Western boundary currents and climate change

A recent paper in Journal of Geophysical Research-Oceans connects recent changes in atmospheric circulation to poleward movement and intensification of western boundary currents. Causes and characteristics of past and future trends in surface wind stress and western boundary currents are discussed here

Quantifying Eddy Feedbacks and Forcings in the Tropospheric Response to Stratospheric Sudden Warmings

This is the final version of the article. It first appeared from American Meteorological Society via https://doi.org/10.1175/JAS-D-16-0056.1Abstract The equatorward shift of the zonal-mean midlatitude tropospheric jet following a stratospheric sudden warming in a comprehensive stratosphere-resolving model is found to be well quantified by the simple model of tropospheric eddy feedbacks proposed by Lorenz and Hartmann. This permits a decomposition of the shift into a component driven by the stratospheric anomalies and a component driven by tropospheric feedbacks. This is done by extending the simple model to include three effective forcing mechanisms by which the stratosphere may influence the tropospheric jet. These include 1) the zonally symmetric adjustments associated with the mean meridional circulation and the direct influence of the stratospheric anomalies on 2) the tropospheric synoptic-scale or 3) the tropospheric planetary-scale eddies. Although the anomalous tropospheric winds are primarily maintained against surface friction by the synoptic-scale eddies, this response can be entirely attributed to the eddy feedback term. The response of the planetary-scale eddies, in contrast, can be directly attributed to the stratosphere. The zonally symmetric tropospheric circulation associated with downward control is found to play little role in driving the tropospheric response. The prospects of applying this methodology to reanalysis data are also considered, but statistical limitations and the relatively weak projection of the vertically integrated composite wind anomalies onto the leading EOF preclude any conclusions from being drawn.PH acknowledges funding support from the European Research Council through the ACCI project (grant number 267760) lead by John Pyle and from an NSERC post-doctoral fellowship. IRS acknowledges support from National Science Foundation funding to the National Center for Atmospheric Research and NSF award AGS-1317469

Impact of diagnosis of type 1 diabetes in children and adolescents

OBJETIVO: Conocer el impacto personal y familiar del diagnóstico de diabetes tipo 1 (DM1) en niños y adolescentes

The size, concentration, and growth of biodiversity-conservation nonprofits

Nonprofit organizations play a critical role in efforts to conserve biodiversity. Their success in this regard will be determined in part by how effectively individual nonprofits and the sector as a whole are structured. One of the most fundamental questions about an organization’s structure is how large it should be, with the logical counterpart being how concentrated the whole sector should be. We review empirical patterns in the size, concentration, and growth of over 1700 biodiversity-conservation nonprofits registered for tax purposes in the United States within the context of relevant economic theory. Conservation-nonprofit sizes vary by six to seven orders of magnitude and are positively skewed. Larger nonprofits access more revenue streams and hold more of their assets in land and buildings than smaller or midsized nonprofits do. The size of conservation nonprofits varies with the ecological focus of the organization, but the growth rates of nonprofits do not

Validating the use of intrinsic markers in body feathers to identify inter-individual differences in non-breeding areas of northern fulmars

Acknowledgments We thank Claire Deacon, Gareth Norton and Andrea Raab for help with laboratory work at the University of Aberdeen, and Barry Thornton and Gillian Martin for running stable isotope analysis at the James Hutton Institute. Thanks to all involved in the collection and processing of dead fulmars through the North Sea plastic pollution project at IMARES, with special thanks to Jens-Kjeld Jensen, Bergur Olsen and Elisa Bravo Rebolledo for samples from the Faroe Islands and Susanne Kühn for those from Iceland. Thanks to Orkney Islands Council for access to Eynhallow and to all the fieldworkers involved in deployment and recovery of the GLS tags. All ringing work was carried out under permit from the BTO, and feather sampling was carried out under licence from the Home Office. We are grateful to James Fox of Migrate Technologies for recovering data from GLS loggers which would not download, and Richard Phillips and Janet Silk of BAS for advice on GLS analysis. We thank Deborah Dawson of the NERC Biomolecular Analysis Facility, University of Sheffield and Stuart Piertney of University of Aberdeen for molecular sexing of the fulmars. Lucy Quinn was supported by a NERC Studentship and additional funding to support fieldwork was gratefully received from Talisman Energy (UK) Ltd. We thank Yves Cherel and two anonymous reviewers for their constructive comments on the manuscript.Peer reviewedPublisher PD

A simple methodology to estimate plant volume in nitrous oxide emission studies

Closed-chamber methodology is widely used for the estimation of greenhouse gas (GHG) emissions in agricultural systems. The volume displaced by plants inside chambers influences GHG flux estimation, although generally it is not discounted from chamber headspace in the calculation. A novel image analysis–based procedure is proposed to estimate plant volume and to assess its impact on nitrous oxide (N2O) flux estimations in a wheat (Triticum aestivum L. ‘Rimbaud’) crop. A maximum of 2.2% of the 13-L chambers was displaced by plants, leading to a systematic 0.9% overestimation in cumulative N2O emissions if plant volume was not considered. Thus, plant canopy volume should be taken into account for improving the accuracy of emissions

Utility of stabilized nitrogen fertilizers to reduce nitrate leaching under optimal management practices

Background: The inadequate application of nitrogen (N) to crops has increased the reactive N in the atmosphere and in the surface and ground waters. Stabilized N-fertilizers with nitrification (NI) and urease (UI) inhibitors have been proposed to reduce these environmental problems without affecting or even increasing crop productivity. Aim: The objective of this study was to evaluate, in a maize–maize–wheat rotation, if the use of the NI 3, 4-dimethylpyrazole phosphate (DMPP) and the UIs N-(n-butyl) thiophosphoric triamide (NBPT) and monocarbamide dihydrogen sulfate (MCDHS) reduces N leaching without compromising yield under optimal management of N and water. Methods: The experiment was conducted in 24 drainage lysimeters with two soil types with contrasting water holding capacity under Mediterranean irrigated conditions. The fertilizer treatments were urea, urea with DMPP, urea with NBPT, and urea with MCDHS. For the maize crop, conventional fertilizer application was split into 6- and 13-leaf stages, whereas stabilized fertilizers were applied as a single application at the 6-leaf stage. All fertilizer treatments were applied at late tillering in the wheat crop. Results: The soil mineral N was measured at the beginning and the end of each crop season, but no differences were found among fertilizer treatments. Differences in the volume of water drained or the cumulative mass of nitrate depending on the fertilizer were not significant (three-year treatment average of 200 L m-2 and 22 kg N ha-1 in the Deep soil, and 334 L m-2 and 40 kg N ha-1 in the Shallow type, respectively). No consistent significant differences were found in agronomic parameters (chlorophyll measurements, yield, and total N uptake) between the fertilizer treatments. Conclusion: Based on the results, the use of stabilized N-fertilizer could be recommended to reduce the number of N applications in maize without compromising grain yield but with no advantages to reduce nitrate-leaching losses if N rates are managed properly under efficient irrigation management practices

Dynamics of the lower stratospheric circulation response to ENSO

A robust feature of the observed response to El Nin˜o–Southern Oscillation (ENSO) is an altered circulation in the lower stratosphere. When sea surface temperatures (SSTs) in the tropical Pacific are warmer there is enhanced upwelling and cooling in the tropical lower stratosphere and downwelling and warming in the midlatitudes, while the opposite is true of cooler SSTs. The midlatitude lower stratospheric response to ENSO is larger in the Southern Hemisphere (SH) than in the Northern Hemisphere (NH). In this study the dynamical version of the Canadian Middle Atmosphere Model (CMAM) is used to simulate 25 realizations of the atmospheric response to the 1982/83 El Nin˜o and the 1973/74 La Nin˜ a. This version ofCMAMis a comprehensive high-top general circulation model that does not include interactive chemistry. The observed lower stratospheric response to ENSO is well reproduced by the simulations, allowing them to be used to investigate the mechanisms involved. Both the observed and simulated responses maximize in December–March and so this study focuses on understanding the mechanisms involved in that season. The response in tropical upwelling is predominantly driven by anomalous transient synoptic-scale wave drag in the SH subtropical lower stratosphere, which is also responsible for the compensating SH midlatitude response. This altered wave drag stems from an altered upward flux of wave activity from the troposphere into the lower stratosphere between 208 and 408S. The altered flux of wave activity can be divided into two distinct components. In the Pacific, the acceleration of the zonal wind in the subtropics from the warmer tropical SSTs results in a region between the midlatitude and subtropical jets where there is an enhanced source of low phase speed eddies. At other longitudes, an equatorward shift of the midlatitude jet from the extratropical tropospheric response to El Nin˜o results in an enhanced source of waves of higher phase speeds in the subtropics. The altered resolved wave drag is only apparent in the SH and the difference between the two hemispheres can be related to the difference in the climatological jet structures in this season and the projection of the wind anomalies associated with ENSO onto those structures