To make statistical statements about differences in the characteristics of 100-year summers in current and pre-industrial summers we complemented the CESM2 large ensemble (LENS2) with rare-event sampling simulations maximizing summer mean temperatures from CESM2.
www.cesm.ucar.edu/community-pr...
www.cesm.ucar.edu/community-pr...
CESM2 Large Ensemble Community Project (LENS2) | Community Earth System Model
www.cesm.ucar.edu
August 17, 2026 at 1:20 PM
To make statistical statements about differences in the characteristics of 100-year summers in current and pre-industrial summers we complemented the CESM2 large ensemble (LENS2) with rare-event sampling simulations maximizing summer mean temperatures from CESM2.
www.cesm.ucar.edu/community-pr...
www.cesm.ucar.edu/community-pr...
Climate change is sparking deadlier wildfires from lightning strikes, threatening lives, air, and forests.
agupubs.onlinelibrary.wiley.com/doi/10.1029/...
agupubs.onlinelibrary.wiley.com/doi/10.1029/...
Projections of Lightning‐Ignited Wildfire Risk in the Western United States
Increases in cloud-to-ground lightning days are projected across the western U.S. in CESM2-LENS2, particularly in the interior Northwest Increases in lightning are driven by rises in moisture and...
agupubs.onlinelibrary.wiley.com
September 6, 2025 at 3:09 PM
Climate change is sparking deadlier wildfires from lightning strikes, threatening lives, air, and forests.
agupubs.onlinelibrary.wiley.com/doi/10.1029/...
agupubs.onlinelibrary.wiley.com/doi/10.1029/...
‼️ Finally out ‼️
esd.copernicus.org/articles/15/...
Our work exploring the impact of changes in shipping emissions on 2023 temperatures is now published on ESD. We used the CESM2 LENS and performed new simulations including changes in SOx, unlike the originals. Here are our findings 🧵
esd.copernicus.org/articles/15/...
Our work exploring the impact of changes in shipping emissions on 2023 temperatures is now published on ESD. We used the CESM2 LENS and performed new simulations including changes in SOx, unlike the originals. Here are our findings 🧵
Modeling 2020 regulatory changes in international shipping emissions helps explain anomalous 2023 warming
Abstract. The summer of 2023 saw an anomalous increase in temperatures even when considering the ongoing greenhouse-gas-driven warming trend. Here we demonstrate that regulatory changes to sulfate emi...
esd.copernicus.org
November 28, 2024 at 2:56 PM
‼️ Finally out ‼️
esd.copernicus.org/articles/15/...
Our work exploring the impact of changes in shipping emissions on 2023 temperatures is now published on ESD. We used the CESM2 LENS and performed new simulations including changes in SOx, unlike the originals. Here are our findings 🧵
esd.copernicus.org/articles/15/...
Our work exploring the impact of changes in shipping emissions on 2023 temperatures is now published on ESD. We used the CESM2 LENS and performed new simulations including changes in SOx, unlike the originals. Here are our findings 🧵
We also find that the observed historical increase in global hydroclimate whiplash is greater than predicted by a leading climate model large ensemble (CESM2-LE) for our present level of warming, though there is considerable uncertainty at regional scales. www.nature.com/artic...
January 11, 2025 at 12:18 AM
We also find that the observed historical increase in global hydroclimate whiplash is greater than predicted by a leading climate model large ensemble (CESM2-LE) for our present level of warming, though there is considerable uncertainty at regional scales. www.nature.com/artic...
Our group's #AGU24 presentations:
Mon: Yan-Ning Kuo - US-Southwest drought
Mon: Richard Zhuang - Freezing rain detection w/ ML
Tue: Ankur Dixit - CESM2 downscaled with WRF
Wed: Flavio Lehner - Colorado River drought
Thu: Hanjun Kim - Runoff sensitivity
Thu: Ankur Dixit - Heatwaves
See you there!
Mon: Yan-Ning Kuo - US-Southwest drought
Mon: Richard Zhuang - Freezing rain detection w/ ML
Tue: Ankur Dixit - CESM2 downscaled with WRF
Wed: Flavio Lehner - Colorado River drought
Thu: Hanjun Kim - Runoff sensitivity
Thu: Ankur Dixit - Heatwaves
See you there!
December 8, 2024 at 8:39 PM
Our group's #AGU24 presentations:
Mon: Yan-Ning Kuo - US-Southwest drought
Mon: Richard Zhuang - Freezing rain detection w/ ML
Tue: Ankur Dixit - CESM2 downscaled with WRF
Wed: Flavio Lehner - Colorado River drought
Thu: Hanjun Kim - Runoff sensitivity
Thu: Ankur Dixit - Heatwaves
See you there!
Mon: Yan-Ning Kuo - US-Southwest drought
Mon: Richard Zhuang - Freezing rain detection w/ ML
Tue: Ankur Dixit - CESM2 downscaled with WRF
Wed: Flavio Lehner - Colorado River drought
Thu: Hanjun Kim - Runoff sensitivity
Thu: Ankur Dixit - Heatwaves
See you there!
The risk of extreme water shortages due to climate change is predicted to affect 74% of drought-prone regions by 2100, according to research in Nature Communications. go.nature.com/42FpNDL ⚒️ 🧪
September 23, 2025 at 10:35 PM
The risk of extreme water shortages due to climate change is predicted to affect 74% of drought-prone regions by 2100, according to research in Nature Communications. go.nature.com/42FpNDL ⚒️ 🧪
Hydrology Paper of the Day @iopp-environment.bsky.social on how climate change affects the Sierra Nevada snowpack and irrigation in California: the need for regional-scale studies; application of the CESM2 model; logistic regression; and why rainfall may cause the mountains to be the Sierra Lluviosa
💧☀️ Read in #ERW how climate change impacts mountain snowpack and the implications this has for agricultural water security in California 🫗🌽
🔗https://iopscience.iop.org/article/10.1088/3033-4942/ade7aa
#Environment #Water #Agriculture #ClimateChange #Snow #Irrigation #Hydrology #WaterResources ⛲🌾
🔗https://iopscience.iop.org/article/10.1088/3033-4942/ade7aa
#Environment #Water #Agriculture #ClimateChange #Snow #Irrigation #Hydrology #WaterResources ⛲🌾
October 28, 2025 at 2:01 AM
Hydrology Paper of the Day @iopp-environment.bsky.social on how climate change affects the Sierra Nevada snowpack and irrigation in California: the need for regional-scale studies; application of the CESM2 model; logistic regression; and why rainfall may cause the mountains to be the Sierra Lluviosa
New paper on cloud feedbacks out! urldefense.com/v3/__https:/...
Should an enhanced East Pacific warming pattern manifest at equilibrium, our results suggest that CESM2’s high climate sensitivity may be realized.
Should an enhanced East Pacific warming pattern manifest at equilibrium, our results suggest that CESM2’s high climate sensitivity may be realized.
Cloud feedback overestimated in coupled CESM2 simulations relative to AMIP simulations and satellite observations: importance of the pattern effect and implications for climate sensitivity
Cloud feedback overestimated in coupled CESM2 simulations relative to AMIP simulations and satellite observations: importance of the pattern effect and implications for climate sensitivity, Raghuraman...
urldefense.com
April 24, 2026 at 3:39 PM
New paper on cloud feedbacks out! urldefense.com/v3/__https:/...
Should an enhanced East Pacific warming pattern manifest at equilibrium, our results suggest that CESM2’s high climate sensitivity may be realized.
Should an enhanced East Pacific warming pattern manifest at equilibrium, our results suggest that CESM2’s high climate sensitivity may be realized.
✅ We have a new study out this week, which projects changes in cloud-to-ground (CG) lightning days across the Western United States, along with the associated risk of lightning-ignited wildfires (LIW).
+ #OpenAccess Paper (@agu.org): doi.org/10.1029/2025...
+ Summary: news.wsu.edu/press-releas...
+ #OpenAccess Paper (@agu.org): doi.org/10.1029/2025...
+ Summary: news.wsu.edu/press-releas...
August 29, 2025 at 12:26 PM
✅ We have a new study out this week, which projects changes in cloud-to-ground (CG) lightning days across the Western United States, along with the associated risk of lightning-ignited wildfires (LIW).
+ #OpenAccess Paper (@agu.org): doi.org/10.1029/2025...
+ Summary: news.wsu.edu/press-releas...
+ #OpenAccess Paper (@agu.org): doi.org/10.1029/2025...
+ Summary: news.wsu.edu/press-releas...
Just published to wrap up the year: “Response of Tipping Elements to Different Strategies of Stratospheric Aerosol Injection”
We analyzed the response of various climate metrics relevant to a set of climate tipping element under SSP2-4.5 and under a set of SAI scenarios modeled using CESM2.
We analyzed the response of various climate metrics relevant to a set of climate tipping element under SSP2-4.5 and under a set of SAI scenarios modeled using CESM2.
December 2, 2025 at 2:50 PM
Just published to wrap up the year: “Response of Tipping Elements to Different Strategies of Stratospheric Aerosol Injection”
We analyzed the response of various climate metrics relevant to a set of climate tipping element under SSP2-4.5 and under a set of SAI scenarios modeled using CESM2.
We analyzed the response of various climate metrics relevant to a set of climate tipping element under SSP2-4.5 and under a set of SAI scenarios modeled using CESM2.
Our new paper with Mengyang Zhou, Elizabeth Yankovsky, and Dustin Carroll is out as a preprint: egusphere.copernicus.org/preprints/20... "Substantial inter-model variation in OAE efficiency between the CESM2/MARBL and ECCO-Darwin ocean biogeochemistry models"
September 4, 2025 at 4:47 PM
Our new paper with Mengyang Zhou, Elizabeth Yankovsky, and Dustin Carroll is out as a preprint: egusphere.copernicus.org/preprints/20... "Substantial inter-model variation in OAE efficiency between the CESM2/MARBL and ECCO-Darwin ocean biogeochemistry models"
I think the most interesting example of this was that when we updated the solar forcing files from CMIP7 in CESM2-WACCM6 we got a slightly lower climate sensitivity because some of the UV bands were just that slightly different enough that they affected ozone circulation->dynamics->sea ice…
May 22, 2026 at 3:51 PM
I think the most interesting example of this was that when we updated the solar forcing files from CMIP7 in CESM2-WACCM6 we got a slightly lower climate sensitivity because some of the UV bands were just that slightly different enough that they affected ozone circulation->dynamics->sea ice…
Using our new "hydroclimate whiplash" metric, which accounts for both precipitation & evaporative demand, we found that such whiplash has *already* (as of 2023) increased by 31–66% globally (depending on dataset)--& could more than double w/3°C of warming. www.nature.com/artic...
January 11, 2025 at 12:18 AM
Using our new "hydroclimate whiplash" metric, which accounts for both precipitation & evaporative demand, we found that such whiplash has *already* (as of 2023) increased by 31–66% globally (depending on dataset)--& could more than double w/3°C of warming. www.nature.com/artic...
We took a capacity expansion model that is trying to decarbonize the electricity sector over the coming decades (it expands solar/wind/hydro and reduces fossil fuels) and subjected it to different climate trajectories from the 100-member CESM2 Large Ensemble (CESM2-LE).
2/9
2/9
October 3, 2024 at 2:07 PM
We took a capacity expansion model that is trying to decarbonize the electricity sector over the coming decades (it expands solar/wind/hydro and reduces fossil fuels) and subjected it to different climate trajectories from the 100-member CESM2 Large Ensemble (CESM2-LE).
2/9
2/9
I really like below figure from @climateofgavin.bsky.social , so I made it with CESM2-LE (25,000 model years). Very similar result, i.e., observations are extreme but within the model range - for now. Triple La Niña ahead of El Niño has only a negligible influence on the story in this model.
September 12, 2024 at 3:15 AM
I really like below figure from @climateofgavin.bsky.social , so I made it with CESM2-LE (25,000 model years). Very similar result, i.e., observations are extreme but within the model range - for now. Triple La Niña ahead of El Niño has only a negligible influence on the story in this model.
Interesting new work out from UArizona colleague, Marcus Lofverstrom (& NCAR's J. Zhu), entitled "Tropical Precipitation Woes in the Community Earth System Model Version 2" showing that CESM2 (paleo-calibrated or otherwise) has bizarre hydroclimates!
agupubs.onlinelibrary.wiley.com/doi/epdf/10....
agupubs.onlinelibrary.wiley.com/doi/epdf/10....
Tropical Precipitation Woes in the Community Earth System Model Version 2
agupubs.onlinelibrary.wiley.com
November 1, 2023 at 6:16 AM
Interesting new work out from UArizona colleague, Marcus Lofverstrom (& NCAR's J. Zhu), entitled "Tropical Precipitation Woes in the Community Earth System Model Version 2" showing that CESM2 (paleo-calibrated or otherwise) has bizarre hydroclimates!
agupubs.onlinelibrary.wiley.com/doi/epdf/10....
agupubs.onlinelibrary.wiley.com/doi/epdf/10....
New paper on something near to my science heart – and still a bit of a blind spot in society:
*Including internal climate variability in risk assessment*
We use the CESM2 Large Ensemble to stress-test renewable energy in the Western U.S.
agupubs.onlinelibrary.wiley.com/doi/10.1029/...
🧵 1/9
*Including internal climate variability in risk assessment*
We use the CESM2 Large Ensemble to stress-test renewable energy in the Western U.S.
agupubs.onlinelibrary.wiley.com/doi/10.1029/...
🧵 1/9
Identifying Robust Decarbonization Pathways for the Western U.S. Electric Power System Under Deep Climate Uncertainty
We identify a decarbonization pathway for the power system that is robust to future climate realizations Our framework is extensible to long-term planning by utilities, regions, and regulators L...
doi.org
October 3, 2024 at 2:06 PM
New paper on something near to my science heart – and still a bit of a blind spot in society:
*Including internal climate variability in risk assessment*
We use the CESM2 Large Ensemble to stress-test renewable energy in the Western U.S.
agupubs.onlinelibrary.wiley.com/doi/10.1029/...
🧵 1/9
*Including internal climate variability in risk assessment*
We use the CESM2 Large Ensemble to stress-test renewable energy in the Western U.S.
agupubs.onlinelibrary.wiley.com/doi/10.1029/...
🧵 1/9
On the heels of the incredible southern U.S. snow event, here's a pair of new papers from Cornell undergrad(!) Haoyu "Richard" Zhuang (now grad student at UW) on a new machine learning-based precipitation typing algorithm.
Methods: tinyurl.com/y3rsphvt
Application to CESM2-LE: tinyurl.com/ykr8w4yr
Methods: tinyurl.com/y3rsphvt
Application to CESM2-LE: tinyurl.com/ykr8w4yr
January 22, 2025 at 9:42 PM
On the heels of the incredible southern U.S. snow event, here's a pair of new papers from Cornell undergrad(!) Haoyu "Richard" Zhuang (now grad student at UW) on a new machine learning-based precipitation typing algorithm.
Methods: tinyurl.com/y3rsphvt
Application to CESM2-LE: tinyurl.com/ykr8w4yr
Methods: tinyurl.com/y3rsphvt
Application to CESM2-LE: tinyurl.com/ykr8w4yr
Don’t have them handy unfortunately, but see if this works? chatgpt.com/share/68c83b...
ChatGPT - CESM2 MPI temperature timeseries
A conversational AI system that listens, learns, and challenges
chatgpt.com
September 15, 2025 at 4:16 PM
Don’t have them handy unfortunately, but see if this works? chatgpt.com/share/68c83b...
New data set alert!
TAMU @tamu_atmo MESACLIP (formerly iHESP) data is available on AWS. This is a 500-year pre-industrial control run of high-resolution version of CESM2, with 25-km land and 10-km ocean resolution.
This is an unprecedented model run.
registry.opendata.aw...
TAMU @tamu_atmo MESACLIP (formerly iHESP) data is available on AWS. This is a 500-year pre-industrial control run of high-resolution version of CESM2, with 25-km land and 10-km ocean resolution.
This is an unprecedented model run.
registry.opendata.aw...
July 10, 2024 at 9:29 PM
New data set alert!
TAMU @tamu_atmo MESACLIP (formerly iHESP) data is available on AWS. This is a 500-year pre-industrial control run of high-resolution version of CESM2, with 25-km land and 10-km ocean resolution.
This is an unprecedented model run.
registry.opendata.aw...
TAMU @tamu_atmo MESACLIP (formerly iHESP) data is available on AWS. This is a 500-year pre-industrial control run of high-resolution version of CESM2, with 25-km land and 10-km ocean resolution.
This is an unprecedented model run.
registry.opendata.aw...
The Skeie et al study looks at five different climate models (CESM2, two versions of NASA GISS ModelE, NorESM2, and OsloCTM3), with two different runs of each (sans OsloCTM3). They just calculate effective radiative forcing, but not temperature response: egusphere.copernicus.org/preprints/20...
June 5, 2024 at 5:28 PM
The Skeie et al study looks at five different climate models (CESM2, two versions of NASA GISS ModelE, NorESM2, and OsloCTM3), with two different runs of each (sans OsloCTM3). They just calculate effective radiative forcing, but not temperature response: egusphere.copernicus.org/preprints/20...
Mao, Zhang, Li, Amaya, Yeager, Zhao: Precursors, Pathways, and State-Dependent Reliability of Long-range ENSO Prediction in the CESM2 Seasonal-to-Multiyear Large Ensemble https://arxiv.org/abs/2609.25706 https://arxiv.org/pdf/2609.25706 https://arxiv.org/html/2609.25706
September 23, 2026 at 6:56 AM
Mao, Zhang, Li, Amaya, Yeager, Zhao: Precursors, Pathways, and State-Dependent Reliability of Long-range ENSO Prediction in the CESM2 Seasonal-to-Multiyear Large Ensemble https://arxiv.org/abs/2609.25706 https://arxiv.org/pdf/2609.25706 https://arxiv.org/html/2609.25706
For these analyses we used, amongst other things, the CESM2 Large Ensemble, produced at NCAR (an NSF facility) by amazing colleagues that always make amazing science available to all. This is what NSF makes possible!
February 6, 2025 at 1:32 PM
For these analyses we used, amongst other things, the CESM2 Large Ensemble, produced at NCAR (an NSF facility) by amazing colleagues that always make amazing science available to all. This is what NSF makes possible!
[7/8] L’étude estime que 753 millions de personnes seront exposées, dont 467 millions en zones urbaines. La Méditerranée concentre à elle seule près de 200 millions d’urbains à risque, tandis que l’Afrique et l’Asie voient surtout leurs campagnes menacées. #geography #water #climate #Anthropocene
September 27, 2025 at 6:30 AM
[7/8] L’étude estime que 753 millions de personnes seront exposées, dont 467 millions en zones urbaines. La Méditerranée concentre à elle seule près de 200 millions d’urbains à risque, tandis que l’Afrique et l’Asie voient surtout leurs campagnes menacées. #geography #water #climate #Anthropocene
Hey Bluesky hivemind, climate modelling data question. Does anyone know where I could find CESM2 and MPI large ensemble annual global mean surface temperature timeseries?
September 15, 2025 at 9:14 AM
Hey Bluesky hivemind, climate modelling data question. Does anyone know where I could find CESM2 and MPI large ensemble annual global mean surface temperature timeseries?