Article
Environmental Sciences
Mohin Patel, Sen Chiao, Qian Tan
Summary: The study investigated the vertical distribution of aerosols in the tropical cyclone main development region using observations from the CALIPSO Satellite. Results showed distinct differences in aerosol concentrations between different regions, and indicated that tropical cyclone genesis and development may not be significantly affected by dust aerosols.
Article
Environmental Sciences
Bantwale D. Enyew, Ademe Mekonnen
Summary: This study revisits the association between African easterly waves (AEWs) and Atlantic tropical cyclone (TC) development and finds that developing AEWs are closely related to deep convection, while non-developing AEWs exhibit scattered and weaker deep convection. Non-developing AEWs also experience unfavorable atmospheric conditions with lower relative humidity. Additionally, developing AEWs maintain stronger features in the lower and middle troposphere.
Article
Meteorology & Atmospheric Sciences
C. Calvo-Sancho, J. J. Gonzalez-Aleman, P. Bolgiani, D. Santos-Munoz, J. I. Farran, M. L. Martin
Summary: The study revealed that tropical transition is a process where extratropical or subtropical cyclones transform into tropical cyclones, with environmental factors such as troughs and geopotential heights playing key roles. Central North Atlantic TT events usually occur in environments with warm sea surface temperatures and low-to-moderate wind shear, while eastern North Atlantic TT events take place in environments with lower sea surface temperatures and higher wind shear. The environmental classifications also indicate that eastern North Atlantic cyclones have a more defined extratropical structure, while central North Atlantic cyclones show more tropical characteristics.
ATMOSPHERIC RESEARCH
(2022)
Article
Meteorology & Atmospheric Sciences
Xinxi Wang, Haiyan Jiang
Summary: This study found that rapidly intensifying (RI) and slowly intensifying (SI) events in tropical cyclones have significantly different characteristics, with RI events showing faster intensification rates and warmer sea surface temperatures compared to SI events.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Margaret A. Hollis, Rachel R. Mccrary, Justin P. Stachnik, Carrie Lewis-Merritt, Elinor R. Martin
Summary: This study is the first attempt to investigate the climatology of tropical easterly waves (TEWs) globally. The results show that TEW activity exists in every tropical ocean basin and has a strong preference for the warm season. No significant linear trends were found globally or hemispherically, but large interannual variability was observed.
Article
Engineering, Aerospace
S. Ponce de Leon, J. H. Bettencourt
Summary: This paper studies the significant wave height distribution of extratropical cyclones in the North Atlantic Ocean, finding that higher waves are mainly found in the southeastern quadrant of the cyclone and peak during the 48-hour period of maximum cyclone strength. The strongest cyclones tend to have higher waves over most of the eastern half due to their northward propagation tendency.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Meteorology & Atmospheric Sciences
Marta Martin-Rey, Ignasi Valles-Casanova, Josep L. Pelegria
Summary: The study investigates the impact of tropical Atlantic Ocean variability modes on the variability of the upper-ocean circulation. Multiple datasets including oceanic reanalyses, simulations, and satellite data were utilized for the period 1982-2018. The results reveal significant changes in the surface and subsurface ocean currents during the emergence of Atlantic meridional mode (AMM), Atlantic zonal mode (AZM), and the connection between AMM and AZM. Ocean waves play a crucial role in connecting tropical and equatorial ocean transport.
JOURNAL OF CLIMATE
(2023)
Article
Geosciences, Multidisciplinary
Anantha Aiyyer, Carl Schreck
Summary: We investigated the surface wind speeds and enthalpy fluxes of African easterly waves using the Cyclone Global Navigation Satellite System (CYGNSS), which led to the formation of 30 Atlantic tropical cyclones from 2018 to 2021. Lag composites revealed the presence of a cyclonic proto-vortex as early as 3 days before tropical cyclogenesis. The distribution of enthalpy fluxes did not show significant variations before cyclogenesis, but there was a noticeable increase in extreme upper values afterwards. In the composites, a negative radial gradient of enthalpy fluxes became evident 2-3 days before cyclogenesis. These results, based on a novel combination of satellite retrievals and global reanalysis, provide support for recent studies indicating that the spin-up of tropical cyclones is associated with a shift of peak convection towards the vortex core and an inward increase of enthalpy fluxes.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Multidisciplinary Sciences
Dongmin Kim, Sang-Ki Lee, Hosmay Lopez, Gregory R. Foltz, Caihong Wen, Robert West, Jason Dunion
Summary: The Atlantic hurricane activity is influenced by multiple climate modes at seasonal-to-interannual scales. Among them, the Atlantic Nino/Nina is the dominant mode of sea surface temperature variability during the hurricane season. The Atlantic Nino enhances African easterly wave activity and increases the likelihood of powerful hurricanes developing near the Cape Verde islands.
NATURE COMMUNICATIONS
(2023)
Article
Geosciences, Multidisciplinary
Franz Philip Tuchen, Renellys C. Perez, Gregory R. Foltz, Peter Brandt, Rick Lumpkin
Summary: Tropical Instability Waves (TIWs) are the dominant source of intraseasonal variability in the central equatorial Atlantic and play a crucial role in redistributing heat in the upper ocean. A study using multidecadal records of various oceanic variables has shown a long-term intensification of intraseasonal variability, particularly due to increased TIW activity. This pattern is driven by enhanced barotropic energy conversion from the covariance of horizontal current fluctuations.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Yi Liu, Ziguang Li, Xiaopei Lin, Jun-Chao Yang
Summary: The study suggests that under greenhouse warming, the connection between El Nino and the tropical North Atlantic will strengthen, leading to an increase in anomalous warming/cooling and related weather extremes in the future.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Meteorology & Atmospheric Sciences
Avantika Gori, Ning Lin, Benjamin Schenkel, Daniel Chavas
Summary: Analyzing historical TC climatology and modeling TC hazards can provide valuable insight to planners and decision makers. To overcome temporally limited TC size data, we develop a database of size estimates that are based on reanalysis data and a physics-based model. Using the estimated size information plus the TC track and intensity, we reconstruct historical storm tides from 1950 to 2020 using a basin-scale hydrodynamic model and show that our reconstructions agree well with observed peak storm tide and storm surge.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Environmental Sciences
Andra J. Garner, Robert E. Kopp, Benjamin P. Horton
Summary: The study found that under a high-emissions scenario, tropical cyclones are more likely to form closer to the US southeast coast, move more slowly, and terminate in the northeastern Atlantic in the future. Additionally, tropical cyclones are more likely to approach Boston and Norfolk, rather than New York City, in the future.
Article
Geosciences, Multidisciplinary
Kristopher B. Karnauskas, Ulla K. Heede, Lei Zhang
Summary: The warming of the eastern Pacific strongly influences the future changes in Atlantic hurricanes, particularly the effect of El Nino. The changes include the formation regions of hurricanes and the intensity of the El Nino/La Nina signal.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
V. M. Torres, C. D. Thorncroft
Summary: This study conducted a time-series analysis of Easterly Wave (EW) activity in the tropical northeastern Pacific (EPAC) and identified a significant interdecadal change in EW activity. The results suggest that this change is modulated by the Atlantic Multidecadal Oscillation (AMO) and the Pacific Decadal Oscillation (PDO), which impact sea surface temperatures (SSTs) and subsequently affect EW-related convection and vorticity generation in the EPAC.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Meteorology & Atmospheric Sciences
Weiran Liu, Kerry H. Cook, Edward K. Vizy
Article
Meteorology & Atmospheric Sciences
Siyu Zhao, Kerry H. Cook
Summary: Walker circulations near East Africa are identified and their impact on East African rainfall variability is explored. Three Walker circulations related to East African rainfall are identified, including the East African, Congo Basin, and Indian Ocean Walker circulations. The strength of the Indian Ocean Walker Circulation influences the amount of precipitation during the short-rains season in East Africa.
Article
Meteorology & Atmospheric Sciences
Yang Liu, Kerry H. Cook, Edward K. Vizy
Summary: The Indochina Peninsula experiences a tropical monsoon climate with a marked impact on moisture and aerosol transport. The zonal wind is primarily controlled by the meridional land-sea temperature gradient, with a positive trend in gradient in the past 40 years contributing to a delay in the summer monsoon retreat. The delayed monsoon retreat in the Indochina Peninsula is most consistent with changes of the East Asian-Western North Pacific monsoon.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2021)
Article
Meteorology & Atmospheric Sciences
Kerry H. Cook, Edward K. Vizy, Yang Liu, Weiran Liu
Summary: Observed surface warming trends over the Arabian Peninsula are significantly higher than the tropical and global means, with projected future warming rates expected to continue increasing, particularly in summer precipitation. Concurrent increases in low-level specific humidity could lead to enhanced summer rainfall in northern Ethiopia by the end of the century.
Article
Meteorology & Atmospheric Sciences
Kerry H. Cook, Edward K. Vizy
Summary: The study reveals that the seasonality of precipitation in the Congo Basin is influenced by various climate processes. Evapotranspiration has minimal impact on the seasonal variation of precipitation, which is mainly driven by moist air flowing into the equatorial trough.
Article
Meteorology & Atmospheric Sciences
Edward K. Vizy, Kerry H. Cook
Summary: This research examines extreme rainfall events in the West African Sahel and Soudan regions. The study finds that these events occur primarily south of 14 degrees N over the Soudan, with clusters in Mali, Burkina Faso, and northern Nigeria. The associated mesoscale convective systems (MCSs) are typically generated upstream, rather than locally. The analysis shows that an increase in atmospheric moisture content prior to development plays a more significant role in extreme storm development than changes in vertical wind shear.
Article
Meteorology & Atmospheric Sciences
Siyu Zhao, Kerry H. Cook, Edward K. Vizy
Summary: The areal changes of Lake Chad have an impact on precipitation, with the shrinkage of the lake increasing rainfall in the afternoon over the lake basin. Reduced precipitation over a large lake is due to decreased convection caused by a shallow planetary boundary layer. Additionally, loss of Lake Chad and adjacent wetlands affects the local climate and circulation patterns.
Article
Meteorology & Atmospheric Sciences
Edward K. K. Vizy, Kerry H. H. Cook
Summary: We utilized NASA IMERG rainfall estimates, various atmospheric reanalyses, and WRF simulations to examine the regional/local conditions that led to extreme rainfall events in the Damergou Gap. Our results indicate that these events occur in anomalously moist environments, but are not necessarily associated with highly unstable conditions. Furthermore, interactions with cold-pool outflow boundaries generated from other convective areas and local terrain features are influential in the development of such convective areas.
QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY
(2023)
Article
Meteorology & Atmospheric Sciences
Patrick C. Andrews, Kerry H. Cook, Edward K. Vizy
Summary: Twenty years of IMERG precipitation estimates were used to evaluate the contributions of mesoscale convective system (MCS) rainfall to total rainfall in the Congo Basin. It was found that MCS rainfall follows the seasonality of total rainfall, with high rainfall in spring, summer, and fall and a dry season in winter. MCS rainfall accounts for over 80% of total rainfall near the equator, with the highest rainfall rates along the eastern and western basin boundaries. The diurnal cycle of MCS rainfall is similar to total rainfall, with highest values at 15Z and lowest at 10Z.