Subfossil trunks of oak (Quercus robur L. and Q. petraea Lieb.) are fundamental for construction of long dendrochronological standards for southern Poland. In the last three years over 400 new oak trunks from alluvial deposits from the basins of the rivers Vistula and Odra were analysed. Most trunks came from the last 2500 years and the produced local chronologies permitted for improvement of the standard chronology POLAND2, covering the period 474 BC-I 555 AD. Subfossil oak trunks from several sites in the river Vistula basin (Grabie, Wolica, Podolsze and others) and from alluvia of the river Odra in Wrocław enabled construction of a new long chronology C_3000E, spanning the years 1795- 612 BC. This chronology was absolutely dated through teleconnection with standards for southern Germany. A row of floating chronologies, dated with the radiocarbon method, was established for the older periods of Holocene. They cover the following intervals: ca. 670-400 BC, ca. 2200-1900 BC, ca. 3400-3100 BC, ca. 3800-3600 BC and ca. 6650-6150 BC. Subfossil oak chronologies constructed by the author, together with standards based on living trees, monuments of wooden architecture, and archaeological timbers from Wielkopolska (449- I 994 AD), Lower Silesia (780-1994 AD) and Małopolska (910-1997 AD) practically allow for absolute dating of oak timbers from the area of southern Poland coming from the last 4000 years.

Extremely dense fog event was studied on the 3rd December 2001, which occurred in the city of Apatity, the Kola Peninsula, northwestern Russia. Fog had low visibility (30–50 m) and lasted 17 h. Variations of atmospheric pressure and electric field before and during the fog event were measured. Multiple Taper Method (MTM) of spectral analysis has revealed pulsations of the atmospheric electric field in the frequency band of 0.007–0.05 Hz with a power-law turbulence spectrum. MTM and wavelet decomposition analysis results indicate the appearance of two types of atmospheric pressure oscillations under the fog conditions: low-frequency variations with periods of internal gravity waves and a substantial increase in pulsation intensity (more than an order of magnitude) in the high frequency (0.03–0.35 Hz) range. These results may help to improve the understanding of the microphysics of fog formation, development, and dissipation. High-frequency pulsations generation of atmospheric pressure under the fog conditions is also of interest because their period is close to the range of infrasonic oscillations, which can have negative consequences for human health.