Jump into Inquiry--without Drowning

We model how to organize inquiry-based learning (IBL) in ways that give students agency while providing structure and support for students and teachers. Participants work through a HyperDoc mimicking the process students use and access a site with resources and activities to support IBL from finding topics to publishing products

Evaluation of sensor placement algorithms for on-orbit identification of space platforms

Anticipating the construction of the international space station, on-orbit modal identification of space platforms through optimally placed accelerometers is an area of recent activity. Unwanted vibrations in the platform could affect the results of experiments which are planned. Therefore, it is important that sensors (accelerometers) be strategically placed to identify the amount and extent of these unwanted vibrations, and to validate the mathematical models used to predict the loads and dynamic response. Due to cost, installation, and data management issues, only a limited number of sensors will be available for placement. This work evaluates and compares four representative sensor placement algorithms for modal identification. Most of the sensor placement work to date has employed only numerical simulations for comparison. This work uses experimental data from a fully-instrumented truss structure which was one of a series of structures designed for research in dynamic scale model ground testing of large space structures at NASA Langley Research Center. Results from this comparison show that for this cantilevered structure, the algorithm based on Guyan reduction is rated slightly better than that based on Effective Independence

Reusable tools for smartphone apps : innovative activities in the European geological sector

This report presents the outcomes of a study to explore “Reusable tools for smartphone apps: innovative activities in the European geological sector” launched by the European Commission’s Joint Research Centre (JRC) with the British Geological Survey (BGS, Contract n°389788). The study is part of A Reusable INSPIRE Reference Platform (ARE3NA), Action 1.17 of the European Union’s Interoperability Solutions for European Public Administrations (ISA) Programme. The general objective of the study was to assist the JRC in explor-ing the developments and behind-the-scene activities that the geology sector in Europe is undertaking in terms of mobile applications (commonly known as ‘apps’) and where geospatial data of relevance to the INSPIRE Directive (2007/2/EC1) was being shared and reused. Mobile apps are increasingly being used across Europe to provide geoscience information and solutions. To understand the extent and approach of these developments, we undertook a survey of the geology sector. The results of this survey were designed to: help national geological organisations and the wider geological community discover more about work being undertaken help organisations not yet active in this area learn and benefit from those that have already taken some first steps, helping to explore the potential reusability of solutions be of benefit to other sectors interested in sharing geospatial data through apps understand whether INSPIRE is contributing to data access via mobile apps In order to accomplish this, we needed to discover which organisations were actively developing apps, what approaches they have taken, what tools they have used and how successful their initiatives have been. We also explore the types of users that are being reached by mobile apps and whether these tools have created new uses for geoscience spatial data, not only the delivery of data to ‘traditional’ organisa-tions involved in data exchange but also where data are being provided in less conventional ways to oth-er/new users, including citizens and those aiming to reuse the data being provided in other apps not only related to geology. Finally, we assessed how other organisations and communities can learn from the software, tools and methodologies that have been developed in the geosciences sector

Ocean and atmosphere feedbacks affecting AMOC hysteresis in a GCM

Theories suggest that the Atlantic Meridional Overturning Circulation (AMOC) can exhibit a hysteresis where, for a given input of fresh water into the north Atlantic, there are two possible states: one with a strong overturning in the north Atlantic (on) and the other with a reverse Atlantic cell (off). A previous study showed hysteresis of the AMOC for the first time in a coupled general circulation model (Hawkins et al. in Geophys Res Lett. doi: 10.1029/2011GL047208, 2011). In this study we show that the hysteresis found by Hawkins et al. (2011) is sensitive to the method with which the fresh water input is compensated. If this compensation is applied throughout the volume of the global ocean, rather than at the surface, the region of hysteresis is narrower and the off states are very different: when the compensation is applied at the surface, a strong Pacific overturning cell and a strong Atlantic reverse cell develops; when the compensation is applied throughout the volume there is little change in the Pacific and only a weak Atlantic reverse cell develops. We investigate the mechanisms behind the transitions between the on and off states in the two experiments, and find that the difference in hysteresis is due to the different off states. We find that the development of the Pacific overturning cell results in greater atmospheric moisture transport into the North Atlantic, and also is likely responsible for a stronger Atlantic reverse cell. These both act to stabilize the off state of the Atlantic overturning

Geospatial Data-sharing in UK Higher Education: informal repositories and users’ perspectives

This report outlines research into the sharing of geospatial datasets by researchers based in UK universities as part of the GRADE project, a scoping exercise for the creation of a geospatial data repository for UK Higher Education. The report contains an informal assessment of technologies used to typically share geographical information and contrasted these through an experiment with novel, informal peer-to-peer data-sharing technologies and the GRADE project’s demonstrator repository. The study adopts a qualitative research approach to help explicate the issues that representatives from the GI community experienced in the context of the experiment and concerns and opportunities presented as a result. The analysis includes a discussion of materials presented at a one day workshop that brought participants together and a SWOT analysis of both the informal sharing methods and the GRADE demonstrator repository. A list of ten recommendations is given towards the end of the report, highlighting a need to consider the wider context of a research data repository in terms of educating its user base in data policy and licensing considerations relating to GI; the need to continue and develop such repositories in relation to wider research and (national) geospatial data infrastructures; to adopt better practice with regard to metadata handling and creation for both the resource and the community using it; and to recognise the opportunities such a resource presents for both the development of technical tools to support research and a environment to support qualitative research into such activities, as part of a wider information society

Ocean heat uptake processes: a model intercomparison

We compare the quasi-equilibrium heat balances, as well as their responses to 4×CO2 perturbation, among three global climate models with the aim to identify and explain inter-model differences in ocean heat uptake (OHU) processes. We find that, in quasi-equilibrium, convective and mixed layer processes, as well as eddy-related processes, cause cooling of the subsurface ocean. The cooling is balanced by warming caused by advective and diapycnally diffusive processes. We also find that in the CO2-perturbed climates the largest contribution to OHU comes from changes in vertical mixing processes and the mean circulation, particularly in the extra-tropics, caused both by changes in wind forcing, and by changes in high-latitude buoyancy forcing. There is a substantial warming in the tropics, a significant part of which occurs because of changes in horizontal advection in extra-tropics. Diapycnal diffusion makes only a weak contribution to the OHU, mainly in the tropics, due to increased stratification. There are important qualitative differences in the contribution of eddy-induced advection and isopycnal diffusion to the OHU among the models. The former is related to the different values of the coefficients used in the corresponding scheme. The latter is related to the different tapering formulations of the isopycnal diffusion scheme. These differences affect the OHU in the deep ocean, which is substantial in two of the models, the dominant region of deep warming being the Southern Ocean. However, most of the OHU takes place above 2000 m, and the three models are quantitatively similar in their global OHU efficiency and its breakdown among processes and as a function of latitude

The influence of eddy parameterizations on the transport of the Antarctic Circumpolar Current in coupled climate models

The transport of the Antarctic Circumpolar Current (ACC) varies strongly across the coupled GCMs (general circulation models) used for the IPCC AR4. This note shows that a large fraction of this across-model variance can be explained by relating it to the parameterization of eddy-induced transports. In the majority of models this parameterization is based on the study by Gent and McWilliams (1990). The main parameter is the quasi-Stokes diffusivity kappa (often referred to less accurately as ’’thickness diffusion’’). The ACC transport and the meridional density gradient both correlate strongly with kappa across those models where kappa is a prescribed constant. In contrast, there is no correlation with the isopycnal diffusivity jiso across the models. The sensitivity of the ACC transport to kappa is larger than to the zonal wind stress maximum. Experiments with the fast GCM FAMOUS show that changing kappa directly affects the ACC transport by changing the density structure throughout the water column. Our results suggest that this limits the role of the wind stress magnitude in setting the ACC transport in FAMOUS. The sensitivities of the ACC and the meridional density gradient are very similar across the AR4 GCMs (for those models where kappa is a prescribed constant) and among the FAMOUS experiments. The strong sensitivity of the ACC transport to kappa needs careful assessment in climate models

A theoretical explanation for the Central Molecular Zone asymmetry

It has been known for more than thirty years that the distribution of molecular gas in the innermost 300 parsecs of the Milky Way, the Central Molecular Zone, is strongly asymmetric. Indeed, approximately three quarters of molecular emission comes from positive longitudes, and only one quarter from negative longitudes. However, despite much theoretical effort, the origin of this asymmetry has remained a mystery. Here we show that the asymmetry can be neatly explained by unsteady flow of gas in a barred potential. We use high-resolution 3D hydrodynamical simulations coupled to a state-of-the-art chemical network. Despite the initial conditions and the bar potential being point-symmetric with respect to the Galactic Centre, asymmetries develop spontaneously due to the combination of a hydrodynamical instability known as the "wiggle instability" and the thermal instability. The observed asymmetry must be transient: observations made tens of megayears in the past or in the future would often show an asymmetry in the opposite sense. Fluctuations of amplitude comparable to the observed asymmetry occur for a large fraction of the time in our simulations, and suggest that the present is not an exceptional moment in the life of our Galaxy.Comment: Accepted for publication in MNRAS. Videos of the simulations are available at http://www.ita.uni-heidelberg.de/~mattia/download.htm

Continental drift and plateau uplift control origination and evolution of Asian and Australian monsoons

Evolutions of Asian and Australian monsoons have important significance for understanding the past global change but are still a controversial subject. Here, we explore systematically the effects of plate movement and plateau uplift on the formation and evolution of the Asian and Australian monsoons by numerical simulations based on land-sea distributions and topographic conditions for five typical geological periods during the Cenozoic. Our results suggest that the timings and causes of formation of the monsoons in South Asia, East Asia and northern Australia are different. The Indian Subcontinent, which was located in the tropical Southern Hemisphere in the Paleocene, was influenced by the austral monsoon system simulated at that time. Once it moved to the tropical Northern Hemisphere in the Eocene, the South Asian monsoon established and remained persistently thereafter. However, the monsoons of East Asia and northern Australia did not appear until the Miocene. The establishment of the simulated low-latitude South Asian (northern Australian) monsoon appeared to have strongly depended on the location of mainland India (Australia), associated with northward plate motion, without much relation to the plateau uplift. On the contrary, the establishment of the mid-latitude East Asian monsoon was mainly controlled by the uplift of Tibetan plateau