Enhanced Simulation of Atmospheric Blocking in a High‐Resolution Earth System Model: Projected Changes and Implications for Extreme Weather Events

Journal of Geophysical Research Atmospheres, Год журнала: 2025, Номер 130(3)

Опубликована: Фев. 1, 2025

Abstract Atmospheric blocking is closely linked to the occurrence of extreme weather events. However, low‐resolution Earth system models often underestimate frequency blocking, undermining confidence in future projections. In this study, we use high‐resolution Community System Model (CESM‐HR; 25 km atm and 10 ocean) show that CESM‐HR reduces biases atmospheric for both winter summer, particularly events lasting longer than days. This improvement partly due reduced sea surface temperature at higher resolution. Additionally, applying a bias correction 500 hPa geopotential height further enhances simulations, highlighting crucial role mean state. Under Representative Concentration Pathway 8.5 scenario, projects decrease wintertime over regions such as Euro‐Atlantic Chukchi‐Alaska, consistent with previous studies. contrast, summer expected become more frequent persistent, driven by weakened zonal winds. The center shifts from historical locations Scandinavia eastern Russia central Eurasia, significantly increasing Ural region. Summer Scandinavia‐Ural region may eventually surpass Euro‐Atlantic. increase could exacerbate heatwaves warming climate, making severe heatwaves, like those observed recently, common future.

Язык: Английский

---

Impact of Pacific blocking on the intraseasonal winter sea ice seesaw between the Bering and Okhotsk Seas

Atmospheric Research, Год журнала: 2024, Номер 300, С. 107227 - 107227

Опубликована: Янв. 6, 2024

Язык: Английский

---

No detectable trend in mid-latitude cold extremes during the recent period of Arctic amplification

Communications Earth & Environment, Год журнала: 2023, Номер 4(1)

Опубликована: Сен. 28, 2023

Abstract It is widely accepted that Arctic amplification—accelerated warming—will increasingly moderate cold air outbreaks to the mid-latitudes. Yet, an increasing number of recent studies also argue amplification can contribute more severe winter weather. Here we show temperature extremes across United States east Rockies, Northeast Asia and Europe have remained nearly constant over decades, in clear contrast a robust warming trend. Analysis trends frequency magnitude mixed US but with clearer decreasing trend occurrence Europe, especially Southern Europe. This divergence between no detectable mid-latitude highlights need for better understanding physical links extremes.

Язык: Английский

---

Arctic amplification‐induced intensification of planetary wave modulational instability: A simplified theory of enhanced large‐scale waviness

Quarterly Journal of the Royal Meteorological Society, Год журнала: 2024, Номер 150(762), С. 2888 - 2905

Опубликована: Май 8, 2024

Abstract In the mid–high latitude atmosphere, instability of planetary waves characterizes enhanced wave activity or amplified large‐scale waviness leading to increased regional weather extremes. this paper, a nonlinear Schrödinger equation is derived describe evolution waves. Then consequences Arctic amplification (AA)‐induced meridional background potential vorticity (PV y ) changes on modulational are examined. It found that uniform trains mainly results from presence high‐order dispersion and nonlinearity, even though such an depends amplitude, vertical structure zonal wavenumber atmospheric stratification. Because nonlinearity depend magnitude PV , significantly influenced by variation associated with AA. also revealed stronger tends occur in smaller region higher latitudes due both weaker for fixed parameters, which conducive more intense waviness. However, because AA can reduce lower troposphere via reductions winter winds temperature gradients, reduced under enhance instability. Thus, role amplify through strengthening further enhances

Язык: Английский

---

Loss of autumn Kara-East Siberian Sea ice intensifies winter Ural blocking and cold anomalies in high latitudes of Eurasia

Atmospheric Research, Год журнала: 2023, Номер 295, С. 107038 - 107038

Опубликована: Сен. 29, 2023

Язык: Английский

---

Will the Globe Encounter the Warmest Winter after the Hottest Summer in 2023?

Advances in Atmospheric Sciences, Год журнала: 2023, Номер 41(4), С. 581 - 586

Опубликована: Дек. 1, 2023

Язык: Английский

---

Rapid Arctic warming and extreme weather events in Eastern Europe and Western to Central Asia

Climate Dynamics, Год журнала: 2024, Номер 62(9), С. 8889 - 8898

Опубликована: Авг. 5, 2024

Язык: Английский

---

Influence of high-latitude blocking and the northern stratospheric polar vortex on cold-air outbreaks under Arctic amplification of global warming

Environmental Research Climate, Год журнала: 2024, Номер 3(4), С. 042004 - 042004

Опубликована: Ноя. 18, 2024

Abstract It is widely accepted that Arctic amplification (AA)—enhanced warming relative to global warming—will increasingly moderate cold-air outbreaks (CAOs) the midlatitudes. Yet, some recent studies also argue AA over last three decades rest of present century may contribute more frequent severe winter weather including disruptive cold spells. To prepare society for future extremes, it necessary resolve whether and midlatitude are coincidental or physically linked. Severe events in northern continents often related a range stratospheric polar vortex (SPV) configurations atmospheric blocking, but these dynamical drivers complex still not fully understood. Here we review research advances paradigms nonlinear theory blocking helps explain location, timing duration AA/midlatitude connections, vortex’s zonal asymmetric intra-seasonal variations, its southward migration continents, surface impacts. We highlight novel understanding SPV variability—polar stretching stratosphere–troposphere oscillation—that have remained mostly hidden predominant focus on sudden warmings. A physical explanation two-way vertical coupling process between highs, taking into account local conditions, remains elusive. conclude evidence exists tropical preconditioning Arctic-midlatitude climate linkages. Recent using very large-ensemble modelling provides an emerging opportunity robustly quantify internal variability when studying potential response CAOs sea-ice loss.

Язык: Английский

---

Hybrid Transition of Subseasonal Atmospheric Regimes and Its Impact on the Extreme ‘West Cold‐East Warm’ Mode in North America

International Journal of Climatology, Год журнала: 2025, Номер unknown

Опубликована: Янв. 7, 2025

ABSTRACT On February 22, 2023, North America experienced an unusual weather phenomenon characterised by extreme cold in the west and warmth east, reflecting a surface air temperature (SAT) seesaw pattern that significantly impacted human activities region. Utilising reanalysis data, we analysed this case as well similar events long‐term climate records. The results indicate mode is caused hybrid evolution of atypical Pacific Oscillation (NPO) Pacific‐North American (PNA) phase relationships, transitioning from dominant positive NPO to strong negative PNA phase, while maintaining developing blocking, which refer transition atmospheric regimes. Further analysis revealed anomalously weak meridional potential vorticity gradient (PVy) southern Alaska prior event provided favourable conditions for northward movement intensification anticyclone central Pacific, serving key driving factor circulation PNA. Additionally, significant anomalous outgoing longwave radiation (OLR) tropical Indian Ocean indicated enhanced convective activity region, may have triggered Rossby waves, thereby influencing between mid high latitudes. Thus, PVy OLR serve precursor indicators such events.

Язык: Английский

---

Why have extreme low-temperature events in northern Asia strengthened since the turn of the 21st century?

Atmospheric Research, Год журнала: 2025, Номер 315, С. 107919 - 107919

Опубликована: Янв. 9, 2025

Язык: Английский

---