Amundsen Sea Ice Loss Contributes to Australian Wildfires

Environmental Science & Technology, Год журнала: 2024, Номер 58(15), С. 6716 - 6724

Опубликована: Апрель 4, 2024

Wildfires in Australia have attracted extensive attention recent years, especially for the devastating 2019–2020 fire season. Remote forcing, such as those from tropical oceans, plays an important role driving abnormal weather conditions associated with wildfires. However, whether high latitude climate change can impact Australian fires is largely unclear. In this study, we reveal a robust relationship between Antarctic sea ice concentration (SIC), primarily over Amundsen Sea region, springtime activity, by using reanalysis data sets, AMIP simulation results, and state-of-the-art model simulation. Specifically, diminished SIC leads to formation of high-pressure system above result eastward propagation Rossby waves. Meanwhile, two strengthened meridional cells originating tropic polar regions also enhance subsiding airflow Australia, resulting prolonged arid high-temperature conditions. This mechanism explains about 28% variability contributed more than 40% 2019 extreme burning event, eastern hotspots. These findings contribute our understanding polar-low teleconnection implications projecting well global environment.

Язык: Английский

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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

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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

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Effects of Stratospheric Warming on Ural blocking Events in Winter

Journal of Geophysical Research Atmospheres, Год журнала: 2024, Номер 129(2)

Опубликована: Янв. 16, 2024

Abstract Utilizing the Open Integrated Forecasting System, responses of Ural blocking (UB) to different stratospheric warming scenarios are investigated. Numerical results show that with moderate strength in minor patterns prolongs UB duration and enhances its intensity, while strong tends shorten weaken even leading collapse events. Further diagnosis reveals planetary wave activity flux propagates downward from stratosphere troposphere after warming. Moreover, convergence is a key factor for enhancement maintenance. In addition, weakened meridional temperature gradients, decelerated zonal westerly winds, reduced potential vorticity gradient (PVy) result response strength. As strengthens, diverges, winds tropospheric mid‐latitudes accelerate PVy sector enlarges, which further weakens UB. Regarding perturbations major patterns, they have similar influences on events, is, However, strengthened would trigger re‐enhancement, closely associated anomalous activities synoptic‐scale waves induced by perturbations. These reveal events respond differently various intensities short term, makes contribution understanding stratosphere‐troposphere coupling.

Язык: Английский

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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

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Cold Waves in Poland: The Relations to Atmospheric Circulation and Arctic Warming

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

Опубликована: Март 12, 2025

ABSTRACT Winter warming in Europe is most apparent the northeastern parts. The minimum temperature increasing there at rate of 0.5°C–0.7°C per decade. main objective paper was to investigate changes characteristics cold days (CDs) and waves (CWs) Poland. Then, study relationships large‐scale circulation with regard CWs Due temperature, Poland characterised by a decreasing number CDs from November March 1978–2023. In recent years, have been significantly less severe are extended, whereas occur frequently shorter. Recent sea‐ice cover Arctic region entail mid high latitudes. 20th century, were mainly related blocking created over Scandinavia North Atlantic (Iceland). 21st some shifts centers action found, primarily associated strong Greenland Ural regions. These situations followed negative NAO/AO positive Blocking Index or Scandinavian (SCAND) pattern, which correlated winter (SCAND only February). It needs be emphasised that one important source areas air masses reach during CDs, this area faces greatest around globe.

Язык: Английский

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Strengthened Impact of Late Autumn Arctic Sea Ice on Asian Winter Cold Extremes after 1999/2000

Environmental Research Letters, Год журнала: 2024, Номер 19(7), С. 074045 - 074045

Опубликована: Июнь 13, 2024

Abstract Winter cold extremes (WCEs) frequently plague densely populated areas of Asia, leading to substantial economic losses and even fatalities. It has been found that the late autumn sea ice concentration (SIC) anomalies in northern (SICN) southern Arctic (SICS) are significantly positively negatively correlated with occurrence frequency WCE respectively (Wang Su 2024). Our study demonstrates impacts SICN SICS have strengthened after 1999/2000. Specifically, before 1999/2000, influences on Asian (AWCE) were relatively weak, possibly related weak intensity limited correlation between SICS. After interannual variability became larger anti-correlated SICN, resulting a stronger teleconnection SIC AWCE. is revealed greater loss modified atmospheric stability through changes surface heat fluxes upward longwave radiation fluxes. This alteration weakened magnitudes westerly winds increased blocking events over Eurasian continent, directly higher Asia. These interdecadal differences influence AWCE may be associated long-term climate change.

Язык: Английский

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A Review on the Arctic–Midlatitudes Connection: Interactive Impacts, Physical Mechanisms, and Nonstationary

Atmosphere, Год журнала: 2024, Номер 15(9), С. 1115 - 1115

Опубликована: Сен. 13, 2024

In light of the rapid Arctic warming and continuous reduction in Sea ice, complex two-way Arctic–midlatitudes connection has become a focal point recent climate research. this paper, we review current understanding interactive influence between midlatitude atmospheric variability ice or thermal conditions on interannual timescales. As sea diminishes, contrast to (cooling) boreal winter (summer), Eurasia North America have experienced anomalously cold (warm) record snowfall (rainfall), forming an opposite oscillation midlatitudes. Both statistical analyses modeling studies demonstrated significant impacts autumn–winter variations cooling, surges, snowfall, as well potential contributions spring–summer warming, heatwaves rainfall, particularly focusing role distinct regional ice. The possible physical processes can be categorized into tropospheric stratospheric pathways, with former encompassing swirling jet stream, horizontally propagated Rossby waves, transient eddy–mean flow interaction, latter manifested anomalous vertical propagation quasi-stationary planetary waves associated downward control anomalies. turn, prevailing patterns midlatitudes also contribute condition anomalies by meridional energy transport. fluctuates over time is influenced multiple factors (e.g., melting climatological different locations magnitudes anomalies, internal variability, other external forcings), undoubtedly increasing difficulty mechanism uncertainty surrounding predictions weather climate. conclusion, provide succinct summary offer suggestions for future

Язык: Английский

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Persistent Trends and Geographic Traits of Heat Waves in a Changing Climate

Environmental Research Communications, Год журнала: 2024, Номер 6(11), С. 115025 - 115025

Опубликована: Ноя. 1, 2024

Abstract By adopting a heatwave (HW) definition with ∼4-year recurrence frequency at world hot spots, we first examined the 1940–2022 HW climatology and trends in lifespan (duration), severity frequency, by comparing last 20-year periods of this 83- year record. Generally, HWs are becoming more frequent severe extra-tropic mid-latitude regions. Increased not temporally uniform tend to cluster together, posing one-two punch for ecosystems. North America, regions affected early 21st Century expanded ∼47% relative those mid-20th Century, contributed primarily starting be exposed Century. Mid-latitude basins vulnerable areas. Geographic shifts can attributed adjustments planetary wavelengths due increased air viscosity (related global warming). Polar amplified warming, leading reduced equator pole temperature gradients an overall reduction zonal wind speeds across midlatitudes, promotes wave amplitudes, persistent blockings cutoffs, thus increase severity, duration. Climate model simulations under business-as-usual emission scenario corroborate increases, supported strong intermodal consensus. correspond heightened boundary layer (PBL) depths, which eddy viscosity. The temperature-dependent nature underscores similarity between PBL depth areal extent warming climate.

Язык: Английский

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Different influences of La Niña types on the winter sub-seasonal Eurasian cold anomalies linked to Ural blocking

Atmospheric Research, Год журнала: 2023, Номер 299, С. 107172 - 107172

Опубликована: Дек. 13, 2023

Язык: Английский

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