Observed anomalous atmospheric patterns in summers of unusual Arctic sea ice melt

The Arctic sea ice retreat has accelerated over the last decade. The negative trend is largest in summer, but substantial interannual variability still remains. Here we explore observed atmospheric conditions and feedback mechanisms during summer months of anomalous sea ice melt in the Arctic. Compositing months of anomalous low and high sea ice melt over 1979–2013, we find distinct patterns in atmospheric circulation, precipitation, radiation, and temperature. Compared to summer months of anomalous low sea ice melt, high melt months are characterized by anomalous high sea level pressure in the Arctic (up to 7 hPa), with a corresponding tendency of storms to track on a more zonal path. As a result, the Arctic receives less precipitation overall and 39% less snowfall. This lowers the albedo of the region and reduces the negative feedback the snowfall provides for the sea ice. With an anticyclonic tendency, 12 W/m2 more incoming shortwave radiation reaches the surface in the start of the season. The melting sea ice in turn promotes cloud development in the marginal ice zones and enhances downwelling longwave radiation at the surface toward the end of the season. A positive cloud feedback emerges. In midlatitudes, the more zonally tracking cyclones give stormier, cloudier, wetter, and cooler summers in most of northern Europe and around the Sea of Okhotsk. Farther south, the region from the Mediterranean Sea to East Asia experiences significant surface warming (up to 2.4◦C), possibly linked to changes in the jet stream

Arctic Summer Sea Ice Melt and Related Atmospheric Conditions in Coupled Regional Climate Model Simulations and Observations

Observations from 1979 to 2014 show a positive trend in the summer sea ice melt rate with an acceleration particularly in June and August. This is associated with atmospheric circulation changes such as a tendency toward a dipole pattern in the mean sea level pressure (SLP) trend with an increase over the Arctic Ocean and a decrease over Siberia. Consistent with previous studies, we here show the statistical relationship between the summer sea ice melt rate and SLP and that more than one SLP pattern is associated with anomalously high melt rates. Most high melt rates occur during high pressure over the Arctic Ocean accompanied by low pressure over Siberia, but a strong Beaufort High and advection of warm air associated with a cyclone located over the Taymyr Peninsula can also trigger anomalous high ice melt. We evaluate 10-member ensemble simulations with the coupled atmosphere-ice-ocean Arctic regional climate model HIRHAM-NAOSIM. The simulations have systematically low acceleration of sea ice melt rate in August, related to shortcomings in representing the strengthening pressure gradient from the Barents/Kara Sea toward Northern Greenland in recent decades. In general, the model shows the same classification of SLP patterns related to anomalous melt rates as the observations. However, the evolution of sea ice melt-related cloud-radiation feedback over the summer reveals contrary effects from low-level clouds in the reanalysis and in the simulations

Genomic Relationships, Novel Loci, and Pleiotropic Mechanisms across Eight Psychiatric Disorders

Genetic influences on psychiatric disorders transcend diagnostic boundaries, suggesting substantial pleiotropy of contributing loci. However, the nature and mechanisms of these pleiotropic effects remain unclear. We performed analyses of 232,964 cases and 494,162 controls from genome-wide studies of anorexia nervosa, attention-deficit/hyper-activity disorder, autism spectrum disorder, bipolar disorder, major depression, obsessive-compulsive disorder, schizophrenia, and Tourette syndrome. Genetic correlation analyses revealed a meaningful structure within the eight disorders, identifying three groups of inter-related disorders. Meta-analysis across these eight disorders detected 109 loci associated with at least two psychiatric disorders, including 23 loci with pleiotropic effects on four or more disorders and 11 loci with antagonistic effects on multiple disorders. The pleiotropic loci are located within genes that show heightened expression in the brain throughout the lifespan, beginning prenatally in the second trimester, and play prominent roles in neurodevelopmental processes. These findings have important implications for psychiatric nosology, drug development, and risk prediction.Peer reviewe

Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors

Background Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors. Results Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged. Conclusions Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.Peer reviewe

Northern Hemisphere storminess in the Norwegian Earth System Model (NorESM1-M)

Metrics of storm activity in Northern Hemisphere high- and midlatitudes are evaluated from historical output and future projections by the Norwegian Earth System Model (NorESM1-M) coupled global climate model. The European Re-Analysis Interim (ERA-Interim) and the Community Climate System Model (CCSM4), a global climate model of the same vintage as NorESM1-M, provide benchmarks for comparison. The focus is on the autumn and early winter (September through December), the period when the ongoing and projected Arctic sea ice retreat is greatest. Storm tracks derived from a vorticity-based algorithm for storm identification are reproduced well by NorESM1-M, although the tracks are somewhat better resolved in the higher-resolution ERA-Interim and CCSM4. The tracks are projected to shift polewards in the future as climate changes under the Representative Concentration Pathway (RCP) forcing scenarios. Cyclones are projected to become generally more intense in the high-latitudes, especially over the Alaskan region, although in some other areas the intensity is projected to decrease. While projected changes in track density are less coherent, there is a general tendency towards less frequent storms in midlatitudes and more frequent storms in high-latitudes, especially the Baffin Bay/Davis Strait region. Autumn precipitation is projected to increase significantly across the entire high-latitudes. Together with the projected increases in storm intensity and sea level and the loss of sea ice, this increase in precipitation implies a greater vulnerability to coastal flooding and erosion, especially in the Alaskan region. The projected changes in storm intensity and precipitation (as well as sea ice and sea level pressure) scale generally linearly with the RCP value of the forcing and with time through the 21st century

Linking Northern High-Latitude Cryospheric Changes to Large-Scale Atmospheric Circulation

Warming twice as fast as the rest of the globe, the northern high-latitudes arguably show the clearest evidences of observed and projected climate changes. Two of these are the rapid loss of Arctic sea ice and the shrinking of the Greenland Ice Sheet. In this dissertation, three papers analyze the interaction between the cryospheric changes and the atmospheric circulation. In the first paper, summers of observed anomalous Arctic sea ice melt are composited in order to distinguish large-scale atmospheric patterns associated with sea ice loss. While a positive cloud feedback characterizes warm high-latitude summers, storms track more zonally in midlatitudes, leaving summers stormier, wetter and cooler in northwestern Europe and around the Sea of Okhotsk. Farther south, a heating band from the Mediterranean Sea to East Asia indicates an increased probability of heat extremes in these areas in summers of high Arctic sea ice melt. The second paper analyzes projected changes in Arctic sea ice and Northern Hemisphere storminess. Here, a general poleward-shift of the main storm tracks is revealed. Cyclone intensities generally follow cyclone frequencies, but with an elevated intensification over new open ocean areas. For most of the domain, precipitation increases significantly, with the highest enhancements along the poleward-shifted storm tracks and in the sea ice diminishing Arctic. Finally, the influence of cyclonic and anticyclonic activities on the observed Greenland Ice Sheet (GrIS) surface mass balance (SMB) variability annually is analyzed in the third paper. The synoptic features correlate with the SMB changes through their impact on temperature and snow accumulation. Generally, enhanced cyclonic activity contributes to increased snow accumulation over the GrIS by transporting more heat and moisture from the south. A warming effect also results from enhanced anticyclonic activity in summer, where fewer clouds increase the incoming shortwave radiation and thus surface temperature. Overall, up to 60 % of the regional SMB variability can be explained by these synoptic activities. All together, the three papers illustrate how the Arctic sea ice and the GrIS interconnect with local and remote changes in the atmospheric circulation. While various studies find the regional changes to significantly alter ecosystems, impact local communities and enhance industry potential, distant consequences might include sea level rise, elevated risks of extreme weather events, decline in agricultural production, economic disruption and hence political instabilities

An analysis of the willingness to adopt new mobility services

This research has contributed to the understanding of how changing customer preferences, technological innovation, and environmental needs will shape future mobility services. Consequently, this thesis explores how the automobile industry should adapt their business models to offer mobility services as a response to these trends. To explore this concept, the study examines to what extent six independent variables of customer preferences- and characteristics affect the customer’s willingness to adopt new mobility services. In turn, the findings have identified the most significant factors for a distributor to integrate when shaping future mobility services. The six independent variables have been extracted based on a literature review on the topic of business models and mobility services, as well as the topic of customer innovativeness and environmentalism. An online survey was distributed to carusers in the greater Oslo region to collect data on the topic. To analyze the data, quantitative research has been applied by conducting a multiple regression analysis to test the hypotheses and to identify the effect of each independent variable on the willingness to adopt new mobility services. The findings show that the significant predictors of a customer’s willingness to adopt new mobility services are the customer preferences on economic flexibility and availability, and the customer characteristics on environmentalism and attitude toward new mobility services. As a result of the findings, the paper argues that the distributor should ensure a high level of economic flexibility for the customer and a high level of availability of the product when shaping new mobility services. Moreover, the distributor should brand future mobility service as environmentally friendly. Lastly, the findings indicate that there is a positive attitude toward new mobility services among the customers in the Norwegian market. Consequently, distributors should take action now by offering mobility services in order to capture economies of scale as a result of first-mover advantages and to avoid becoming industry laggards

Environmental conditions for polar low formation and development over the Nordic Seas: study of January cases based on the Arctic System Reanalysis

The sparse observational network over the Arctic region makes severe storms such as polar lows (PLs) still hard to predict. To improve their forecasting and detection, it is of great importance to gain better understanding of their formation and development. Therefore, we have analyzed the environment of PLs at their genesis and mature stages using a set of parameters: the difference between sea surface and 500 hPa temperature (or at 2 m height), lapse rate (LR) and relative humidity below 850 hPa (RH), near-surface wind speed and geopotential height anomaly. We evaluate which of these conditions (or which combination) is(are) the most favourable for PL formation and persistence. The analysis was performed on 33 January cases over 12 years (2000-2011) using the Arctic System Reanalysis. The results showed that, for the cases with lower thermal instability during formation stage, LRs throughout the boundary layer were stronger and steeper; therefore, these PLs were fostering convective development. However, for few cases, it was noted that when convection decreased simultaneously with increased thermal stability, RH most of the times was above 90%. It was also noted that the higher amount of RH at lower levels during genesis stage promoted stronger winds at the maturity stage

Spermatozoon ultrastructure and sperm production in wolffish

The ultrastructure of spermatozoon and sperm production were observed in wolffish (Anarhichas lupus), a species with internal fertilization, from a broodstock. The mature spermatozoon has an elongated head, eccentric flagellum, and comparatively well developed middle piece. Based on the observations of sperm cells with the optical microscope, the mean lengths of spermatozoon head and flagellum were 3.3 and 21.2 μm respectively. A high variability of sperm cell size was observed due to the presence of spermatids and degenerated spermatozoa in the ejaculate. In most males, sperm production was registered throughout the whole year with a peak in December and January. Sperm production decreased to the end of the breeding season. The difference in volumes of ejaculate and sperm concentrations between males kept at two light cycles (18D: 6L and 6D: 18L) was not significant. Features of wolffish sperm are compared with data reported in the literature on other internally and externally fertilizing fish