Forecasting and Intercepting the 28 May 2013 Bennington, KS Tornadic Supercell: A Student Perspective

This project examines the 28 May 2013 mesoscale case over north-central Kansas and focuses on the step-by-step process from a student perspective. The project describes the tools, models, parameters, and observations used to determine the focus for the day, including a classic loaded-gun sounding measured and observed by the field team. The decisions made by the team on this day placed them in position to observe an EF-3 tornado near Bennington, Kansas. The main goal of the project is to educate students about how to forecast and safely observe severe weather events through a how-to-guide compiled from experiences in the Valparaiso University Meteorology Department program, Severe Convective Storms Field Study. The project will demonstrate how to apply the knowledge from the course to a real-time, in the field, forecast. Although forecasting is not an exact science just yet, the guide will help educate future students and others on how to utilize various tools and techniques in order to accurately forecast for convective weather

On the Mass Function, Multiplicity, and Origins of Wide-Orbit Giant Planets

A major outstanding question regarding the formation of planetary systems is whether wide-orbit giant planets form differently than close-in giant planets. We aim to establish constraints on two key parameters that are relevant for understanding the formation of wide-orbit planets: 1) the relative mass function and 2) the fraction of systems hosting multiple companions. In this study, we focus on systems with directly imaged substellar companions, and the detection limits on lower-mass bodies within these systems. First, we uniformly derive the mass probability distributions of known companions. We then combine the information contained within the detections and detection limits into a survival analysis statistical framework to estimate the underlying mass function of the parent distribution. Finally, we calculate the probability that each system may host multiple substellar companions. We find that 1) the companion mass distribution is rising steeply toward smaller masses, with a functional form of $N\propto M^{-1.3\pm0.3}$, and consequently, 2) many of these systems likely host additional undetected sub-stellar companions. Combined, these results strongly support the notion that wide-orbit giant planets are formed predominantly via core accretion, similar to the better studied close-in giant planets. Finally, given the steep rise in the relative mass function with decreasing mass, these results suggest that future deep observations should unveil a greater number of directly imaged planets.Comment: 19 pages, 10 figures, accepted to Ap

Forecasting and Intercepting the 28 May 2013 Bennington, KS Tornadic Supercell: A Student Perspective

This project examines the 28 May 2013 mesoscale case over north-central Kansas and focuses on the step-by-step process from a student perspective. The project describes the tools, models, parameters, and observations used to determine the focus for the day, including a classic loaded-gun sounding measured and observed by the field team. The decisions made by the team on this day placed them in position to observe an EF-3 tornado near Bennington, Kansas. The main goal of the project is to educate students about how to forecast and safely observe severe weather events through a how-to-guide compiled from experiences in the Valparaiso University Meteorology Department program, Severe Convective Storms Field Study. The project will demonstrate how to apply the knowledge from the course to a real-time, in the field, forecast. Although forecasting is not an exact science just yet, the guide will help educate future students and others on how to utilize various tools and techniques in order to accurately forecast for convective weather

Texas Watershed Planning Short Course Final Report

Proper training of watershed coordinators and water professionals is needed to ensure that watershed protection efforts are adequately planned, coordinated and implemented. To provide this training, the Texas Watershed Planning Short Course was developed through a coordinated effort led by the Texas Water Resources Institute and funded by the U.S. Environmental Protection Agency through the Texas Commission on Environmental Quality. The Texas Water Resources Institute partnered with the Texas AgriLife Extension Service, Texas AgriLife Research, Texas State Soil and Water Conservation Board, Texas Commission on Environmental Quality, U.S. Environmental Protection Agency, Texas State University-River Systems Institute and the Texas Institute for Applied Environmental Research to develop and conduct this short course. Since 2008, four week-long Watershed Planning Short Courses have been hosted, providing training to over 160 watershed professionals on sustainable proactive approaches to managing water quality throughout the state. The Watershed Planning Short Course provides guidance on stakeholder coordination, education, and outreach; meeting the U.S. Environmental Protection Agency’s nine key elements of a watershed protection plan; data collection and analysis; and the tools available for plan development. Along with the Watershed Planning Short Courses, water professionals were invited to attend Texas Watershed Coordinator Roundtables, held biannually, to (1) provide a forum for establishing and maintaining dialogue between watershed coordinators, (2) facilitate interactive solutions to common watershed issues faced throughout the state, and (3) add to the fundamental knowledge conveyed at the short courses. More than 250 water professionals attended the four Texas Watershed Coordinator Roundtables held in Temple, Georgetown and Dallas. Topics of discussion included sustainable organizational structure for long-term watershed protection plan implementation; the U.S. Environmental Protection Agency’s Region 6 review guide of watershed-based plans; strategies and expectations for demonstrating successful implementation and financing watershed protection plans. Additional workshops also offered to further familiarize watershed coordinators with watershed management tools provided by the U.S. Environmental Protection Agency included Getting In Step Workshops and Key EPA Internet Tools for Watershed Management courses. The Getting In Step Workshop aims to improve the effectiveness of nonpoint source outreach in Texas and the internet tools course familiarizes users with online watershed management tools provided by the U.S. Environmental Protection Agency. More than 90 watershed professionals participated in four Getting In Step Workshops offered in Houston, Austin, Dallas and Georgetown. Nearly 40 watershed professionals participated in the two Key EPA Internet Tools for Watershed Management courses offered in San Marcos and Dallas. Also, the Texas Water Resources Institute coordinated with Wildland Hydrology to provide an Applied Fluvial Geomorphology Short Course with 40 water resource professionals participating to better understand the fundamentals and general principles of river behavior. To assist watershed professionals in searching for funding programs, the Texas Water Resources Institute worked with the Environmental Finance Center at Boise State University to update the Directory of Watershed Resources to include Texas-specific funding programs. The Environmental Finance Center Network is an EPA-sponsored, university-based program providing financial outreach services. The Directory of Watershed Resources is an on-line, searchable database for watershed restoration funding. The database includes information on federal, state, private, and other funding sources and assistance and allows Texas users to query information in a variety of ways including by agency sponsor or keyword, or by a detailed search. In total, the combined courses, workshops and meetings have reached out to more than 350 watershed coordinators and water professionals and will continue to do so by hosting biannual Watershed Coordinator Roundtable meetings and training opportunities

On the centroid of increasing trees

A centroid node in a tree is a node for which the sum of the distances to all other nodes attains its minimum, or equivalently a node with the property that none of its branches contains more than half of the other nodes. We generalise some known results regarding the behaviour of centroid nodes in random recursive trees (due to Moon) to the class of very simple increasing trees, which also includes the families of plane-oriented and $d$-ary increasing trees. In particular, we derive limits of distributions and moments for the depth and label of the centroid node nearest to the root, as well as for the size of the subtree rooted at this node

Multi-epoch Direct Imaging and Time-variable Scattered Light Morphology of the HD 163296 Protoplanetary Disk

We present H-band polarized scattered light imagery and JHK high-contrast spectroscopy of the protoplanetary disk around HD 163296 observed with the High-Contrast Coronographic Imager for Adaptive Optics (HiCIAO) and Subaru Coronagraphic Extreme Adaptive Optics (SCExAO)/Coronagraphic High Angular Resolution Imaging Spectrograph (CHARTS) instruments at Subaru Observatory. The polarimetric imagery resolve a broken ring structure surrounding HD 163296 that peaks at a distance along the major axis of 0 ''.65 (66 au) and extends out to 0 ''.98 (100 au) along the major axis. Our 2011 H-band data exhibit clear axisymmetry, with the NW and SE side of the disk exhibiting similar intensities. Our data are clearly different from 2016 epoch H-band observations of the Very Large Telescope (VLT)/Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE), which found a strong 2.7 x asymmetry between the NW and SE side of the disk. Collectively, these results indicate the presence of time-variable, non-azimuthally symmetric illumination of the outer disk. While our SCExAO/CHARIS data are sensitive enough to recover the planet candidate identified from NIRC2 in the thermal infrared (IR), we fail to detect an object with JHK brightness nominally consistent with this object. This suggests that the candidate is either fainter in JHK bands than model predictions, possibly due to extinction from the disk or atmospheric dust/clouds, or that it is an artifact of the data set/data processing, such as a residual speckle or partially subtracted disk feature. Assuming standard hot-start evolutionary models and a system age of 5 Myr, we set new, direct mass limits for the inner (outer) Atacama Large Millimeter/submillimeter Array (ALMA)-predicted protoplanet candidate along the major (minor) disk axis of of 1.5 (2) M-J.NASA XRP program [NNX-17AF88G]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]