About

Professor Michael J Prather is associated with the UCI Research Group, where his research interests include tracer environment and related scientific investigations. The group has a history dating back to 1969 and is involved in various research activities and publications. The group also includes members and collaborators from diverse institutions, reflecting a broad engagement in environmental and atmospheric sciences. Specific details about his educational background, career milestones, or individual research projects are not provided in the page text.

Research topics

• Atmospheric sciences
• Climatology
• Environmental science
• Meteorology
• Geography
• Geology
• Chemistry
• Oceanography
• Ecology
• Physics

Selected publications

• E3SMv1 branch used for the GMD submission

  Zenodo (CERN European Organization for Nuclear Research) · 2026-04-24

  otherOpen access

  This is an archive branches of E3SMv1 used for the GMD submission. These two branches are modified versions of the original E3SMv1 (Golaz et al., 2019, 10.1029/2018ms001603) model with chemUCI (branch tangq/atm/UCI-chem_Jan2021, last access: 2026/03/20) and trop_strat_mozart (branch tangq/atm/trop_strat_mam4_resus_mom, last access:2026/03/20). The input files for these two branches are standard E3SMv1 input files.

  PublisherDOI

• Perspectives on IPCC assessment of SLCF role in climate

  npj Clean Air · 2026-01-14 · 1 citations

  articleOpen accessSenior author

  From our experience in the 6th Intergovernmental Panel on Climate Change assessment report (AR6), we found difficulties in communicating clear messages to policymakers due to the intricacies inherent to Short Lived Climate Forcers (SLCFs). Here, we highlight some of the limitations in knowledge or methodologies that restricted this assessment, and identify challenges for the upcoming 7th cycle if it is to adequately distill the knowledge on SLCFs relevant to climate actions.

  PublisherOA PDFDOI

• Data from: Projecting nitrous oxide over the 21^st century, uncertainty related to stratospheric loss

  Open MIND · 2026-01-01

  dataset1st authorCorresponding

  This data set includes the analysis and graphical data in the PNAS publication entitled "Projecting nitrous oxide over the 21st century, uncertainty related to stratospheric loss". The data is in the form of column vectors of various derived products involving N2O, NOy, O3, and QBO indices that are plotted in the paper. The abscissa can be year, month, or lag time (months). The data is provided in an Excel spreadsheet with tabs for each figure. The data is available for open use, and there are no ethical or legal considerations related to its use in subsequent research. The abstract and significance statement of the publication follow. Abstract. Extending the N2O lifetime derived from Microwave Limb Sounder satellite observations, we find a mean value of 117 yr and a likely decrease of –1.4 ± 0.9 % per decade over the period 2004-2024. This trend is consistent with the previously published 2004-2021 value of –2.1 ± 1.2 % per decade. A more careful analysis of uncertainty now provides a more robust likely (one-sigma) range. From analyses of a range of factors controlling the N2O lifetime, we find that the decrease in lifetime can be explained by recent changes in stratospheric circulation and temperature. Projection of the lifetime change to 2100 shows that this effect is comparable to differences across the shared socioeconomic pathways used for climate projections and cannot be ignored. An updated evaluation of the N2O chemical feedbacks shows that this effect produces a relatively small shift in atmospheric abundance over the 21st century, but still an important shift, –11%, in the global warming potential of N2O. Significance. Projecting atmospheric nitrous oxide (N2O) abundance is critical for climate and ozone assessments. Research has focused on projecting the changing emissions of N2O from direct anthropogenic sources, the dominant cause of the recent growth. Earth system models are now projecting natural sources perturbed by climate change. There has been little effort to understand how climate and compositional changes may change the stratospheric sink of N2O, which balances all these sources and also controls the atmospheric abundance. Here, we review recent observational and modeling evidence for an increase in the sink caused by decreasing N2O lifetime and show that it introduces uncertainties comparable to shifts across the different shared socioeconomic pathway (SSP) scenarios used in current assessments.

  DOI

• Comment on egusphere-2025-6012

  2026-01-23

  peer-reviewOpen accessSenior author

  <strong class="journal-contentHeaderColor">Abstract.</strong> We calculate the global change in the production of tropospheric ozone (O₃) and loss of methane (CH₄) caused by 45 days of summertime South Korean anthropogenic emissions during the Korea-US Air Quality (KORUS-AQ) mission. Our modelling system consists of three stages: the boundary layer-residual layer (BL-RL) stage processes the emissions, photochemistry, deposition, aerosol reactivity, and transport over terrestrial South Korea at 0.1&deg; x 0.1&deg; with hourly resolution. The plume (PL) stage continues to integrate the chemistry of air masses from the BL-RL stage as they are transported offshore, simulating offshore pollution plumes observed by aircraft. After three days of chemical aging in non-diluting plumes, the pollution remnants are dispersed (DP stage) into the background atmosphere and integrated until the pollution disappears. Net O₃ production is diagnosed in each stage using the integrated ozone change and our calculated perturbation lifetimes. In total, these 45 days of South Korean emissions create an excess CH₄ sink of 4.3 Gmol and a net O₃ source of 31.2 Gmol. Scaling these values to annual global emissions suggests around 10 % of CH₄ loss and 30 % of net O₃ production is attributable to anthropogenic air pollution, but our Korean summertime case may exaggerate the proportions. Reducing plume aging time to 2 days increases these terms by about 10 %, and immediate dispersion (no plume aging) more than doubles them. Our model supports the typical result that rapid dispersion of pollution, <em>e.g. </em>through coarse resolution, overestimates its impact on tropospheric O₃ and CH₄.

  PublisherDOI

• The Energy Exascale Earth System Model Version 3: 2. Overview of the Coupled System

  Journal of Advances in Modeling Earth Systems · 2026-04-01

  articleOpen access

  Abstract The Energy Exascale Earth System Model version 3 (E3SMv3) represents the latest advancement in Earth system modeling developed by the U.S. Department of Energy (DOE). Building upon previous versions, E3SMv3 introduces significant updates across its coupled components to enhance capability and improve fidelity. The atmosphere component incorporates advancements in chemistry, aerosol‐cloud interactions, convection, and microphysics. The ocean features a new time‐stepping scheme and a higher‐resolution unstructured mesh with sub‐ice‐shelf cavities, while the sea ice model integrates advanced snow and ice physics for more realistic cryospheric simulations. The land model introduces prognostic vegetation dynamics and a new sub‐grid topographic treatment of solar radiation. A new tri‐grid configuration harmonizes the horizontal grids of the land and river components for improved process coupling. It is enabled by a new non‐linear remapping between the atmosphere and land. E3SMv3 underwent extensive testing through a comprehensive simulation campaign, including pre‐industrial control, idealized experiments, and historical simulations spanning 1850–2024. The model demonstrates significant improvements in simulating the evolution of the historical surface temperature, particularly addressing the “pothole cooling” bias in earlier versions. Reduced aerosol‐related forcing contributes to more realistic radiative forcing and better alignment with the observational record. Ocean heat content (OHC) and sea ice trends are also improved as a result.

  PublisherDOI

• E3SMv1 branch used for the GMD submission

  Zenodo (CERN European Organization for Nuclear Research) · 2026-04-24

  otherOpen access

  This is an archive branches of E3SMv1 used for the GMD submission. These two branches are modified versions of the original E3SMv1 (Golaz et al., 2019, 10.1029/2018ms001603) model with chemUCI (branch tangq/atm/UCI-chem_Jan2021, last access: 2026/03/20) and trop_strat_mozart (branch tangq/atm/trop_strat_mam4_resus_mom, last access:2026/03/20). The input files for these two branches are standard E3SMv1 input files.

  PublisherDOI

• The Energy Exascale Earth System Model Version 3. Part I: Overview of the Atmospheric Component

  2025-04-13 · 9 citations

  preprintOpen access

  This paper describes the atmospheric component of the U.S. Department of Energy’s Energy Exascale Earth System Model (E3SM) version 3. Significant updates have been made to the atmospheric physics compared to earlier versions. Specifically, interactive gas chemistry has been implemented, along with improved representations of aerosols and dust emissions. A new stratiform cloud microphysics scheme more physically treats ice processes and aerosol-cloud interactions. The deep convection parameterization has been largely improved with sophisticated microphysics for convective clouds, making model convection sensitive to large-scale dynamics, and incorporating the dynamical and physical effects of organized mesoscale convection. Improvements in aerosol wet removal processes and parameter re-tuning of key aerosol and cloud processes have improved model aerosol radiative forcing. The model’s vertical resolution has increased from 72 to 80 layers with the extra 8 layers added in the lower stratosphere to better simulate the Quasi-Biennial Oscillation (QBO). These improvements have enhanced E3SM’s capability to couple aerosol, chemistry, and biogeochemistry and reduced some long-standing biases in simulating tropical variability. Compared to its predecessors, the model shows a much stronger signal for the Madden-Julian Oscillation, Kelvin waves, mixed Rossby-gravity waves, and eastward inertia-gravity waves. Aerosol radiative forcing has been considerably reduced and is now better aligned with community best estimates, leading to significantly improved skill in simulating historical temperature records. Its simulated mean-state climate is largely comparable to E3SMv2, but with some notable degradation in shortwave cloud radiative effect, precipitable water, and surface wind stress, which will be addressed in future updates.

  PublisherOA PDFDOI

• The Energy Exascale Earth System Model version 3. Part II: Overview of the coupled system

  2025-06-26 · 7 citations

  preprintOpen access

  The Energy Exascale Earth System Model version 3 (E3SMv3) represents the latest advancement in Earth system modeling developed by the U.S. Department of Energy (DOE) to address critical scientific questions related to the Earth system and energy. Building upon previous versions, E3SMv3 introduces significant updates across its coupled components to enhance capability and improve fidelity. The atmosphere component incorporates advancements in chemistry, aerosol-cloud interactions, convection, and microphysics. The ocean features a new time-stepping scheme and a higher-resolution unstructured mesh with sub-ice-shelf cavities, while the sea ice model integrates advanced snow and ice physics for more realistic cryospheric simulations. The land model introduces prognostic vegetation dynamics and a new sub-grid topographic treatment of solar radiation. A new tri-grid configuration harmonizes the horizontal grids of the land and river components for improved process coupling. It is enabled by a new non-linear remapping between the atmosphere and land. E3SMv3 underwent extensive testing through a comprehensive simulation campaign, including pre-industrial control, idealized CO$_2$ experiments, and historical simulations spanning 1850–2024. The model demonstrates significant improvements in simulating the evolution of the historical surface temperature, particularly addressing the “pothole cooling” bias in earlier versions. Reduced aerosol-related forcing contributes to more realistic radiative forcing and better alignment with the observational record. Ocean heat content and sea ice trends are also improved as a result.

  PublisherOA PDFDOI

• Implementation of solar UV and energetic particle precipitation within the LINOZ scheme in ICON-ART

  Geoscientific model development · 2025-10-27 · 1 citations

  articleOpen accessSenior author

  Abstract. We extended the Linearized ozone scheme – LINOZ in the ICON (ICOsahedral Nonhydrostatic) – ART (the extension for Aerosols and Reactive Trace gases) model system to include NOy formed by auroral and medium-energy electrons in the upper mesosphere and lower thermosphere, and the corresponding ozone loss, as well as changes in the rate of ozone formation due to the variability of the solar radiation in the ultraviolet wavelength range. This extension allows us to realistically represent variable solar and geomagnetic forcing in the middle atmosphere using a very simple ozone scheme. The LINOZ scheme is computationally very cheap compared to a full middle atmosphere chemistry scheme, yet provides realistic ozone fields consistent with the stratospheric circulation and temperatures, and can thus be used in climate models instead of prescribed ozone climatologies. To include the reactive nitrogen (NOy) produced by auroral and radiation belt electron precipitation in the upper mesosphere and lower thermosphere during polar winter, the so-called energetic particle precipitation indirect effect, an upper boundary condition for NOy has been implemented into the simplified parameterization scheme of the N2O/NOy reactions. This parameterization, which uses the geomagnetic Ap index, is also recommended for chemistry-climate models in the CMIP6 experiments. With this extension, the model simulates realistic “tongues” of NOy propagating downward in polar witner from the model top in the upper mesosphere into the mid-stratosphere with an amplitude that is modulated by geomagnetic activity. We then expanded the simplified ozone description used in the model by applying LINOZ version 3. The additional ozone tendency from NOy is included by applying the corresponding terms of the version 3 of LINOZ. This NOy, coupled as an additional term in the linearized ozone chemistry, led to significant ozone losses in the polar upper stratosphere in both hemispheres which is qualitatively in good agreement with ozone observations and model simulations with EPP-NOy and full stratospheric chemistry. In a subsequent step, the tabulated coefficients forming the basis of the LINOZ scheme were provided separately for solar maximum and solar minimum conditions. These coefficients were then interpolated to ICON-ART using the F10.7 index as a proxy for daily solar spectra (UV) variability to account for solar UV forcing. This solar UV forcing in the model led to changes in ozone in the tropical and mid-latitude stratosphere consistent with observed solar signals in stratospheric ozone.

  PublisherOA PDFDOI

• Opinion: The role of AerChemMIP in advancing climate and air quality research

  Atmospheric chemistry and physics · 2025-07-31 · 7 citations

  articleOpen accessCorresponding

  Abstract. The Aerosol Chemistry Model Intercomparison Project (AerChemMIP) was endorsed by the Coupled Model Intercomparison Project 6 (CMIP6) and was designed to quantify the climate and air quality impacts of aerosols and chemically reactive gases. AerChemMIP provided the first consistent calculation of effective radiative forcing (ERF) for a wide range of forcing agents, which was a vital contribution to the Sixth Assessment Report (AR6) of the Intergovernmental Panel on Climate Change. It supported the quantification of composition–climate feedback parameters and the climate response to short-lived climate forcers (SLCFs), as well as enabled the future impacts of air pollution mitigation to be identified, and the study of interactions between climate and air quality in a transient simulations. Here we review AerChemMIP in detail and assess the project against its stated objectives, its contribution to the CMIP6 project, and the wider scientific efforts designed to understand the role of aerosols and chemistry in the Earth system. We assess the successes of the project and the remaining challenges and gaps. We conclude with some recommendations that we hope will provide input to planning for future MIPs in this area. In particular, we highlight the necessity of sufficient ensemble size for the attribution of regional climate responses and the need for coordination across projects to ensure key science questions are addressed. Summary data for CMIP6 and AerChemMIP models such as model components, model configurations, and emergent quantities are included.

  PublisherOA PDFDOI

Recent grants

• Relational Metrics to Evaluate Chemistry-Transport and Chemistry-Climate Models

  NSF · $616k · 2022–2027

• Global Atmospheric Chemistry: Uncertainties and Errors; Modes and Parametric Models

  NSF · $666k · 2006–2010

Frequent coauthors

• Philip J. Rasch

  Pacific Northwest National Laboratory

  87 shared

• Peter S. Connell

  87 shared

• A. R. Douglass

  Goddard Space Flight Center

  87 shared

• D. Rotman

  Lawrence Livermore National Laboratory

  86 shared

• Arlene M. Fiore

  Massachusetts Institute of Technology

  86 shared

• J. M. Rodríguez

  Goddard Space Flight Center

  84 shared

• Darryn W. Waugh

  Planetary Science Institute

  83 shared

• D. E. Kinnison

  NSF National Center for Atmospheric Research

  83 shared

Labs

• Prather GroupPI

  Not provided

Education

• B.A., Mathematics

  Yale

  1969

• B.S., Physics

  Merton College, Oxford

  1971

• Ph.D., Astronomy and Astrophysics

  Yale

  1976

Awards & honors

• UCI Lauds & Laurels Faculty Award 2008
• Fellow of the AGU (1997)
• Fellow of AAAS (2004)
• Vilhelm Bjerknes Medal (EGU, 2020)
• Member of the Norwegian Academy of Science and Letters