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  • Author or Editor: Justin R. Minder x
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Ronald B. Smith
,
Justin R. Minder
,
Alison D. Nugent
,
Trude Storelvmo
,
Daniel J. Kirshbaum
,
Robert Warren
,
Neil Lareau
,
Philippe Palany
,
Arlington James
, and
Jeffrey French

The Dominica Experiment (DOMEX) took place in the eastern Caribbean from 4 April to 10 May 2011 with 21 research flights of the Wyoming King Air and several other observing systems. The goal was an improved understanding of the physics of convective orographic precipitation in the tropics. Two types of convection were found. During a period of weak trade winds, diurnal thermal convection was seen over Dominica. This convection caused little precipitation but carried aloft air with island-derived aerosol and depleted CO2. During periods of strong trades, mechanically forced convection over the windward slopes brought heavy rain to the high terrain. This convection was “seeded” by trade-wind cumuli or neutrally buoyant cool wet patches of air. In this mechanically forced convection, air parcels did not touch the island surface to gain buoyancy so no island-derived tracers were lofted. With fewer aerosols, the mean cloud droplet diameter increased from 15 to 25 μm. Plunging airflow and a wake were found in the lee of Dominica. The DOMEX dataset will advance our understanding and test our theories of cumulus triggering and aerosol influence on precipitation.

Full access
David A. R. Kristovich
,
Richard D. Clark
,
Jeffrey Frame
,
Bart Geerts
,
Kevin R. Knupp
,
Karen A. Kosiba
,
Neil F. Laird
,
Nicholas D. Metz
,
Justin R. Minder
,
Todd D. Sikora
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W. James Steenburgh
,
Scott M. Steiger
,
Joshua Wurman
, and
George S. Young

Abstract

Intense lake-effect snowstorms regularly develop over the eastern Great Lakes, resulting in extreme winter weather conditions with snowfalls sometimes exceeding 1 m. The Ontario Winter Lake-effect Systems (OWLeS) field campaign sought to obtain unprecedented observations of these highly complex winter storms.

OWLeS employed an extensive and diverse array of instrumentation, including the University of Wyoming King Air research aircraft, five university-owned upper-air sounding systems, three Center for Severe Weather Research Doppler on Wheels radars, a wind profiler, profiling cloud and precipitation radars, an airborne lidar, mobile mesonets, deployable weather Pods, and snowfall and particle measuring systems. Close collaborations with National Weather Service Forecast Offices during and following OWLeS have provided a direct pathway for results of observational and numerical modeling analyses to improve the prediction of severe lake-effect snowstorm evolution. The roles of atmospheric boundary layer processes over heterogeneous surfaces (water, ice, and land), mixed-phase microphysics within shallow convection, topography, and mesoscale convective structures are being explored.

More than 75 students representing nine institutions participated in a wide variety of data collection efforts, including the operation of radars, radiosonde systems, mobile mesonets, and snow observation equipment in challenging and severe winter weather environments.

Full access
Justin R. Minder
,
Nick Bassill
,
Frédéric Fabry
,
Jeffrey R. French
,
Katja Friedrich
,
Ismail Gultepe
,
John Gyakum
,
David E. Kingsmill
,
Karen Kosiba
,
Mathieu Lachapelle
,
Daniel Michelson
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Leonid Nichman
,
Cuong Nguyen
,
Julie M. Thériault
,
Andrew C. Winters
,
Mengistu Wolde
, and
Joshua Wurman

Abstract

During near-0°C surface conditions, diverse precipitation types (p-types) are possible, including rain, drizzle, freezing rain, freezing drizzle, ice pellets, wet snow, snow, and snow pellets. Near-0°C precipitation affects wide swaths of the United States and Canada, impacting aviation, road transportation, power generation and distribution, winter recreation, ecology, and hydrology. Fundamental challenges remain in observing, diagnosing, simulating, and forecasting near-0°C p-types, particularly during transitions and within complex terrain. Motivated by these challenges, the field phase of the Winter Precipitation Type Research Multiscale Experiment (WINTRE-MIX) was conducted from 1 February to 15 March 2022 to better understand how multiscale processes influence the variability and predictability of p-type and amount under near-0°C surface conditions. WINTRE-MIX took place near the U.S.–Canadian border, in northern New York and southern Quebec, a region with plentiful near-0°C precipitation influenced by terrain. During WINTRE-MIX, existing advanced mesonets in New York and Quebec were complemented by deployment of 1) surface instruments, 2) the National Research Council Convair-580 research aircraft with W- and X-band Doppler radars and in situ cloud and aerosol instrumentation, 3) two X-band dual-polarization Doppler radars and a C-band dual-polarization Doppler radar from the University of Illinois, and 4) teams collecting manual hydrometeor observations and radiosonde measurements. Eleven intensive observing periods (IOPs) were coordinated. Analysis of these WINTRE-MIX IOPs is illuminating how synoptic dynamics, mesoscale dynamics, and microscale processes combine to determine p-type and its predictability under near-0°C conditions. WINTRE-MIX research will contribute to improving nowcasts and forecasts of near-0°C precipitation through evaluation and refinement of observational diagnostics and numerical forecast models.

Open access
Sara Lance
,
Jie Zhang
,
James J. Schwab
,
Paul Casson
,
Richard E. Brandt
,
David R. Fitzjarrald
,
Margaret J. Schwab
,
John Sicker
,
Cheng-Hsuan Lu
,
Sheng-Po Chen
,
Jeongran Yun
,
Jeffrey M. Freedman
,
Bhupal Shrestha
,
Qilong Min
,
Mark Beauharnois
,
Brian Crandall
,
Everette Joseph
,
Matthew J. Brewer
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Justin R. Minder
,
Daniel Orlowski
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Amy Christiansen
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Annmarie G. Carlton
, and
Mary C. Barth

Abstract

Aqueous chemical processing within cloud and fog water is thought to be a key process in the production and transformation of secondary organic aerosol mass, found abundantly and ubiquitously throughout the troposphere. Yet, significant uncertainty remains regarding the organic chemical reactions taking place within clouds and the conditions under which those reactions occur, owing to the wide variety of organic compounds and their evolution under highly variable conditions when cycled through clouds. Continuous observations from a fixed remote site like Whiteface Mountain (WFM) in New York State and other mountaintop sites have been used to unravel complex multiphase interactions in the past, particularly the conversion of gas-phase emissions of SO2 to sulfuric acid within cloud droplets in the presence of sunlight. These scientific insights led to successful control strategies that reduced aerosol sulfate and cloud water acidity substantially over the following decades. This paper provides an overview of observations obtained during a pilot study that took place at WFM in August 2017 aimed at obtaining a better understanding of Chemical Processing of Organic Compounds within Clouds (CPOC). During the CPOC pilot study, aerosol cloud activation efficiency, particle size distribution, and chemical composition measurements were obtained below-cloud for comparison to routine observations at WFM, including cloud water composition and reactive trace gases. Additional instruments deployed for the CPOC pilot study included a Doppler lidar, sun photometer, and radiosondes to assist in evaluating the meteorological context for the below-cloud and summit observations.

Free access
Sara Lance
,
Jie Zhang
,
James J. Schwab
,
Paul Casson
,
Richard E. Brandt
,
David R. Fitzjarrald
,
Margaret J. Schwab
,
John Sicker
,
Cheng-Hsuan Lu
,
Sheng-Po Chen
,
Jeongran Yun
,
Jeffrey M. Freedman
,
Bhupal Shrestha
,
Qilong Min
,
Mark Beauharnois
,
Brian Crandall
,
Everette Joseph
,
Matthew J. Brewer
,
Justin R. Minder
,
Daniel Orlowski
,
Amy Christiansen
,
Annmarie G. Carlton
, and
Mary C. Barth
Full access
Francina Dominguez
,
Roy Rasmussen
,
Changhai Liu
,
Kyoko Ikeda
,
Andreas Prein
,
Adam Varble
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Paola A. Arias
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Julio Bacmeister
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Maria Laura Bettolli
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Patrick Callaghan
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Leila M. V. Carvalho
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Christopher L. Castro
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Fei Chen
,
Divyansh Chug
,
Kwok Pan (Sun) Chun
,
Aiguo Dai
,
Luminita Danaila
,
Rosmeri Porfírio da Rocha
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Ernani de Lima Nascimento
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Erin Dougherty
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Jimy Dudhia
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Trude Eidhammer
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Zhe Feng
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Lluís Fita
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Rong Fu
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Julian Giles
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Harriet Gilmour
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Kate Halladay
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Yongjie Huang
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Angela Maylee Iza Wong
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Miguel Ángel Lagos-Zúñiga
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Charles Jones
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Jorge Llamocca
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Marta Llopart
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J. Alejandro Martinez
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J. Carlos Martinez
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Justin R. Minder
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Monica Morrison
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Zachary L. Moon
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Ye Mu
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Richard B. Neale
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Kelly M. Núñez Ocasio
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Sujan Pal
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Erin Potter
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German Poveda
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Franciano Puhales
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Kristen L. Rasmussen
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Amanda Rehbein
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Rosimar Rios-Berrios
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Christoforus Bayu Risanto
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Alan Rosales
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Lucia Scaff
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Anton Seimon
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Marcelo Somos-Valenzuela
,
Yang Tian
,
Peter Van Oevelen
,
Daniel Veloso-Aguila
,
Lulin Xue
, and
Timothy Schneider
Open access