Professor Steven Businger Atmospheric Sciences University of Hawaii at Manoa
Abstract
This talk will provide a historical review of our understanding of the workings of the atmospheric boundary layer (ABL); that part of the lower atmosphere, typically ≤1 km in depth, that directly feels the influence of the Earth’s surface. The review is a celebration of the career of Joost A. Businger (1924-2023), a pioneer in this area, who realized early in his studies that the atmospheric boundary layer holds great practical importance in the sense that most of humankind’s activities take place within it, and scientific importance in the sense that the boundary layer forms the interface between the free atmosphere and the Earth’s surface and therefore plays a major role in our weather and climate. The talk will review progress in our understanding of relationships between the surface layer and circulations in the ABL and in our understanding air-sea interaction during the past century. The relationships form a cornerstone that numerical weather and climate models rely upon.
Dr. Anastasios Rovithakis Postdoctoral Researcher Convection, Clouds, and Extremes Lab Department of Atmospheric Sciences University of Hawaii at Manoa
ABSTRACT
This presentation examines the impact of climate change on wildfire danger focusing over Greece through meteorological analysis and modeling techniques. It highlights the projected increase in fire risk, particularly in high-risk areas, and the potential for longer fire seasons under more severe climate scenarios. Using models like WRF-Chem and JULES-INFERNO the mechanisms of how wildfire aerosols affect the short-term weather and how changing vegetation dynamics influence future burned areas were explored. The presentation underscores the importance of integrating climate models, satellite data, and adaptive management strategies to address the growing wildfire threats and mitigate their effects on ecosystems, human health, and the economy.
BIO
Anastasios Rovithakis is a postdoctoral researcher working with Dr. Torri at UH Manoa. He got his Ph.D. from the Technical University of Crete, in Greece. His research is focused on performing statistical analysis on future wildfire danger using the Canadian Fire Weather Index as well as atmospheric modeling with WRF-Chem to see the effects of wildfires in short-term weather. He has also developed a methodology for accurately and automatically selecting smoke plumes from satellites and checked the effects of future vegetation on burnt area with output from a land surface model.As a security precaution, unmuting microphones, starting video, screen share, and using the ‘chat’ feature will be disabled for those attending the seminar, except for ATMO faculty. If you would like to say something, please use the ‘raise hand’ feature. The host or a co-host can then enable you to unmute your microphone.
Dr. Leandro Alex Moreira Viscardi Postdoctoral Researcher Atmospheric Sciences UH Manoa
ABSTRACT
The Amazon rainforest is a vital component of the global climate system, influencing the hydrological cycle and tropical circulation. However, understanding and modeling the evolution of convection in this region remains a scientific challenge. In this study, we combined recent observations and high-resolution simulations to evaluate the relative importance of different environmental controls on locally-driven convection in the Amazon. Observationally, we assessed the environmental conditions associated with shallow, congestus, and isolated deep convection days during the wet season (December to April), employing data from the GoAmazon (2014-2015) experiment. Composites of deep days show moister than average conditions below 3 km early in the morning. Water vapor convergence increases significantly in the afternoon when the shallow-to-deep convective transition occurs around 16-17 LST. Moreover, afternoon precipitation increases with large-scale vertical velocity, humidity at different levels and periods of the day, and low-level wind shear. Numerical simulations indicated that daytime convection shows a noticeable sensitivity to pre-convective low-level humidity and a weaker response to free troposphere humidity. Vertical wind shear primarily influences ice content, but its role is smaller than that of humidity in the shallow-to-deep convective transition.
BIO
Leandro Alex Moreira Viscardi is a postdoctoral researcher in the Department of Atmospheric Sciences at UH Manoa. He received a Ph.D. from the University of São Paulo, where he conducted research on the environmental controls of isolated convection in the Amazon, employing both observations and idealized numerical simulations. Currently, he is involved in a project named Change Hawaii, focusing primarily on the process of precipitation recycling over the Hawaiian Islands and investigating how changes in land use and land cover impact the climate in Hawaiʻi.
Layne Washington Human Resources Business Advisor NOAA | Office of Human Capital Services Consulting Branch A, National Weather Service Western, Pacific, and Alaska Regions
ABSTRACT
This presentation provides an in-depth guide to applying for federal jobs, offering insights into the unique hiring process used by the U.S. government. Attendees will learn about USAJOBS, the official portal for federal job applications, and how to effectively search for and identify opportunities that match their qualifications. The session will cover essential elements such as creating a competitive federal resume, understanding the various hiring authorities, and preparing for the distinct application and interview process. Special attention will be given to understanding federal job announcements, addressing specialized experience requirements, and utilizing resources for veterans, students, and individuals with disabilities. By the end of the presentation, participants will be equipped with the knowledge and tools to successfully navigate the federal job market and enhance their chances of securing employment in public service
As a security precaution, unmuting microphones, starting video, screen share, and using the ‘chat’ feature will be disabled for those attending the seminar, except for ATMO faculty. If you would like to say something, please use the ‘raise hand’ feature. The host or a co-host can then enable you to unmute your microphone.
Dr. Fei-Fei Jin Professor Atmospheric Sciences School of Ocean and Earth Science and Technology University of Hawaii at Manoa
ABSTRACT
The El Niño-Southern Oscillation (ENSO) phenomenon greatly modulates the global weather and climate conditions with great socio-economic implications. At the meantime, ENSO provides most of the global seasonal to interannual climate forecast skill. However, quantifying and understanding the sources of the skillful predictions and improving ENSO forecast skill at long-time leads are long-standing challenges. We developed an ENSO-theory based eXtended low-order nonlinear Recharge Oscillator (XRO) model which parsimoniously incorporates the core ENSO dynamics and ENSO’s seasonally modulated interactions with other climatic modes of variability in the global oceans with only about 10 prognostic key indices. We show that XRO exhibits skillful ENSO forecasts at lead-times up to 16-18 months, better than that of the state of art comprehensive global climate models and comparable to the most skillful AI forecasts. The XRO’s holistic treatment of ENSO’s multi-timescale interactions with other climate modes allows us to quantitatively attribute intrinsic enhancement of ENSO’s long-range forecast skill to the initial conditions of other climate modes via their memory and interactions with ENSO and to count for these modes’ contributions to forecast ENSO amplitudes. Examples are given to demonstrate that there are some remarkable global to locality pathways which are season- and locality-dependent connections of some coastal hazards to ENSO, yielding cases of potential high predictive skills for the hazards even at final scales. Implications of ENSO and climate predictability and its implications/utilities for impact/risk forecasts from global to coastal/island scales will be briefly discussed.
Dr. Nicole K. Murray Postdoctoral Researcher Karamperidou Lab Atmospheric Sciences University of Hawaii at Manoa
ABSTRACT
Tropical Pacific seawater and precipitation stable oxygen isotope (δ 18 O) data record distinct oceanic and atmospheric processes in a region where local hydroclimate variability amounts to changes in global climate. These data provide further utility as long-term stable oxygen isotope data record ocean-atmospheric interactions across the tropical Pacific and these processes are archived in isotope-based paleoclimate proxy records. There is growing interest in interpreting western Pacific oxygen isotope data as information on past ENSO variability; however, modern δ 18 O records are often too short to disentangle the competing influences of oceanic and atmospheric processes or to parse a robust ENSO signal. In this talk, I will present 10 years of precipitation and seawater δ 18 O data from Koror, Palau, and show that both are influenced by ENSO variability over the observation period. This talk will cover the regional climate variability driving this isotope signal and discuss subsequent implications for paleoclimate records from the western tropical Pacific.
BIO
Nicole K. Murray is a postdoctoral researcher in the Karamperidou lab at UH Manoa. Her work has focused on tropical Pacific hydroclimate, paleoceanography and paleoclimatology, and using stable isotope records to understand past environments. Currently, her research interests include Pacific equatorial undercurrent variability and its influences on tropical climate, as well as regional hydroclimate phenomena (e.g. fog/garúa in Galápagos). She is a member of the Island Systems Integration Consortium for the Galápagos Islands, which works to develop interdisciplinary work in climate science, geology, and biology. Nicole received her M.S. and Ph.D. from the University of Illinois at Urbana Champaign.
to Uncover High Pollution Stations near the Foothills of Central Taiwan
Presented on May 1, 2024, by
Sheng-Hsiang (Carlo) Wang Professor in atmospheric sciences National Central University Taiwan
ABSTRACT
The presentation will showcase our recent research findings, which integrate surface data, UAV profiling, and WRF simulation to pinpoint and comprehend pollution hotspots near the foothills of central Taiwan. Sea breeze dynamics play a pivotal role in transporting coastal air pollutants inland. UAV observations provide detailed insights into the vertical structure of sea breezes and aerosol distribution. The accumulation of pollutants near the foothills results from poor ventilation and a stable nocturnal boundary layer. Terrain-induced downslope winds can exacerbate atmospheric stability and reduce boundary layer height. The presentation will delve into the severe nighttime air pollution exacerbated by these combined effects. UAV observations serve as a valuable tool in elucidating previously perplexing air pollution events.
BIO
Dr. Sheng-Hsiang (Carlo) Wang has long been dedicated to the study of atmospheric radiation and aerosols, with a focus on the optical properties of aerosols and their radiative effects. In recent years, Dr. Wang has actively participated in the 7-SEAS international research program, conducting field observation experiments in Thailand and Vietnam to gain a deeper understanding of the optical properties and vertical distribution of aerosols in the major biomass burning emission areas of northern Indochina. Additionally, he has been involved in the establishment of the Taiwan Lidar Network to study the vertical distribution characteristics of aerosols, the background atmospheric radiation monitoring stations, the development of unmanned aerial vehicle observation technology to address shortcomings in atmospheric vertical observation, and the development of miniature sensors to construct environmental Internet of Things (IoT) technology.
Neng-Huei (George) Lin Department of Atmospheric Sciences National Central University Taoyuan, Taiwan
ABSTRACT
Initiated in 2007, the Seven South East Asian Studies (7-SEAS) program seeks to perform interdisciplinary research in the field of aerosol-meteorology and climate interaction in the Southeast Asian region. Primary participating countries include Indonesia, Malaysia, Philippines, Singapore, Thailand, Taiwan, Vietnam, and USA. The primary scientific goal is to investigate the impact of biomass burning on clouds, atmospheric radiation, the hydrological cycle, and ultimately regional weather and climate. Field experiments have been primarily conducted in boreal springtime SE Asian region: Phase I – Dongsha Experiment in 2010, Son La Campaigns I in 2011 and II in 2012, and Phase II – BASELInE (Biomass-burning Aerosols & Stratocumulus Environment: Lifecycles and Interactions Experiment) in 2013-2015, respectively. Phase III of 7-SEAS in 2016-2019 focuses on data integration, and establishing a regional network of PM 2.5 . The main goals of these 7-SEAS spring campaigns are (1) to characterize the chemical, physical, optical, and radiative properties of biomass-burning aerosols in the northern SEA, and (2) to assess the impact of biomass burning on cloud, atmospheric radiation, hydrological cycle, and regional climate. This presentation will briefly overview and focus on the concept and experimental design of the 7-SEAS spring campaigns, and discuss major findings and their implications. While, owing to the COVID-19, the 7-SEAS activity was limited till October 2022 when the annual workshop was resumed in Taiwan. The air urban air quality and health impact in big Southeast Asian cities became a focus. Furthermore, the URBAN-AQ (Air Quality) was proposed for the main theme of the next phase of 7-SEAS in 2024-2026.
BIO
Dr. Lin is presently leading the Cloud and Aerosol Laboratory (CAL), NCU, which consists of 5 professors and researchers, 15 staff and 18 graduate students. In 2019/2-2023/1, he was appointed as the Director of the Center for Environmental Monitoring and Training (CEMT), NCU, which is a joint center primarily funded by US EPA and the Taiwan Ministry of Environment.
Global Navigation Satellite System Radio Occultation (GNSS-RO) is an emerging technology for remotely sensing the Earth’s stratosphere and stratosphere. GNSS-RO missions began in the mid-90s through a proof of concept mission called GPS-Met, with an increase in GNSS-RO atmospheric profiles through the past two decades. GNSS-RO systems now provide more than 10,000 profiles each day for operational and research purposes. This presentation summarizes the ability of GNSS-RO to resolve interannual variability of tropospheric moisture. This includes an analysis of El Nino-Southern Oscillation (ENSO) structure from 2007 through 2019 using the FORMOSAT-3/COSMIC-1 mission and follows with the ability of the FORMOSAT-7/COSMIC-2 mission to resolve tropical and subtropical moisture variability since 2019.
BIO
Dr. Braun is the Deputy Director of the COSMIC program at UCAR where he serves as the leader of the science applications group. He has previously served as a project scientist and program manager, this includes leading Satellite Systems Development in the COSMIC Program at UCAR. His research interests are focused on using GNSS signals to remotely sense the Earth and its atmosphere. He was the UCAR Principal Investigator for the Continuously Operating Caribbean Observational Network (COCONet). He is a co-recipient of the Creativity Prize for the 6th Award of the International Prize for Water and 2017 Colorado Governor’s Award for High Impact Research.
Cheng-Ku Yu Professor and Chair Department of Atmospheric Sciences National Taiwan University Taipei, Taiwan
ABSTRACT
Outer tropical cyclone rainbands (TCRs) are a concentrated region of heavy precipitation and hazardous weather within tropical cyclones (TCs). Outer TCRs pose considerable risk to human societies, but the origin of outer TCRs is a long-standing, unresolved topic in the TC research community. This study performs analyses on a total of 1029 outer TCRs identified during their formative stage by long-term radar observations collected near Taiwan from 2002 to 2019. The observations provide a robust foundation of our knowledge regarding the natural diversity of the outer TCR origin. One of the striking findings is that a dominant portion of the identified TCRs (97%) tend to be initiated locally in the outer TC region. This outer-origin dominance is in distinct contrast to numerous theoretical modeling studies of outer TCRs that propose inner-origin scenarios. Large discrepancies between these observed propagation characteristics and theoretically predicted propagation velocities of both gravity waves and vortex Rossby waves are found, suggesting that wave disturbances do not have a direct impact on the origin of the observed outer TCRs. Moreover, the observed outer TCRs appear to have a statistical preference for both a squall-line environment and cold pool propagation behavior. In particular, the initiation of faster, squall-line-like outer TCRs preferentially take place immediately adjacent to the outer boundary of prominent precipitation in the outer regions of TCs, and this preexisting outer precipitation may act as an initial, critical provider of cold pools to activate the operation of squall-line dynamics. Examining the causes of outer precipitation and clarifying its roles in contributing to the occurrence of cold pools during the preformation stage of rainbands would thus be a necessary task that would help improve our understanding of the initiation of outer TCRs.
Reference: Yu, C.- K., C.- Y. Lin and C.- H. Pun, 2023: Origin of outer tropical cyclone rainbands. Nat. Commun., 14, 7061 (2023). doi:10.1038/s41467-023-42896-x.
BIO
Prof. Yu’s reseach Interests include orographic precipitation, severe weather and mesoscale atmospheric phenomena, and structure and dynamics of tropical cyclone (frontal) rainbands.
