;Klein et al, 1999;Xue et al, 2000;Eccles and Tziperman, 2004;Varotsos, 2007, 2011;Lin, 2007;Chattopadhyay and Chattopadhyay, 2011;Efstathiou et al, 1998Efstathiou et al, , 2011Varotsos, 2013;C. Varotsos et al, 2009C.…”

Effect of tropospheric and stratospheric temperatures on tropopause height

“…Thus, the study is important in view of the stratospheric ozone thinning scenario (Tolba and Osama 1992). Some studies (Varotsos et al 2004(Varotsos et al , 2008Varotsos, Efstathiou, and Tzanis 2009) explained the inverse relationship between column ozone and TH at various geographical sites, showed a longitudinal and latitudinal variability and also analysed the TH variability reducing the existing uncertainties in assessing the climatic characteristics. The decreasing trend in the ozone of this Figure 4.…”