Wind-stress variability over the Benguela upwelling system

Bibliography: leaves 119-133.Regional wind-stress variability over the Benguela Upwelling System is described using 16 months (01 August 1999 29 November 2000) of satellite derived QuikSCA T wind data. The QuikSCA T data are compared to the climatologies presented by Kamstra (1985) and Bakun and Nelson (1991), as well as the long-term climatology (1968-1996) of the surface vector wind speed field off the coast of southern Africa, as derived from the 2.5° resolution NCEPINCAR reanalysis dataset. Broad scale similaritie"s are found between the QuikSCA T and the long-term NCEPINCAR climatology (1968-1996) data sets. This allows one to have confidence in using this scatterometer data to investigate details of spatial and temporal variability over the Benguela System. During summer, wind-stress maxima are found at approximately 17, 29 and 34°S. These maxima strengthen in late summer. The seasonal northward migration of the South Atlantic Anticyclone becomes apparent in late autumn, when the strongest wind-stress occurs north of 28°S. A significant wind-stress minimum is observed to develop slightly north of Cape Columbine (33°S) during autumn. To the north (10-23.5°S) the Benguela is characterised by relatively strong south-easterly wind-stress during winter. To the south (24-35°S) the Benguela is characterised by relatively weak westerly to south-westerly wind-stress during winter. A southward migration of southeasterly wind-stress is observed during early spring. By November the entire Benguela Upwelling System is once again characterised by southerly to south-easterly wind stress. Wind-stress variability is investigated using both a type of artificial neural network, known as the Kohonen Self Organising Map (SOM), as well as a wavelet analysis. Two independent SOM studies are conducted. The first study produced a 6x4 SOM output array, which is used to examine seasonal variability as well as the temporal evolution of two synoptic-scale wind events. For the second study both a SOM and a wavelet analysis are applied to an extracted data set to find that the system can be divided into six discrete wind regimes, 10-15°S; 15.5-18.5°S; 19-23.5°S; 24-28.5°S; 29-32.5°S; and 33-35°S. The wavelet power spectra for these wind cells span a range of frequencies from 4 to 64 days, with each region appearing to contain distinct periodicities. To the north, 10-23.5°S, the majority of the power occurs during winter, with a 6-16 day periodicity. Further south, 24-35°S, the majority of the power occurs in the summer. Here a bi-modal distribution occurs, with peaks of 6-16 and 35-40 days. Lastly a case study sequence of the spatial distribution of wind-stress, windstress curl and SST, at a location off the west coast of southern Africa (25-300S and 12-17°E), is discussed in relation to an intense, upwelling favourable, wind event that occurred from 11-20 February 2000

Boundary Dynamics of a Transformative Learning Network : Improving Connection at the Interface of Science and Society

Transformative learning networks are a specific type of loose network with geographically distributed members and member organizations. They hold particular promise for transformation when both top-down and bottom-up processes have failed to support desired systems-level change. The aim of this dissertation is to build knowledge about the social-interactional processes, roles, and practices that build transformative capacity of a network. I apply poststructural and interpretivist point of view to understand the dynamics of boundaries and boundary work in the National Alliance for Broader Impacts. The meso-theory herein claims that two types of boundary work - building boundaries and navigating across boundaries - operate in productive tension to expand knowledge resources and increase network authority and influence in the system over time. This suggests that network leaders can dynamically manage boundaries, shifting emphasis between strength and fluidity to support multi-sited and multi-scalar change. The primary claim of the applied research contribution is that a variety of both structures and interdependent roles and practices work in concert to support transformation across sites and scales. To support this claim, I detail common network substructures, across which critical practices occur and develop a typology of network practices in two distinct, but interdependent roles. Those in the sojourner role focus on site-based work to shift everyday norms. They demonstrate keen awareness of how their institutions enable and constrain change efforts and contribute that knowledge to the network. Those in an expert role, design networks to support meaningful member engagement opportunities across sites and at the same time build identity and coherence within the network to enable transformation at multiple scales. The expert and sojourner roles generally correspond with boundary building and boundary navigation respectively. In addition to the focus on boundary dynamics in networks, this study also examines “Broader Impacts” as a path for connecting science and society in a time when the realms of science and other sectors of society need to come together to address increasingly complex social, educational, and environmental challenges. The final contribution describes a manifestation of one of many possible transformative pathways that emerged from and evolves within the network. The concept of helping scientists develop their “impact identity”, integrates scholarship in a scientific discipline with societal needs, personal preferences, capacities and skills, and one’s institutional context. I understand identity, or a scientists’ self-concept, as a productive driver that can improve outcomes for scientists and for society by bridging the gap between them through public engagement activities. This body of work ties together the theory of morphogenesis from critical realism, boundary concepts from across disciplines, and the landscapes of practice conceptual framework. The aim is to expand understanding about the design and potential of learning networks, which disrupt the status quo to guide change in social-ecological and social-educational systems. The new theory and insights about structures, roles, and practices can inform network and transformation scholars across disciplines. Network leaders, designers, and evaluators can also apply this work to their practice

A satellite-derived climatology of global ocean winds

A satellite-derived Climatology of Global Ocean Winds (COGOW) on a 0.5° latitude by 0.5° latitude grid is presented based on 5-years (August 1999 July 2004) of measurements from the SeaWinds scatterometer that was launched on 19 June 1999 onboard the QuikSCAT satellite. SeaWinds is an active microwave radar that estimates wind speed and direction from measurements of electromagnetic backscatter from the wind roughened ocean surface. The accuracy of these wind estimates is equivalent to that of measurements by well-calibrated buoys. This five-year climatology provides the first high spatial resolution, observationally based, online atlas of global ocean winds. COGOW is a web-based interactive atlas from which users can retrieve climatological wind maps as well as wind statistics, both in tabular and graphic form, for any particular region of interest. The global coverage of these data provides valuable information about the wind statistics in the many regions of the world ocean that are sparsely sampled by ships and buoys. An example of one of the anticipated uses of this climatology is presented in a case study of NOAA OR&R's involvement in the recovery of Ehime Maru, a Japanese training and fishing vessel that sank in 2001 off the island of Oahu. In addition, four wind phenomena observable within COGOW are discussed: the South Asian Monsoon, evidence of air-sea interaction over the Aguihas Return Current, gap winds in Central America, and corner accelerations south of Greenland as well as off the southern and northern tips of Madagascar. The possible utility of COGOW is discussed with regard to operational communities such as the U.S. and Canadian Coast Guard search and rescue teams as well as the scientific research community. Finally, recommendations for extensions that could be included in future versions of COGOW are made

Understanding faculty and student perceptions about reward and advancement : survey of four STEM departments at research intensive universities

This report summarizes the results of a survey exploring four STEM departments that have engaged in meaningful reforms in academic systems of reward and advancement including promotion and tenure (P&T). The survey was administered as part of a study seeking to expose the strengths and challenges of reform efforts by understanding the lived experiences of faculty and graduate trainees. The four departments are relatively large (>40 faculty), and are situated in public, very high research activity (Carnegie R1) institutions located in relatively small, suburban or rurally-situated college towns in the Northwest and Midwest United States. It aims to provide insights into faculty and student perceptions of and experiences with departmental level practices. University leaders and those working on national-scale initiatives to improve reward and advancement in higher education may find these results useful

Landscape Overview of University Systems and People Supporting Scientists in their Public Engagement Efforts: Summary of Existing Recommendations and Evidence from the Field - Executive Summary

Scientists (and engineers) wishing to conduct public engagement do so in the context of established disciplinary norms and complex institutional systems that may support or limit their success. The report seeks to convey the known complexity and unique challenges for universities to better support for scientists in their public engagement work and summarize potential levers of change to improve this system. Insights in the report come from review of 26 recent reports that include recommendations for universities in supporting public engagement and a series of seven video conference focus groups across levels of the university hierarchy. Each group included three to five individuals across 22 institutions

Grounding Institutional Partnerships in Structures for Broader Impact Design: Summative Evaluation Report

This report presents summative evaluation results for a National Science Foundation funded project entitled Grounding Institutional Partnerships in Structures for Broader Impacts Design (BID). The project represents a collaboration between five institutions: Institute for Learning Innovation, The STEM Research Center at Oregon State University, Scicenter, University of Washington-Bothell, and University of Wisconsin-Madison. BID aimed at creating an inter-institutional structure and toolkit to assist higher education institutions (HEIs) and informal science education organizations (ISEs) in developing sustainable institutional partnerships through collaboration around the design of informal STEM education-based Broader Impacts (BI) experiences. The project built upon the Portal to the Public (PoP) framework, bringing together research support professionals, STEM education professionals and Principal Investigators at HEIs with practitioners at ISEs (i.e., BID partners) to enhance BI experiences for the public by leveraging human resources through intentional coordination and partnerships. This report addresses the impact of this collective work, serves as a record of the project, and as a resource for future partnerships that support BI

Boundaries Crossed and Boundaries Made: The Productive Tension Between Learning and Influence in Transformative Networks

We present an in-depth case study of a learning network that aims to transform infrastructure and practice across the research enterprise to advance societal impacts. The theory of social morphogenesis guides our processual qualitative analysis of the network. We describe how different types of boundary work, both building and navigating across boundaries, operate in tension while contributing to transformative capacity. We conclude that learning networks can play a robust role in fostering transformation by drawing together and holding together forces which expand knowledge and authority over time iteratively and recursively. In addition to this theoretical contribution, we provide practical guidance for how network leaders can dynamically manage boundaries, shifting emphasis between strength and fluidity to support transformative change across sites and scales

Blended sea level anomaly fields with enhanced coastal coverage along the U.S. West Coast.

We form a new data set of fields of sea level anomalies by combining gridded daily fields derived from altimeter data with coastal tide gauge data. Within approximately 50-80 km of the coast, the altimeter data are discarded and replaced by a linear interpolation between the tide gauge and remaining offshore altimeter data. A 20-year mean is subtracted from each time series (tide gauge or altimeter) before combining the data sets to form the merged sea level anomaly data set. Geostrophic velocity anomaly fields are formed from the surface heights. Daily mean fields are produced for the period 1 January 1993 - 31 December 2014. The primary validation compares geostrophic velocities calculated from the height fields and velocities measured at four moorings covering the north-south range of the new data set. The merged data set improves the alongshore (meridional) component of the currents, indicating an improvement in the data set

Zonal and Meridional Discontinuities and Other Issues with the HadISST1.1 Dataset

3) The standard deviations of the SST anomalies in the HadISST1.1 dataset are 0.2–0.4°C smaller prior to 1949 than after 1949. This nonstationarity could complicate interpretations of the long HadISST1.1 data record for some studies of climate variability. It is likely attributable mostly to the improved sampling of SST observations in the later time period.4) There is a large zonal discontinuity of SST in the HadISST1.1 dataset along 179.5°W that results in SST variations that are typically smaller in magnitude by about 0.2°C compared with the adjacent 1° grid cells to the west and east. It appears that this discontinuity becomes noticeable abruptly in 1949.1) The HadISST1.1 maps are much smoother than maps of SST from the Reynolds et al. (2007) Daily Optimal Interpolation SST (OISST) dataset. This is attributable at least partly to the coarser grid resolution of 1°×1° for HadISST1.1 compared with 0.25°×0.25° for OISST. The lower resolution of the HadISST1.1 dataset is not a major issue for many studies of large-scale climate variability.5) There are additional zonal discontinuities of SST at very regular intervals of 4° and 2° of longitude in, respectively, the pre-1949 and post-1949 portions of the HadISST1.1 data record. These discontinuities in zonal first differences of SST are manifest as step-like structures in SST itself, with typical jumps of 0.1°C prior to 1949 and 0.05°C after 1949.While all of the above issues are significant concerns, we show that the HadISST1.1 dataset is useful for studies of the large-scale signals associated with short-term climate variability (interannual to decadal time scales). The dataset is inadequate, however, for studies that require information about spatial derivatives of the SST field. An example is investigation of ocean-atmosphere interaction on oceanic mesoscales of 100–1000 km.A detailed analysis of the Version 1.1 Hadley Centre Sea Ice and Sea Surface Temperature (HadISST1.1) dataset has identified numerous problems, some of which limit the utility of the dataset for certain scientific applications. The issues identified from our analysis are:2) The standard deviations of the SST anomalies are 0.2–0.4°C smaller in the HadISST1.1 dataset than in the OISST dataset. This is likely also attributable at least partly to the coarser grid resolution of the HadISST1.1 dataset. However, the magnitudes of these differences seem larger than could be accounted for solely by the coarser resolution of the HadISST1.1 dataset.6) There are also meridional discontinuities at intervals of 4° and 2° of latitude in, respectively, the pre-1949 and post-1949 portions of the HadISST1.1 data record. The amplitudes of the meridionally oscillating striations in the standard deviations of meridional first differences are as large or larger than the amplitudes of the zonally oscillating striations in the standard deviations of zonal first differences

Authentic Research through Collaborative Learning (ARC-Learn): Undergraduate Research Experiences in Data Rich Arctic Science

This report serves the formative evaluation of ARC-Learn. The goal of this document is to support the use of evidence to inform programmatic changes and improvements for year two of the program, during which time Cohort One will complete its second year and Cohort Two will complete its first year of activities