Article
Oceanography
Ali Tamizi, Jose-Henrique Alves, Ian R. Young
Summary: Nonlinear wave-wave interactions play a critical role in the evolution of wave spectra in tropical cyclones, transferring energy from wind-sea to remotely generated waves. The peak waves act in a parasitic manner, taking energy from wind-sea to sustain their growth. This study provides strong validation of the importance of nonlinear processes in wind-wave evolution.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2021)
Article
Meteorology & Atmospheric Sciences
Udai Shimada
Summary: This study examines the variations in environmental conditions among rapidly intensifying tropical cyclones (TCs) and identifies factors that can offset negative factors for intensification. The results suggest that suitable combinations of environmental conditions and TC structural features are important for rapid intensification, even in the presence of unfavorable conditions.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Robert G. Nystrom, Chris Snyder, Mohamad EL Gharamti
Summary: In this study, a one-step-ahead ensemble Kalman smoother (EnKS) is introduced for parameter estimation. It is found that the EnKS has the potential to provide new constraints on surface-exchange coefficients of momentum and enthalpy through observing system simulation experiments (OSSEs). The results show that the EnKS can accurately constrain these parameters, but its success varies throughout the tropical cyclone life cycle and is influenced by the ensemble size and smoothing forecast length.
MONTHLY WEATHER REVIEW
(2023)
Article
Meteorology & Atmospheric Sciences
I-I Lin, Robert F. Rogers, Hsiao-Ching Huang, Yi-Chun Liao, Derrick Herndon, Jin-Yi Yu, Ya-Ting Chang, Jun A. Zhang, Christina M. Patricola, Iam-Fei Pun, Chun-Chi Lien
Summary: In October 2019, Supertyphoon Hagibis devastated Japan and was an important typhoon in Pacific history. The rapid intensification and various factors such as sea temperature, ocean heat content, storm motion, and thunderstorm activity contributed to Hagibis's impressive strength evolution. Despite favorable conditions, Hagibis's intensification stalled after a significant size expansion, contrasting Haiyan which continued to intensify and reach record-breaking intensity.
BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
(2021)
Article
Meteorology & Atmospheric Sciences
Yuhao l Iu, Shoude Guan, I. -I. Lin, Wei Mei, Fei-Fei Jin, Mengya Huang, Yihan Zhang, Wei Zhao, Jiwei Tian
Summary: This study systematically examined the effect of storm size on TC-induced sea surface temperature (SST) anomalies (SSTA) and subsequent TC intensification in the western North Pacific. The results show that large TCs generate stronger and more widespread SSTA than small TCs, and storm size regulates TC intensification through an oceanic pathway.
JOURNAL OF CLIMATE
(2023)
Article
Meteorology & Atmospheric Sciences
Song Yang, Vincent Lao, Richard Bankert, Timothy R. Whitcomb, Joshua Cossuth
Summary: This study presents an accurate precipitation climatology for tropical depression (TD), tropical storm (TS), and tropical cyclone (TC) occurrences over oceans using high-quality precipitation datasets and TC center positions. The study analyzes the impacts of TC movement direction and wind shear on the spatial distribution of TC precipitation, as well as the eyewall contraction process during TC intensification. The research confirms previously published results on TC precipitation distributions in relation to wind shear direction and provides detailed distributions for each TC category and TS.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Huijun Huang, Jinnan Yuan, Guanhuan Wen, Xueyan Bi, Ling Huang, Mingsen Zhou
Summary: Researchers examined the dynamic and thermodynamic variables of 74 tropical depressions over the South China Sea and proposed seven criteria to determine whether a tropical depression will develop into a tropical storm. These criteria, including the diabatic heating rate, can help forecasters identify the likelihood of tropical depression development with an average lead time of 36.6 hours.
WEATHER AND FORECASTING
(2021)
Article
Meteorology & Atmospheric Sciences
Joshua B. Wadler, David S. Nolan, Jun A. Zhang, Lynn K. Shay
Summary: In idealized simulations of category-3 and category-5 tropical cyclones, the thermodynamic effects of downdrafts on the boundary layer and nearby updrafts were explored. It was found that in category-5 cyclones, downdrafts had no negative thermodynamic influence due to a thermodynamic shield created by eye-eyewall mixing, while in category-3 cyclones, downdrafts had a significant negative impact on nearby updrafts. The study highlights the importance of considering storm structure and individual downdraft characteristics when discussing paradigms for tropical cyclone intensity evolution.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2021)
Article
Meteorology & Atmospheric Sciences
Elliott M. Sainsbury, Reinhard K. H. Schiemann, Kevin I. Hodges, Alexander J. Baker, Len C. Shaffrey, Kieran T. Bhatia
Summary: This study investigates the interannual variability of recurving tropical cyclones (TCs) and finds that it is primarily determined by the frequency of TCs in the subtropical Atlantic and hurricanes in the main development region (MDR). The seasonal anomalies in the steering flow have a smaller impact on the frequency of recurving TCs.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Christopher J. Slocum, Muhammad Naufal Razin, John A. Knaff, Justin P. Stow
Summary: The synoptic environment around tropical cyclones is crucial for their evolution. The Tropical Cyclone Precipitation, Infrared, Microwave, and Environmental Dataset (TC PRIMED) combines different data sources to capture the environment. ERA5, a reanalysis product, is used to provide a more complete representation of the storm environment. However, ERA5 shows biases in environmental diagnostics, especially in thermodynamic fields. These comparisons help users of TC PRIMED assess the uncertainty and implications for specific research and operational applications.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Yanjie Wu, Robert L. Korty
Summary: Analyses of two high-resolution reanalysis products indicate that high values of hurricane potential intensity (PI) are becoming more frequent and covering a larger area of the Atlantic, consistent with the previously reported lengthening of the tropical cyclone season. Specifically, the increase in high PI is most pronounced in the early months of the storm season in subtropical latitudes. The western subtropical Atlantic experiences an increase in mean PI, as well as the areal coverage and frequency of high PI throughout the storm season, with the length of the season with high PI growing since 1980. While the number of days with low vertical wind shear increases in the tropical North Atlantic during the early and middle months of the storm season, trends elsewhere are mixed and generally insignificant. The choice of pressure level(s) used to calculate a thermodynamic parameter, which measures the ratio of midlevel entropy deficits to the strength of surface fluxes, as well as subtle differences in temperature and humidity values near the surface in different reanalysis datasets, can lead to divergent results in metrics like the ventilation index that rely on its value. Projections from a high-resolution simulation for the rest of the twenty-first century suggest that the number of days with high PI is likely to continue increasing in the North Atlantic basin, particularly in the western subtropical Atlantic during the early and late months of the season.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Philip J. Klotzbach, Carl J. Schreck, Gilbert P. Compo, Steven G. Bowen, Ethan J. Gibney, Eric C. J. Oliver, Michael M. Bell
Summary: The 1933 Atlantic hurricane season was exceptionally active, setting multiple historical records with 20 named storms, 11 hurricanes, and 6 major hurricanes. Favorable dynamic conditions and above-normal tropical Atlantic sea surface temperatures created an optimal environment for hurricane formation and intensification. Statistical models used by Colorado State University predicted the high activity of the 1933 hurricane season.
BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
(2021)
Article
Meteorology & Atmospheric Sciences
Yu-an Chen, Chun-chieh Wu
Summary: The interaction between Typhoon Nepartak and the upper-tropospheric cold low is simulated to understand the impact of the cold low on tropical cyclones. An experiment without the cold low is performed to highlight its quantitative impacts. Sensitivity experiments are carried out to investigate different configurations leading to various interactions. The study shows that the interaction between a tropical cyclone and the cold low is associated with a more axisymmetric inner-core structure and earlier rapid intensification.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2023)
Article
Meteorology & Atmospheric Sciences
Yi-Jie Zhu, Jennifer M. Collins, Philip J. Klotzbach
Summary: Understanding the spatial variation of tropical cyclone wind speed decay over the continental United States is crucial for hazard preparation inland. Tropical cyclones making landfall over the Gulf Coast tend to decay faster within the first 24 hours compared to those making landfall over the Atlantic East Coast. The presence of spatial variations in wind speed decay raises questions about the accuracy of a uniform wind decay model.
JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY
(2021)
Article
Meteorology & Atmospheric Sciences
Yuqing Wang, Yuanlong Li, Jing Xu, Zhe-Min Tan, Yanluan Lin
Summary: The study modified a simple energetically based dynamical system model of tropical cyclone intensification to account for the observed dependence of the intensification rate on the storm intensity. According to the modified model, the intensification potential and the weakening rate due to surface friction beneath the eyewall control the intensification rate of the tropical cyclone.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2021)
Article
Meteorology & Atmospheric Sciences
Jian Huang, Zhongshui Zou, Qingcun Zeng, Peiliang Li, Jinbao Song, Lin Wu, Jun A. Zhang, Shuiqing Li, Pak-Wai Chan
Summary: The study investigates the turbulent structure within the marine atmospheric boundary layer based on four levels of observations at a fixed marine platform. Different behaviors of velocity variances are observed under cold front and swell conditions, confirming the attached eddy model and the top-down model of turbulence over the ocean surface. The results reveal a significant difference in the quadrant analysis of momentum flux for the two conditions.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2021)
Article
Astronomy & Astrophysics
Sundararaman Gopalakrishnan, Andrew Hazelton, Jun A. Zhang
Summary: This study investigates why different planetary boundary layer parameterization schemes applied to hurricane models produce diverse forecasts of structure and intensity change. Model output from NOAAs next-generation, FV3-based Hurricane Analysis and Forecast System, along with a wealth of observations from previous Hurricane Field Programs conducted by NOAA, were analyzed. Results show that uncertainty related to key variables used in the definition of eddy diffusivity leads to diverse solutions in model forecasts, but two diverse parameterization schemes can converge to a similar forecast state when key variables are adjusted based on observations.
EARTH AND SPACE SCIENCE
(2021)
Article
Meteorology & Atmospheric Sciences
Nuo Chen, Jie Tang, Jun A. Zhang, Lei-Ming Ma, Hui Yu
Summary: This study analyzes GPS dropsonde data to investigate the boundary layer structure in tropical cyclones, focusing on helicity distribution. A helicity-based method for boundary layer height is developed and compared to other height scales, showing that the boundary layer height defined by helicity is closest to the height of the maximum tangential wind speed. Radial variations of boundary layer heights are confirmed, and kinematic height scales generally decrease with storm intensity.
ATMOSPHERIC RESEARCH
(2021)
Article
Meteorology & Atmospheric Sciences
Xiaomin Chen, Jian-Feng Gu, Jun A. Zhang, Frank D. Marks, Robert F. Rogers, Joseph J. Cione
Summary: This study found that in tropical cyclones experiencing vertical wind shear, precipitation symmetrization is maintained by the continuous development of deep convection. Boundary layer recovery is more efficient for warmer sea surface temperatures, with buoyancy acceleration playing a predominant role in convective development. In contrast, cooler sea surface temperatures result in weaker convective development.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2021)
Article
Meteorology & Atmospheric Sciences
Jonathan Zawislak, Robert F. Rogers, Sim D. Aberson, Ghassan J. Alaka, George R. Alvey, Altug Aksoy, Lisa Bucci, Joseph Cione, Neal Dorst, Jason Dunion, Michael Fischer, John Gamache, Sundararaman Gopalakrishnan, Andrew Hazelton, Heather M. Holbach, John Kaplan, Hua Leighton, Frank Marks, Shirley T. Murillo, Paul Reasor, Kelly Ryan, Kathryn Sellwood, Jason A. Sippel, Jun A. Zhang
Summary: Since 2005, NOAA has conducted the annual Intensity Forecasting Experiment (IFEX) to improve tropical cyclone forecasts by analyzing observations from aircraft, evaluating forecast models, and developing new observing strategies. This article highlights recent contributions of IFEX and lays the foundation for the next generation of the program.
BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
(2022)
Article
Multidisciplinary Sciences
Jie Tang, Jun A. Zhang, Pakwai Chan, Kaikwong Hon, Xiaotu Lei, Yuan Wang
Summary: The study analyzes aircraft-collected data during Typhoon Kalmaegi (1415) and Typhoon Nida (1604) to confirm the existence of sub-kilometer-scale rolls in the atmospheric boundary layer of tropical cyclones. The presence of these rolls in the outer-core region is determined to significantly modulate turbulent transfer. Flight legs with rolls were found to have an averaged momentum flux 2.5 times higher than legs without rolls, suggesting a significant impact on turbulent fluxes in the tropical cyclone boundary layer.
SCIENTIFIC REPORTS
(2021)
Article
Geosciences, Multidisciplinary
Guosheng Zhang, Xiaofeng Li, William Perrie, Jun A. Zhang
Summary: A morphological model for Tropical Cyclone (TC) wind and inflow angle asymmetry based on sea surface wind fields derived from spaceborne synthetic aperture radar (SAR) images is developed and validated in this study. The model demonstrates reliable reconstruction of the entire TC structure and can capture the main asymmetrical TC structure.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
Chong Wang, Gang Zheng, Xiaofeng Li, Qing Xu, Bin Liu, Jun Zhang
Summary: In this study, a set of deep convolutional neural networks (CNNs) were designed to estimate the intensity of tropical cyclones (TCs) over the Northwest Pacific Ocean from satellite data. The study showed that the selection of different infrared (IR) channels had a significant impact on the performance of the TC intensity estimate. The CNN models demonstrated good accuracy and stability in estimating TC intensity.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Article
Meteorology & Atmospheric Sciences
Joshua B. Wadler, Joseph J. Cione, Jun A. Zhang, Evan A. Kalina, John Kaplan
Summary: This study investigates the relationship between deep-layer environmental wind shear direction and tropical cyclone boundary layer thermodynamic structures. The results show that when the wind comes from the south, there is a significant asymmetry in temperature and moisture distribution in the tropical cyclone boundary layer, while when the wind comes from the north, the temperature and moisture distribution is more uniform. Furthermore, the study finds that tropical cyclones in the Atlantic Ocean basin tend to intensify in northward wind shear environments and weaken in southward wind shear environments.
MONTHLY WEATHER REVIEW
(2022)
Article
Oceanography
Travis Miles, Dongxiao Zhang, Gregory Foltz, Jun Zhang, Christian Meinig, Francis Bringas, Joaquin Trinanes, Matthieu Le Henaff, Maria Aristizabal Vargas, Sam Coakley, Catherine Edwards, Donglai Gong, Robert Todd, Matthew Oliver, Douglas Wilson, Kerri Whilden, Barbara Kirkpatrick, Patricia Chardon-Maldonado, Julio Morell, Debra Hernandez, Gerhard Kuska, Cheyenne Stienbarger, Kathleen Bailey, Chidong Zhang, Scott Glenn, Gustavo Goni
Summary: Hurricanes have caused significant damages and human casualties, especially in regions without effective early warning systems and with high population density near sea level. Efforts to improve hurricane forecasting and understand the complex interactions driving storm intensity are crucial in mitigating the increasing impacts of tropical cyclones in the face of climate change and coastal urbanization.
Article
Oceanography
Changlong Liu, Xinyu Li, Jinbao Song, Zhongshui Zou, Jian Huang, Jun A. Zhang, Ganxin Jie, Jun Wang
Summary: The deviation of the mean wind profile from Monin-Obukhov similarity theory (MOST) within the wave boundary layer (WBL) is investigated in this study. The results show that the mean wind profile follows MOST under wind-sea conditions, but pronounced swell-related peaks appear under swell conditions.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Environmental Sciences
Xin Li, Zhaoxia Pu, Jun A. Zhang, George David Emmitt
Summary: This study examines the impact of assimilating DWL winds and TDR radial winds on the prediction of Hurricane Earl (2016) and finds that DWL data has a positive impact on hurricane analysis and prediction, particularly providing better forecasts of hurricane track and intensity.
Article
Meteorology & Atmospheric Sciences
Joshua B. Wadler, David. S. Nolan, Jun A. Zhang, Lynn K. Shay, Joseph B. Olson, Joseph J. Cione
Summary: This study estimates the distribution of turbulent kinetic energy (TKE) and its budget terms in simulated tropical cyclones. The results show that TKE is maximized at low levels and inward of the region of maximum wind speed. The study has implications for improving hurricane simulations.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2023)