A BALLOON-BORNE PARTICLE SIZE, IMAGING, AND VELOCITY PROBE FOR IN SITU MICROPHYSICAL MEASUREMENTS

A balloon-borne instrument known as the PArticle Size, Image, and Velocity (PASIV) probe has been developed at the National Severe Storms Laboratory to provide in situ microphysical measurements in storms. These observations represent a critical need of microphysical observations for use in lightning studies, cloud microphysics simulations, and dual-polarization radar validation. The instrument weighs approximately 2.72 kg and consists of an HD video camera, a camera viewing chamber, and a modified Parsivel laser disdrometer mounted above the camera viewing chamber. Precipitation particles fall through the Parsivel sampling area and then into the camera viewing chamber, effectively allowing both devices to sample the same particle stream. The data are collected onboard for analysis after retrieval. Taken together, these two instruments are capable of providing a vertical profile of the size, shape, velocity, orientation, and composition of particles along the balloon path within severe weather. The PASIV probe has been deployed across several types of weather environments including thunderstorms, supercells, and winter storms. Initial results from two cases in the Deep Convective Clouds and Chemistry Experiment are shown that demonstrate the ability of the instrument to obtain high temporal and spatial resolution observations of the particle size distributions (PSD) within convection. The ability to resolve the PSD into different particle habits and compare to observed radar and model analysis values is also demonstrated

The "U-Tube": An improved aspirated temperature system for mobile meteorological observations, especially in severe weather

The ability to obtain quality air temperature measurements in and around thunderstorms is often problematic, and even more challenging from a moving platform such as a ground-based vehicle. Since the original Verification of the Origin of Rotation in Tornadoes Experiment (VORTEX) project in 1994-1995, mobile weather platforms known as Mobile Mesonets (MMs) from the National Severe Storms Laboratory (NSSL) and the Center for Analysis and Prediction of Stotms (CAPS) have used an aspirated temperature shield design called a "J-Tube" that address some, but not all of the issues commonly encountered. Due to these concerns, for VORTEX 2: 2009 an R.M. Young model 43408 temperature shield was added to complement the J-tube. However, it too was found to have certain shortcomings in severe weather environments. Between the end of VORTEX 2: 2009 and the start of VORTEX 2: 2010, a third new and new shield was designed, tested and installed called the "U-Tube."The results of efforts to better characterize the J-Tube, the RM Young shield, and the design and performance characteristics of the U-Tube, in and around thunderstorms, are reported. Additionally the entire 2010 season of the VORTEX 2 project was used for an intercomparison of these shield designs. Results indicate that compared to the J-tube and the RM Young shield, the U-tube improves the response time, and reduces errors due to solar radiation, rain, varying wind directions, and speed.This work was partially funded by NSF grant AGS-1036237.Ye

Intercomparison of Unmanned Aircraftborne and Mobile Mesonet Atmospheric Sensors

Results are presented from an intercomparison of temperature, humidity, and wind velocity sensors of the Tempest unmanned aircraft system (UAS) and the National Severe Storms Laboratory (NSSL) mobile mesonet (NSSL-MM). Contemporaneous evaluation of sensor performance was facilitated by mounting the Tempest wing with attached sensors to the NSSL-MM instrument rack such that the Tempest and NSSL-MM sensors could collect observations within a nearly identical airstream. This intercomparison was complemented by wind tunnel simulations designed to evaluate the impact of the mobile mesonet vehicle on the observed wind velocity. The intercomparison revealed strong correspondence between the temperature and relative humidity (RH) data collected by the Tempest and the NSSL-MM with differences generally within sensor accuracies. Larger RH differences were noted in the presence of heavy precipitation; however, despite the exposure of the Tempest temperature and humidity sensor to the airstream, there was no evidence of wet bulbing within precipitation. Wind tunnel simulations revealed that the simulated winds at the location of the NSSL-MM wind monitor were ~4% larger than the expected winds due to the acceleration of the flow over the vehicle. Simulated vertical velocity exceeded 1 ms-1 for tunnel inlet speeds typical of a vehicle moving at highway speeds. However, the theoretical noncosine reduction in winds that should result from the impact of vertical velocity on the laterally mounted wind monitor was found to be negligible across the simulations. Comparison of the simulated and observed results indicates a close correspondence, provided the crosswind component of the flow is small

Remote-sensing and radiosonde datasets collected in the San Luis Valley during the LAPSE-RATE campaign

In July 2018, the International Society for Atmospheric Research using Remotely piloted Aircraft (ISARRA) hosted a flight week to showcase the role remotely piloted aircraft systems (RPASs) can have in filling the atmospheric data gap. This campaign was called Lower Atmospheric Process Studies at Elevation &ndash; a Remotely-piloted Aircraft Team Experiment (LAPSE-RATE). In support of this campaign, ground-based remote and in situ systems were also deployed for the campaign. The University of Oklahoma deployed the Collaborative Lower Atmospheric Mobile Profiling System (CLAMPS), the University of Colorado deployed two Doppler wind lidars, and the National Severe Storms Laboratory deployed a mobile mesonet with the ability to launch radiosondes. This paper focuses on the data products from these instruments that result in profiles of the atmospheric state. The data are publicly available in the Zenodo LAPSE-RATE community portal (https://zenodo.org/communities/lapse-rate/, 19 January 2021). The profile data discussed are available at https://doi.org/10.5281/zenodo.3780623 (Bell and Klein,&nbsp;2020), https://doi.org/10.5281/zenodo.3780593 (Bell et&nbsp;al.,&nbsp;2020b), https://doi.org/10.5281/zenodo.3727224 (Bell et&nbsp;al.,&nbsp;2020a), https://doi.org/10.5281/zenodo.3738175 (Waugh,&nbsp;2020b), https://doi.org/10.5281/zenodo.3720444 (Waugh,&nbsp;2020a), and https://doi.org/10.5281/zenodo.3698228 (Lundquist et&nbsp;al.,&nbsp;2020). &nbsp;</p

Data Generated during the 2018 LAPSE-RATE Campaign: An Introduction and Overview

Unmanned aircraft systems (UASs) offer innovative capabilities for providing new perspectives on the atmosphere, and therefore atmospheric scientists are rapidly expanding their use, particularly for studying the planetary boundary layer. In support of this expansion, from 14 to 20 July 2018 the International Society for Atmospheric Research using Remotely piloted Aircraft (ISARRA) hosted a community flight week, dubbed the Lower Atmospheric Profiling Studies at Elevation – a Remotely-piloted Aircraft Team Experiment (LAPSE-RATE; de Boer et al., 2020a). This field campaign spanned a 1-week deployment to Colorado\u27s San Luis Valley, involving over 100 students, scientists, engineers, pilots, and outreach coordinators. These groups conducted intensive field operations using unmanned aircraft and ground-based assets to develop comprehensive datasets spanning a variety of scientific objectives, including a total of nearly 1300 research flights totaling over 250 flight hours. This article introduces this campaign and lays the groundwork for a special issue on the LAPSE-RATE project. The remainder of the special issue provides detailed overviews of the datasets collected and the platforms used to collect them. All of the datasets covered by this special issue have been uploaded to a LAPSE-RATE community set up at the Zenodo data archive (https://zenodo.org/communities/lapse-rate/, last access: 3 December 2020)

Teaching tobacco dependence treatment and counseling skills during medical school: rationale and design of the Medical Students helping patients Quit tobacco (MSQuit) group randomized controlled trial

INTRODUCTION: Physician-delivered tobacco treatment using the 5As is clinically recommended, yet its use has been limited. Lack of adequate training and confidence to provide tobacco treatment is cited as leading reasons for limited 5A use. Tobacco dependence treatment training while in medical school is recommended, but is minimally provided. The MSQuit trial (Medical Students helping patients Quit tobacco) aims to determine if a multi-modal and theoretically-guided tobacco educational intervention will improve tobacco dependence treatment skills (i.e. 5As) among medical students. METHODS/DESIGN: 10 U.S. medical schools were pair-matched and randomized in a group-randomized controlled trial to evaluate whether a multi-modal educational (MME) intervention compared to traditional education (TE) will improve observed tobacco treatment skills. MME is primarily composed of TE approaches (i.e. didactics) plus a 1st year web-based course and preceptor-facilitated training during a 3rd year clerkship rotation. The primary outcome measure is an objective score on an Objective Structured Clinical Examination (OSCE) tobacco-counseling smoking case among 3rd year medical students from schools who implemented the MME or TE. DISCUSSION: MSQuit is the first randomized to evaluate whether a tobacco treatment educational intervention implemented during medical school will improve medical students\u27 tobacco treatment skills. We hypothesize that the MME intervention will better prepare students in tobacco dependence treatment as measured by the OSCE. If a comprehensive tobacco treatment educational learning approach is effective, while also feasible and acceptable to implement, then medical schools may substantially influence skill development and use of the 5As among future physicians. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved

The TropD software package (v1): standardized methods for calculating tropical-width diagnostics

Observational and modeling studies suggest that Earth's tropical belt has widened over the late 20th century and will continue to widen throughout the 21st century. Yet, estimates of tropical-width variations differ significantly across studies. This uncertainty, to an unknown degree, is partly due to the large variety of methods used in studies of the tropical width. Here, methods for eight commonly used metrics of the tropical width are implemented in the Tropical-width Diagnostics (TropD) code package in the MATLAB programming language. To consolidate the various methods, the operations used in each of the implemented methods are reduced to two basic calculations: finding the latitude of a zero crossing and finding the latitude of a maximum. A detailed description of the methods implemented in the code and of the code syntax is provided, followed by a method sensitivity analysis for each of the metrics. The analysis provides information on how to reduce the methodological component of the uncertainty associated with fundamental aspects of the calculations, such as monthly vs. seasonal averaging biases, grid dependence, sensitivity to noise, and sensitivity to threshold criteria

Gravitational Energy in Spherical Symmetry

Various properties of the Misner-Sharp spherically symmetric gravitational energy E are established or reviewed. In the Newtonian limit of a perfect fluid, E yields the Newtonian mass to leading order and the Newtonian kinetic and potential energy to the next order. For test particles, the corresponding Hajicek energy is conserved and has the behaviour appropriate to energy in the Newtonian and special-relativistic limits. In the small-sphere limit, the leading term in E is the product of volume and the energy density of the matter. In vacuo, E reduces to the Schwarzschild energy. At null and spatial infinity, E reduces to the Bondi-Sachs and Arnowitt-Deser-Misner energies respectively. The conserved Kodama current has charge E. A sphere is trapped if E>r/2, marginal if E=r/2 and untrapped if E<r/2, where r is the areal radius. A central singularity is spatial and trapped if E>0, and temporal and untrapped if E<0. On an untrapped sphere, E is non-decreasing in any outgoing spatial or null direction, assuming the dominant energy condition. It follows that E>=0 on an untrapped spatial hypersurface with regular centre, and E>=r_0/2 on an untrapped spatial hypersurface bounded at the inward end by a marginal sphere of radius r_0. All these inequalities extend to the asymptotic energies, recovering the Bondi-Sachs energy loss and the positivity of the asymptotic energies, as well as proving the conjectured Penrose inequality for black or white holes. Implications for the cosmic censorship hypothesis and for general definitions of gravitational energy are discussed.Comment: 23 pages. Belatedly replaced with substantially extended published versio