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
Estimating the climate significance of halogen-driven ozone loss in the tropical marine troposphere Atmospheric Chemistry and Physics DOI 10.5194/acp-12-3939-2012 4 May 2012 We find that the implementation of oceanic halogen sources and chemistry in climate models is an important component of the natural background ozone budget and we suggest that it needs to be considered when estimating both preindustrial ozone baseline levels and long term changes in tropospheric ozone. Read more
The regulation of the air: a hypothesis Solid Earth DOI 10.5194/se-3-87-2012 12 March 2012 We propose the hypothesis that natural selection, acting on the specificity or preference for CO2 over O2 of the enzyme rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase), has controlled the CO2:O2 ratio of the atmosphere since the evolution of photosynthesis and has also sustained the Earth’s greenhouse-set surface temperature. 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. Read more
Evidence of a possible turning point in solar UV-B over Canada, Europe and Japan Atmospheric Chemistry and Physics DOI 10.5194/acp-12-2469-2012 5 March 2012 This study examines the long-term variability of UV solar irradiances at 305 nm and 325 nm over selected sites in Canada, Europe and Japan. Site selection was restricted to the availability of the most complete UV spectroradiometric datasets during the period 1990–2011. The analysis includes the long-term variability of total ozone, aerosol optical depth and cloud fraction at the sites studied. Read more
A tsunami wave recorded near a glacier front Natural Hazards and Earth System Sciences DOI 10.5194/nhess-12-415-2012 27 February 2012 We observed a tsunami wave near the glacier front in the Temple Fjord (Spitsbergen). Two temperature and pressure recorders were deployed on a wire from the ice approximately 300 m from the glacier front. The measurements allowed us to estimate the wave number of these waves and the Young’s modulus of the ice. 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. Read more
Tomography of the 2011 Iwaki earthquake (M 7.0) and Fukushima nuclear power plant area Solid Earth DOI 10.5194/se-3-43-2012 14 February 2012 High-resolution tomographic images of the crust and upper mantle in and around the area of the 2011 Iwaki earthquake (M 7.0) and the Fukushima nuclear power plant are determined by inverting a large number of high-quality arrival times with both the finite-frequency and ray tomography methods. The similar structures under the Iwaki source area and the Fukushima nuclear power plant suggest that the security of the nuclear power plant site should be strengthened to withstand potential large earthquakes in the future. 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