Article
Meteorology & Atmospheric Sciences
Pengfei Zhang, Gang Chen, Yi Ming
Summary: This study provides a new analysis on the circulation response to increasing CO2 concentration in an aquaplanet atmospheric model. The results show that the zonal advection feedback plays a significant role in changes to the eddy-driven jet shift and Hadley cell expansion, contributing to the subtropical precipitation decline. The study highlights the distinct effect of zonal mean advecting wind and direct thermodynamic effects in atmospheric response to greenhouse gas increases.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Ori Adam
Summary: This study derives axisymmetric solutions for the response of atmospheric circulation to concentrated equatorial cooling. It captures the response of the large-scale realistic atmosphere to equatorial cooling, including weakening and widening of the meridional overturning circulation and weakening and poleward shift of the subtropical jet. For sufficiently strong cooling, a tropical anti-Hadley cell emerges.
JOURNAL OF CLIMATE
(2023)
Article
Meteorology & Atmospheric Sciences
Qin Hong, Juan Feng, Jianping Li
Summary: Based on observational data, this study investigates the effects of Central Pacific (CP) El Nino events on the relationship between the Hadley circulation (HC) and tropical sea surface temperature (SST) under different meridional structures. It is found that the variability of HC and SST, decomposed into equatorially symmetric and asymmetric components, shows decreased explained variances during CP El Nino events. The HC's response to SST under different meridional structures is suppressed, mainly due to the inhomogeneous variations of SST anomalies in the tropical eastern Pacific (EP), particularly with a greater amplitude in the north EP.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Geosciences, Multidisciplinary
Juan Feng, Xuanliang Ji, Jianping Li, Enye He
Summary: The impact of El Nino on the Hadley Circulation (HC) has been a topic of previous studies, but the results have been inconclusive. This study investigates how El Nino affects the HC during different stages of its cycle, resolving previous discrepancies among studies. The differences in tropical sea surface temperature (SST) during different stages of El Nino cause differences in SST meridional gradients, which determine the location of convergence and thus explain the different spatial structures of HC anomalies during El Nino development and decay years.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Meteorology & Atmospheric Sciences
Shinu Sheela Wilson, K. Mohanakumar
Summary: This study finds that the wind patterns, tropospheric temperature, and velocity potential of the upper troposphere and lower troposphere have a significant impact on the variability of Indian summer monsoon rainfall; the spatial variability and intensity of Australian High in the southern hemisphere play a prominent role in the characteristics of the Indian summer monsoon; subtropical circulations in both hemispheres influence monsoon conditions over India regardless of the El Nino condition.
ATMOSPHERIC RESEARCH
(2021)
Article
Meteorology & Atmospheric Sciences
Xiaohui Wang, Tim Li, Suxiang Ya
Summary: Enhanced rainbands in East Asia during the regular El Nino decaying summer progressed northward from June to August, but were only observed in the earlier summer and disappeared in August in the super El Nino composite. A combined observational and modeling study was conducted to investigate the cause of this distinctive feature. The relative roles of the mean state and anomalous heating in causing the northward progression were assessed through numerical experiments. The distinctive rainfall feature in the super El Nino composite was primarily contributed by the 1982/83 and 2015/16 events.
JOURNAL OF CLIMATE
(2023)
Article
Meteorology & Atmospheric Sciences
Mingxin Yu, Juan Feng, Jianping Li, Ran An
Summary: This study investigates the connection between the meridional structure of tropical sea surface temperature (SST) and the Hadley circulation (HC) under the influence of ENSO. The results suggest that ENSO has an interdecadal modulation on the relationship between tropical SST and HC, with a clear shift in the impacts of ENSO on the tropical Indian Ocean (TIO) SST. These findings increase our understanding of the complex interaction between ENSO, SST, and HC.
Article
Meteorology & Atmospheric Sciences
B. J. Hoskins, G. -Y. Yang
Summary: The global perspective presented in this paper emphasizes the importance of deep tropical convection in influencing the dynamics of the upper branch of the Hadley cell. The westward movement of filamentary outflows from tropical convection events and their interaction with the winter subtropical jet contribute to the flux of westerly momentum from the winter tropics to the summer hemisphere. The interaction between tropical and extratropical systems plays a significant role in the dynamics of the Hadley cell.
JOURNAL OF CLIMATE
(2023)
Article
Meteorology & Atmospheric Sciences
Ori Adam, Alexander Farnsworth, Daniel J. Lunt
Summary: The variation of the tropical rain belt is largely driven by equatorial precipitation inhibition. The tropical modality is a fundamental characteristic of tropical climate, which is associated with the width of the rain belt and the meridional overturning circulation. Low modality regions exhibit monsoonal seasonal variations, while high modality regions have three independent seasonal modes of variation.
JOURNAL OF CLIMATE
(2023)
Article
Meteorology & Atmospheric Sciences
Xieyuan Wang, Tim Li, Chao He
Summary: Through diagnostic analysis of 29 AMIP experiments, the study found that the difference in precipitation patterns in the Indo-western Pacific Ocean warm pool impacts the WNPAC, with different mechanisms affecting the WNPAC response during decaying summers of EP and CP El Nino events.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Christopher Lucas, Irina Rudeva, Hanh Nguyen, Ghyslaine Boschat, Pandora Hope
Summary: This study examines the global mean meridional circulation (MMC) from 1979 to 2017 using ERA-Interim reanalysis data, identifying various features such as the Hadley circulation and extratropical storm track. Significant changes were found in the Southern Hemisphere in the late-1990s, linked to the Interdecadal Pacific Oscillation, while the Northern Hemisphere showed less substantial changes. Multiple non-reanalysis-based datasets support the findings of large changes occurring in the Southern Hemisphere during the 1990s.
Article
Meteorology & Atmospheric Sciences
Xianglin Dai, Yang Zhang, Xiu-Qun Yang
Summary: This study investigates the energy budget and maintenance mechanism of low-frequency transient eddies, revealing distinct structures and sources of LF EAPE in midlatitude continents and subpolar regions. The generated LF EAPE is transported downstream and southward to midlatitude continents via background flow, while also being dissipated by HF eddies and converted to LF EKE through vertical motions, indicating a complex dynamics of LF variabilities.
JOURNAL OF CLIMATE
(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
Meteorology & Atmospheric Sciences
B. J. Hoskins, G-Y Yang
Summary: This paper provides a detailed analysis of the December-February Hadley cell as seen in a 30-yr climatology of ERA-Interim data, focusing on the dynamics of the upper branch of the Hadley cell. The results show that active convection predominantly leads to upper-tropospheric outflows and structures, affecting the interaction between tropical eddies and higher-latitude systems. The study supports a new conceptual model of the Hadley cell based on the sporadic nature of active tropical convection in time and space.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Spencer A. Hill, Simona Bordoni, Jonathan L. Mitchell
Summary: This paper presents a theory for the latitudinal extents of the Hadley cells throughout the annual cycle. By combining recent scaling for the ascending edge latitude based on low-latitude supercriticality with the theory for the poleward, descending edge latitudes based on baroclinic instability and a uniform Rossby number, the authors derive predictive expressions for all three Hadley cell edges. The theory is validated through simulations in an idealized aquaplanet general circulation model.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Xiyue Zhang, Clara Deser, Lantao Sun
Summary: Despite global warming, the Southern Ocean SSTs have cooled in recent decades due to internal variability. The cooling has a significant impact on the tropical South Atlantic, leading to increased clouds and strengthened trade winds cooling the sea surface, partially offsetting the radiatively forced warming trend. The cooling also results in increased Antarctic sea ice, but it is not enough to offset radiatively induced ice loss, leading to a biased trend in sea ice in the Southern Ocean ensemble.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Savini M. Samarasinghe, Charlotte Connolly, Elizabeth A. Barnes, Imme Ebert-Uphoff, Lantao Sun
Summary: This study investigates the changes in causal pathways between the Madden-Julian Oscillation (MJO) and the North Atlantic Oscillation (NAO) using historical and SSP585 simulations of the CESM2-WACCM coupled climate model. The results show that the influence of MJO on the North Atlantic strengthens in the future, primarily through teleconnections via the tropospheric pathway.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Alexandre Audette, Robert A. Fajber, Paul J. Kushner, Yutian Wu, Yannick Peings, Gudrun Magnusdottir, Rosie Eade, Michael Sigmond, Lantao Sun
Summary: The PAMIP project separates the effects of sea ice loss and ocean surface warming on atmospheric transport and moisture, revealing a competitive relationship between the two and suggesting that climate change can have competing impacts on global energy transport from the tropics to the Arctic.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Jezabel Curbelo, Gang Chen, Carlos Roberto Mechoso
Summary: This study examines the northern stratosphere in April 2020, where the polar vortex split into two cyclonic vortices during a period with record ozone depletion. The research investigates the dynamical evolution leading to the split, the fate of fluid parcels on the vortex boundary, and the ozone distribution between the vortices resulting from the split. The findings highlight the key role of a flow with a special configuration of barriers to the motion of parcels in causing the split.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Weiming Ma, Gang Chen, Yannick Peings, Noah Alviz
Summary: The response of atmospheric rivers to Arctic sea ice loss in the Northern hemisphere winter is dominated by dynamic effects and related to climatological characteristics of the rivers. Improving the representation of atmospheric river climatology can help reduce response uncertainty to Arctic sea ice loss.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Meteorology & Atmospheric Sciences
Gang Chen, Yu Nie, Yang Zhang
Summary: This paper examines the mechanisms of jet meandering in the winter through the lens of a potential vorticity-like tracer. The study provides a new modeling framework to quantify the effects of mean flow and transient eddies on jet meandering, showing the similarity between the tracer wave activity and observed PV wave activity.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Lantao Sun, Clara Deser, Isla Simpson, Michael Sigmond
Summary: The response of atmospheric circulation to Arctic sea ice loss is inherently uncertain due to the small impact of the stratospheric polar vortex and the influence of internal variability. This study highlights the importance of considering these factors when analyzing the tropospheric response to sea ice loss.
JOURNAL OF CLIMATE
(2022)
Article
Geosciences, Multidisciplinary
Xiuyuan Ding, Gang Chen, Lantao Sun, Pengfei Zhang
Summary: This study compares the surface signatures of zonally symmetric and asymmetric modes of stratospheric variability and finds that strong stratospheric wave activity is a more reliable predictor for cold spells in North America.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Elizabeth A. Barnes, James W. Hurrell, Lantao Sun
Summary: This study uses climate model simulations to investigate the detectability of extreme temperature and precipitation changes after stratospheric aerosol injection (SAI). The results show that regional changes in extreme temperature can be detected within 1 year, while changes in extreme precipitation can be detected within 15 years of SAI injection.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Meteorology & Atmospheric Sciences
Lantao Sun, Martin P. Hoerling, Jadwiga H. Richter, Andrew Hoell, Arun Kumar, James W. Hurrell
Summary: The skill of NOAA's official monthly U.S. precipitation forecasts has historically been low, and this study explores the origins and limitations of North American subseasonal precipitation predictions. The results show that the skill is influenced by boundary constraints, particularly those related to El Nino-Southern Oscillation. Despite the low overall skill, there are still forecasting opportunities.
WEATHER AND FORECASTING
(2022)
Article
Geosciences, Multidisciplinary
Joonsuk M. M. Kang, Tiffany A. Shaw, Lantao Sun
Summary: Observations show that Arctic sea ice has decreased and midlatitude storminess has weakened during Northern Hemisphere summertime. This study quantifies the impact of Arctic sea ice loss on summertime storminess using climate model simulations. The results indicate that Arctic sea ice loss weakens summertime storminess in the mid-to-late 21st century, but only when there is ocean coupling. Transient simulations show that Arctic sea ice loss does not significantly weaken summertime storminess until the late 21st century. Additionally, Arctic Amplification does not significantly impact the present-day weakening of summertime storminess.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
Daniel M. Hueholt, Elizabeth A. Barnes, James W. Hurrell, Jadwiga H. Richter, Lantao Sun
Summary: Two framing approaches were used to analyze the effects of stratospheric aerosol injection (SAI) on short-term climate change. The study found that SAI deployment can effectively reduce changes in various high-impact climate variables, but the specific impacts depend on model versions, greenhouse gas emissions scenarios, and other experimental design factors.
Article
Environmental Sciences
Ye Wang, Natalie Mahowald, Peter Hess, Wenxiu Sun, Gang Chen
Summary: This study investigates the correlation between the anticyclonic wave activity (AWA) and fine particulate matter (PM2.5) concentrations in the US. The results show a positive correlation between PM2.5 and AWA changes, with higher sensitivity in regions with high aerosol days. Future changes in AWA are estimated to increase PM2.5 concentrations, particularly in areas where PM2.5 variations are influenced by meteorological changes.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2022)
Article
Environmental Sciences
Antara Banerjee, Amy H. Butler, Lorenzo M. Polvani, Alan Robock, Isla R. Simpson, Lantao Sun
Summary: Research suggests that future stratospheric sulfate geoengineering could result in winter warming over Eurasia and a positive phase of the North Atlantic Oscillation, with potential side effects such as precipitation changes and seasonal surface responses.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2021)