Historical and Projected Distributions of Daily Temperature and Pressure in the Arctic

Changes in extreme temperatures and pressures in the Arctic have received little attention in the context of climate change. Here we examine the distributions and extremes of surface air temperature and pressure in the Arctic for the late 20th century, using Alaskan weather station data, an atmospheric reanalysis, and general circulation models (GCMs). There is good agreement among these sources for the late 20th century, with broader distributions for both temperature and pressure in winter as compared to summer, and over land as compared to over ocean. We used the output from 21st-century greenhouse simulations by the GCMs to address the occurrence of extremes in the coming decades. The model projections of the 21st-century extremes largely agree with changes in the mean state, with record low temperatures decreasing in frequency and record high temperatures increasing in frequency. The changes in 21st-century extremes are more pronounced over the ocean, where the present-day distributions are narrower. The projected decreases of mean pressure result in more frequent occurrences of extreme low pressure, especially over the Arctic Ocean, although the extremes of pressure are less affected by changes of the means than are the extremes of temperature. Lastly, we find that the transition from sea ice to open water, and associated changes in the salinity of the surface water, can cause changes in the temperature distribution that are more complex than simple shifts in the distribution, leading to unexpected changes in the occurrence of extreme temperatures.Les changements en matière de températures et de pressions extrêmes dans l’Arctique reçoivent peu d’attention dans le contexte du changement climatique. Ici, nous examinons les répartitions et les extrêmes de la température de l’air en surface et de la pression dans l’Arctique vers la fin du XXe siècle et ce, en nous appuyant sur les données de la station météorologique de l’Alaska, sur une nouvelle analyse atmosphérique et sur des modèles de circulation générale. Il existe une bonne concordance quant aux sources visant la fin du XXe siècle, avec des répartitions plus vastes pour les températures et pressions d’hiver comparativement à celles de l’été, ainsi que pour les températures et pressions terrestres par rapport aux températures et pressions océaniques. Nous nous sommes également servi des données émanant de simulations de serres au XXIe siècle, réalisées au moyen des modèles de circulation générale afin d’être en mesure de nous pencher sur l’occurrence des extrêmes au cours des décennies à venir. Les projections de modèles relatives aux extrêmes du XXIe siècle concordent largement avec les changements caractérisant l’état de la moyenne, la fréquence des basses températures record étant à la baisse et la fréquence des hautes températures record étant à la hausse. Les changements en matière d’extrêmes au XXIe siècle sont plus prononcés au-dessus de l’océan, là où les répartitions actuelles sont plus étroites. Les diminutions projetées de la pression moyenne se traduisent par des occurrences plus fréquentes de basses pressions extrêmes, surtout au-dessus de l’océan Arctique, bien que les extrêmes en matière de pressions soient moins touchés par les changements des moyennes que les extrêmes de températures. De plus, nous estimons que la transition allant de la glace de mer à l’eau libre, de même que les changements connexes du point de vue de la salinité de l’eau de surface, peuvent entraîner des changements sur le plan de la répartition des températures qui sont plus complexes que de simples décalages de répartition, ce qui mène à des changements inattendus en matière d’occurrence de températures extrêmes

Effect of Phosphorus Nutrition on Growth and Physiology of Cotton Under Ambient and Elevated Carbon Dioxide

Phosphorous deficiency in soil limits crop growth and productivity in the majority of arable lands worldwide and may moderate the growth enhancement effect of rising atmospheric carbon dioxide (CO2) concentration. To evaluate the interactive effect of these two factors on cotton (Gossypium hirsutum) growth and physiology, plants were grown in controlled environment growth chambers with three levels of phosphate (Pi) supply (0.20, 0.05 and 0.01 mM) under ambient and elevated (400 and 800 μmol mol‒1, respectively) CO2. Phosphate stress caused stunted growth and resulted in early leaf senescence with severely decreased leaf area and photosynthesis. Phosphate stress led to over 77 % reduction in total biomass across CO2 levels. There was a below-ground (roots) shift in biomass partitioning under Pi deficiency. While tissue phosphorus (P) decreased, tissue nitrogen (N) content tended to increase under Pi deficiency. The CO2 × Pi interactions were significant on leaf area, photosynthesis and biomass accumulation. The stimulatory effect of elevated CO2 on growth and photosynthesis was reduced or highly depressed suggesting an increased sensitivity of cotton to Pi deficiency under elevated CO2. Although, tissue P and stomatal conductance were lower at elevated CO2, these did not appear to be the main causes of cotton unresponsiveness to elevated CO2 under severe Pi-stress. The alteration in the uptake and utilization of N was suggested due to a consistent reduction (18–21 %) in the cotton plant tissue N content under elevated CO2

The ABCD of usability testing

We introduce a methodology for tracking and auditing feedback, errors and suggestions for software packages. This short paper describes how we innovate on the evaluation mechanism, introducing an (Antecedent, Barrier, Consequence and Development) ABCD form, embedded within an eParticipation platform to enable end users to easily report on any usability issues. This methodology will be utilised to improve the STEP cloud eParticipation platform (part of the current STEP Horizon2020 project http://step4youth.eu. The platform is currently being piloted in real life contexts, with the participation of public authorities that are integrating the eParticipation platform into their regular decision-making practices. The project is involving young people, through engagement and motivation strategies and giving them a voice in Environmental decision making at the local level. The pilot evaluation aims to demonstrate how open engagement needs to be embedded within public sector processes and the usability methodology reported here will help to identify the key barriers for wide scale deployment of the platform

Determination of composition and structure of spongy bone tissue in human head of femur by Raman spectral mapping

Biomechanical properties of bone depend on the composition and organization of collagen fibers. In this study, Raman microspectroscopy was employed to determine the content of mineral and organic constituents and orientation of collagen fibers in spongy bone in the human head of femur at the microstructural level. Changes in composition and structure of trabecula were illustrated using Raman spectral mapping. The polarized Raman spectra permit separate analysis of local variations in orientation and composition. The ratios of ν2PO43−/Amide III, ν4PO43−/Amide III and ν1CO32−/ν2PO43− are used to describe relative amounts of spongy bone components. The ν1PO43−/Amide I ratio is quite susceptible to orientation effect and brings information on collagen fibers orientation. The results presented illustrate the versatility of the Raman method in the study of bone tissue. The study permits better understanding of bone physiology and evaluation of the biomechanical properties of bone

From Too Much to Too Little: How the central U.S. drought of 2012 evolved out of one of the most devastating floods on record in 2011

Table of Contents Section 1: Introduction....................................................................... 1 Section 2: Regional Drought Perspective................................. 2 Section 3: State Drought Perspectives........................................ 3 Section 3.1: Colorado........................................................................... 20 Section 3.2: Illinois.................................................................. 25 Section 3.3: Indiana................................................. 29 Section 3.4: Iowa...................... 36 Section 3.5: Kansas............................................................... 42 Section 3.6: Kentucky............................................................................ 46 Section 3.7: Michigan.............................. 52 Section 3.8: Minnesota............................................................ 58 Section 3.9: Missouri..................................................... 63 Section 3.10: Nebraska................................................. 67 Section 3.11: North Dakota............................................ 73 Section 3.12: Ohio................................................... 79 Section 3.13: South Dakota..................................... 85 Section 3.14: Wyoming........................................... 96 Section 4: Conclusions.............................................................. 9

Radiation hardness qualification of PbWO4 scintillation crystals for the CMS Electromagnetic Calorimeter

This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2010 IOPEnsuring the radiation hardness of PbWO4 crystals was one of the main priorities during the construction of the electromagnetic calorimeter of the CMS experiment at CERN. The production on an industrial scale of radiation hard crystals and their certification over a period of several years represented a difficult challenge both for CMS and for the crystal suppliers. The present article reviews the related scientific and technological problems encountered