Article
Meteorology & Atmospheric Sciences
Yechul Shin, Sarah M. Kang, Ken Takahashi, Malte F. Stuecker, Yen-Ting Hwang, Doyeon Kim
Summary: The study found that high-frequency extratropical forcing does not affect tropical precipitation, while low-frequency extratropical forcing allows atmospheric transient eddies to diffuse moist static energy to perturb midlatitude sea surface temperatures, ultimately achieving further equatorward advection through the Hadley circulation.
JOURNAL OF CLIMATE
(2021)
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
Multidisciplinary Sciences
Stefanie Kaboth-Bahr, William D. Gosling, Ralf Vogelsang, Andre Bahr, Eleanor M. L. Scerri, Asfawossen Asrat, Andrew S. Cohen, Walter Dusing, Verena Foerster, Henry F. Lamb, Mark A. Maslin, Helen M. Roberts, Frank Schabitz, Martin H. Trauth
Summary: The study reveals a close correlation between moisture availability in Africa and ENSO variability, likely driven by changes in Earth's eccentricity. Low-latitude insolation is identified as a key driver of pan-African climate change, impacting vegetation and mammal evolution.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(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
Yen-Ting Hwang, Hung-Yi Tseng, Kuan-Chen Li, Sarah M. Kang, Yung-Jen Chen, John C. H. Chiang
Summary: This study investigates the transient responses of atmospheric energy and momentum fluxes to an extratropical thermal heating in a model coupled to an aquaplanet mixed layer ocean. Two stages are observed in the teleconnection: a decrease in the meridional temperature gradient in midlatitudes leads to weakening of the eddy momentum flux and a reduction of the Hadley cell, followed by the development of a deep tropical cross-equatorial cell. The response time scale differs between the two stages, with the latter stage dependent on mixed layer depth.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Yen-Ting Hwang, Po-Chun Chung
Summary: This study investigates the seasonal sensitivity of tropical circulation responses to an idealized extratropical thermal forcing and finds that the anomalous cross-equatorial cell has a strong impact on the strength of the Hadley cell and subtropical jet in the winter hemisphere. The small seasonal variation of the anomalous cross-equatorial cell can be explained by the seasonal heat uptake within the deep tropics.
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
Haijin Dai, Qiang Yao
Summary: Idealized numerical simulations reveal the response of atmospheric and oceanic circulations to Arctic warming at different timescales. Arctic warming leads to sea-ice melting and inhibits deep-water formation, weakening the Atlantic Meridional Overturning Circulation (AMOC). The strength and width of the Hadley cell (HC) are affected by the nearly uniform surface warming in mid-low latitudes and the temperature-wind-gyre-temperature cycle triggered by long-term response to high latitude warming. The HC response is also influenced by tropical warming, reduced surface albedo, and weakened AMOC.
ADVANCES IN ATMOSPHERIC SCIENCES
(2023)
Article
Geosciences, Multidisciplinary
R. Chemke
Summary: The study reveals that ocean heat transport plays a critical role in the evolution of the Hadley circulation, significantly affecting its widening and weakening. OHT can reduce the expansion and mitigate the weakening, delaying the emergence of circulation changes.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Meteorology & Atmospheric Sciences
Katrina L. Hui, Simona Bordoni
Summary: Recent studies show that the rapid onset of the monsoon can be explained by a shift in tropical circulation, from a regime controlled by eddy momentum fluxes to one controlled by energetic constraints. The position of the equatorward coastal boundary influences these transitions, with tropical continents facilitating the establishment of an overturning circulation conducive to a monsoon regime. Conversely, lack of land at tropical latitudes prevents rapid displacement of moist static energy into the subtropics, hindering the establishment of an angular momentum-conserving monsoon regime.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2021)
Article
Meteorology & Atmospheric Sciences
Jian Cao, Xuanqiang Lian, Min Cao, Bin Wang, Hao Wang, Xiaowei Zhu, Haikun Zhaoa
Summary: The causes of historical changes in the Southern Hemisphere monsoon are less understood compared to the Northern Hemisphere. This study finds that, unlike the decline in the Northern Hemisphere monsoon, the precipitation of the Southern Hemisphere land monsoon significantly increased during 1901-2014. The increase is mainly attributed to the strengthening of monsoon circulation, influenced by the sea surface temperature gradient. The results provide valuable insights for future projections of the Southern Hemisphere monsoon and understanding the long-term changes in Hadley circulation.
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
Multidisciplinary Sciences
Rei Chemke, Janni Yuval
Summary: The Hadley circulation plays a crucial role in determining precipitation and temperature patterns at low latitudes. However, there is currently a large uncertainty in the recent changes of the Hadley circulation in the Northern Hemisphere. This study demonstrates that the circulation has considerably weakened over recent decades and attributes the weakening to anthropogenic emissions, which enhances our confidence in projections of tropical climate change caused by human activities.
Article
Meteorology & Atmospheric Sciences
Chia-Wei Lan, Yen-Ting Hwang, Rong-You Chien, Agnes Ducharne, Min-Hui Lo
Summary: The representation of groundwater dynamics in land surface models and their roles in global precipitation variations have been studied recently. The incorporation of the groundwater component in climate models has led to higher soil moisture and diverse precipitation changes. However, the effects of groundwater on large-scale atmospheric energy transport, a fundamental atmospheric variable regulating Earth's climate, have not been thoroughly explored.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Nicholas A. Davis, Thomas Birner
Summary: The poleward expansion of the Hadley cells is a robust response to increasing greenhouse gas concentrations, and the adjustment of the eddies and the mean flow complicates the understanding of this process. By modifying a model and analyzing simulations, it is found that the increase in subtropical angular momentum drives the poleward shift of eddy stresses, leading to Hadley cell expansion.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2022)
Article
Meteorology & Atmospheric Sciences
Michael F. Howland, Oliver R. A. Dunbar, Tapio Schneider
Summary: This study develops methods for calibrating and quantifying uncertainty in climate model parameters using the seasonal cycle. The methods are demonstrated with an idealized GCM, and the calibration and uncertainty quantification based on seasonally averaged climate statistics significantly reduces error and narrows posterior distributions compared to annually averaged data, leading to a reduction in climate model prediction uncertainty.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2022)
Article
Meteorology & Atmospheric Sciences
Xiyue Zhang, Tapio Schneider, Zhaoyi Shen, Kyle G. Pressel, Ian Eisenman
Summary: This study investigates the seasonal cycle of polar clouds using large eddy simulations (LES) to improve the understanding of cloud response to climate warming. The results show that the simulated cloud cycle closely resembles observations.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2022)
Article
Geosciences, Multidisciplinary
L. A. Roach, I Eisenman, T. J. W. Wagner, E. Blanchard-Wrigglesworth, C. M. Bitz
Summary: This article suggests that solar radiation is the driving force behind the asymmetry in the seasonal cycle of Antarctic sea ice. The ice retreat period is approximately two months shorter than the ice advance period, and this asymmetry is consistent in observations and satellite products. Using idealized climate models, the study shows that the seasonal cycle of incident solar radiation at the top of the atmosphere is responsible for this asymmetry, as the high latitudes in the Southern Hemisphere experience a narrow peak of intense brightness in summer and a long period of low light in winter.
Article
Meteorology & Atmospheric Sciences
Zhaoyi Shen, Akshay Sridhar, Zhihong Tan, Anna Jaruga, Tapio Schneider
Summary: This paper aims to create a public library of large-eddy simulations (LES) of clouds to improve parameterizations in global climate models (GCMs). The LES are driven by large-scale forcings from GCMs and are used to study cloud behavior in different climate states.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2022)
Article
Computer Science, Interdisciplinary Applications
Daniel Zhengyu Huang, Tapio Schneider, Andrew M. Stuart
Summary: This paper focuses on the optimization approach to solve inverse problems using stochastic dynamical systems and techniques from nonlinear Kalman filtering. The extended Kalman filter, ensemble Kalman filters, and unscented Kalman inversion are applied in the study. The paper presents a novel stochastic dynamical system and shows improved inversion results compared to previous work.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
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
Meteorology & Atmospheric Sciences
Ignacio Lopez-Gomez, Costa Christopoulos, Haakon Ludvig Langeland Ervik, Oliver R. A. Dunbar, Yair Cohen, Tapio Schneider
Summary: Most machine learning applications in Earth system modeling rely on gradient-based supervised learning, but it imposes strict constraints on the training data and complicates learning about interactions between machine-learned parameterizations and other components. Using Kalman inversion methods as an inverse problem can overcome these issues and provide effective training for parameterizations. The unscented and ensemble Kalman inversion algorithms are highly parallelizable and do not require gradient computations, making them robust and efficient in training hybrid parameterizations. The training results demonstrate the ability to learn efficiently from noisy and indirectly informative data.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2022)
Article
Meteorology & Atmospheric Sciences
Ana H. Lobo, Simona Bordoni
Summary: This study investigates the response of large-scale atmospheric circulation to changes in shortwave and longwave radiation through idealized aquaplanet simulations of Earth-like planets. It finds that increasing the planet obliquity leads to a weakening of extratropical circulation and precipitating storm tracks, which is counterintuitive. On high-obliquity planets with low thermal inertia, the net energy deficit is balanced by the latent energy component of atmospheric heat capacity, preventing significant atmospheric cooling. On planets with larger thermal inertia, the net energy loss during winter is primarily balanced by energy storage in the ocean surface. These results highlight the importance of accurate representation of polar properties in planetary modeling and observations.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Article
Geosciences, Multidisciplinary
Matthew T. Luongo, Shang-Ping Xie, Ian Eisenman, Yen-Ting Hwang, Hung-Yi Tseng
Summary: Previous studies have shown that aerosol-like cooling in the Northern Hemisphere leads to a La Nina-like response in the tropical Indo-Pacific. This study investigates the communication and sustainability of this response through a coupled ocean-atmosphere feedback pathway. The results suggest that the buoyancy-forced response dominates in the subtropics, amplifying sea surface temperature anomalies and communicating wind-driven evaporative cooling to the tropics. In the equatorial Indo-Pacific, buoyancy-forced ocean dynamics cool the surface while the Bjerknes feedback creates zonally asymmetric SST patterns. Robustness of the subtropical low cloud feedback pathway is observed across multiple models.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Meteorology & Atmospheric Sciences
E. K. de Jong, T. Bischoff, A. Nadim, T. Schneider
Summary: This method introduces a flexible spectral microphysics approach for tracking particle distributions of different categories, providing a computational framework for unifying liquid, ice, and aerosol microphysics.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2022)
Editorial Material
Meteorology & Atmospheric Sciences
Stephen M. Griffies, Jiwen Fan, Natasha MacBean, Tapio Schneider
Summary: The editors of Journal of Advances in Modeling Earth Systems express their gratitude to the 702 reviewers who contributed 1362 reviews in 2022. Their diligent work and valuable insights, often provided anonymously, benefit authors, readers, and the wider scientific community.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2023)
Editorial Material
Meteorology & Atmospheric Sciences
Stephen M. Griffies, Jiwen Fan, Natasha MacBean, Tapio Schneider
Summary: The mission of AGU's Journal of Advances in Modeling Earth Systems (JAMES) is to publish original research papers that advance the science underlying Earth system models and emerging from their use. JAMES' scope encompasses the outer envelope of the Earth system including the atmosphere, oceans, land surface, and cryosphere. It publishes papers that expand capabilities to model, understand, and predict the Earth system and the physical, chemical, and biological processes shaping it. In this editorial, we present general principles as well as specific notions that guide the strategy of JAMES' editors in realizing the journal's mission. This document serves as an update to Griffies et al. (2021).
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2023)
Article
Multidisciplinary Sciences
Yidongfang Si, Andrew L. Stewart, Ian Eisenman
Summary: The Antarctic Slope Front (ASF) is a strong gradient in water mass properties near the Antarctic margins, separating warm water from the Antarctic ice sheet. Heat transport across the ASF plays a crucial role in Earth's climate, affecting ice shelves melting, bottom water formation, and global meridional overturning circulation. Previous studies using low-resolution global models have contradictory findings on the impact of additional meltwater on heat transport toward the Antarctic continental shelf, and it remains unclear whether meltwater enhances shoreward heat transport or isolates the continental shelf from the open ocean. In this study, eddy- and tide-resolving simulations are used to investigate heat transport across the ASF, and it is found that freshening of coastal waters increases shoreward heat flux, indicating a positive feedback in a warming climate: increased meltwater leads to greater shoreward heat transport, causing further ice shelf melting.
Article
Meteorology & Atmospheric Sciences
Sheide Chammas, Qing Wang, Tapio Schneider, Matthias Ihme, Yi-fan Chen, John Anderson
Summary: This study demonstrates the use of tensor processing units (TPUs) to simulate low clouds, providing valuable insights into their role in climate. The simulations conducted using TPUs show unprecedented speed and scalability, allowing for the generation of large datasets for training climate models.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2023)
Article
Geosciences, Multidisciplinary
Akshay Sridhar, Yassine Tissaoui, Simone Marras, Zhaoyi Shen, Charles Kawczynski, Simon Byrne, Kiran Pamnany, Maciej Waruszewski, Thomas H. Gibson, Jeremy E. Kozdon, Valentin Churavy, Lucas C. Wilcox, Francis X. Giraldo, Tapio Schneider
Summary: We introduce ClimateMachine, an opensource atmosphere modeling framework using Julia language that is scalable on CPUs and GPUs. It can be applied to both global simulations and limited-area large-eddy simulations (LESs). Through comparisons with existing LES codes, we demonstrate the effectiveness of ClimateMachine as a modeling tool for limited-area LES flow configurations.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2022)
