The use of circulation weather types to predict upwelling activity along the western Iberian Peninsula coast

The Mediterranean region is characterized by frequent summer wildfires, which represent an environmental and socioeconomic burden [1]. Some Mediterranean countries (or provinces) are particularly prone to Large Fires (LF), namely Portugal, Galicia (Spain), Greece, and southern France [1,2]. Moreover, the Mediterranean basin corresponds to a major hotspot of climate change, and anthropogenic warming is expected to increase the total burned area due to wildfires in Iberian Peninsula (IP) [3].Here, we propose to classify summer LF (June-September) for fifty-four provinces of the IIP according to their local-scale weather conditions (i.e. temperature, relative humidity, wind speed) and to fire danger weather conditions as measured by two fire weather indices (Duff Moisture Code and Drought Code). A cluster analysis was applied to identify a limited set of Fire Weather Types (FWT), each characterized by a combination of meteorological conditions leading to a better understanding of the relationship between meteorological drivers and fire occurrence. For each of the provinces, two significant FWT were identified with different characteristics, one dominated by high positive temperature anomalies and negative humidity anomalies (FWT1), and the other by intense zonal wind anomalies (FWT2) with two distinct subtypes in Iberia (FWT2_E and FWT2_W). Consequently, three distinct regions in the IP are identified: 1) dominated by FWT1, which is responsible for the largest amount of area burned in most of central-West provinces of Iberia; 2) the regions where the FWT2_E, associated with east winds is predominant, which are concentrated in the Northwest regions of the IP and the 3) regions where second subtype dominates, related with west winds (FWT2_W) in the easternmost provinces of the peninsula. Additionally, it was possible to verify that for each of the three regions the influence of the variables under study varies at different timescales. We reinforce the importance of studying the problem associated with LF for regions where similar conditions were verified regardless national borders.&#160;[1] Trigo, R. M., Sousa, P. M., Pereira, M. G., Rasilla, D., & Gouveia, C. M. (2013). &#8220;Modelling wildfire activity in Iberia with different atmospheric circulation weather types&#8221;. International Journal of Climatology 36(7), 2761&#8211;2778. https://doi.org/10.1002/joc.3749.[2] Ruffault, J., Moron, V., Trigo, R. M., & Curt, T. (2016). &#8220;Objective identification of multiple large fire climatologies: An application to a Mediterranean ecosystem&#8221;. Environmental Research Letters 11(7). https://doi.org/10.1088/1748-9326/11/7/075006.[3] Sousa, P. M., Trigo, R. M., Pereira, M. G., Bedia, J., & Guti&#233;rrez, J. M. (2015).&#8221;Different approaches to model future burnt area in the Iberian Peninsula&#8221;. Agricultural and Forest Meteorology 202, 11&#8211;25. https://doi.org/10.1016/j.agrformet.2014.11.018.&#160;Acknowledgements: This work was supported by national funds through FCT (Funda&#231;&#227;o para a Ci&#234;ncia e a Tecnologia, Portugal) under project IMPECAF (PTDC/CTA-CLI/28902/2017). The authors also thank Miguel M. Pinto for extracting the ERA-Interim reanalysis, the MSG and the FWI data used in this study.

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Identifying Local-Scale Weather Forcing Conditions Favorable to Generating Iberia’s Largest Fires

Forests ◽

10.3390/f11050547 ◽

2020 ◽

Vol 11 (5) ◽

pp. 547 ◽

Cited By ~ 1

Author(s):

Inês Vieira ◽

Ana Russo ◽

Ricardo M. Trigo

Keyword(s):

Iberian Peninsula ◽

Weather Conditions ◽

Local Scale ◽

Fire Weather ◽

Positive Temperature ◽

Weather Types ◽

Mediterranean Countries ◽

Large Fires ◽

The Mediterranean ◽

The Impact

The Mediterranean region is characterized by the frequent occurrence of summer wildfires, representing an environmental and socioeconomic burden. Some Mediterranean countries (or provinces) are particularly prone to large fires, namely Portugal, Galicia (Spain), Greece, and southern France. Additionally, the Mediterranean basin corresponds to a major hotspot of climate change, and anthropogenic warming is expected to increase the total burned area due to fires in Mediterranean Europe. Here, we propose to classify summer large fires for fifty-four provinces of the Iberian Peninsula according to their local-scale weather conditions and fire danger weather conditions. A composite analysis was used to investigate the impact of local and regional climate drivers at different timescales, and to identify distinct climatologies associated with the occurrence of large fires. Cluster analysis was also used to identify a limited set of fire weather types, each characterized by a combination of meteorological conditions. For each of the provinces, two significant fire weather types were identified—one dominated by high positive temperature anomalies and negative humidity anomalies, and the other by intense zonal wind anomalies with two distinct subtypes in the Iberian Peninsula., allowing for the identification of three distinct regions.

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Circulation weather types and wildland forest fires in the western Iberian Peninsula

International Journal of Climatology ◽

10.1002/joc.3520 ◽

2012 ◽

Vol 33 (6) ◽

pp. 1401-1408 ◽

Cited By ~ 3

Author(s):

Luis Rivas Soriano ◽

Clemente Tomás ◽

Fernando de Pablo ◽

Eulogio García

Keyword(s):

Iberian Peninsula ◽

Forest Fires ◽

Weather Types

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High resolution reconstruction of monthly precipitation of Iberian Peninsula using circulation weather types

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-9-6935-2012 ◽

2012 ◽

Vol 9 (6) ◽

pp. 6935-6977 ◽

Cited By ~ 2

Author(s):

N. Cortesi ◽

R. Trigo ◽

J. C. Gonzalez-Hidalgo ◽

A. M. Ramos

Keyword(s):

High Resolution ◽

Iberian Peninsula ◽

Model Performance ◽

High Density ◽

Monthly Precipitation ◽

Precipitation Series ◽

Forward Selection ◽

Weather Types ◽

Mountainous Regions ◽

Very High

Abstract. Precipitation over the Iberian Peninsula (IP) is highly variable and shows large spatial contrasts between wet mountainous regions, to the north, and dry regions in the inland plains and southern areas. In this work, a high-density monthly precipitation dataset for the IP was coupled with a set of 26 atmospheric circulation weather types (Trigo and DaCamara, 2000) to reconstruct Iberian monthly precipitation from October to May with a very high resolution of 3030 precipitation series (overall mean density one station each 200 km2). A stepwise linear regression model with forward selection was used to develop monthly reconstructed precipitation series calibrated and validated over 1948–2003 period. Validation was conducted by means of a leave-one-out cross-validation over the calibration period. The results show a good model performance for selected months, with a mean coefficient of variation (CV) around 0.6 for validation period, being particularly robust over the western and central sectors of IP, while the predicted values in the Mediterranean and northern coastal areas are less acute. We show for three long stations (Lisbon, Madrid and Valencia) the comparison between model and original data as an example to how these models can be used in order to obtain monthly precipitation fields since the 1850s over most of IP for this very high density network.

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