How important are future marine and shipping aerosol emissions in a warming Arctic summer and autumn?

Future sea ice retreat in the Arctic in summer and autumn is expected to affect both natural and anthropogenic aerosol emissions: sea ice acts as a barrier between the ocean and the atmosphere, and reducing it increases dimethyl sulfide and sea salt emissions. Additionally, a decrease in the area and thickness of sea ice could lead to enhanced Arctic ship traffic, for example due to shorter routes of cargo ships. Changes in the emissions of aerosol particles can then influence cloud properties, precipitation, surface albedo, and radiation. Next to changes in aerosol emissions, clouds will also be affected by increases in Arctic temperatures and humidities. In this study, we quantify how future aerosol radiative forcings and cloud radiative effects might change in the Arctic in late summer (July–August) and early autumn (September–October). Simulations were conducted for the years 2004 and 2050 with the global aerosol–climate model ECHAM6-HAM2. For 2050, simulations with and without additional ship emissions in the Arctic were carried out to quantify the impact of these emissions on the Arctic climate. In the future, sea salt as well as dimethyl sulfide emissions and burdens will increase in the Arctic. The increase in cloud condensation nuclei, which is due to changes in aerosol particles and meteorology, will enhance cloud droplet number concentrations over the Arctic Ocean (+10 % in late summer and +29 % in early autumn; in-cloud values averaged between 75 and 90∘ N). Furthermore, both liquid and total water path will increase (+10 % and +8 % in late summer; +34 % and +26 % in early autumn) since the specific humidity will be enhanced due to higher temperatures and the exposure of the ocean's surface. Changes in both aerosol radiative forcings and cloud radiative effects at the top of the atmosphere will not be dominated by the aerosol particles and clouds themselves but by the decrease in surface albedo (and by the increase in surface temperature for the longwave cloud radiative effect in early autumn). Mainly due to the reduction in sea ice, the aerosol radiative forcing will become less positive (decreasing from 0.53 to 0.36 W m−2 in late summer and from 0.15 to 0.11 W m−2 in early autumn). The decrease in sea ice is also mainly responsible for changes in the net cloud radiative effect, which will become more negative in late summer (changing from −36 to −46 W m−2). Therefore, the cooling component of both aerosols and clouds will gain importance in the future. We found that future Arctic ship emissions related to transport and oil and gas extraction (Peters et al., 2011) will not have a large impact on clouds and radiation: changes in aerosols only become significant when we increase these ship emissions by a factor of 10. However, even with 10-fold ship emissions, the net aerosol radiative forcing shows no significant changes. Enhanced black carbon deposition on snow leads to a locally significant but very small increase in radiative forcing over the central Arctic Ocean in early autumn (no significant increase for average between 75 and 90∘ N). Furthermore, the 10-fold higher ship emissions increase the optical thickness and lifetime of clouds in late summer (net cloud radiative effect changing from −48 to −52 W m−2). These aerosol–cloud effects have a considerably larger influence on the radiative forcing than the direct effects of particles (both aerosol particles in the atmosphere and particles deposited on snow). In summary, future ship emissions of aerosols and their precursor gases might have a net cooling effect, which is small compared to other changes in future Arctic climate such as those caused by the decrease in surface albedo

Global relevance of marine organic aerosol as ice nucleating particles

Ice nucleating particles (INPs) increase the temperature at which supercooled droplets start to freeze. They are therefore of particular interest in mixed-phase cloud temperature regimes, where supercooled liquid droplets can persist for extended periods of time in the absence of INPs. When INPs are introduced to such an environment, the cloud can quickly glaciate following ice multiplication processes and the Wegener–Bergeron–Findeisen (WBF) process. The WBF process can also cause the ice to grow to precipitation size and precipitate out. All of these processes alter the radiative properties. Despite their potential influence on climate, the ice nucleation ability and importance of different aerosol species is still not well understood and is a field of active research. In this study, we use the aerosol–climate model ECHAM6-HAM2 to examine the global relevance of marine organic aerosol (MOA), which has drawn much interest in recent years as a potentially important INPs in remote marine regions. We address the uncertainties in emissions and ice nucleation activity of MOA with a range of reasonable set-ups and find a wide range of resulting MOA burdens. The relative importance of MOA as an INP compared to dust is investigated and found to depend strongly on the type of ice nucleation parameterisation scheme chosen. On the zonal mean, freezing due to MOA leads to relative increases in the cloud ice occurrence and in-cloud number concentration close to the surface in the polar regions during summer. Slight but consistent decreases in the in-cloud ice crystal effective radius can also be observed over the same regions during all seasons. Regardless, MOA was not found to affect the radiative balance significantly on the global scale, due to its relatively weak ice activity and a low sensitivity of cloud ice properties to heterogeneous ice nucleation in our model

Cancer Curriculum for Appalachian Kentucky Middle and High Schools

Background: Appalachian Kentucky faces the highest cancer incidence and mortality rates in the country due to poor health behaviors and lifestyle choices. These poor health behaviors are facilitated by a lack of cancer education. Youth represent a vulnerable population that could be greatly impacted by increased cancer education. Teachers have the power to facilitate this learning. Purpose: This study examined the need for cancer education curriculum in Appalachian Kentucky middle and high schools from the perspective of educators. Methods: An online survey was conducted with science and health teachers (n=21) in Appalachian Kentucky, consisting of questions that investigated existing cancer education efforts, relevance of cancer education, and feasibility of such curriculum being delivered in the classroom. Content analysis was used to analyze teacher comments. A 3-part cancer education curriculum was developed that is culturally relevant and aligned with science and health education standards. Results: All participating teachers agree that cancer education is important to students’ lives. Teachers also agree that there is an inconsistent amount of cancer education within schools, and qualitative content analysis revealed that cancer education likely fits best in certain course subjects. Cancer education could feasibly be integrated into science and health classrooms, although the perception of needing to teach to the academic standards and having limited time to teach additional lessons outside of the standards are significant barriers. To combat this, a cancer curriculum that aligns with state and national science and health education standards was developed. Implications: Cancer education curriculum could play an important role in improving the cancer outlook in Appalachian Kentucky. Teachers have expressed a desire for increased cancer education in the classroom. By disseminating and implementing cancer curriculum in schools in the region and revising the curriculum -based on teacher and student feedback to better fit their needs, it has the potential to increase cancer literacy and improve related health behaviors and outcomes

A 0.6V, 8mW 3D Vision Processor for a Navigation Device for the Visually Impaired

This paper presents an energy-efficient computer vision processor for a navigation device for the visually impaired. Utilizing a shared parallel datapath, out-of-order processing and co-optimization with hardware-oriented algorithms, the processor consumes 8mW at 0.6V while processing 30 fps input data stream in real time. The test chip fabricated in 40nm is demonstrated as a core part of a navigation device based on a ToF camera, which successfully detects safe areas and obstacles.Texas Instruments Incorporate

Under­lying Determinants of and Solutions for Malnutrition in Low-­and Middle-­Income Countries

The text provides a much-needed resource for established researchers and practitioners of public health nutrition. Each chapter is authored by preeminent experts in the field, and the book includes aids for classroom learning, including case studies, learning objectives, and review questions. A rigorous introduction to foundational knowledge, Public Health Nutrition concludes with a discussion of current and future solutions for pressing health issues

Empathy: a review of the concept

The inconsistent definition of empathy has had a negative impact on both research and practice. The aim of this article is to review and critically appraise a range of definitions of empathy and, through considered analysis, to develop a new conceptualisation. From the examination of 43 discrete definitions, 8 themes relating to the nature of empathy emerged: “distinguishing empathy from other concepts”; “cognitive or affective?”; “congruent or incongruent?”; “subject to other stimuli?”; “self/other distinction or merging?”; “trait or state influences?”; “has a behavioural outcome?”; and “automatic or controlled?” The relevance and validity of each theme is assessed and a new conceptualisation of empathy is offered. The benefits of employing a more consistent and complete definition of empathy are discussed

The chance of freezing – a conceptional study to parameterize temperature-dependent freezing by including randomness of ice-nucleating particle concentrations

Ice-nucleating particle concentrations (INPCs) can spread over several orders of magnitude at any given temperature. However, this variability is rarely accounted for in heterogeneous ice-nucleation parameterizations. In this paper, we present an approach to incorporate the random variation in the INPC into the parameterization of immersion freezing and analyze this novel concept with various sensitivity tests. In the new scheme, the INPC is drawn from a relative frequency distribution of cumulative INPCs. At each temperature, this distribution describing the INPCs is expressed as a lognormal frequency distribution. The new parameterization scheme does not require aerosol information from the driving model to represent the heterogeneity of INPCs. The scheme's performance is tested in a large-eddy simulation of a relatively warm Arctic mixed-phase stratocumulus. We find that it leads to reasonable ice masses in the cloud, especially when compared to immersion freezing schemes that yield one fixed INPC per temperature and lead to almost no ice production in the simulated cloud. The scheme is sensitive to the median of the frequency distribution and highly sensitive to the standard deviation of the distribution, as well as to the frequency of drawing a new INPC and the resolution of the model. Generally, a higher probability of drawing large INPCs leads to substantially more ice in the simulated cloud. We expose inherent challenges to introducing such a parameterization and explore possible solutions and potential developments.</p