Extreme temperature events on the Iberian Peninsula: Statistical trajectory analysis and synoptic patterns

Abstract

The occurrence of heat waves and cold spells has been receiving special attention in recent years due to their impact on human health, ecosystems and other aspects, such as the economy. The present work uses a Lagrangian approach to analyse the physical processes leading to temperature extremes in the Iberian Peninsula (IP) for the 20‐year period 1994–2013. Principal component analysis has also been carried out to identify the associated synoptic scale configurations. Spatial pattern analysis shows that the highest temperatures during hot events are reached in the SW region and the lowest ones in the NE, while a latitudinal gradient of 26 K was obtained for the cold events, with the lowest values in the NE regions and the Pyrenees. Most of the extremes persisted between 1 and 3 days for both hot and cold events. Rather than meridional advection, the primary cause behind the occurrence of hot extremes seems to be progressive diabatic warming, which becomes accentuated in its final stage and is caused, on the one hand, by air masses with long residence times over the IP and, on the other hand, by recirculation processes during summer days of weak baric gradient. The air masses producing the extreme cold events have faster trajectories and mainly originate in north and northeast Europe, due to a relative low in the central Mediterranean and a blocking high in the North Atlantic and/or in northeast Europe.

Heat and cold waves in mainland Spain: Origins, characteristics, and trends

“…For CWs, the different WTs indicated an advection from north to north-east through a corridor, with a relatively low pressure in the Western Mediterranean and, in a few cases, a cut-off-low at 500 hPa over the Iberian Peninsula. These situations also showed a blocking high over Great Britain (Mohammed et al, 2018). The slight differences with other studies are attributed to the different classification methods, but they This first analysis of the atmospheric drivers of HW/CW events exemplify a static picture already analysed from different perspectives (Sánchez-Benítez et al, 2020) that is, indeed, changing.…”

Summer Heatwaves Trends and Hotspots in the Barcelona Metropolitan Region (1914-2020)

“…El Kenawy et al (2013) detected a signi cant linkage for the period 1960-2006 between the negative phase of WeMO and maximum temperatures during the warm season in NE Spain. However, opposite results were obtained for the Iberian Peninsula for the period 1994-2013 (Mohammed et al, 2018), concluding that the values of the extreme hot temperatures are higher for years with a positive WeMO phase. Due to the mentioned controversies about the relationship between the WeMOi and hot summer temperatures, this research would contribute to a new analysis of the possible correlations, restricted to Barcelona city, although they could also be assumed for the Barcelona metropolitan area, very close to the north-western coast of the Mediterranean.…”

Evaluating the Spatial and Temporal Characteristics of Summer Urban Overheating through Weather Types in the Attica Region, Greece

“…In the present study, in order to identify the WTs over the Attica region, we employed a combination of two main statistical methods: k-means cluster analysis (CA) and components analysis (PCA). In climatology, both statistical methods are often employed [23][24][25].…”