Long-term variations in the correlation between NAO and solar activity: the importance of North-South solar activity asymmetry for atmospheric circulation

General atmospheric circulation is the system of atmospheric motions over the Earth on the scale of the whole globe. Two main types of circulation have been identified: zonal - characterized by low amplitude waves in the troposphere moving quickly from west to east, and meridional with stationary high amplitude waves when the meridional transfer is intensified. The prevailing type of circulation is related to global climate. Based on many years of observations, certain circulation epochs have been defined when the same type of circulation prevails for years or decades. Here we study the relation between long-term changes in solar activity and prevailing type of atmospheric circulation, using NAO index reconstructed for the last four centuries as a proxy for large-scale atmospheric circulation. We find that when the southern solar hemisphere is more active, increasing solar activity in the secular solar cycle results in increasing zonality of the circulation, while when the northern solar hemisphere is more active, increasing solar activity increases meridional circulation. In an attempt to explain the observations, we compare the short-term reaction of NAO and NAM indices to different solar drivers: powerful solar flares, high speed solar wind streams, and magnetic cloudsComment: submitted to Advances in Space Research - a special issue with the proceedings of The Second International Symposium on Space Climate: "Long-term Change in the Sun, and its effects in the Heliosphere and Planet Earth" - Sinaia, Romania, September 13-16, 200

Solar wind-atmospheric electricity-cloud microphysics connections to weather and climate

We review recent research articles that present observations of the large-scale day-to-day dynamic tropospheric response to changes in the downward current density Jz of the global atmospheric electric circuit (GEC). The evidence for the global circuit downward current density, Jz, causing changes in atmospheric dynamics is now even stronger than as reviewed by Tinsley (Reports on Progress in Physics volume 71, 2008). We consider proposed mechanisms for these responses, and suggest future directions for research

A Review of the Evidence for Extinction Chronologies for Five Species of Upper Pleistocene Megafauna in Siberia

From the 18th International Radiocarbon Conference held in Wellington, New Zealand, September 1-5, 2003.A review of the radiocarbon chronology of some late Upper Pleistocene mammals from Siberia is presented. Previously published data has been supplemented by new 14C dates for 5 species (woolly mammoth, woolly rhinoceros, bison, horse, and muskox) to reconstruct chronological extinction patterns. The final extinction of woolly rhinoceros and bison in Siberia can be dated to approximately 11,000-9700 BP, but some megafaunal species (woolly mammoth, horse, and muskox) survived into the Late Holocene, about 3700-2200 BP.The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202