286 research outputs found
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Estimation of optimal gravity wave parameters for climate models using data assimilation
There is a current need to constrain the parameters of gravity wave drag (GWD) schemes in climate models using observational information instead of tuning them subjectively. In this work, an inverse technique is developed using data assimilation principles to estimate gravity wave parameters. Because mostGWDschemes assume instantaneous vertical propagation of gravity waves within a column, observations in a single column can be used to formulate a one-dimensional assimilation problem to estimate the unknown parameters. We define a cost function that measures the differences between the unresolved drag inferred from observations (referred to here as the ‘observed’ GWD) and the GWD calculated with a parametrisation scheme. The geometry of the cost function presents some difficulties, including multiple minima and ill-conditioning because of the non-independence of the gravity wave parameters. To overcome these difficulties we propose a genetic algorithm to minimize the cost function, which provides a robust parameter estimation over a broad range of prescribed ‘true’ parameters. When real experiments using an independent estimate of the ‘observed’ GWD are performed, physically unrealistic values of the parameters can result due to the non-independence of the parameters. However, by constraining one of the parameters to lie within a physically realistic range, this degeneracy is broken and the other parameters are also found to lie within physically realistic ranges. This argues for the essential physical self-consistency of the gravity wave scheme. A much better fit to the observed GWD at high latitudes is obtained when the parameters are allowed to vary with latitude. However, a close fit can be obtained either in the upper or the lower part of the profiles, but not in both at the same time. This result is a consequence of assuming an isotropic launch spectrum. The changes of sign in theGWDfound in the tropical lower stratosphere, which are associated with part of the quasi-biennial oscillation forcing, cannot be captured by the parametrisation with optimal parameters
Preventing violence: an overview
Bei diesem Beitrag handelt es sich um ein Kapitel aus den Kongressbänden des Deutschen Präventionstags (DPT-ID: 1935)
Developing ecosystem service indicators: experiences and lessons learned from sub-global assessments and other initiatives
People depend upon ecosystems to supply a range of services necessary for their survival and well-being. Ecosystem service indicators are critical for knowing whether or not these essential services are being maintained and used in a sustainable manner, thus enabling policy makers to identify the policies and other interventions needed to better manage them. As a result, ecosystem service indicators are of increasing interest and importance to governmental and inter-governmental processes, including amongst others the Convention on Biological Diversity (CBD) and the Aichi Targets contained within its strategic plan for 2011-2020, as well as the emerging Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES). Despite this growing demand, assessing ecosystem service status and trends and developing robust indicators is o!en hindered by a lack of information and data, resulting in few available indicators. In response, the United Nations Environment Programme World Conservation Monitoring Centre (UNEP-WCMC), together with a wide range of international partners and supported by the Swedish International Biodiversity Programme (SwedBio)*, undertook a project to take stock of the key lessons that have been learnt in developing and using ecosystem service indicators in a range of assessment contexts. The project examined the methodologies, metrics and data sources employed in delivering ecosystem service indicators, so as to inform future indicator development. This report presents the principal results of this project
Preventing intimate partner and sexual violence against women: Taking action and generating evidence
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Is missing orographic gravity wave drag near 60°S the cause of the stratospheric zonal wind biases in chemistry–climate models?
Nearly all chemistry–climate models (CCMs) have a systematic bias of a delayed springtime breakdown of the Southern Hemisphere (SH) stratospheric polar vortex, implying insufficient stratospheric wave drag. In this study the Canadian Middle Atmosphere Model (CMAM) and the CMAM Data Assimilation System (CMAM-DAS) are used to investigate the cause of this bias. Zonal wind analysis increments from CMAMDAS reveal systematic negative values in the stratosphere near 608S in winter and early spring. These are interpreted as indicating a bias in the model physics, namely, missing gravity wave drag (GWD). The negative analysis increments remain at a nearly constant height during winter and descend as the vortex weakens, much
like orographic GWD. This region is also where current orographic GWD parameterizations have a gap in wave drag, which is suggested to be unrealistic because of missing effects in those parameterizations. These findings motivate a pair of free-runningCMAMsimulations to assess the impact of extra orographicGWDat 608S. The control simulation exhibits the cold-pole bias and delayed vortex breakdown seen in the CCMs. In the simulation with extra GWD, the cold-pole bias is significantly reduced and the vortex breaks down earlier. Changes in resolved wave drag in the stratosphere also occur in response to the extra GWD, which reduce stratospheric SH polar-cap temperature biases in late spring and early summer. Reducing the dynamical biases, however, results in degraded Antarctic column ozone. This suggests that CCMs that obtain realistic column ozone in the presence of an overly strong and persistent vortex may be doing so through compensating errors
Synergies for Improving Oil Palm Production and Forest Conservation in Floodplain Landscapes
Lowland tropical forests are increasingly threatened with conversion to oil palm as global demand and high profit drives crop expansion throughout the world’s tropical regions. Yet, landscapes are not homogeneous and regional constraints dictate land suitability for this crop. We conducted a regional study to investigate spatial and economic components of forest conversion to oil palm within a tropical floodplain in the Lower Kinabatangan, Sabah, Malaysian Borneo. The Kinabatangan ecosystem harbours significant biodiversity with globally threatened species but has suffered forest loss and fragmentation. We mapped the oil palm and forested landscapes (using object-based-image analysis, classification and regression tree analysis and on-screen digitising of high-resolution imagery) and undertook economic modelling. Within the study region (520,269 ha), 250,617 ha is cultivated with oil palm with 77% having high Net-Present-Value (NPV) estimates (637/ha?yr); but 20.5% is under-producing. In fact 6.3% (15,810 ha) of oil palm is commercially redundant (with negative NPV of -65/ha?yr) due to palm mortality from flood inundation. These areas would have been important riparian or flooded forest types. Moreover, 30,173 ha of unprotected forest remain and despite its value for connectivity and biodiversity 64% is allocated for future oil palm. However, we estimate that at minimum 54% of these forests are unsuitable for this crop due to inundation events. If conversion to oil palm occurs, we predict a further 16,207 ha will become commercially redundant. This means that over 32,000 ha of forest within the floodplain would have been converted for little or no financial gain yet with significant cost to the ecosystem. Our findings have globally relevant implications for similar floodplain landscapes undergoing forest transformation to agriculture such as oil palm. Understanding landscape level constraints to this crop, and transferring these into policy and practice, may provide conservation and economic opportunities within these seemingly high opportunity cost landscapes
Applying the WHO-INTEGRATE evidence-to-decision framework in the development of WHO guidelines on parenting interventions: step-by-step process and lessons learnt
Background: Development of guidelines for public health, health system, and health policy interventions demands complex systems thinking to understand direct and indirect effects of interventions within dynamic systems. The WHO-INTEGRATE framework, an evidence-to-decision framework rooted in the norms and values of the World Health Organization (WHO), provides a structured method to assess complexities in guidelines systematically, such as the balance of an intervention’s health benefits and harms and their human rights and socio-cultural acceptability. This paper provides a worked example of the application of the WHO-INTEGRATE framework in developing the WHO guidelines on parenting interventions to prevent child maltreatment, and shares reflective insights regarding the value added, challenges encountered, and lessons learnt. Methods: The methodological approach comprised describing the intended step-by-step application of the WHO-INTEGRATE framework and gaining reflective insights from introspective sessions within the core team guiding the development of the WHO guidelines on parenting interventions and a methodological workshop. Results: The WHO-INTEGRATE framework was used throughout the guideline development process. It facilitated reflective deliberation across a broad range of decision criteria and system-level aspects in the following steps: (1) scoping the guideline and defining stakeholder engagement, (2) prioritising WHO-INTEGRATE sub-criteria and guideline outcomes, (3) using research evidence to inform WHO-INTEGRATE criteria, and (4) developing and presenting recommendations informed by WHO-INTEGRATE criteria. Despite the value added, challenges, such as substantial time investment required, broad scope of prioritised sub-criteria, integration across diverse criteria, and sources of evidence and translation of insights into concise formats, were encountered. Conclusions: Application of the WHO-INTEGRATE framework was crucial in the integration of effectiveness evidence with insights into implementation and broader implications of parenting interventions, extending beyond health benefits and harms considerations and fostering a whole-of-society-perspective. The evidence reviews for prioritised WHO-INTEGRATE sub-criteria were instrumental in guiding guideline development group discussions, informing recommendations and clarifying uncertainties. This experience offers important lessons for future guideline panels and guideline methodologists using the WHO-INTEGRATE framework
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