Article
Environmental Sciences
Ju-Mee Ryoo, Taejin Park
Summary: An atmospheric river (AR) is a vital component for regional hydroclimate systems, and its association with wildfire patterns in the western U.S. has been investigated. Record-high wildfire activity in 2020 was linked to hotter, drier, and windier conditions, with a shift in peak from July to August. ARs were found to be more frequent but weaker in the summer and less frequent in the fall of 2020 compared to 2016. Contrasting precipitation-wind patterns under ARs in 2020 and 2016 were observed, with dry-windy conditions in 2020 and wet-windy conditions in 2016.
ENVIRONMENTAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Hamish D. Prince, Peter B. Gibson, Michael J. DeFlorio, Thomas W. Corringham, Alison Cobb, Bin Guan, F. Martin Ralph, Duane E. Waliser
Summary: Atmospheric rivers (ARs) are responsible for the vast majority of flood damage in the Western U.S., causing an annual average of $1.1 billion in damages. Damaging ARs tend to have genesis locations further from the coastline, travel longer distances, and have higher moisture flux.
GEOPHYSICAL RESEARCH LETTERS
(2021)
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)
Article
Environmental Sciences
Jeongwoo Han, Vijay P. Singh
Summary: The study highlights the significant impacts of atmospheric variability, specifically RRWPs and ARs, on drought occurrences. RRWPs increase the likelihood and severity of drought, while drying ARs contribute to extreme droughts. The co-occurrence of ARs and RRWPs has a greater impact on extreme droughts than either individually. These findings offer potential for improving drought mitigation measures.
WATER RESOURCES RESEARCH
(2021)
Article
Multidisciplinary Sciences
Yizhou Zhuang, Rong Fu, Benjamin D. Santer, Robert E. Dickinson, Alex Hall
Summary: Recent studies have shown that the increase in wildfire activity in the western United States in recent years is likely attributed to both natural weather pattern changes and anthropogenic warming, with approximately 68% of the observed trend in vapor pressure deficit (VPD) being due to human influence. Climate models indicate that anthropogenic forcing explains an even larger fraction (88%) of the VPD trend, providing a lower and upper bound on the true impact of anthropogenic warming on VPD trends in the region. In August 2020, during the occurrence of the August Complex Gigafire, it is estimated that anthropogenic warming explained 50% of the exceptionally high VPD anomalies.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
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
Multidisciplinary Sciences
Yitao Li, Zhao-Liang Li, Hua Wu, Chenghu Zhou, Xiangyang Liu, Pei Leng, Peng Yang, Wenbin Wu, Ronglin Tang, Guo-Fei Shang, Lingling Ma
Summary: Vegetation greening has a unidirectional negative impact on radiometric surface temperature, with significant spatial and seasonal variability. Snow cover, vegetation greenness, and shortwave radiation are the main driving factors of this temperature response. Globally, the observed greening trend leads to a cooling effect that slows down a percentage of global warming, while regionally, it can offset a considerable portion of warming in India and China. These findings emphasize the importance of considering vegetation-related biophysical climate effects in local climate adaptation strategies.
NATURE COMMUNICATIONS
(2023)
Review
Environmental Sciences
Erica R. Siirila-Woodburn, Alan M. Rhoades, Benjamin J. Hatchett, Laurie S. Huning, Julia Szinai, Christina Tague, Peter S. Nico, Daniel R. Feldman, Andrew D. Jones, William D. Collins, Laurna Kaatz
Summary: Anthropogenic climate change is decreasing seasonal snowpacks globally, with significant impacts on water resources, especially in the western United States. Projections show a decline of about 25% in snow water equivalent by 2050, with potential persistent low-to-no snow conditions in 35-60 years if greenhouse gas emissions continue unabated. These changes will alter groundwater and streamflow dynamics in the region.
NATURE REVIEWS EARTH & ENVIRONMENT
(2021)
Article
Environmental Sciences
Xingying Huang, Samantha Stevenson
Summary: The study investigates future changes in precipitation extremes over the western US and North Pacific Ocean using a multi-model ensemble archive. It shows large inter-model differences in the frequency and intensity of heavy precipitation, with a more consistent signal in the Pacific Northwest compared to California. The analysis highlights the dominance of thermodynamic contributions in extreme precipitation, but also emphasizes the need for accurate projections of North Pacific coupled circulation changes to reduce uncertainty in future precipitation extremes.
Article
Environmental Sciences
Yangyang Yong, Ju Liang, Kai Yang
Summary: This study aims to investigate the characteristics of atmospheric rivers (ARs) from the western Pacific to Southeast Asia. The results show frequent AR activities in this region during the autumn-winter season, with increasing trends and eastward shift. These dynamic changes contribute to increasing extreme precipitation amounts in the surrounding coastal areas of the South China Sea. This study emphasizes the importance of ARs in understanding the climatology, trends, and variability of regional precipitation in Southeast Asia.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Meteorology & Atmospheric Sciences
Jorge Eiras-Barca, Alexandre M. Ramos, Iago Algarra, Marta Vazquez, Francina Dominguez, Gonzalo Miguez-Macho, Raquel Nieto, Luis Gimeno, Juan Taboada, F. Martin Ralph
Summary: This study applies the newly-created atmospheric river intensity and impacts scale (AR Scale) to the European continent, finding remarkable variability in the distribution of AR events across Europe. AR1 and AR2 events are the most frequent, explaining most of the precipitation, but with a low probability of extreme rainfall, while AR3, AR4, and AR5 events, although less common, are associated with a high probability of extreme rainfall.
WEATHER AND CLIMATE EXTREMES
(2021)
Article
Geosciences, Multidisciplinary
Simon H. Lee, Lorenzo M. Polvani, Bin Guan
Summary: This article investigates the impact of the polar vortex on atmospheric river frequency and other related variables in the Northern Hemisphere winter. The study finds significant differences between strong and weak vortex states, which have important implications for the occurrence of atmospheric rivers and precipitation, particularly in Europe and the Pacific Northwest of North America.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Environmental Sciences
Wei Liu, Michaela Hegglin, Ramiro Checa-Garcia, Shouwei Li, Nathan P. Gillett, Kewei Lyu, Xuebin Zhang, Neil C. Swart
Summary: Atmospheric ozone changes in the stratosphere and troposphere have contributed to warming in the Southern Ocean, with tropospheric ozone changes being more important. Tropospheric increases primarily cause subsurface warming through the deepening of isopycnals, while stratospheric ozone causes depletion via spiciness changes along isopycnals.
NATURE CLIMATE CHANGE
(2022)
Article
Environmental Sciences
Xiaodong Chen, L. Ruby Leung, Yang Gao, Ying Liu, Mark Wigmosta
Summary: The spatial structures of large storms are not well understood in most climate models. Using high-resolution models, the authors demonstrate that winter storms become sharper under warming, with precipitation in the storm center increasing more than the storm area. Winter storms lead to significant economic losses in the western US. Ignoring storm sharpening could overestimate changes in design storms used in infrastructure planning.
NATURE CLIMATE CHANGE
(2023)
Article
Meteorology & Atmospheric Sciences
Emily A. Slinskey, Alex Hall, Naomi Goldenson, Paul C. Loikith, Jesse Norris
Summary: This study analyzes atmospheric rivers (ARs) along the US West Coast and identifies a subseasonal temporal clustering phenomenon among these events. Clusters of ARs occur more frequently and for longer periods in Northern California and the Sierra Nevada. These clusters have significant impacts on precipitation and extreme rainfall in the region, and are important in determining whether a water year is anomalously wet or dry. However, the mechanisms behind this clustering phenomenon remain unclear and require further investigation.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Meteorology & Atmospheric Sciences
Nicolas E. Bambach, Alan M. Rhoades, Benjamin J. Hatchett, Andrew D. Jones, Paul A. Ullrich, Colin M. Zarzycki
Summary: The study introduced variable-resolution enabled Community Earth System Model (VR-CESM) results simulating historical and future climate conditions in South America and the Andes. The findings showed broad warming patterns and heterogeneous precipitation responses in South America by the end of the century, consistent with prior modelling efforts.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2022)
Article
Meteorology & Atmospheric Sciences
Mark D. Risser, William D. Collins, Michael F. Wehner, Travis A. O'Brien, Christopher J. Paciorek, John P. O'Brien, Christina M. Patricola, Huanping Huang, Paul A. Ullrich, Burlen Loring
Summary: This study develops a framework for regional detection and attribution of precipitation using output from global climate models, and applies it to the contiguous United States. By conducting tests using model output, the study is able to detect systematic trends in precipitation, attribute these trends to anthropogenic forcings, compute the effects of forcings over time, and map the effects of individual forcings.
Article
Geosciences, Multidisciplinary
Benjamin J. Hatchett, Arielle L. Koshkin, Kristen Guirguis, Karl Rittger, Anne W. Nolin, Anne Heggli, Alan M. Rhoades, Amy E. East, Erica R. Siirila-Woodburn, W. Tyler Brandt, Alexander Gershunov, Kayden Haleakala
Summary: Increasing wildfire activity and declining snowpacks in California's mountain regions have led to a nearly tenfold increase in fire activity during 2020-2021 compared to 2001-2019. The decrease in snow albedo and canopy coverage have contributed to midwinter snow melt during a dry spell in 2022. Satellite measurements confirm the post-fire differences in snowpack, highlighting the increasing vulnerability of California's snowpack to the combined effects of dry spells and wildfires.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
Erica R. Siirila-Woodburn, P. James Dennedy-Frank, Alan Rhoades, Pouya Vahmani, Fadji Maina, Benjamin Hatchett, Yang Zhou, Andrew Jones
Summary: In the coastal regions of the western United States, atmospheric rivers (ARs) contribute significantly to precipitation, but their impact on groundwater storage and hydrodynamics is not well understood. To study this, a combination of two water tracking methods was used to track water parcels generated by ARs. Simulations showed that although ARs contribute more precipitation, less of it is stored in aquifers compared to non-AR storms. Rain-on-snow events were found to play an important role in AR-driven discharge. Despite record-breaking annual precipitation, groundwater depletion still occurred due to pumping activities.
WATER RESOURCES RESEARCH
(2023)
Review
Environmental Sciences
Sonali McDermid, Mallika Nocco, Patricia Lawston-Parker, Jessica Keune, Yadu Pokhrel, Meha Jain, Jonas Jaegermeyr, Luca Brocca, Christian Massari, Andrew D. Jones, Pouya Vahmani, Wim Thiery, Yi Yao, Andrew Bell, Liang Chen, Wouter Dorigo, Naota Hanasaki, Scott Jasechko, Min-Hui Lo, Rezaul Mahmood, Vimal Mishra, Nathaniel D. Mueller, Dev Niyogi, Sam S. Rabin, Lindsey Sloat, Yoshihide Wada, Luca Zappa, Fei Chen, Benjamin I. Cook, Hyungjun Kim, Danica Lombardozzi, Jan Polcher, Dongryeol Ryu, Joe Santanello, Yusuke Satoh, Sonia Seneviratne, Deepti Singh, Tokuta Yokohata
Summary: Irrigation accounts for a large majority of global freshwater withdrawals and consumptive water use, causing significant impacts on the Earth system. This Review provides a summary of how irrigation currently affects key components of the Earth system. It is estimated that over 3.6 million km(2) of land is currently being irrigated, with hot spots in the US High Plains, California Central Valley, Indo-Gangetic Basin, and northern China. Process-based models estimate that around 2,700 +/- 540 km(3) of irrigation water is withdrawn globally each year, and this is broadly consistent with reported values from countries, despite uncertainties.
NATURE REVIEWS EARTH & ENVIRONMENT
(2023)
Article
Multidisciplinary Sciences
Mohammed Ombadi, Mark D. Risser, Alan M. Rhoades, Charuleka Varadharajan
Summary: The intensity of extreme precipitation events is projected to increase in a warmer climate, posing challenges to water sustainability. This study shows that the increase in rainfall extremes in high-elevation regions is double the rate expected from increases in atmospheric water vapour due to a shift from snow to rain. The findings highlight the vulnerability of high-altitude regions to extreme-rainfall-related hazards and the need for climate adaptation plans.
Article
Meteorology & Atmospheric Sciences
Alan M. Rhoades, Colin M. Zarzycki, Hector A. Inda-Diaz, Mohammed Ombadi, Ulysse Pasquier, Abhishekh Srivastava, Benjamin J. Hatchett, Eli Dennis, Anne Heggli, Rachel McCrary, Seth McGinnis, Stefan Rahimi-Esfarjani, Emily Slinskey, Paul A. Ullrich, Michael Wehner, Andrew D. Jones
Summary: The 1997 New Year's flood in California, driven by an atmospheric river and snowmelt, was the most costly flood in the state's history. This study recreates the flood using a regional Earth system model and evaluates the performance of different resolution grids and forecast lead times. The findings provide insights into the causes of extreme events and the importance of resolution in representing reservoir inflows.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2023)
Article
Multidisciplinary Sciences
Andrew D. Jones, Deeksha Rastogi, Pouya Vahmani, Alyssa M. Stansfield, Kevin A. Reed, Travis Thurber, Paul A. Ullrich, Jennie S. Rice
Summary: Regional climate models are used to simulate analogue versions of past weather events under different climate conditions. This study downscaled a 40-year sequence of past weather using a range of time-evolving thermodynamic warming signals based on future warming trajectories. The resulting dataset provides insights into the possible range of future climate conditions and their effects on historical extreme events.
Article
Meteorology & Atmospheric Sciences
S. Vishnu, Mark D. Risser, Travis A. O'Brien, Paul A. Ullrich, William R. Boos
Summary: Most extreme precipitation in central India is caused by monsoon lows and monsoon depressions. Using satellite data and atmospheric reanalysis, this study reveals that rain rates have increased in the southwest quadrant of monsoon depressions and decreased in the eastern quadrants. The intensity of rotational winds around the storm center showed no clear trends.
NPJ CLIMATE AND ATMOSPHERIC SCIENCE
(2023)
Correction
Environmental Sciences
Sonali McDermid, Mallika Nocco, Patricia Lawston-Parker, Jessica Keune, Yadu Pokhrel, Meha Jain, Jonas Jagermeyr, Luca Brocca, Christian Massari, Andrew D. Jones, Pouya Vahmani, Wim Thiery, Yi Yao, Andrew Bell, Liang Chen, Wouter Dorigo, Naota Hanasaki, Scott Jasechko, Min-Hui Lo, Rezaul Mahmood, Vimal Mishra, Nathaniel D. Mueller, Dev Niyogi, Sam S. Rabin, Lindsey Sloat, Yoshihide Wada, Luca Zappa, Fei Chen, Benjamin I. Cook, Hyungjun Kim, Danica Lombardozzi, Jan Polcher, Dongryeol Ryu, Joe Santanello, Yusuke Satoh, Sonia Seneviratne, Deepti Singh, Tokuta Yokohata
NATURE REVIEWS EARTH & ENVIRONMENT
(2023)
Article
Geosciences, Multidisciplinary
Abhishekh Kumar Srivastava, Paul Aaron Ullrich, Deeksha Rastogi, Pouya Vahmani, Andrew Jones, Richard Grotjahn
Summary: This study evaluates the quality of historical precipitation simulated by the WRF v 4.2.1 model compared to ERA5 in the contiguous United States. The results show that the WRF model accurately captures the timing and magnitude of the summer diurnal precipitation peak, but exhibits a delayed diurnal peak over the Great Plains. The WRF model improves upon ERA5 in simulating the month and magnitude of the precipitation peak annual cycle. Additionally, the WRF model better represents the probability density distribution of annual and seasonal maximum precipitation compared to ERA5.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2023)
Article
Geosciences, Multidisciplinary
Zexuan Xu, Erica R. Siirila-Woodburn, Alan M. Rhoades, Daniel Feldman
Summary: This study utilizes meteorological data to simulate the processes of mountain hydrology, and through experiments, it is found that the variations in meteorological data have a greater impact on surface and subsurface hydrological processes than the variations in physics models.
HYDROLOGY AND EARTH SYSTEM SCIENCES
(2023)
Article
Water Resources
Benjamin J. Hatchett, Alan M. Rhoades, Daniel J. McEvoy
Summary: The research findings indicate that during a simulated severe drought in the 21st century, the snowpack in California's mountains significantly decreases and undergoes seasonality transitions, resulting in negative impacts on statewide water supply reliability. Furthermore, the study also predicts an increase in wildfire area in high elevation areas under drought conditions.
