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Martin P. King
,
Ivana Herceg-Bulić
,
Ileana Bladé
,
Javier García-Serrano
,
Noel Keenlyside
,
Fred Kucharski
,
Camille Li
, and
Stefan Sobolowski

Abstract

Recent studies have indicated the importance of fall climate forcings and teleconnections in influencing the climate of the northern mid- to high latitudes. Here, we present some exploratory analyses using observational data and seasonal hindcasts, with the aim of highlighting the potential of the El Niño–Southern Oscillation (ENSO) as a driver of climate variability during boreal late fall and early winter (November and December) in the North Atlantic–European sector, and motivating further research on this relatively unexplored topic. The atmospheric ENSO teleconnection in November and December is reminiscent of the east Atlantic pattern and distinct from the well-known arching extratropical Rossby wave train found from January to March. Temperature and precipitation over Europe in November are positively correlated with the Niño-3.4 index, which suggests a potentially important ENSO climate impact during late fall. In particular, the ENSO-related temperature anomaly extends over a much larger area than during the subsequent winter months. We discuss the implications of these results and pose some research questions.

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Ariel E. Cohen
,
Richard L. Thompson
,
Steven M. Cavallo
,
Roger Edwards
,
Steven J. Weiss
,
John A. Hart
,
Israel L. Jirak
,
William F. Bunting
,
Jaret W. Rogers
,
Steven F. Piltz
,
Alan E. Gerard
,
Andrew D. Moore
,
Daniel J. Cornish
,
Alexander C. Boothe
, and
Joel B. Cohen

Abstract

During the 2014–15 academic year, the National Oceanic and Atmospheric Administration (NOAA) National Weather Service Storm Prediction Center (SPC) and the University of Oklahoma (OU) School of Meteorology jointly created the first SPC-led course at OU focused on connecting traditional theory taught in the academic curriculum with operational meteorology. This class, “Applications of Meteorological Theory to Severe-Thunderstorm Forecasting,” began in 2015. From 2015 through 2017, this spring–semester course has engaged 56 students in theoretical skills and related hands-on weather analysis and forecasting applications, taught by over a dozen meteorologists from the SPC, the NOAA National Severe Storms Laboratory, and the NOAA National Weather Service Forecast Offices. Following introductory material, which addresses many theoretical principles relevant to operational meteorology, numerous presentations and hands-on activities focused on instructors’ areas of expertise are provided to students. Topics include the following: storm-induced perturbation pressure gradients and their enhancement to supercells, tornadogenesis, tropical cyclone tornadoes, severe wind forecasting, surface and upper-air analyses and their interpretation, and forecast decision-making. This collaborative approach has strengthened bonds between meteorologists in operations, research, and academia, while introducing OU meteorology students to the vast array of severe thunderstorm forecast challenges, state-of-the-art operational and research tools, communication of high-impact weather information, and teamwork skills. The methods of collaborative instruction and experiential education have been found to strengthen both operational–academic relationships and students’ appreciation of the intricacies of severe thunderstorm forecasting, as detailed in this article.

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Shelley D. Crausbay
,
Aaron R. Ramirez
,
Shawn L. Carter
,
Molly S. Cross
,
Kimberly R. Hall
,
Deborah J. Bathke
,
Julio L. Betancourt
,
Steve Colt
,
Amanda E. Cravens
,
Melinda S. Dalton
,
Jason B. Dunham
,
Lauren E. Hay
,
Michael J. Hayes
,
Jamie McEvoy
,
Chad A. McNutt
,
Max A. Moritz
,
Keith H. Nislow
,
Nejem Raheem
, and
Todd Sanford
Open access
B. G. Heusinkveld
,
G. Sterenborg
,
G. J. Steeneveld
,
J. J. Attema
,
R. J. Ronda
, and
A. A. M. Holtslag
Open access
Linnea M. Avallone
and
Brigitte Baeuerle

Abstract

Over the past two decades, the National Science Foundation’s Division of Atmospheric and Geospace Sciences (AGS) has funded nearly 200 atmospheric science–related field campaigns that have included deployment of AGS-sponsored observing facilities. These projects have spanned the range from modest, single-investigator experiments to massive, multi-investigator, multiagency campaigns. They have occurred both domestically and abroad, on every continent and over most oceans. In this article, we present an analysis of some of the details about these campaigns, including such elements as deployment location and cost of the campaign, and of statistics related to the principal investigators (e.g., type and location of institution, gender, years since degree). In addition, we assess trends in field campaign cost. These results provide a retrospective view of atmospheric science field work that has been supported since 1992.

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Ian M. Giammanco
,
Benjamin R. Maiden
,
Heather E. Estes
, and
Tanya M. Brown-Giammanco

Abstract

The emergence of 3D scanning technologies has provided a new opportunity to explore the shape characteristics of hailstones in great detail. The ability to effectively map the shape of hailstones will improve assessments of hailstone aerodynamic properties, how their density relates to their strength, and how radar energy is scattered. Ultimately, 3D scanning of hailstones will contribute toward research in hail detection, forecasting, and damage mitigation of severe hail, which accounts for well over $1 billion in annual insured losses.

The use of a handheld 3D laser scanner in a field setting was explored during field campaigns in 2015 and 2016. Hailstones were collected following thunderstorm passages and were measured, weighed, and scanned. The system was successful in capturing 3D models of more than 40 hailstones. A full scan takes approximately 3 minutes to complete, and data can be captured at a resolution of 0.008 cm. It is believed this is the first time such a system has been used to produce 3D digital hailstone models. Analysis of the model data has shown that hailstones depart from spherical shapes as they increase in diameter, and that bulk density and strength show little correlation. While the dataset presented here is small, the use of 3D scanners in the field is a practical method to obtain detailed datasets on hailstone characteristics. In addition, these data could be used to 3D-print hailstones to explore their aerodynamics, to produce cavity molds for ice impact tests, and for modeling radar scattering properties of natural hailstone shapes.

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Neil Stenhouse
,
Allison Harper
,
Xiaomei Cai
,
Sara Cobb
,
Anne Nicotera
, and
Edward Maibach

Abstract

This article analyzes open-ended survey responses to understand how members of the American Meteorological Society (AMS) perceive conflict within the AMS over global warming. Of all survey respondents, 53% agreed that there was conflict within the AMS; of these individuals who perceived conflict, 62% saw it as having at least some productive aspects, and 53% saw at least some unproductive aspects. Among members who saw a productive side to the conflict, most agreed as to why it was productive: debate and diverse perspectives enhance science. However, among members who saw an unproductive side, there was considerable disagreement as to why. Members who are convinced of largely human-caused climate change expressed that debate over global warming sends an unclear message to the public. Conversely, members who are unconvinced of human-caused climate change often felt that their peers were closed-minded and suppressing unpopular views. These two groups converged, however, on one point: politics was seen as an overwhelmingly negative influence on the debate. This suggests that scientific organizations faced with similar conflict should understand that there may be a contradiction between legitimizing all members’ views and sending a clear message to the public about the weight of the evidence. The findings also reinforce the conclusion that attempts by scientific societies to directly address differences in political views may be met with strong resistance by many scientists.

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Jeffrey A. Hicke
,
John T. Abatzoglou
,
Steven Daley-Laursen
,
Jamie Esler
, and
Lauren E. Parker

Abstract

Climate change is often perceived as controversial in the public’s view. One meaningful way scientists can address this problem is to engage with the public to increase understanding of climate change. Attendees of scientific conferences address climate change within meetings yet rarely interact with the public as part of conference attendance. Here, we describe outreach (sending experts into the community) and inreach (bringing the public to a conference) activities at the 2015 Northwest Climate Conference in Idaho that were designed to increase the local community’s understanding of climate change and foster interaction between scientists and the public. Conference attendees volunteered to visit community schools and civic groups to give presentations and engage in a discussion on climate change. We designed a well-attended evening plenary session for the public that featured an experienced speaker who described local climate change impacts important to the community. Local high school students attended the conference, and several were mentored by conference attendees. We reached an estimated 1,000 students and 500 other members of the public in person and many others via advertising and newspaper articles. Keys to our success were local contacts with excellent connections to schools, civic organizations, local government officials, interest groups, and a pool of motivated, enthusiastic conference attendees who were already traveling to the area. We encourage other conference organizers to consider these activities in their future meetings to increase public knowledge of climate change, particularly given the urgency of action needed to limit future climate change and its impacts.

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Linda O. Mearns
,
Melissa S. Bukovsky
, and
Vanessa J. Schweizer

Abstract

In this brief article, we report the initial results of an expert elicitation with the co-PIs (regional climate modelers) of the North American Regional Climate Change Assessment Program regarding their evaluation of the relative quality of regional climate model simulations focusing on the subregion dominated by the North American monsoon (NAM). We assumed that an expert elicitation framework might reveal interesting beliefs and understanding that would be different from what would be obtained from calculating quantitative metrics associated with model quality.

The simulations considered were of six regional climate models (RCMs) that used NCEP Reanalysis 2 as boundary conditions for the years 1980–2004. The domain covers most of North America and adjacent oceans. The seven participating regional modelers were asked to complete surveys on their background beliefs about model credibility and their judgments regarding the quality of the six models based on a series of plots of variables related to the NAM (e.g., temperature, winds, humidity, moisture flux, precipitation). The specific RCMs were not identified.

We also compared the results of the expert elicitation with those obtained from using a series of metrics developed to evaluate a European collection of climate model simulations. The results proved to be quite different in the two cases.

The results of this exercise proved very enlightening regarding regional modelers’ perceptions of model quality and their beliefs about how this information should or should not be used. Based on these pilot study results, we believe a more complete study is warranted.

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Paquita Zuidema
,
Julie Haggerty
,
Maria Cadeddu
,
Jorgen Jensen
,
Emiliano Orlandi
,
Mario Mech
,
J. Vivekanandan
, and
Zhien Wang
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