The effect of energetic electron precipitation on middle mesospheric night-time ozone during and after a moderate geomagnetic storm

Using a ground-based microwave radiometer at Troll Station, Antarctica (72°S, 2.5°E, L = 4.76), we have observed a decrease of 20–70% in the mesospheric ozone, coincident with increased nitric oxide, between 60 km and 75 km altitude associated with energetic electron precipitation (E > 30 keV) during a moderate geomagnetic storm (minimum Dst of −79 nT) in late July 2009. NOAA satellite data were used to identify the precipitating particles and to characterize their energy, spatial distribution and temporal variation over Antarctica during this isolated storm. Both the ozone decrease and nitric oxide increase initiate with the onset of the storm, and persist for several days after the precipitation ends, descending in the downward flow of the polar vortex. These combined data present a unique case study of the temporal and spatial morphology of chemical changes induced by electron precipitation during moderate geomagnetic storms, indicating that these commonplace events can cause significant effects on the middle mesospheric ozone distribution

Results from the intercalibration of optical low light calibration sources 2011

Following the 38th Annual European Meeting on Atmospheric Studies by Optical Methods in Siuntio in Finland, an intercalibration workshop for optical low light calibration sources was held in Sodankylä, Finland. The main purpose of this workshop was to provide a comparable scale for absolute measurements of aurora and airglow. All sources brought to the intercalibration workshop were compared to the Fritz Peak reference source using the Lindau Calibration Photometer built by Wilhelm Barke and Hans Lauche in 1984. The results were compared to several earlier intercalibration workshops. It was found that most sources were fairly stable over time, with errors in the range of 5–25%. To further validate the results, two sources were also intercalibrated at UNIS, Longyearbyen, Svalbard. Preliminary analysis indicates agreement with the intercalibration in Sodankylä within about 15–25%

Epistasis for Growth Rate and Total Metabolic Flux in Yeast

Studies of interactions between gene deletions repeatedly show that the effect of epistasis on the growth of yeast cells is roughly null or barely positive. These observations relate generally to the pace of growth, its costs in terms of required metabolites and energy are unknown. We measured the maximum rate at which yeast cultures grow and amounts of glucose they consume per synthesized biomass for strains with none, single, or double gene deletions. Because all strains were maintained under a fermentative mode of growth and thus shared a common pattern of metabolic processes, we used the rate of glucose uptake as a proxy for the total flux of metabolites and energy. In the tested sample, the double deletions showed null or slightly positive epistasis both for the mean growth and mean flux. This concordance is explained by the fact that average efficiency of converting glucose into biomass was nearly constant, that is, it did not change with the strength of growth effect. Individual changes in the efficiency caused by gene deletions did have a genetic basis as they were consistent over several environments and transmitted between single and double deletion strains indicating that the efficiency of growth, although independent of its rate, was appreciably heritable. Together, our results suggest that data on the rate of growth can be used as a proxy for the rate of total metabolism when the goal is to find strong individual interactions or estimate the mean epistatic effect. However, it may be necessary to assay both growth and flux in order to detect smaller individual effects of epistasis

Atmospheric ozone above Troll station, Antarctica observed by a ground based microwave radiometer

This paper describes the stratospheric and mesospheric ozone profiles retrieved from spectral measurements of the 249.96 GHz O3 line, using the British Antarctic Survey's ground-based Microwave Radiometer at Troll (BAS-MRT), Antarctica (72°01' S, 02°32' E, 62° Mlat). The instrument operated at Troll from February 2008 through January 2010, and hourly averaged spectra were used to retrieve approximately 22 ozone profiles per day. The ozone profiles cover the pressure range from 3 to 0.02 hPa (approximately 38 to 72 km) which includes the topside of the stratospheric ozone layer and the peak of the tertiary maximum. Comparing the retrieved ozone volume mixing ratio (vmr) values to Aura/MLS and SD-WACCM shows no significant bias to within the instrumental uncertainties. The long-term variations (> 20 days) between MLS and SD-WACCM agree well with BAS-MRT at all altitudes with significant correlation coefficients of at least 0.9 (0.7 with SD-WACCM) in the upper stratosphere and middle mesosphere. A weaker correlation is found for the long-term variations in summer when most of the vmr values are below the random noise level of Aura/MLS. The correlation of short-term variations (< 20 days) between MLS and BAS-MRT agree well at all altitudes with significant correlation coefficients of at least 0.7 in the upper stratosphere and middle mesosphere. The ozone profiles retrieved at Troll, Antarctica extend the sparse data coverage of middle atmospheric ozone above Antarctica, where, due to the dynamic nature of the ozone concentrations, systematic observations with a high temporal resolution are desirable. The O3 profiles presented here are stored at the UK's Polar Data Centre (http://doi.org/nc3) and are available for public scientific use

Is affluence a risk for adolescents in Norway?

Studies suggest that affluence poses a risk for adolescents, but this has rarely been studied outside the United States. We examined the unique and additive roles of family and school affluence for adolescent outcomes among 10th‐grade students (n = 7,203) in Oslo, Norway. Multilevel models were estimated separately by gender. For both boys and girls, school affluence was a risk for alcohol abuse and family affluence was a risk for conduct problems, although for conduct the risk was only at the very highest end of income distribution and adolescents in very poor families were also at risk. There was also a complex pattern of risk for early sexual debut; family affluence posed risk, but school affluence appeared protective. © 2017 Wile

Overvåking av miljøforholdene i Sørfjorden 2010. Metaller i vannmassene, Oksygen, nitrogen og fosfor i vannmassene, Miljøgifter i organismer

Resultatene av overvåkingen i 2010 kan oppsummeres som følger: Til tross for en økning i utslipp til vann sammenlignet med 2009 er det små forskjeller i konsentrasjonene av metaller i overflatevannet. I dypere vannlag er nivåene sporadisk høyere enn i overflatevannet. Nitratkonsentrasjonene i fjorden var de laveste observert siden 2001, som viser at utviklingen med avtakende utlekking av nitrogen fra sedimentene fortsetter. Fosfor viser en økning i 2010, sammenlignet med perioden 2005-2008 som har vært stabil. Konsentrasjonene av kvikksølv i torsk fra Sørfjorden tilsvarte Kl. II (moderat). Kvikksølv i blåskjell viste konsentrasjoner opp til Kl. II. Det var ingen overskridelser av Kl. I (lite/ubetydelig forurenset) for kobber og sink i blåskjell, med unntak av kobber ved Utne (Kl. II). Kadmium og bly i blåskjell viste konsentrasjoner fra Kl. I og opp til Kl. III (markert). PCB7- og DDT-konsentrasjonene i torsk fra Sørfjorden tilsvarte Kl. III i lever og Kl. II i filet. DDT i blåskjell tilsvarte opp til Kl. V (meget sterkt forurenset) og de høyeste konsentrasjonene ble observert ved Utne. Blåskjell fra Sørfjorden var lite/ubetydelig forurenset med PCB7 (Kl. I), unntatt ved Tyssedal (Kl. II). TEPCDF/D i blåskjell var moderat (Kl..II) til markert (Kl. III)