A5068307150- Climate variability and models
- Oceanographic and Atmospheric Processes
- Meteorological Phenomena and Simulations
- Arctic and Antarctic ice dynamics
- Atmospheric and Environmental Gas Dynamics
- Tropical and Extratropical Cyclones Research
- Atmospheric Ozone and Climate
- Geophysics and Gravity Measurements
- Methane Hydrates and Related Phenomena
- Cryospheric studies and observations
- Climate change and permafrost
- Marine and coastal ecosystems
- Ocean Waves and Remote Sensing
- Geology and Paleoclimatology Research
- Ionosphere and magnetosphere dynamics
- Geological Studies and Exploration
- Ocean Acidification Effects and Responses
- Geological and Geophysical Studies
- Precipitation Measurement and Analysis
- Geomagnetism and Paleomagnetism Studies
- Solar and Space Plasma Dynamics
- Natural Language Processing Techniques
- Computational Physics and Python Applications
- Scientific Computing and Data Management
- Seismology and Earthquake Studies
University of California, Irvine
2016-2025
Irvine University
2018-2025
John Wiley & Sons (United States)
2019
Charles River Laboratories (Netherlands)
2019
University of California System
2005-2018
University of California, Los Angeles
2018
Research Center for Environmental Changes, Academia Sinica
2009
UC Irvine Health
2007
NSF National Center for Atmospheric Research
1999
University of Cambridge
1996
Geostationary satellites have provided routine, high temporal resolution Earth observations since the 1970s. Despite long period of record, use these data in climate studies has been limited for numerous reasons, among them that no central archive geostationary all international exists, full and spatial are voluminous, diverse calibration navigation formats encumber uniform processing needed multisatellite studies. The International Satellite Cloud Climatology Project (ISCCP) set stage...
Abstract. The Atmospheric River Tracking Method Intercomparison Project (ARTMIP) is an international collaborative effort to understand and quantify the uncertainties in atmospheric river (AR) science based on detection algorithm alone. Currently, there are many AR identification tracking algorithms literature with a wide range of techniques conclusions. ARTMIP strives provide community information different methodologies guidance most appropriate for given question or region interest. All...
Abstract The wintertime Northern Hemisphere (NH) atmospheric circulation response to current (2007–12) and projected (2080–99) Arctic sea ice decline is examined with the latest version of Community Atmospheric Model (CAM5). numerical experiments suggest that conditions force a remote in late winter favors cold land surface temperatures over midlatitudes, as has been observed recent years. Anomalous Rossby waves forced by anomalies penetrate into stratosphere February weaken stratospheric...
Abstract Atmospheric rivers (ARs) are now widely known for their association with high‐impact weather events and long‐term water supply in many regions. Researchers within the scientific community have developed numerous methods to identify track of ARs—a necessary step analyses on gridded data sets, objective attribution impacts ARs. These different been answer specific research questions hence use criteria (e.g., geometry, threshold values key variables, time dependence). Furthermore,...
The North Atlantic sea surface temperature exhibits fluctuations on the multidecadal time scale, a phenomenon known as Multidecadal Oscillation (AMO). This letter demonstrates that of wintertime (NAO) are tied to AMO, with an opposite-signed relationship between polarities AMO and NAO. Our statistical analyses suggest signal precedes NAO by 10–15 years interesting predictability window for decadal forecasting. footprint is also detected in variability intraseasonal weather regimes sector....
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,...
The wintertime atmospheric circulation responses to observed patterns of North Atlantic sea surface temperature and ice cover trends in recent decades are studied by means experiments with an general model. Here the relationship between forced dominant pattern internally generated variability is focused on. total response partioned into a portion that projects onto leading mode internal (the indirect response) residual from projection direct response). This empirical decomposition yields...
Observed multidecadal trends in extratropical atmospheric flow, such as the positive trend North Atlantic Oscillation (NAO) index, may be attributable to a number of causes. This study addresses question whether caused by observed oceanic boundary forcing. Experiments were carried out using NCAR general circulation model with specified sea surface temperature (SST) and ice anomalies confined sector. The spatial pattern anomalous forcing was chosen realistic that it corresponds recent 40-yr...
Polar regions have great sensitivity to climate forcing; however, understanding of the physical processes coupling atmosphere and ocean in these is relatively poor. Improving our knowledge high-latitude surface fluxes will require close collaboration among meteorologists, oceanographers, ice physicists, climatologists, between observationalists modelers, as well new combinations situ measurements satellite remote sensing. This article describes deficiencies current state about air–sea high...
Abstract Objective analysis of several hundred thousand anticyclonic and cyclonic breaking Rossby waves is performed for the Northern Hemisphere (NH) winters 1958–2006. A winter climatology both wave (RWB) frequency size (zonal extent) presented 350-K isentropic surface over NH, spatial distribution RWB shown to agree with theoretical ideas in shear flow. Composites two types reveal their characteristic sea level pressure anomalies, upper- lower-tropospheric velocity fields, forcing...
Abstract A large-scale analysis of landfalling atmospheric rivers (ARs) along the west coast North America and their association with upper-tropospheric flow is performed for extended winter (November–March) years 1979–2011 using Modern-Era Retrospective Analysis Research Applications (MERRA) reanalysis data. The climatology, relationship to El Niño–Southern Oscillation Madden–Julian oscillation, upper-level characteristics approximately 750 ARs are presented based on 85th percentile peak...
Abstract Landfalling atmospheric rivers over the North Pacific are evaluated in historical (1980–2005) simulations from 28 models participating fifth phase of Coupled Model Intercomparison Project (CMIP5) and compared to Modern‐Era Retrospective Analysis for Research Applications ERA‐Interim reanalyses. dates identified as having spatially elongated high wind moisture features physical proximity coastline. performance relative reanalysis is found be quite variable. The majority can resolve...
Abstract Because of limited high-quality satellite and in situ observations, less attention has been given to the trends Arctic sea ice thickness therefore volume than extent. This study evaluates spatial temporal variability using Pan-Arctic Ice Ocean Modeling Assimilation System (PIOMAS). Additionally, Community Earth Model Large Ensemble Project (LENS) is used quantify forced response internal model. A dipole pattern shown both PIOMAS LENS with opposite signs polarity between East...
Abstract The effect of future Arctic amplification (AA) on the extratropical atmospheric circulation remains unclear in modeling studies. Using a collection coordinated and coupled global climate model perturbation experiments, we find an emergent relationship between high‐latitude 1,000–500 hPa thickness response enhancement Siberian High winter. This wave number‐1‐like sea level pressure anomaly pattern is linked to equatorward shift eddy‐driven jet dynamical cooling eastern Asia....
Abstract This study presents results from the Polar Amplification Multimodel Intercomparison Project (PAMIP) single-year time-slice experiments that aim to isolate atmospheric response Arctic sea ice loss at global warming levels of +2°C. Using two general circulation models (GCMs), ensemble size is increased up 300 members, beyond recommended 100 members. After partitioning in groups reproducibility evaluated, with a focus on midlatitude jet streams North Atlantic and Pacific. Both...
Abstract Ural blocking (UB) is a prominent mode of variability the Northern Hemisphere atmospheric circulation, particularly in fall. It can persist for several days and exert lagged influence on wintertime NH providing predictability at subseasonal time scale. Using two models, we explore how early winter circulation responds to 2‐week persistent UB anomaly imposed November. Experiments are carried out with different configurations Barents‐Kara (BK) sea‐ice concentration examine whether it...
Abstract Feedback between the North Atlantic Oscillation (NAO) and winter sea ice variability is detected quantified using approximately 30 years of observations, a vector autoregressive model (VAR), testable definitions Granger causality feedback. Sea based on leading empirical orthogonal function concentration over [the Greenland dipole (GSD)], which, in its positive polarity, has anomalously high concentrations Labrador region to southwest low Barents northeast Greenland. In weekly data...
Abstract This study examines the relationship between Atlantic Multidecadal Variability (AMV) and wintertime atmospheric circulation of North in simulations fifth Coupled Model Intercomparison Project (CMIP5). Comparisons internal (using preindustrial control simulations) externally forced historical Representative Concentration Pathways 8.5 simulated AMV with observations suggest that CMIP5 models lack internally generated AMV, except for two (GFDL‐ESM2G HadGEM2‐ES). A long‐term influence...
Abstract The ITCZ in the central and eastern Pacific on synoptic time scales is highly dynamic. active season extends roughly from May through October. During season, continuously breaks down re-forms, produces a series of tropical disturbances. life span varies several days to 3 weeks. Sixty-five cases breakdown have been visually identified over five seasons (1999–2003) three independent datasets. can be triggered by two mechanisms: 1) interaction with westward-propagating disturbances...
Abstract Projected changes in the midlatitude atmospheric circulation at end of twenty-first century are investigated using coupled ocean–atmosphere simulations from Community Earth System Model Large Ensemble (CESM-LENS). Different metrics used to describe response dynamics 40 ensemble members covering 1920–2100 period. Contrasted responses identified depending on season and longitudinal sector that considered. In winter, a slowdown zonal flow an increase waviness is found over North...
Abstract Recent modeling studies have shown an important role for stratosphere‐troposphere coupling in the large‐scale atmospheric response to Arctic sea ice loss. Evidence is growing that Quasi‐biennial Oscillation (QBO) can contribute or even mitigate teleconnections from surface forcing. Here, influence of QBO phase on projected loss examined using general circulation model with a well‐resolved stratosphere and prescribed observations. The determined by compositing seasons easterly...
Abstract With warm sea surface temperature (SST) anomalies in the tropical Atlantic and cold SST east Pacific, unusually quiet hurricane season 2013 was a surprise to community. The authors’ analyses suggest that substantially suppressed cyclone (TC) activity August can be attributed frequent breaking of midlatitude Rossby waves, which led equatorward intrusion dry extratropical air. resultant mid- upper-tropospheric dryness strong vertical wind shear hindered TC development. Using empirical...
The future response of the atmospheric circulation to increased anthropogenic forcing is uncertain, in particular due competing influences large projected warming at surface Arctic, and upper-levels tropics. In present study two ensembles fully-coupled 21st century climate simulations are used analyze changes wintertime eddy-driven jet North Atlantic relation well-defined thermal signatures change. models project a robust reinforcement decrease waviness blockings, that we attribute narrowing...