Dependence of Present and Future European Temperature Extremes on the Location of Atmospheric Blocking

Brunner, Lukas; Schaller, Nathalie; Anstey, James; Sillmann, Jana; Steiner, Andrea

doi:10.1029/2018gl077837

Cited by 105 publications

(94 citation statements)

References 38 publications

(78 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This high validation error could result from “false alarms” (blockings without extreme) and “missed events” (extremes without blocking). Looking at a few cases of false alarms, we find that most of them are blockings over ocean, which is not surprising because we count surface hot extremes only over continents, and that blockings have stronger local impact than remote impact when it comes to hot extremes (Brunner et al, ; Röthlisberger et al, ). For missed events, we will see an example in section .…”

Section: Resultsmentioning

confidence: 77%

“…Such factors need to be considered in future work. However, Schaller et al () and Brunner et al () found no significant change in the blocking‐heat wave link in the future under Representative Concentration Pathway 8.5, though these studies come with the caveat of a strong underestimation of blocking in the used models. One may also consider a strong blocking‐extreme link for the present day as a necessary but not sufficient condition for using changes in blocking to predict changes in weather extreme in a future climate.…”

Section: Introductionmentioning

confidence: 93%

See 1 more Smart Citation

Evaluating Indices of Blocking Anticyclones in Terms of Their Linear Relations With Surface Hot Extremes

Chan

Hassanzadeh

Kuang

2019

Geophysical Research Letters

View full text Add to dashboard Cite

Changes in frequencies of blocking anticyclones are sometimes used to explain changes in surface hot extremes. However, there is no consensus on the definition of blocking anticyclones, and several indices have been developed to measure them. Here we linearly regress interannual variations of hemispheric continental summer surface hot extreme area on the corresponding variations of blocking anticyclones in the ERA‐Interim reanalysis data and use cross‐validation test error to measure the blocking‐extreme link. Relative mean square validation error is at least 0.91 (relative to no knowledge of blocking) for existing indices defined on 500‐hPa geopotential height, when summed over land and ocean. This can be reduced to 0.55, largely by excluding blocks over ocean and optimizing parameters/thresholds and partly by using anomaly‐based or anomaly‐reversal hybrid indices. This framework helps to quantify the association of hot extremes and blocks with an uncertainty estimate and can be used for other extremes as well.

show abstract

Section: Resultsmentioning

confidence: 77%

Section: Introductionmentioning

confidence: 93%

Evaluating Indices of Blocking Anticyclones in Terms of Their Linear Relations With Surface Hot Extremes

Chan

Hassanzadeh

Kuang

2019

Geophysical Research Letters

View full text Add to dashboard Cite

show abstract

“…Three points regarding our methodology should be kept in mind. First, the threshold for identifying hot spells is slightly lower than that used in other studies (Brunner et al, ; Sillmann et al, ). However, the average T2mmax anomaly during hot spells defined by our approach ranges from +4 to +7 K over most land areas (Figure S3), which illustrates that these periods are indeed rather hot.…”

Section: Methodsmentioning

confidence: 91%

Quantifying the Local Effect of Northern Hemisphere Atmospheric Blocks on the Persistence of Summer Hot and Dry Spells

Röthlisberger

Martius

2019

Geophysical Research Letters

View full text Add to dashboard Cite

The persistence of heat waves and droughts is a key factor in determining their societal impact. Here, the local effect of atmospheric blocks on the persistence of summer hot and dry spells is quantified by comparing their climatological daily survival probability, that is, the probability to survive the next day, to their daily survival probability when they co‐occur with a block. The survival odds of hot spells are increased by more than 50% over most of the Northern Hemisphere extratropical land masses when co‐occurring with blocks. Dry spell persistence is also strongly increased by colocated blocks over western North America, Europe, and southern Russia, while it is significantly decreased over the western North Atlantic and the western North Pacific. These spatial differences in the effect of blocks on both spell types are explained by considering the spatially varying surface temperature and precipitation anomalies induced by the blocks.

show abstract

“…Over the past decade, various studies have established a link between atmospheric blocking and different weather situations (e.g., Sillmann and Croci‐Maspoli, ; Brunner et al . ; Sousa et al . ; Woollings et al .…”

Section: Introductionmentioning

confidence: 97%

Relationship between atmospheric blocking and warm‐season thunderstorms over western and central Europe

Mohr

Wandel

Lenggenhager

et al. 2019

Quart J Royal Meteoro Soc

View full text Add to dashboard Cite

A statistically significant link is presented between atmospheric blocking located over the eastern North Atlantic and northern Europe and warm‐season thunderstorm activity over western and central Europe. Lightning data from 2001 to 2014 were used to identify thunderstorm days and blocking events were extracted from the ERA‐Interim reanalysis using an objective identification algorithm. The statistical link between the two phenomena is established through odds ratio analysis. Two areas – one over the eastern part of the North Atlantic and one over the Baltic Sea – were identified as locations where blocking influences the occurrence of deep moist convection in parts of western and central Europe. Based on the mean ambient conditions on days with blocking in these two areas, well‐known dynamic and thermodynamic mechanisms supporting or suppressing the development of thunderstorms were confirmed. The anticyclonic circulation of a block over the eastern part of the North Atlantic leads to a northerly to northwesterly advection of dry and stable air masses into Europe on the eastern flank of the block. In addition, these environmental conditions are on average associated with large‐scale subsidence of air masses (convection‐inhibiting conditions). In contrast, the southerly to southwesterly advection of warm, moist and unstable air masses on the western flank of a block over the Baltic Sea results in convection‐favouring conditions over western and central Europe. Both blocking situations are on average associated with weak wind speeds at mid‐tropospheric levels and with weak wind shear. As a consequence, thunderstorms related to atmospheric blocking over the Baltic Sea tend to be on average less organised.

show abstract

Dependence of Present and Future European Temperature Extremes on the Location of Atmospheric Blocking

Cited by 105 publications

References 38 publications

Evaluating Indices of Blocking Anticyclones in Terms of Their Linear Relations With Surface Hot Extremes

Evaluating Indices of Blocking Anticyclones in Terms of Their Linear Relations With Surface Hot Extremes

Quantifying the Local Effect of Northern Hemisphere Atmospheric Blocks on the Persistence of Summer Hot and Dry Spells

Relationship between atmospheric blocking and warm‐season thunderstorms over western and central Europe

Contact Info

Product

Resources

About