China’s dimming and brightening: evidence, causes and hydrological implications Annales Geophysicae DOI 10.5194/angeo-32-41-2014 28 January 2014 In this study, we synthesize reliable results and conclusively address recent advances and insufficiencies in studies on dimming and brightening in China. Read more
Stereoscopic determination of all-sky altitude map of aurora using two ground-based Nikon DSLR cameras Annales Geophysicae DOI 10.5194/angeo-31-1543-2013 6 September 2013 A new stereoscopic measurement technique is developed to obtain an all-sky altitude map of aurora using two ground-based digital single-lens reflex (DSLR) cameras. DSLR cameras">Read more
Detection of a plasmaspheric wind in the Earth’s magnetosphere by the Cluster spacecraft Annales Geophysicae DOI 10.5194/angeo-31-1143-2013 2 July 2013 Analysis of ion measurements, acquired in the outer plasmasphere by the CIS experiment onboard the four Cluster spacecraft, provide now an experimental confirmation of the plasmaspheric wind. Read more
The Geminid meteor shower during the ECOMA sounding rocket campaign: specular and head echo radar observations Annales Geophysicae DOI 10.5194/angeo-31-473-2013 12 March 2013 The ECOMA (Existence of Charge state Of meteoric smoke particles in the Middle Atmosphere) sounding rocket campaign was conducted during the Geminid meteor shower in December 2010 in order to explore whether there is a change of the properties of meteoric smoke particles due to the stream. ECOMA sounding rocket campaign: specular and head echo radar observations">Read more
The “step feature” of suprathermal ion distributions: a discriminator between acceleration processes? Annales Geophysicae DOI 10.5194/angeo-30-1315-2012 5 September 2012 With this study, we draw the attention to the so-called “step feature” of the velocity distributions of suprathermal particles in the solar wind and offer a criterion that allows one to distinguish between those scenarios that employ velocity diffusion, i.e. second-order Fermi processes, which are prime candidates in the present debate. Read more
On the role of ozone in long-term trends in the upper atmosphere-ionosphere system Annales Geophysicae DOI 10.5194/angeo-30-811-2012 8 May 2012 Recently, Walsh and Oliver (2011) suggested that the long-term cooling of the upper thermosphere (above 200 km) may be due largely to the stratospheric ozone depletion. Here, we show that the role of ozone is very important in the mesosphere and lower thermosphere but not in the upper thermosphere. Read more
Global characteristics of the lunar tidal modulation of the equatorial electrojet derived from CHAMP observations Annales Geophysicae DOI 10.5194/angeo-30-527-2012 8 March 2012 It has been known since many decades that lunar tide has an influence on the strength of the equatorial electrojet (EEJ). There has, however, never been a comprehensive study of the tidal effect on a global scale. Based on the continuous magnetic field measurements by the CHAMP satellite over 10 years it is possible to investigate the various aspects of lunar effects on the EEJ. CHAMP observations">Read more
Revisiting “Narrow Bipolar Event” intracloud lightning using the FORTE satellite Annales Geophysicae DOI 10.5194/angeo-30-389-2012 24 February 2012 The lightning stroke called a “Narrow Bipolar Event”, or NBE, is an intracloud discharge responsible for significant charge redistribution. The NBE occurs within 10–20 μs, and some associated process emits irregular bursts of intense radio noise, fading at shorter timescales, sporadically during the charge transfer. FORTE satellite">Read more
Magnetopause displacements: the possible role of dust Annales Geophysicae DOI 10.5194/angeo-29-2219-2011 1 December 2011 Large compressions of the magnetopause are proposed to occasionally result from temporary encounters of the magnetosphere with dust streams in interplanetary space. Such streams may have their origin in cometary dust tails or asteroids which cross the inner heliosphere or in meteoroids in Earth’s vicinity. Read more
