Statistics of long-term ionospheric measurements

It is shown that after elimination of the dominant influence of solar activity, the height hmF2 of the maximum ionisation of the ionosphere (which is inversely linearly related to M(3000)F2 as described for example by the Shimazaki formula) shows a marked decrease during the recent solar minimum (2005 to 2009) of about 20 km. This is in accordance with results of studies of the decreased neutral density of the lower thermosphere and the density decrease at about 400 km during the unusual recent solar minimum. It is also shown that there is a trend reversal in the height of the ionosphere hmF2 in about 1963/1964 with a negative trend from 1942 to 1963 and a positive trend from 1964 to 2005. This is in contrast to the results reported in most other publications of ionospheric long-term trends. There is no significant trend in foF2 and, particularly, none of the effects described above for hmF2 could be found in foF2

Resolving the Evolutionary History of Campanula (Campanulaceae) in Western North America

Recent phylogenetic works have begun to address long-standing questions regarding the systematics of Campanula (Campanulaceae). Yet, aspects of the evolutionary history, particularly in northwestern North America, remain unresolved. Thus, our primary goal in this study was to infer the phylogenetic positions of northwestern Campanula species within the greater Campanuloideae tree. We combined new sequence data from 5 markers (atpB, rbcL, matK, and trnL-F regions of the chloroplast and the nuclear ITS) representing 12 species of Campanula with previously published datasets for worldwide campanuloids, allowing us to include approximately 75% of North American Campanuleae in a phylogenetic analysis of the Campanuloideae. Because all but one of North American Campanula species are nested within a single campanuloid subclade (the Rapunculus clade), we conducted a separate set of analyses focused specifically on this group. Our findings show that i) the campanuloids have colonized North America at least 6 times, 4 of which led to radiations, ii) all but one North American campanuloid are nested within the Rapunculus clade, iii) in northwestern North America, a C. piperi – C. lasiocarpa ancestor gave rise to a monophyletic Cordilleran clade that is sister to a clade containing C. rotundifolia, iv) within the Cordilleran clade, C. parryi var. parryi and C. parryi var. idahoensis exhibit a deep, species-level genetic divergence, and v) C. rotundifolia is genetically diverse across its range and polyphyletic. Potential causes of diversification and endemism in northwestern North America are discussed

The Regional Warning Center Darmstadt (from the 1960s until 1993)

The work and achievements of the Regional Warning Center Darmstadt at the Research Institute of the Deutsche Bundespost in Darmstadt, Germany, are briefly reviewed. After privatisation of the Deutsche Bundespost (now Deutsche Telekom) in 1993, research in HF propagation and hence the RWC was disbanded

A simple method of estimating the ionospheric parameters foF2 and M(3000) with the aid of a home computer

SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman