Atlantic Multidecadal Variability modulates the climate impacts of El Niño-Southern Oscillation in Australia

Atlantic Multidecadal Variability (AMV) modulates El Niño-Southern Oscillation (ENSO) dynamics. Here, we explore the effect of warm (AMV+) and cold (AMV-) AMV conditions on the austral summer teleconnection of ENSO to Australia using idealized simulations performed with the NCAR-CESM1 model. AMV+ strengthens the mean and extreme precipitation and temperature responses to El Niño in south-western Australia and weakens the mean precipitation and temperature impacts in north-eastern Australia. The modulation of La Niña impacts by AMV is asymmetric to El Niño, with a weakening of the mean and extreme precipitation and temperature responses in eastern Australia. Decomposing the total difference in ENSO response between AMV phases, we find that the signals are mainly explained by the direct AMV modulation of ENSO and its teleconnections rather than by changes in background climate induced by AMV. The exception is ENSO-driven fire impacts, where there is a significant increase in burned area in south-eastern Australia only when El Niño and AMV+ co-occur. However, modulation of ENSO between AMV+ and AMV- does offset ~37% of the decrease in burned area extent during La Niña summers. The altered surface climate response to ENSO in Australia by AMV is attributed to variations in large-scale atmospheric circulation. Under AMV+, there is increased subsidence over western Australia during El Niño associated with a westward shift of the local Walker circulation. A weakening of the upwelling branch of the local Hadley circulation over north-eastern Australia is responsible for the weakening of La Niña impacts in AMV+, accompanied by a strengthening of subsidence in south central Australia due to a weakening of the local Hadley circulation, amplifying La Niña impacts over this region. The results suggest the potential for AMV to drive multidecadal variability in ENSO impacts over Australia.P.T.-C. was supported by a PhD scholarship from the Natural Environment Research Council PANORAMA Doctoral Training Partnership (NE/S007458/1). Y.R.-R. received the support of a fellowship from ”la Caixa” Foundation (ID 100010434) and from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 847648. The fellowship code is LCF/BQ/PR21/11840016. A.C.M. was supported by the European Union’s Horizon 2020 research and innovation program under grant agreement no. 820829 (CONSTRAIN project) and The Leverhulme Trust (PLP-2018-278). M.T. acknowledges funding by the Spanish Ministry of Science, Innovation and Universities through the Ramón y Cajal Grant Reference RYC2019-027115-I and through the project ONFIRE, grant PID2021-123193OB-I00, funded by MCIN/AEI/10.13039/501100011033. Computing facilities were provided by the Barcelona Supercomputing Center and the University of LeedsPeer ReviewedPostprint (author's final draft

Dads make a difference: an exploratory study of paternal support for breastfeeding in Perth, Western Australia

<p>Abstract</p> <p>Background</p> <p>The ability to breastfeed and continue the practice requires dedication, commitment, persistence and support. Mothers often need to overcome many obstacles to successfully breastfeed their babies and maintain their balance of home, family and work commitments. Evidence suggests that fathers want to be involved and be part of the parenthood process, including infant feeding. The role transition from couple to family poses challenges to both parents. Sharing the experience of childbirth and supporting each other in the subsequent infant feeding practices is one of those challenges.</p> <p>Methods</p> <p>A qualitative exploratory design was chosen to identify parents' perceptions of what constitutes support for breastfeeding, particularly focusing upon paternal support. Focus groups were conducted with mothers and a focus group, interviews and an online survey were developed for fathers. Thematic analysis was used to identify the main themes.</p> <p>Results</p> <p>From a total of 76 participants, the major theme emerging from mothers' data identified that "Dads do make a difference". Three sub-themes included: Anticipating needs and getting the job done; Encouragement to do your best; and Paternal determination and commitment, associated with effective partner support. "Wanting to be involved" was identified from fathers' data as the major theme around their needs. Three sub-themes included: Wanting more information; Learning the role; and Being an advocate.</p> <p>Conclusion</p> <p>Sharing the experience of childbirth and supporting each other in the subsequent infant feeding practices was perceived as the best outcome for the majority of new mothers and fathers. Paternal emotional, practical and physical supports were identified as important factors to promote successful breastfeeding and to enrich the experience for the mother and subsequently the father.</p> <p>Trail Regristration</p> <p>Australia and New Zealand Clinical Trials Registry: ACTRN12609000667213.</p

Space Station Engineering Design Issues

Space Station Freedom topics addressed include: general design issues; issues related to utilization and operations; issues related to systems requirements and design; and management issues relevant to design

Estimating logged-over lowland rainforest aboveground biomass in Sabah, Malaysia using airborne LiDAR data

Unprecedented deforestation and forest degradation in recent decades have severely depleted the carbon storage in Borneo. Estimating aboveground biomass (AGB) with high accuracy is crucial to quantifying carbon stocks for Reducing Emissions from Deforestation and Forest Degradation-plus implementation (REDD+). Airborne Light Detection and Ranging (LiDAR) is a promising remote sensing technology that provides fine-scale forest structure variability data. This paper highlights the use of airborne LiDAR data for estimating the AGB of a logged-over tropical forest in Sabah, Malaysia. The LiDAR data was acquired using an Optech Orion C200 sensor onboard a fixed wing aircraft. The canopy height of each LiDAR point was calculated from the height difference between the first returns and the Digital Terrain Model (DTM) constructed from the ground points. Among the obtained LiDAR height metrics, the mean canopy height produced the strongest relationship with the observed AGB. This single-variable model had a root mean squared error (RMSE) of 80.02 t ha-1 or 22.31% of the mean AGB, which performed exceptionally when compared with recent tropical rainforest studies. Overall, airborne LiDAR did provide fine-scale canopy height measurements for accurately and reliably estimating the AGB in a logged-over forest in Sabah, thus supporting the state's effort in realizing the REDD+ mechanism

Northern hemisphere cold air outbreaks are more likely to be severe during weak polar vortex conditions

Severe cold air outbreaks have significant impacts on human health, energy use, agriculture, and transportation. Anomalous behavior of the Arctic stratospheric polar vortex provides an important source of subseasonal-to-seasonal predictability of Northern Hemisphere cold air outbreaks. Here, through reanalysis data for the period 1958–2019 and climate model simulations for preindustrial conditions, we show that weak stratospheric polar vortex conditions increase the risk of severe cold air outbreaks in mid-latitude East Asia by 100%, in contrast to only 40% for moderate cold air outbreaks. Such a disproportionate increase is also found in Europe, with an elevated risk persisting more than three weeks. By analysing the stream of polar cold air mass, we show that the polar vortex affects severe cold air outbreaks by modifying the inter-hemispheric transport of cold air mass. Using a novel method to assess Granger causality, we show that the polar vortex provides predictive information regarding severe cold air outbreaks over multiple regions in the Northern Hemisphere, which may help with mitigating their impact

Regional climate impacts of a possible future grand solar minimum.

This is the final published version. It first appeared at http://www.nature.com/ncomms/2015/150623/ncomms8535/full/ncomms8535.html.Any reduction in global mean near-surface temperature due to a future decline in solar activity is likely to be a small fraction of projected anthropogenic warming. However, variability in ultraviolet solar irradiance is linked to modulation of the Arctic and North Atlantic Oscillations, suggesting the potential for larger regional surface climate effects. Here, we explore possible impacts through two experiments designed to bracket uncertainty in ultraviolet irradiance in a scenario in which future solar activity decreases to Maunder Minimum-like conditions by 2050. Both experiments show regional structure in the wintertime response, resembling the North Atlantic Oscillation, with enhanced relative cooling over northern Eurasia and the eastern United States. For a high-end decline in solar ultraviolet irradiance, the impact on winter northern European surface temperatures over the late twenty-first century could be a significant fraction of the difference in climate change between plausible AR5 scenarios of greenhouse gas concentrations.This work was supported by the Joint DECC/Defra Met Office Hadley Centre Climate Programme (GA01101) and also by the EU project SPECS funded by the European Commission’s Seventh Framework Research Programme under the grant agreement 308378 (Met Office Hadley Centre authors), by the NERC National Centre for Atmospheric Science (NCAS) Climate directorate (L.J.G. and A.C.M.), an ERC ACCI grant (A.C.M) and an AXA Postdoctoral Fellowship (A.C.M.)

Roundabout accident prediction model: random-parameter negative binomial approach

Roundabouts have been used widely on all road classes in the United Kingdom because they are considered safer than other types of intersections in general. The objective of this study was to examine geometric and traffic characteristics and their influences on the number of accidents. Data from each of 70 roundabouts (with 284 approaches) included all recorded vehicle accidents as well as geometric and traffic characteristics for the entire roundabout, within circulatory lanes, and at roundabout approaches. Resulting estimates were compared with those from random-parameter and fixed-parameter negative binomial count data models. The random-parameter results provided better goodness of fit than the fixed-parameter results, and more variables were found to be significant. Significant variables that influenced the number of accidents were total approach traffic, truck percentage, entry width, inscribed circle diameter, number of lanes, and presence of traffic signals

The role of experience and advanced training on performance in a motorcycle simulator

Motorcyclists are over-represented in collision statistics. While many collisions may be the direct fault of another road user, a considerable number of fatalities and injuries are due to the actions of the rider. While increased riding experience may improve skills, advanced training courses may be required to evoke the safest riding behaviours. The current research assessed the impact of experience and advanced training on rider behaviour using a motorcycle simulator. Novice riders, experienced riders and riders with advanced training traversed a virtual world through varying speed limits and roadways of different curvature. Speed and lane position were monitored. In a comparison of 60 mph and 40 mph zones, advanced riders rode more slowly in the 40 mph zones, and had greater variation in lane position than the other two groups. In the 60 mph zones, both advanced and experienced riders had greater lane variation than novices. Across the whole ride, novices tended to position themselves closer to the kerb. In a second analysis across four classifications of curvature (straight, slight, medium, tight) advanced and experienced riders varied their lateral position more so than novices, though advanced riders had greater variation in lane position than even experienced riders in some conditions. The results suggest that experience and advanced training lead to changes in behaviour compared to novice riders which can be interpreted as having a potentially positive impact on road safety

A large ozone-circulation feedback and its implications for global warming assessments.

State-of-the-art climate models now include more climate processes which are simulated at higher spatial resolution than ever1. Nevertheless, some processes, such as atmospheric chemical feedbacks, are still computationally expensive and are often ignored in climate simulations1,2. Here we present evidence that how stratospheric ozone is represented in climate models can have a first order impact on estimates of effective climate sensitivity. Using a comprehensive atmosphere-ocean chemistry-climate model, we find an increase in global mean surface warming of around 1°C (~20%) after 75 years when ozone is prescribed at pre-industrial levels compared with when it is allowed to evolve self-consistently in response to an abrupt 4×CO2 forcing. The difference is primarily attributed to changes in longwave radiative feedbacks associated with circulation-driven decreases in tropical lower stratospheric ozone and related stratospheric water vapour and cirrus cloud changes. This has important implications for global model intercomparison studies1,2 in which participating models often use simplified treatments of atmospheric composition changes that are neither consistent with the specified greenhouse gas forcing scenario nor with the associated atmospheric circulation feedbacks3-5.We thank the European Research Council for funding through the ACCI project, project number 267760. The model development was part of the QESM-ESM project supported by the UK Natural Environment Research Council (NERC) under contract numbers RH/H10/19 and R8/H12/124. We acknowledge use of the MONSooN system, a collaborative facility supplied under the Joint Weather and Climate Research Programme, which is a strategic partnership between the UK Met Office and NERC. A.C.M. acknowledges support from an AXA Postdoctoral Research Fellowship.This is the accepted manuscript. The final version is available from Nature Publishing at http://www.nature.com/nclimate/journal/v5/n1/full/nclimate2451.html