A5076498687- Climate variability and models
- Arctic and Antarctic ice dynamics
- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Meteorological Phenomena and Simulations
- Climate change and permafrost
- Oceanographic and Atmospheric Processes
- Cryospheric studies and observations
- Ocean Acidification Effects and Responses
- Climate Change and Geoengineering
- Climate Change, Adaptation, Migration
- Atmospheric chemistry and aerosols
- Tropical and Extratropical Cyclones Research
- Methane Hydrates and Related Phenomena
- Arctic and Russian Policy Studies
- Geophysics and Gravity Measurements
- Planetary Science and Exploration
- Mosquito-borne diseases and control
- Viral Infections and Vectors
- Distributed and Parallel Computing Systems
- Spacecraft and Cryogenic Technologies
- Space exploration and regulation
- Space Science and Extraterrestrial Life
- Marine and coastal ecosystems
- Astro and Planetary Science
Colorado State University
2019-2025
University of Hawaii System
2022
Cooperative Institute for Research in Environmental Sciences
2015-2019
University of Colorado Boulder
2015-2019
NOAA Earth System Research Laboratory
2015-2018
Physical Sciences (United States)
2018
Climate and Global Dynamics Laboratory
2014-2018
NSF National Center for Atmospheric Research
2013-2018
Henan University of Economic and Law
2017
Henan Institute of Geological Survey
2017
Abstract The role of ocean–atmosphere coupling in the zonal-mean climate response to projected late twenty-first-century Arctic sea ice loss is investigated using Community Climate System Model version 4 (CCSM4) at 1° spatial resolution. Parallel experiments with different ocean model configurations (full-depth, slab, and no interactive ocean) allow roles dynamical thermodynamic feedbacks be isolated. In absence coupling, atmospheric confined north 30°N, consisting a weakening equatorward...
Abstract The emergence of rapid Arctic warming in recent decades has coincided with unusually cold winters over Northern Hemisphere continents. It been speculated that this “Warm Arctic, Cold Continents” trend pattern is due to sea ice loss. Here we use multiple models examine whether such a indeed forced by loss specifically and anthropogenic forcing general. While show much amplification surface result from loss, find neither nor overall yield trends toward colder continental temperatures....
Abstract The impact of projected Arctic sea ice loss on the atmospheric circulation is investigated using Whole Atmosphere Community Climate Model (WACCM), a model with well-resolved stratosphere. Two 160-yr simulations are conducted: one surface boundary conditions fixed at late twentieth-century values and other identical except for ice, which prescribed twenty-first-century values. Their difference isolates future upon atmosphere. tropospheric response to imposed resembles negative phase...
The role of transient Arctic sea ice loss in the projected greenhouse gas–induced late-twentieth- to late-twenty-first-century climate change is investigated using Geophysical Fluid Dynamics Laboratory’s Coupled Model version 3. Two sets simulations have been conducted, one with representative concentration pathway (RCP) 8.5 radiative forcing and second RCP but nudged its 1990 state. difference between two five-member indicates influence decreasing on system. Within Arctic, found be a...
The possibility that Arctic sea ice loss weakens mid-latitude westerlies, promoting more severe cold winters, has sparked than a decade of scientific debate, with apparent support from observations but inconclusive modelling evidence. Here we show sixteen models contributing to the Polar Amplification Model Intercomparison Project simulate weakening westerlies in response projected loss. We develop an emergent constraint based on eddy feedback, which is 1.2 3 times too weak models,...
Abstract The question of whether ocean coupling matters for the extratropical Northern Hemisphere atmospheric response to projected late 21st century Arctic sea ice loss is addressed using a series experiments with Community Climate System Model version 4 at 1° spatial resolution under different configurations model component: no interactive ocean, thermodynamic slab and full‐depth (dynamic plus thermodynamic) ocean. Ocean‐atmosphere magnifies but does not change its overall structure;...
Abstract In early January 2014, an Arctic air outbreak brought extreme cold and heavy snowfall to central eastern North America, causing widespread disruption monetary losses. The media extensively reported the snap, including debate on whether human-induced climate change was partly responsible. Related this, one particular hypothesis garnered considerable attention: that rapid sea ice loss may be increasing risk of extremes in midlatitudes. Here we use large ensembles model simulations...
Abstract The purpose of this study is to elucidate the individual and combined roles thermodynamic dynamic ocean–atmosphere coupling in equilibrium global climate response projected Arctic sea ice loss using a suite experiments conducted with Community Climate System Model, version 4, at 1° latitude–longitude spatial resolution. results highlight contrasting structures partially compensating effects coupling. In combination, produce pattern that largely symmetric about equator, whereas alone...
Stratospheric conditions are increasingly being recognized as an important driver of North Atlantic and Eurasian climate variability. Mindful that the observational record is relatively short, internal variability can be large, authors here analyze a new 10-member ensemble integrations stratosphere-resolving, atmospheric general circulation model, forced with observed evolution sea surface temperature (SST) during 1952–2003. Previous studies confirmed, showing El Niño enhance frequency...
Abstract Prediction systems to enable Earth system predictability research on the subseasonal time scale have been developed with Community System Model, version 2 (CESM2) using two configurations that differ in their atmospheric components. One uses Atmosphere 6 (CAM6) its top near 40 km, referred as CESM2(CAM6). The other employs Whole Climate (WACCM6) whose extends ∼140 and it includes fully interactive tropospheric stratospheric chemistry [CESM2(WACCM6)]. Both are utilized carry out...
Abstract Arctic sea ice has declined rapidly over the past four decades and climate models project a seasonally ice-free Ocean by middle of this century, with attendant consequences for regional climate. However, modeling studies lack consensus on how large-scale atmospheric circulation will respond to loss. In study, authors conduct series 200-member ensemble experiments Community Atmosphere Model version 6 (CAM6) isolate response future loss following Polar Amplification Intercomparison...
The decline in Arctic sea ice cover has been widely documented and it is clear that this change having profound impacts locally. An emerging highly uncertain area of scientific research, however, whether such a tangible effect on weather climate at lower latitudes. Of particular societal relevance the open question: will continued loss make mid-latitude more extreme? Here we analyse idealized atmospheric general circulation model simulations, using two independent models, both forced by...
Abstract Models project that Antarctic sea ice area will decline considerably by the end of this century, but consequences remain largely unexplored. Here, atmospheric response to future loss in is investigated, and contrasted Arctic case, using Community Earth Systems Model (CESM) Whole Atmosphere Coupled Climate (WACCM). Time-slice model runs with historic concentrations are compared concentrations, from late twenty-first each hemisphere separately. As for Arctic, results indicate act...
Abstract The role of ocean dynamics in the transient adjustment coupled climate system to an abrupt loss Arctic sea ice is investigated using experiments with Community Climate System Model version 4 two configurations: a thermodynamic slab mixed layer and full‐depth that includes both thermodynamics. Ocean produce distinct surface temperature warming maximum eastern equatorial Pacific, accompanied by equatorward intensification Intertropical Convergence Zone Hadley Circulation. These...
Abstract. It has been suggested that increased stratospheric sulfate aerosol loadings following large, low latitude volcanic eruptions can lead to wintertime warming over Eurasia through dynamical stratosphere–troposphere coupling. We here investigate the proposed connection in context of hypothetical future geoengineering Geoengineering Large Ensemble simulations. In those simulations, we find circulation anomalies resemble positive phase Northern Annular Mode winter are a distinguishing...
Abstract Observations show Arctic sea ice has declined and midlatitude storminess weakened during Northern Hemisphere (NH) summertime. It is currently unclear whether loss impacts summertime because most previous work focuses on other seasons. Here we quantify the impact of NH using equilibrium transient climate model simulations. The simulations mid‐to‐late 21st century weakens storminess, but only in presence ocean coupling. With coupling, equator‐to‐pole temperature atmospheric energy...
Abstract Although El Niño and global warming are both characterized by in the tropical upper troposphere, latitudinal changes of Hadley cell edge midlatitude eddy-driven jet opposite sign. Using an idealized dry atmospheric model, zonal mean circulation investigated with respect to different patterns warming. Generally speaking, equatorward shift takes place presence enhanced temperature gradient or narrow warming, similar associated events. In contrast, circulations expand poleward response...
The tropospheric response to sudden stratospheric warmings (SSWs) is analyzed in an idealized model setup regarding the respective roles of planetary‐scale and synoptic‐scale waves. control run includes a full interactive wave spectrum, while second waves but only time‐mean forcing from run. In both runs, characterized by negative phase annular mode. But given their different latitudinal structure, shows expected response, i.e., equatorward shift jet, whereas absence synoptic eddies poleward...
The effects of the tropical Pacific El Niño Southern Oscillation (ENSO) phenomenon are communicated to rest globe via atmospheric teleconnections. Traditionally, ENSO teleconnections have been viewed as tropospheric phenomena, propagating higher latitudes Rossby waves. Recent studies, however, suggest an influence stratosphere on extra-tropical is highly variable: in tropics, primary mode variability quasi-biennial oscillation (QBO), and extra-tropics sudden stratospheric warmings (SSWs)...
Abstract Key questions remain about the atmospheric response to variability in oceanic western boundary currents (WBCs). Here we exploit a unique high‐resolution slab‐ocean coupled climate model investigate how ocean heat transport (OHT) anomalies major WBCs of both hemispheres affect circulation. Prescribed OHT lead robust changes convective precipitation equatorward maximum surface warming. The is deepest and most pronounced over Northern Hemisphere (NH) WBCs, where it associated with...
Abstract This paper investigates the connection between delay in final breakdown of stratospheric polar vortex, warming (SFW), and Southern Hemisphere climate trends. The authors first analyze Interim European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-Interim) three model outputs with different forcings. Climate trends appear when there is a timing SFWs. When regressed onto SFW dates (which reflect anomaly delayed one standard deviation its onset dates), pattern...
Abstract Coupled ocean‐atmosphere models have been utilized to investigate the global climate response polar sea ice loss using different approaches constrain concentration and thickness. The goal of this study is compare two commonly used methods within a single model framework: albedo reduction, which energy conserving, ice‐flux nudging, not conserving. generate virtually identical equilibrium responses same seasonal cycle loss. However, while nudging able control state year‐round,...