ARL Weekly News – June 25, 2021

Recent Events

2021 HYSPLIT Workshop Trains New Users

The 2021 Annual HYSPLIT Workshop was conducted entirely online, as was piloted last year due to COVID-19. The Workshop was presented over four days, from June 15-18, 2021, reaching over 250 people in real time, with about 100 other participants tuning in to access the recordings. The videos are publicly available to those who were not able to attend an entire session or who want to go back and review portions of the course. Overall, about half of the participants were from the U.S. and about half were international; affiliations included approximately half from international, federal, state, or local agencies; the remaining half were university students and professors with a few participants from NGO’s or the private sector. The considerable effort ARL invests in each year’s event ensures future users are trained and HYSPLIT is continuously improved to generate new collaborations and partnerships.

The program began with a welcome from ARL Deputy Director Ariel Stein and was moderated/coordinated by Mark Cohen and Sonny Zinn. Roland Draxler (ARL, retired), was the primary instructor for the course. Roland carefully explained the scientific basis of HYSPLIT and the way the model works, and he expertly guided participants through their own hands-on application of the model’s many capabilities. ARL’s IT Team (Rick Jiang and Fred Shen) played a key role in the planning and implementation of the event, to ensure that the complex IT challenges associated with the event were successfully met. Thy HYSPLIT Team also worked tirelessly throughout the event to answer questions raised by participants. At any given time during the event, ~8 people from ARL were providing one or more kinds of behind-the-scenes support and ARL staff expertly addressed and resolved all questions and issues that arose, in real-time, as the event was proceeding. The Workshop webpage has been continuously updated before, during, and now after the event, to communicate and share important information with the participants.
For more info, visit: 2021 Online HYSPLIT Workshop

Kim Receives Commendation from South Korean Ministry.

ARL researcher HyunCheol Kim received an award from the South Korean government. The certificate states “I commend you for your contribution to environmental conservation with extraordinary interest and dedication.”  The Minister’s commendation was issued by the  Ministry of Environment, South Korea. Hyun Cheol is an active collaborator with a number of Korean researchers on regional air quality.

Land Atmospheric Interaction Workshop

Praveena Krishnan and Tilden Meyers participated in the land-atmospheric interaction workshop on 10-11 June, 2021. The virtual workshop focused on “Improving understanding of land-atmosphere interactions through integration of surface flux and atmospheric boundary layer measurements.”  This workshop is organized in connection with the AmeriFlux “Year of Water Fluxes,” and with support from the AmeriFlux Management Project and the Department of Energy’s Office of Science and in collaboration with community representation from the U.S. Department of Energy’s ARM User Facility, and ASR and ESS programs.

Upcoming Meetings

International Meetings

Tianfeng Chai will attend the CTBT (Comprehensive Nuclear-Test-Ban Treaty) Science and Technology 2021 Conference Mon, Jun 28, 2021 – Fri, Jul 2, 2021, Vienna, Austria.  He will present one e-poster “Comparison of forward and backward source-receptor sensitivities for atmospheric inverse modeling using the HYSPLIT model with the Cross-Appalachian Tracer Experiment (CAPTEX) field experiment measurements,” authored by  Tianfeng Chai, Mark Cohen, and Fong Ngan.

Tianfeng will also attend the IAEA (International Atomic Energy Agency) workshop to present: “Meeting on Sharing Experience in Source Term Estimation and Air Dispersion Modelling for Nuclear Emergency Preparedness and Response”,  5 – 7 July 2021,  hosted in Beijing, China, to present two talks: NOAA’s experience in source inversion and radioactivity emergency response problems; and NOAA’s experience in the use of HYSPLIT in inverse modelling (with demo).

Recent Publications

Published: Developing and Validating Heat Exposure Products Using the U.S. Climate Reference Network

Rennie, J.J.R.; Palecki, M.A.; Heuser, S.P.; Diamond H.J.; Developing and Validating Heat Exposure Products Using the U.S. Climate Reference Network. Journal of Applied Meteorology and Climatology 60, 10.1175/JAMC-D-20-0282.1. DOI: 10.1175/JAMC-D-20-0282.1

Abstract: Extreme heat is one of the most pressing climate risks in the United States and is exacerbated by a warming climate and aging population. Much work in heat health has focused only on temperature-based metrics, which do not fully measure the physiological impact of heat stress on the human body. The U.S. Climate Reference Network (USCRN) consists of 139 sites across the United States and includes meteorological parameters that fully encompass human tolerance to heat, including relative humidity, wind, and solar radiation. Hourly and 5-min observations from USCRN are used to develop heat exposure products, including heat index (HI), apparent temperature (AT), and wet-bulb globe temperature (WBGT). Validation of this product is conducted with nearby airport and mesonet stations, with reanalysis data used to fill in data gaps. Using these derived heat products, two separate analyses are conducted. The first is based on standardized anomalies, which place current heat state in the context of a long-term climate record. In the second study, heat events are classified by time spent at various levels of severity of conditions. There is no consensus as to what defines a heat event, so a comparison of absolute thresholds (i.e., ≥30.0°, 35.0°, and 40.0°C) and relative thresholds (≥90th, 95th, and 98th percentile) will be examined. The efficacy of the product set will be studied using an extreme heat case study in the southeastern United States. While no heat exposure metric is deemed superior, each has their own advantages and caveats, especially in the context of public communication.