Article
Meteorology & Atmospheric Sciences
Yuepeng Hu, Botao Zhou, Tingting Han, Huixin Li, Huijun Wang
Summary: Using the S-EOF analysis, this study finds an in-phase change of drought from spring to summer in Northeast China, associated with geopotential height anomalies around Lake Baikal. The study also shows that the spring NAO plays a significant role in the in-phase change of spring-summer droughts over Northeast China, through the combined effects of zonal wave train and central Siberian soil moisture. These findings contribute to a better understanding of drought in Northeast China and have implications for disaster prevention and mitigation.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Chunzai Wang, Jiayu Zheng, Wei Lin, Yuqing Wang
Summary: In late June 2021, western North America experienced an extraordinary and unprecedented heatwave, resulting in severe consequences. Observational data suggests that atmospheric circulation variabilities were associated with the development and movement of the heatwave. However, current climate models are not designed to simulate such specific heatwave events.
ADVANCES IN ATMOSPHERIC SCIENCES
(2023)
Article
Environmental Sciences
Anthony R. Lupo, Nina K. Kononova, Inna G. Semenova, Maria G. Lebedeva
Summary: The study examines the atmospheric general circulation during summer-season droughts over Eastern Europe/Western Russia and North America from late twentieth to early twenty-first century. It uses various methods to analyze the relationship between drought and atmospheric dynamics, showing that extreme droughts over North America are associated with warm and dry weather, while those over Eastern Europe/Western Russia are driven by prolonged blocking episodes.
Article
Meteorology & Atmospheric Sciences
Haili Wang, Chunzai Wang
Summary: Based on observational data, this study finds that there are large-scale anomalous cyclones and anticyclones in the western North Pacific (WNP), with similar occurrence numbers. The WNP anomalous cyclone is identified as an interannual circulatory anomaly that can persist from autumn to spring during La Niña years and from spring to summer during developing El Niño years. The central equatorial Pacific warming contributes to the WNP anomalous cyclone during developing El Niño years, while the combination of central equatorial Pacific cooling, tropical Indian Ocean cooling, and central WNP warming induces the WNP anomalous cyclone during La Niña years.
JOURNAL OF CLIMATE
(2023)
Article
Meteorology & Atmospheric Sciences
Kenta Kawasaki, Yoshihiro Tachibana, Tetsu Nakamura, Koji Yamazaki
Summary: The Okhotsk Sea, with its colder temperatures in summer compared to the surrounding continent, has a remote impact on summer climates; ideal numerical experiments show that the presence of the Okhotsk Sea strengthens precipitation in the western North Pacific and intensifies the subtropical high pressure system.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Yuqiong Zheng, Shangfent Chen, Wen Chen, Bin Yu
Summary: This study finds that the impact of the spring North Pacific meridional mode (PMM) on the following-winter El Niño-Southern Oscillation (ENSO) has been increasing. The study compares high- and low-correlation periods to understand the factors behind the strengthened impact of PMM. In the high-correlation period, PMM-related sea surface temperature (SST) and atmospheric anomalies propagate southwestward to the tropical central Pacific via wind-evaporation-SST feedback, resulting in a stronger ENSO-like pattern. In the low-correlation period, PMM-related anomalies do not extend to the deep tropics, leading to weaker impact on ENSO.
JOURNAL OF CLIMATE
(2023)
Article
Meteorology & Atmospheric Sciences
Sarah M. Larson, Yuko Okumura, Katinka Bellomo, Melissa L. Breeden
Summary: Careful attribution of the role of El Nino-Southern Oscillation (ENSO) is necessary for identifying the origins of wintertime climate variations in the Northern Hemisphere. This study uses coupled model experiments to investigate how ENSO affects the responses of Aleutian low variability to sea surface temperature (SST) and precipitation in North America. The results show that ENSO modulates the SST anomalies induced by non-ENSO Aleutian low variability, leading to wet precipitation anomalies in the southeastern United States.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Jilan Jiang, Tonghua Su, Yimin Liu, Guoxiong Wu, Wei Yu, Jinxiao Li
Summary: This study reveals the synergistic effects of midlatitude and tropical circulation on an extreme drought in Southeast China in August 2019, emphasizing the coupling and locking of two cyclones at different latitudes. The results further confirm the connection between the Tibetan Plateau and the western North Pacific with tropical convection and precipitation in Southeast China, and uncover the impact mechanisms of the North Atlantic tripole sea surface temperature anomaly pattern and the TP precipitation deficiency on precipitation in Northeast China.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Chenbin Gao, Shujuan Hu, Jiankai Zhang, Wenxin Zhang, Deqian Li, Guolin Feng
Summary: In this study, the three-pattern decomposition of global atmospheric circulation (3P-DGAC) is used to investigate the dynamic synergistic effects of horizontal circulation, local meridional circulation, and local zonal circulation on the record-breaking extreme cold wave (ECW) in February 2021 across North America. The study reveals that the strengthening of blocking highs over the North Pacific and North Atlantic, along with the development of the North American trough and the subsequent strengthening of local meridional and zonal circulations, played significant roles in the formation and persistence of this ECW. The research highlights the effectiveness of 3P-DGAC in investigating the three-dimensional structural characteristics of anomalous circulations in ECWs.
ATMOSPHERIC RESEARCH
(2023)
Article
Meteorology & Atmospheric Sciences
Piyush Jain, Mike Flannigan
Summary: The polar jet stream greatly influences midlatitude weather patterns in North America, impacting storm tracks and conducive weather conditions for wildfires. Research has shown that extreme wildfire events are associated with upper-level ridges and high-pressure centers, with variations in duration based on region and season. Surface weather drivers including temperature, vapor pressure, and precipitation anomalies also play a role in fire spread. These findings are crucial for understanding North American fire regimes and improving fire management strategies through better weather forecasting.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Clara Orbe, David Rind, Ron l. Miller, Larissa S. Nazarenko, Anastasia Romanou, Jeffrey Jonas, Gary l. Russell, Maxwell Kelley, Gavin A. Schmidt
Summary: Climate models project a future weakening of the AMOC, but the impacts of this on climate are uncertain. By using a unique ensemble of CMIP6 GISS ModelE (E2.1) SSP 2-4.5 integrations, we isolate the climate impacts of a weakened AMOC and find that it results in a northward shift and strengthening of the NH Hadley cell and intensification of the northern midlatitude eddy-driven jet.
JOURNAL OF CLIMATE
(2023)
Article
Meteorology & Atmospheric Sciences
Yijia Zhang, Zhicong Yin, Botao Zhou, Huijun Wang
Summary: This study found a close relationship between the warm Arctic-cold Eurasia (WACE) pattern in January and the weakened February haze pollution in North China. The warming signal in sea ice and the cooling signal in Eurasian soil temperatures contributed to the persistence of the WACE pattern from January to February. The combined signal of sea ice and soil temperature anomalies created an environment conducive to the dispersion of pollutants. The relationship between the WACE pattern and the cyclonic circulation anomaly could also be observed in the large-ensemble CMIP6 simulations. Furthermore, the relationship between the January WACE pattern and the reduction of February haze pollution has been prominently enhanced since the late 1990s, which corresponds to the deep Arctic warming that has emerged during that time.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Simchan Yook, David W. J. Thompson, Lantao Sun, Casey Patrizio
Summary: Observations reveal two distinct patterns of atmospheric variability associated with wintertime variations in midlatitude sea surface temperatures (SSTs) in the North Pacific sector. One pattern is characterized by peak atmospheric circulation anomalies 2-3 weeks prior to large SST anomalies in the western North Pacific, consistent with atmospheric forcing of the SST field. The other pattern shows atmospheric circulation anomalies lagging behind SST anomalies in the western North Pacific by several weeks, consistent with the atmospheric response to the SST field. Numerical simulations support the interpretation of these lead-lag relationships, providing evidence for the influence of SST variability on the large-scale atmospheric circulation.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Erik T. Smith, Omon Obarein, Scott C. Sheridan, Cameron C. Lee
Summary: This study classified circulation patterns in five regions across North America using self-organized maps, showing that trends in the z500 circulation patterns were generally larger than those in mean sea-level pressure, indicating a stronger influence of geopotential heights on atmospheric conditions.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2021)
Article
Meteorology & Atmospheric Sciences
Yu Yang, Qin Su, Lin Wang, Ruowen Yang, Jie Cao
Summary: There is a robust linkage between the early spring North Pacific Victoria mode (VM) and the position of the South Asian high (SAH) in May. The positive phase of the early spring VM impedes the movement of the SAH in May, while the negative phase promotes its northwestward movement. This relationship has been verified through observational results and numerical experiments.
JOURNAL OF CLIMATE
(2022)
Article
Multidisciplinary Sciences
Dmitri A. Kalashnikov, Jordan L. Schnell, John T. Abatzoglou, Daniel L. Swain, Deepti Singh
Summary: Wildfires and meteorological conditions have a significant impact on the co-occurrence of PM2.5 and ground-level ozone in the western US. The frequency and intensity of these co-occurrences have increased over the past two decades, leading to an increase in population exposure to harmful air pollutants. The extent of co-occurrence is linked to atmospheric ridging patterns and the extent of extreme heat and wildfires.
Article
Meteorology & Atmospheric Sciences
Meredith A. Fish, James M. Done, Daniel L. Swain, Anna M. Wilson, Allison C. Michaelis, Peter B. Gibson, F. Martin Ralph
Summary: Successive atmospheric river (AR) events, known as AR families, can result in prolonged and elevated hydrological impacts compared to single AR events. This study introduces a new catalog of AR family events affecting California, identifying distinct large-scale patterns associated with AR families, some of which are strongly related to phases of the El Nino-Southern Oscillation. The potential predictability of AR families, especially on subseasonal to seasonal time scales, may be enhanced compared to single AR events.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Jiabao Wang, Michael J. DeFlorio, Bin Guan, Christopher M. Castellano
Summary: This study provides observational evidence of the Madden-Julian oscillation's impacts on precipitation extreme intensity, frequency, and duration over the western United States. Results show a robust increase in precipitation extremes, especially in frequency, when the MJO is in its western Pacific phases during the extended boreal winter. Opposite changes are observed when the MJO is located over the Indian Ocean and Maritime Continent.
JOURNAL OF HYDROMETEOROLOGY
(2023)
Article
Environmental Sciences
Pengfei Zhang, Gang Chen, Mingfang Ting, L. Ruby Leung, Bin Guan, Laifang Li
Summary: The frequency of atmospheric rivers reaching the Arctic has increased in recent decades, which has slowed down the recovery of sea ice during the winter season. This is due to intensified precipitation and melting caused by the more frequent atmospheric rivers. Additionally, tropical Pacific variability also contributes to the observed changes in Arctic atmospheric rivers.
NATURE CLIMATE CHANGE
(2023)
Article
Meteorology & Atmospheric Sciences
Bin Guan, Duane E. Waliser, F. Martin Ralph
Summary: Atmospheric rivers (ARs) are narrow corridors of enhanced water vapor transport that play important roles in the global water cycle. The AR scale helps evaluate and communicate the global influences of ARs, with AR event count inversely related to AR rank and peaking in midlatitude oceans. As precipitation intensity increases, ARs account for a larger fraction of precipitation occurrences.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Geosciences, Multidisciplinary
Christine A. Shields, Ashley E. Payne, Eric Jay Shearer, Michael F. Wehner, Travis Allen O'Brien, Jonathan J. Rutz, L. Ruby Leung, F. Martin Ralph, Allison B. Marquardt Collow, Paul A. Ullrich, Qizhen Dong, Alexander Gershunov, Helen Griffith, Bin Guan, Juan Manuel Lora, Mengqian Lu, Elizabeth McClenny, Kyle M. Nardi, Mengxin Pan, Yun Qian, Alexandre M. Ramos, Tamara Shulgina, Maximiliano Viale, Chandan Sarangi, Ricardo Tome, Colin Zarzycki
Summary: Atmospheric rivers are important for Earth's hydrological cycle, delivering precipitation to local climates. The response of atmospheric rivers to climate change depends on how they are defined. Comparing 16 detection tools, it is found that atmospheric rivers generally increase in frequency and intensity, but the scale of the response varies depending on algorithmic criteria. The precipitation response to climate change is diverse and dependent on the chosen detection tools.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Letter
Geosciences, Multidisciplinary
Chanil Park, Seok-Woo Son, Bin Guan
Summary: This study provides evidence for the multiscale nature of atmospheric rivers (ARs) by differentiating them based on high- (HF) and low-frequency (LF) moisture transports. The HF-dominant ARs exhibit migratory behavior as they are typically accompanied by extratropical cyclones. On the other hand, the LF-dominant ARs stay in place as they are associated with quasi-stationary circulation. The ARs are often jointly affected by HF and LF processes.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Meteorology & Atmospheric Sciences
Christopher M. Castellano, Michael J. DeFlorio, Peter B. Gibson, Luca Delle Monache, Julie F. Kalansky, Jiabao Wang, Kristen Guirguis, Alexander Gershunov, F. Martin Ralph, Aneesh C. Subramanian, Michael L. Anderson
Summary: This paper examines the relationship between the Madden-Julian oscillation (MJO), the quasi-biennial oscillation (QBO), atmospheric river (AR) activity, and precipitation in California on subseasonal time scales. An experimental forecast tool is introduced to predict the probability of above- and below-normal AR activity and precipitation based on MJO and QBO phase and amplitude. The results demonstrate that subseasonal AR activity and precipitation in California are strongly influenced by MJO and QBO, with certain combinations of MJO phase, QBO phase, lag time, and season yielding higher skill scores.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Meteorology & Atmospheric Sciences
Zhenhai Zhang, Michael J. DeFlorio, Luca Delle Monache, Aneesh C. Subramanian, F. Martin Ralph, Duane E. Waliser, Minghua Zheng, Bin Guan, Alexander Goodman, Andrea M. Molod, Frederic Vitart, Arun Kumar, Hai Lin
Summary: This study focuses on the assessment of multi-model subseasonal-to-seasonal (S2S) prediction skill of atmospheric rivers (ARs) using a new metric, accumulated water vapor transport. Four dynamical model hindcast data sets and three reanalysis data sets are used to evaluate the prediction skill at lead time 1-4 weeks. The results show variations in AR-related water vapor transport among different models and the Madden-Julian Oscillation can modulate the prediction skill with large uncertainties across models.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Meteorology & Atmospheric Sciences
Bin Guan, Sumant Nigam
Summary: During Christmas week in 2021, winter storms brought record-breaking snowfall and low temperatures to the Pacific Northwest, particularly in Oregon. Despite a seasonal outlook of below-normal precipitation, the region experienced disruptive snowfall due to the negative phase of the Pacific-North American (PNA) teleconnection pattern. This episode, the strongest in over 50 years, led to significant snowfall and precipitation in coastal, Cascade, and Sierra regions.
BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
(2023)
Article
Meteorology & Atmospheric Sciences
Peter B. Gibson, Daithi Stone, Marcus Thatcher, Ashley Broadbent, Samuel Dean, Suzanne M. Rosier, Stephen Stuart, Abha Sood
Summary: Detection and attribution experiments aim to diagnose the causal factors behind climate system features, including trends in mean climate and extreme events. The coarse resolution of climate models often limits their application in topographically complex regions and small island nations. To overcome this limitation, a new set of high-resolution atmospheric simulations from the CCAM model is introduced, enabling targeted simulations over New Zealand and the South Pacific region. These simulations show promising results for studying weather and climate extremes in attribution studies.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Environmental Sciences
Daniel L. Swain, John T. Abatzoglou, Crystal Kolden, Kristen Shive, Dmitri A. Kalashnikov, Deepti Singh, Edward Smith
Summary: Escalating wildfire activity in the western United States has adverse societal impacts, but intentional use of fire as a vegetation management tool can reduce the risk of destructive fires. Global warming will decrease the overall number of prescribed fire days, but winter may become a favorable window for prescribed fire in northern states.
COMMUNICATIONS EARTH & ENVIRONMENT
(2023)
Article
Geosciences, Multidisciplinary
Sol Kim, L. Ruby Leung, Bin Guan, John C. H. Chiang
Summary: The study evaluates the performance of the Energy Exascale Earth System Model (E3SM) in simulating atmospheric rivers (ARs) and identifies biases related to the double intertropical convergence zone (ITCZ) and intensified North Pacific jet and Northern Hemisphere westerlies during summer.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2022)
Article
Environmental Sciences
Sudip Chakraborty, Bin Guan, Duane E. Waliser, Arlindo M. da Silva
Summary: The study characterizes and quantifies the features of aerosol atmospheric rivers (AARs) using a detection technique based on atmospheric rivers (ARs) concept. It provides insights into AARs' seasonality, event characteristics, vertical profiles of aerosol mass mixing ratio and wind speed, and the fraction of total annual aerosol transport conducted by AARs. The study also analyzes the sensitivity of AAR detection to the criteria and thresholds used by the algorithm. The results show that AARs occur more frequently in regions with higher aerosol emission and contribute significantly to the total annual aerosol transport.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2022)