Petrology of the Hopen mangerite-charnockite intrusion, Lofoten, north Norway

The Hopen massif, intrusive age 1900 m.y., exposed area 15 km², in the Lofoten-Vesterålen granulite facies province has the mineral assemblages: (1) mesoperthite+plagioclase (An_7–20)+quartz+clinopyroxene (Di_20–25)+orthopyroxene En_15–25+opaques±minor amphibole±minor biotite; (2) mesoperthite+plagioclase (An <2)+quartz+clinopyroxene (Di <10)+olivine Fe lt;5)+opaques. By using mineral and whole rock analyses, the crystallization conditions were estimated to be 1000°C, 12 kb load pressure and an oxygen fugacity approximately corresponding to the WM buffer. Rocks with the assemblage of type (2) contain secondary orthoferrosilite (Fe_0.90–0.95Mn_0.04–0.07Mg_0.01Ca_0.01)₂Si₂O₆, generated by reactions involving fayalite, magnetite and quartz at 800°C, 10kb load pressure and at oxygen fugacities approaching QFM buffer conditions. Subsequent to a crustal thickening, the mangeritic rocks in Lofoten-Vesterålen were emplaced in a tensional environment comparable with modern continental rifts. A ‘gabbro pillow’ magma chamber at the crustal base is proposed as parental magma for the mangeritic rocks, of which the Hopen massif represents a late differentiation.     

Tropical cyclones in enhanced resolution CMIP5 experiments

This study investigates the possible effects of global warming on tropical cyclone (TC) activity. The study is conducted using the coupled ocean–atmosphere global climate model EC-Earth configured at a relatively high resolution (T159 with 62 vertical levels), which is integrated following the CMIP5 protocol. By considering the late twentieth century (1979–2009) in the historical simulation and the twenty-first century end (2070–2100) in the RCP4.5 and RCP8.5 scenarios, significant future annual mean frequency decreases are found globally and in both hemispheres, accompanied by significant mean lifetime decreases and significant intensity increases, the latter being found through several different measures (but with caveats). In addition, the relatively novel aspect of simulating TCs of the past (1900–1930) is studied to further assess the robustness of the climate change results. These results suggest that TCs in the early twentieth century were more frequent in the southern hemisphere and dissipated more energy in the southern hemisphere and the South Indian Ocean. Although some model biases are present and the coarse model resolution prevents intense TCs in being simulated, reasonable TC simulation skill for other metrics (e.g., TC genesis, frequency of occurrence) is found when validated against present day observations. Thus the model displays an acceptable ability to connect TC climatology with the larger scale circulation.     

High voltage transmission lines and their effect on reindeer: a research programme in progress

We review literature on high voltage transmission lines and their effect on wild reindeer ( Rangifer tarandus ) migration patterns and area use. We conclude that reliable knowledge is lacking on the effects of transmission lines on reindeer ecology. This condition relates to the lack of long-term monitoring of reindeer migration patterns in relation to existing lines. It is also related to the fact that nothing is known about hearing in reindeer (or any other deer species in Norway) in relation to transmission line noise, which is considered an obstacle for migrating reindeer.
We then outline a research programme that includes a laboratory study to determine the audiogram in reindeer and two field studies to examine the proximate effects of transmission lines - independently as well as combined with ambient environmental variables - on reindeer behaviour. The audiogram in two yearling male reindeer has been determined; this part of the study will be completed this year with the determination of a corresponding audiogram in two female yearlings. The behaviour study of domestic reindeer under high voltage transmission lines was completed in September 1999. The behaviour study of wild reindeer in the area crossed by a 420 kV power line will continue this year and its completion is anticipated in 2001.     

Barents-Kara sea ice and European winters in EC-Earth

Climate Dynamics - The potential link between decreasing Barents-Kara sea ice and cold winters in Europe is investigated using the enhanced resolution (horizontal atmospheric resolution of $$\sim...     

Comment on “Trends and low frequency variability of extra-tropical cyclone activity in the ensemble of twentieth century reanalysis” by Xiaolan L. Wang,Y. Feng,G. P. Compo,V. R. Swail,F. W. Zwiers,R. J. Allan,and P. D. Sardeshmukh,Climate Dynamics, 2012

The main subject of this article is to comment on the issue of storminess trends derived from the twentieth century reanalysis (20CR) and from observations in the North Atlantic region written about in Wang et al. (Clim Dyn 40(11–12):2775–2800, 2012). The statement that the 20CR estimates would be consistent with storminess derived from pressure-based proxies does not hold for the time prior to 1950.