Article
Meteorology & Atmospheric Sciences
Sandro W. Lubis, Muhamad R. Respati
Summary: The research indicates that rainfall extremes in Java Island, Indonesia are influenced not only by seasonal and intraseasonal variability, but also by convectively coupled equatorial waves on a shorter time scale, significantly impacting the probability of extreme rainfall events.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Yuan-Ming Cheng, Juliana Dias, George Kiladis, Zhe Feng, L. Ruby Leung
Summary: Mesoscale convective systems (MCSs) contribute significantly to tropical precipitation and extreme rainfall events. The impact of convectively coupled equatorial waves (CCEWs) on organized convection and MCS characteristics is examined using global tracking data. During the active phase of CCEWs, MCSs exhibit increased frequency, intensity, size, and probability of extreme events, particularly when associated with Kelvin waves and tropical depression-type waves.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Astronomy & Astrophysics
Tao Cai, Cong Yu, Xing Wei
Summary: This paper investigates convectively coupled equatorially trapped waves in rotating stars with and without magnetic fields. It identifies various types of waves and analyzes the effects of stratification and nontraditional Coriolis force terms. The magnetic field has a significant effect when strong and specific magnetic field strengths are present. The study also applies the model to the solar atmosphere and tachocline, providing insights into the Rieger-type periodicities and the influence of nontraditional Coriolis terms.
ASTROPHYSICAL JOURNAL
(2021)
Article
Meteorology & Atmospheric Sciences
Yuhi Nakamura, Yukari N. Takayabu
Summary: This study investigates the precipitation patterns and heat sources related to equatorial Kelvin waves and equatorial Rossby waves using TRMM PR level 2 data products. Through the analysis of synoptic structures, it is found that Rossby waves have a vertically upright structure, while Kelvin waves show a gravity wave-like structure. Precipitation activity is closely associated with column water vapor anomalies for Rossby waves, while specific humidity changes with the progression of Kelvin waves. The study also reveals the different mechanisms driving precipitation for these two wave types - column water vapor fluctuations for Rossby waves and buoyancy-driven fluctuations for Kelvin waves.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Juliana Dias, Maria Gehne, George N. Kiladis, Linus Magnusson
Summary: Convectively coupled equatorial waves (CCEWs) have the potential to improve sub-seasonal predictions, but are poorly represented in forecast systems. The European Center for Medium-Range Weather Forecasts (ECMWF) has improved representation of tropical variability. However, ECMWF system's CCEWs tend to be weaker in amplitude and have deviations in propagation characteristics compared to observations.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Meteorology & Atmospheric Sciences
Shuguang Wang, Juan Fang, Xiaodong Tang, Zhe-Min Tan
Summary: This study examines the relationship between equatorial Rossby waves (ERW) and tropical cyclone genesis (TCG) over major global TC basins. It finds that westward-propagating ERWs are significant in four tropical ocean basins during the summer hemisphere, with northeast-southwest (southeast-northwest) tilted phase lines and appreciable poleward advance of wave energy in TC basins. The study also shows that convectively active (suppressed) phases of ERWs coincide with increased (reduced) TCG occurrences, and the total number of TCG occurrences varies significantly according to the ERW phase.
ADVANCES IN ATMOSPHERIC SCIENCES
(2022)
Article
Meteorology & Atmospheric Sciences
Lin Lin, Xiaohong Liu, Yunpeng Shan, Qiang Fu
Summary: We improved the treatments of convective cloud microphysics in the NCAR Community Atmosphere Model version 5.3 (CAM5.3) by implementing new parameterizations for convective ice and snow particles' terminal velocities, adding graupel microphysics, considering convective snow detrainment, and enhancing rain initiation and generation rate in warm clouds. The impacts of the improved microphysics on simulated global climate were evaluated, with a focus on cloud radiative forcing, graupel microphysics, convective cloud ice amount, and tropical precipitation. The results showed that the enhancements in rain initiation and generation rate alleviated the excessive cloud shortwave radiative forcing over the tropics and midlatitudes, bringing the simulations in better agreement with the observations. The addition of graupel microphysics and the accompanying increase in hydrometeor fall speed played a crucial role in alleviating the overestimation of convective ice mass.
JOURNAL OF CLIMATE
(2023)
Article
Meteorology & Atmospheric Sciences
Young-Ha Kim, Gergely Boeloeni, Sebastian Borchert, Hye-Yeong Chun, Ulrich Achatz
Summary: This paper examines intermittency of gravity waves (GWs) modeled by the Multiscale Gravity Wave Model (MS-GWaM). It finds high intermittency of convective GWs in tropical regions, which remains fairly consistent in the vertical direction. In contrast, non-convective GWs in the extratropics exhibit lower intermittency compared to tropical regions in the stratosphere, gradually increasing with altitude and resembling lognormal distributions.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2021)
Article
Environmental Sciences
Guy Dagan, Philip Stier, George Spill, Ross Herbert, Max Heikenfeld, Susan C. van den Heever, Peter J. Marinescu
Summary: The impact of aerosols on clouds remains uncertain in climate predictions. The evolution of cloud properties is influenced by both the clouds themselves and the environmental conditions, and aerosol-driven changes in cloud properties can feedback to the evolution of the environment. The representation of boundary conditions in models strongly affects the simulated response of the environment to aerosol perturbations.
COMMUNICATIONS EARTH & ENVIRONMENT
(2022)
Article
Geosciences, Multidisciplinary
Yuhi Nakamura, Yukari N. Takayabu
Summary: Utilizing spaceborne cloud radar and lidar observations, this study examines the vertical distributions of clouds and their radiative effects in equatorial Rossby and Kelvin waves. The results show that radiative heating enhances the generation of available potential energy in the waves by 19% and 40% for Rossby and Kelvin waves, respectively. Composite analyses reveal the simultaneous development of deep-convective anvil clouds and stratiform clouds in Rossby waves, and a transition from low-level to stratiform clouds in Kelvin waves. These findings provide important insights into the coupling mechanisms between equatorial waves and convective activity in tropical meteorology.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
Christian Barthlott, Amirmahdi Zarboo, Takumi Matsunobu, Christian Keil
Summary: In order to improve the accuracy of precipitation prediction in convective-scale ensemble prediction systems, this study investigates the impact of microphysical and land-surface uncertainties on convective-scale predictability. By using a novel perturbation strategy, the researchers analyze the response of convective precipitation to different soil moisture fields, cloud condensation nuclei concentrations, and cloud droplet size distribution shape parameters. The results reveal that these uncertainties significantly influence the quantitative precipitation forecasting of summertime convection in central Europe.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2022)
Article
Environmental Sciences
Yan Zhu, Tim Li
Summary: This study examines the modulation of convectively coupled equatorial waves (CCEWs) by the Madden-Julian Oscillation (MJO). It was found that the mixed-Rossby gravity (MRG) wave is strengthened on the west of MJO convection, while the Kelvin, westward inertio-gravity (WIG), and eastward inertio-gravity (EIG) waves are mostly strengthened over the MJO convective center. Further analysis showed a significant negative correlation between MJO-scale vertical wind shear and MRG intensity variation, suggesting the MRG wave is primarily modulated by the dynamic field.
ENVIRONMENTAL RESEARCH COMMUNICATIONS
(2021)
Article
Meteorology & Atmospheric Sciences
Guosen Chen
Summary: The study investigates the n=1 CCER wave over the Indo-Pacific warm pool and proposes a linear two-layer model to understand its dynamics. The analysis reveals the characteristics and influencing mechanisms of this wave, including its horizontal structures, frequency range, and amplification patterns. The findings are important for enhancing our understanding and prediction of tropical and extratropical climate variations.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2022)
Article
Oceanography
Marina Azaneu, Adrian J. Matthews, Dariusz B. Baranowski
Summary: Atmospheric convectively coupled equatorial Kelvin waves (CCKWs) are a major tropical weather feature influenced by ocean-atmosphere interactions. Prediction of CCKWs remains a challenge, but studying their impact on the ocean has revealed cooling, deepening of the mixed layer, and subsurface responses. Additionally, CCKWs generate downwelling signals and zonal velocity anomalies consistent across distinct populations, highlighting their importance as a source of oceanic Kelvin waves in the eastern Indian Ocean.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Meteorology & Atmospheric Sciences
Tao Zhang, Wuyin Lin, Andrew M. Vogelmann, Minghua Zhang, Shaocheng Xie, Yi Qin, Jean-Christophe Golaz
Summary: A novel machine learning trigger function was developed to address deficiencies in convection trigger functions in General Circulation Models, outperforming traditional CAPE-based triggers and offering promising improvements to climate simulations.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2021)
Article
Meteorology & Atmospheric Sciences
Tyler Cox, Kyle C. Armour, Gerard H. Roe, Aaron Donohoe, Dargan M. W. Frierson
Summary: This study focuses on the controls of atmospheric heat transport, specifically radiation and dynamics. The research shows that rotation rate and radiative tendency influence the strength of the Hadley cell and the efficiency of heat transport by eddies, with these controls not always operating independently and sometimes reinforcing each other. The study also examines how different components of atmospheric heat transport vary with latitude and how they sum to produce a smoothly varying total heat transport with latitude.
JOURNAL OF CLIMATE
(2021)
Article
Marine & Freshwater Biology
Gyundo Pak, Yign Noh, Myong-In Lee, Sang-Wook Yeh, Daehyun Kim, Sang-Yeob Kim, Joon-Lee Lee, Ho Jin Lee, Seung-Hwon Hyun, Kwang-Yeon Lee, Jae-Hak Lee, Young-Gyu Park, Hyunkeun Jin, Hyukmin Park, Young Ho Kim
Summary: The KIOST-ESM model, developed by the Korea Institute of Ocean Science and Technology, showed improved performance compared to the base model in simulating features such as sea surface temperatures and tropical variability, despite exhibiting cold biases in the Northern Hemisphere and the double Intertropical Convergence Zone. The model displayed a equilibrium climate sensitivity of 3.36 K, which is close to the average obtained from CMIP5 simulations.
OCEAN SCIENCE JOURNAL
(2021)
Article
Geosciences, Multidisciplinary
Yoo-Geun Ham, Ji-Gwang Kim, Jeong-Gil Lee, Tim Li, Myong-In Lee, Seok-Woo Son, Yu-Kyung Hyun
Summary: This study found that successfully predicting East Asian rainfall anomalies can be achieved by correcting tropical sea surface temperature (SST) forcing. The cold and dry mean state bias over the Indian Ocean and central-eastern Pacific is responsible for the weak anomalous atmospheric teleconnection patterns from the tropics to East Asia. Correcting the model mean climatological fields can directly impact the operational seasonal forecast skill.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Meteorology & Atmospheric Sciences
Joonlee Lee, Myong-In Lee, Joong-Bae Ahn
Summary: This study investigates the impact of imbalanced oceanic initial conditions on seasonal prediction skills using a coupled forecasting system. The results show that balanced initial conditions significantly improve prediction skills, particularly in the winter forecasts for ocean, sea ice, and atmospheric variables. The study also highlights the negative impact of initialization shock caused by spatial discontinuity and dynamic imbalance on prediction skills.
Article
Geosciences, Multidisciplinary
Seunghee Lee, Seohui Park, Myong-In Lee, Ganghan Kim, Jungho Im, Chang-Keun Song
Summary: This study used a machine learning algorithm to estimate ground-level particulate matter (PM) and applied it to a weather forecasting model. Initializing the model with the new analysis data significantly reduced analysis error and improved forecast skill. The synergistic use of data assimilation and machine learning can maximize the effectiveness of satellite-based air quality forecasts at the ground.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Environmental Sciences
Hyeon-Kook Kim, Seunghee Lee, Kang-Ho Bae, Kwonho Jeon, Myong-In Lee, Chang-Keun Song
Summary: Knowledge of the effectiveness of new observation instruments or data streams is important for policy and budget planning. Observing System Simulation Experiments (OSSE) assesses the impact of new observations on monitoring or forecasting systems, making it valuable. This study introduces the OSSE framework and its components for air quality forecasting and presents case study results from Northeast Asia, showing potential benefits of new observation data on PM2.5 forecasting skills.
Article
Meteorology & Atmospheric Sciences
Tyler Cox, Aaron Donohoe, Gerard H. Roe, Kyle C. Armour, Dargan M. W. Frierson
Summary: Despite differences in stationary eddy atmospheric heat transport (AHT) between the Northern and Southern Hemispheres, total AHT remains similar due to compensation by other dynamic components. The addition of midlatitude mountains does not significantly alter total AHT, as changes induced by orography are compensated by changes in other AHT components. In summary, the atmosphere has mechanisms in place - including dynamic, energetic, and diffusive processes - to maintain relatively invariant total AHT in response to various factors such as orography.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Donghyuck Yoon, Kyoungmin Kim, Dong-Hyun Cha, Myong-In Lee, Jungho Im, Dongjin Cho, Ki-Hong Min
Summary: Regression models based on least absolute shrinkage and selection operator methods were developed to forecast next-day maximum surface air temperature (TMAX) in South Korea. Results showed that the MOS models performed significantly better than the numerical models, reducing the mean TMAX errors by over 1°C. However, the TMAX forecast performance was generally lower in the higher-resolution LDAPS-based MOS than in the lower-resolution GDAPS-based MOS. A new MOS model was developed by combining outputs from LDAPS and GDAPS, resulting in an improved forecast accuracy of up to 0.3°C.
QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY
(2022)
Article
Environmental Sciences
Seunghee Lee, Ganghan Kim, Myong-In Lee, Yonghan Choi, Chang-Keun Song, Hyeon-Kook Kim
Summary: This study examines the performance of a data assimilation and forecasting system that incorporates satellite and ground-based observations, and finds that data assimilation improves the accuracy of PM10 and PM2.5 forecasts in South Korea. However, the accuracy varies depending on the season and atmospheric circulation patterns. A simple statistical correction can help maintain the forecast skill at a useful level. Overall, data assimilation has a positive impact on pollution forecasting, but there are limitations that need to be addressed.
Article
Environmental Sciences
M. T. Dvorak, K. C. Armour, D. M. W. Frierson, C. Proistosescu, M. B. Baker, C. J. Smith
Summary: This study suggests that even with emissions halted, the Earth will continue to warm; we may already be on track to exceed 1.5 degrees Celsius of warming; and with decreasing greenhouse gas concentrations, the expected warming of 1.5 degrees Celsius may not occur until 2055.
NATURE CLIMATE CHANGE
(2022)
Article
Meteorology & Atmospheric Sciences
Da-Seul Kim, Sang-Yoon Jun, Myong-In Lee, Jong-Seong Kug
Summary: A significant relationship between Arctic warming and hot summers in East Asia has been identified. The warming over the Barents and Kara seas leads to the development of anomalous anticyclones and downstream wave trains, resulting in hot summer conditions in East Asia.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2022)
Article
Meteorology & Atmospheric Sciences
Donghyuck Yoon, Taehun Kang, Dong-Hyun Cha, Chang-Keun Song, Myong-In Lee, Ki-Hong Min, Joowan Kim, Jong Ahn Chun, Eunkyo Seo
Summary: This study investigated the impact of soil moisture initialization on the 2016 Northeast Asian heat wave using the Land Information System (LIS) Weather Research and Forecasting (WRF) model. The assimilated soil moisture estimates were used as the initial condition for the WRF model, showing a more realistic simulation of surface air temperature and geopotential height compared to the experiment using operational soil moisture product. The assimilated soil moisture product revealed drier land surface conditions and played a role in the intensification of the heat wave.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Meteorology & Atmospheric Sciences
Jinyoung Park, Jihong Moon, Woojin Cho, Dong-Hyun Cha, Myong-In Lee, Eun-Chul Chang, Joowan Kim, Sang-Hun Park, Jooneun An
Summary: The selection of physics parameterization schemes has a significant impact on the performance of typhoon track and intensity forecasts in numerical weather prediction models. In this study, we simulated six typhoons using the WRF model to investigate the influence of physics parameterization schemes on real-time short-term forecasts. The results showed that different physics schemes led to significant differences in simulated typhoon tracks and intensities. On average, applying the Kain-Fritsch scheme for cumulus parameterization and the WSM6 scheme for cloud microphysics improved the typhoon forecast performances.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Meteorology & Atmospheric Sciences
Jihae Kim, Daehyun Kang, Myong-In Lee, Emilia Kyung Jin, Jong-Seong Kug, Won Sang Lee
Summary: West Antarctica's sea ice variability is influenced by ENSO and IOD, which explain 20%-30% of the variation during austral spring. The variation is primarily linked with anomalous atmospheric circulation in the Amundsen-Bellingshausen Sea (ABS), affecting poleward atmospheric temperature advection and radiative forcing. An idealized experiment shows that ENSO in the Pacific Ocean contributes more to the anticyclonic circulation anomaly in ABS compared to IOD in the Indian Ocean.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Geosciences, Multidisciplinary
Tyler Cox, Aaron Donohoe, Kyle C. Armour, Dargan M. W. Frierson, Gerard H. Roe
Summary: Given the key role of atmospheric heat transport in Earth's climate system, documenting its changes over the satellite era is valuable. Clark et al. (2022) found significant discrepancies in trends of atmospheric heat transport among four reanalysis data sets. However, accounting for mass-conservation issues in reanalysis data sets revealed smaller magnitude trends and better agreement among the reanalyses. This highlights the importance of mass corrections in calculating atmospheric heat transport.
GEOPHYSICAL RESEARCH LETTERS
(2023)
