Little influence of Arctic amplification on mid-latitude climate

Nature Climate Change, Год журнала: 2020, Номер 10(3), С. 231 - 237

Опубликована: Фев. 10, 2020

Язык: Английский

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CASEarth Poles: Big Data for the Three Poles

Bulletin of the American Meteorological Society, Год журнала: 2020, Номер 101(9), С. E1475 - E1491

Опубликована: Апрель 6, 2020

Abstract Unprecedented changes in the climate and environment have been observed three poles, including North Pole, South Third Pole–Tibetan Plateau. Although considerable data collected several observation networks built these polar regions, poles are relatively data-scarce regions due to inaccessible acquisition, high-cost labor, difficult living environments. To address obstacles better understanding unprecedented their effects on global humans, there is a pressing need for curation, integration, service, application support fundamental scientific research sustainable development poles. CASEarth Poles, project within framework of “CAS Big Earth Data Science Engineering” program Chinese Academy Sciences, aims construct big platform Poles will be devoted 1) breaking bottleneck sharing; 2) developing high-resolution remote sensing products over poles; 3) generating atmospheric reanalysis datasets regions; 4) exploring synchronization, asynchronization, teleconnection environmental 5) investigating climate, water cycle, ecosystem dynamics interactions among multispheres effects; 6) supporting decision-making with regard sea ice forecasting, infrastructure, regions. collaborate international efforts enable information services era.

Язык: Английский

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Increased Quasi Stationarity and Persistence of Winter Ural Blocking and Eurasian Extreme Cold Events in Response to Arctic Warming. Part II: A Theoretical Explanation

Journal of Climate, Год журнала: 2017, Номер 30(10), С. 3569 - 3587

Опубликована: Янв. 18, 2017

Abstract In Part I of this study, it was shown that the Eurasian cold anomalies related to Arctic warming depend strongly on quasi stationarity and persistence Ural blocking (UB). The analysis here revealed under weak mean westerly wind (MWW) vertical shear (VS) (quasi barotropic) conditions with synoptic-scale eddies a large planetary wave anomaly, growth UB is slow its amplitude small. For case, quasi-stationary persistent seen. However, strong MWW VS baroclinic) conditions, are stronger rapid; resulting less has amplitude. marked retrogression observed. dynamical mechanism behind dependence movement upon background further examined using nonlinear multiscale model. results show when quasi-baroclinic blocking-induced westward displacement greatly exceeds zonal-wind-induced eastward hence generates blocking. By contrast, quasi-barotropic because relatively small distinct, giving rise It mid–high-latitude North Atlantic zonal condition suppresses UB’s thus conducive UB. model duration longer in region or eddy strength weaker.

Язык: Английский

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Extreme Cold Wave over East Asia in January 2016: A Possible Response to the Larger Internal Atmospheric Variability Induced by Arctic Warming

Journal of Climate, Год журнала: 2018, Номер 32(4), С. 1203 - 1216

Опубликована: Дек. 17, 2018

It is argued that anthropogenic global warming may decrease the occurrence of cold waves. However, a historical record-extreme wave, popularly called “boss level” attacked East Asia in January 2016, which gives rise to discussion why this boss-level wave occurred during winter with warmest recorded mean surface air temperature (SAT). To explore impacts human-induced and natural internal atmosphere variability, we investigated cold-wave-related circulation regime (i.e., large-scale atmospheric pattern) compared observation large ensemble simulations MIROC5 model. Our results showed Asian extreme mainly exhibited an extremely strong anomaly Ural blocking high (UBH) record-breaking Siberian (SH), it largely originated from variability. because dynamic effect Arctic amplification, increase likelihood waves through shifting responsible toward stronger amplitude. The probability anomalies UBH, SH, area SAT have been increased by 58%, 57%, 32%, respectively, as consequence warming. Therefore, Asia, such one be enhanced response larger variability modulated

Язык: Английский

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Atmospheric blocking events: a review

Annals of the New York Academy of Sciences, Год журнала: 2020, Номер 1504(1), С. 5 - 24

Опубликована: Дек. 31, 2020

Abstract Even though meteorologists have been aware of atmospheric blocking for more than 100 years, it is a phenomenon still not well forecast or completely understood. Also, while there one standard accepted definition, are some commonalities known about the understanding behavior. Blocking occurs less often other destructive phenomena, but globally their occurrence has increased since beginning century. The longevity means can negatively impact agricultural and economic activity human comfort by bringing extreme conditions only to areas where they occur also locations upstream downstream. Additionally, general character described, operational models struggle replicate intensity duration even improvement noted in timing location onset. Climatologically, underestimate occurrence. In last 40 investigators used case study analysis numerical theoretical understand onset maintenance blocking. Comparatively few examined block decay. This review endeavors cover highlights history investigations, especially decades, order provide an scientific audience.

Язык: Английский

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Ural Blocking Driving Extreme Arctic Sea Ice Loss, Cold Eurasia, and Stratospheric Vortex Weakening in Autumn and Early Winter 2016–2017

Journal of Geophysical Research Atmospheres, Год журнала: 2019, Номер 124(21), С. 11313 - 11329

Опубликована: Окт. 31, 2019

Abstract This study investigates the dynamics that led to repeated cold surges over midlatitude Eurasia, exceptionally warm conditions and sea ice loss Arctic, unseasonable weakening of stratospheric polar vortex in autumn early winter 2016–2017. We use ERA‐Interim reanalysis data COBE surface temperature observational trace dynamical pathways caused these extreme phenomena. Following abnormally low Pacific sector Arctic basin, blocking anticyclones became dominant Eurasia throughout autumn. Ural (UB) activity was four times above climatological levels organized several successive events. UB episodes played a key role unprecedented observed late 2016 Barents‐Kara Seas vortex. Each induced circulation anomalies resulted air advection its south north. The near‐surface warming cooling varied phase with life cycles episodes. cover minimum not summer but rather mid‐November December shortly after two strongest episode drove intense upward flux wave November. impact this can be linked migration spells toward Europe 2017.

Язык: Английский

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The winter midlatitude-Arctic interaction: effects of North Atlantic SST and high-latitude blocking on Arctic sea ice and Eurasian cooling

Climate Dynamics, Год журнала: 2018, Номер 52(5-6), С. 2981 - 3004

Опубликована: Июнь 19, 2018

Язык: Английский

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A Nonlinear Theory of Atmospheric Blocking: A Potential Vorticity Gradient View

Journal of the Atmospheric Sciences, Год журнала: 2019, Номер 76(8), С. 2399 - 2427

Опубликована: Май 9, 2019

Abstract In this paper, an extended nonlinear multiscale interaction model of blocking events in the equivalent barotropic atmosphere is used to investigate effect a slowly varying zonal wind meridional direction on dipole that regarded as Rossby wave packet. It shown gradient potential vorticity (PVy=∂PV/∂y) prior onset, which related background and its nonuniform shear, can significantly affect lifetime, intensity, north–south asymmetry blocking, while itself driven by preexisting incident synoptic-scale eddies. The magnitude PVy determines energy dispersion nonlinearity blocking. revealed small prerequisite for strong long-lived eddy-driven behaves persistent meandering westerly jet stream, establishment further reduces within region, resulting positive feedback between PVy. When core shifts from higher lower latitudes, shows northwest–southeast-oriented with anticyclonic anomaly northwest weak cyclonic southeast northern pole moves westward more rapidly has weaker stronger than southern because smaller latitudes. opposite true when toward vanishes symmetric double-peak structure. Thus, favorable precursor occurrence large-amplitude

Язык: Английский

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Collaborative impact of the NAO and atmospheric blocking on European heatwaves, with a focus on the hot summer of 2018

Environmental Research Letters, Год журнала: 2020, Номер 15(11), С. 114003 - 114003

Опубликована: Июль 16, 2020

Abstract Two intense heatwaves of July and early August 2018 are found to be associated with a European blocking (EB) event accompanied by series consecutive positive North Atlantic Oscillation (NAO + ) events. Further analyses show that the collaborative role an EB its upstream NAO pattern could increase frequency, persistence, magnitude scale over Europe. Compared -unrelated events, -related events less movable (quasi-stationary) more persistent Europe, which contribute in intensity persistence heatwaves. In addition, high this type has northeast–southwest orientation stronger warm airflow precipitation northern western where large scopes higher temperatures tend occur. contrast, without correspond trough south, results increased cold air southern part thus contract Moreover, considering leads formation event, might serve as potential predictor for Our conclusions strongly supported analysis CMIP6 historical simulations also capture differences atmospheric circulations between

Язык: Английский

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The Influence of Stratospheric Wave Reflection on North American Cold Spells

Monthly Weather Review, Год журнала: 2020, Номер 148(4), С. 1675 - 1690

Опубликована: Фев. 13, 2020

Abstract Understanding and predicting midlatitude cold spells is of scientific public interest, given often associated severe impacts. However, large-scale atmospheric dynamics related to these events are not fully understood. The winter 2017/18 was characterized by several affecting large parts North America Eurasia. Here, the role stratosphere–troposphere coupling for occurrence in this investigated using different wave propagation diagnostics. While European spell late February 2018 influenced a major sudden stratospheric warming (SSW) with absorption, over at end December 2017 early were downward reflected waves Pacific. Previously proposed reflection indices, however, either miss or able distinguish them from SSW absorption. To overcome this, novel simple index based on eddy heat flux here, capturing regional Reflection detected shown be followed Pacific blocking negative temperature anomalies America. An improved understanding contribution crucial better predict such future.

Язык: Английский

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