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Dr. Marcelo Fragoso
Centro de Estudos Geográficos, Instituto de Geografia e Ordenamento do Território, Universidade de Lisboa, Lisboa, Portugal

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0 Climatology
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Journal article
Published: 24 August 2021 in Atmosphere
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Heatwaves are an extreme meteorological event in which affected populations may also be exposed to deteriorated air quality conditions due to the increase in air pollutant concentrations, such as PM10 (particulate matter < 10 µg/m3). In order to identify heatwaves (1973–2019) in the region of Faro (Algarve) during the hot season (April–September), the Excess Heat Factor (EHF) index was applied. The Mann–Kendall test revealed an upward trend in three heatwave metrics in Faro, and the trend of accumulated heat load (EHF load) was also positive as would be expected, but its signal was not statistically significant. An inventory of North African dust events (2006–2019) was made, and their simultaneous occurrence with heatwaves was assessed, pointing to only 20% of dust events of the Sahara occurring simultaneously with heatwave days. A cluster analysis was conducted on daily geopotential height fields at 850 hPa level over the 2006–2019 period, and four distinct patterns were identified as the most prominent synoptic circulations promoting both heatwave conditions and North African dust over the Algarve.

ACS Style

Raquel Fernandes; Marcelo Fragoso. Assessing Heatwaves and Their Association with North African Dust Intrusions in the Algarve (Portugal). Atmosphere 2021, 12, 1090 .

AMA Style

Raquel Fernandes, Marcelo Fragoso. Assessing Heatwaves and Their Association with North African Dust Intrusions in the Algarve (Portugal). Atmosphere. 2021; 12 (9):1090.

Chicago/Turabian Style

Raquel Fernandes; Marcelo Fragoso. 2021. "Assessing Heatwaves and Their Association with North African Dust Intrusions in the Algarve (Portugal)." Atmosphere 12, no. 9: 1090.

Data descriptor
Published: 20 July 2021 in Scientific Data
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Climate proxy data are required for improved understanding of climate variability and change in the pre-instrumental period. We present the first international initiative to compile and share information on pro pluvia rogation ceremonies, which is a well-studied proxy of agricultural drought. Currently, the database has more than 3500 dates of celebration of rogation ceremonies, providing information for 153 locations across 11 countries spanning the period from 1333 to 1949. This product provides data for better understanding of the pre-instrumental drought variability, validating natural proxies and model simulations, and multi-proxy rainfall reconstructions, amongst other climatic exercises. The database is freely available and can be easily accessed and visualized via http://inpro.unizar.es/.

ACS Style

Fernando Domínguez-Castro; María João Alcoforado; Nieves Bravo-Paredes; María Isabel Fernández-Fernández; Marcelo Fragoso; María Cruz Gallego; Ricardo García Herrera; Emmanuel Garnier; Gustavo Garza-Merodio; Ahmed M. El Kenawy; Borja Latorre; Iván Noguera; Dhais Peña-Angulo; Fergus Reig-Gracia; Luís Pedro Silva; José M. Vaquero; Sergio M. Vicente Serrano. Dating historical droughts from religious ceremonies, the international pro pluvia rogation database. Scientific Data 2021, 8, 1 -8.

AMA Style

Fernando Domínguez-Castro, María João Alcoforado, Nieves Bravo-Paredes, María Isabel Fernández-Fernández, Marcelo Fragoso, María Cruz Gallego, Ricardo García Herrera, Emmanuel Garnier, Gustavo Garza-Merodio, Ahmed M. El Kenawy, Borja Latorre, Iván Noguera, Dhais Peña-Angulo, Fergus Reig-Gracia, Luís Pedro Silva, José M. Vaquero, Sergio M. Vicente Serrano. Dating historical droughts from religious ceremonies, the international pro pluvia rogation database. Scientific Data. 2021; 8 (1):1-8.

Chicago/Turabian Style

Fernando Domínguez-Castro; María João Alcoforado; Nieves Bravo-Paredes; María Isabel Fernández-Fernández; Marcelo Fragoso; María Cruz Gallego; Ricardo García Herrera; Emmanuel Garnier; Gustavo Garza-Merodio; Ahmed M. El Kenawy; Borja Latorre; Iván Noguera; Dhais Peña-Angulo; Fergus Reig-Gracia; Luís Pedro Silva; José M. Vaquero; Sergio M. Vicente Serrano. 2021. "Dating historical droughts from religious ceremonies, the international pro pluvia rogation database." Scientific Data 8, no. 1: 1-8.

Article
Published: 15 March 2021 in Climatic Change
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Extreme meteorological events have had devastating consequences all over the world throughout the ages. In this study, we look into the floods at the mouth of the Douro River (Porto, Portugal) in the eighteenth century to expand the data series of floods in Northern Portugal. Information was gathered mostly from documentary narrative sources, either individual or institutional (administrative and ecclesiastic), some of which include reports of Pro Serenitate ceremonies. A study by the priest Rebelo Costa (1789) and the memories of the merchant Ignacio Henckell from 1717 to 1800 stand out among the individual sources. We concluded that there was great interannual variability in the occurrence of the 54 recorded floods, the highest number of which occurred in the 1780s. The “catastrophic” floods were recorded in 1727, 1739, 1769, 1774, 1777, 1788 and 1798, four of which are studied in detail in this paper. The greatest number of flood events took place in winter and autumn, and most of them lasted between 1 and 3 days. An analysis of the description of the floods, their impacts and the associated meteorological causes was carried out. In most cases, the frontal activity associated with Atlantic cyclonic systems was the cause of positive precipitation anomalies in NW Iberia. The great variability in heavy precipitation was confirmed by the new data. However, hardly any temporal simultaneity was found with other case studies in Southern Europe, except for Spain, especially several localities of Galicia and the mid Douro Valley (Zamora).

ACS Style

Maria João Alcoforado; Luís Pedro Silva; Inês Amorim; Marcelo Fragoso; João Carlos Garcia. Historical floods of the Douro River in Porto, Portugal (1727–1799). Climatic Change 2021, 165, 1 -20.

AMA Style

Maria João Alcoforado, Luís Pedro Silva, Inês Amorim, Marcelo Fragoso, João Carlos Garcia. Historical floods of the Douro River in Porto, Portugal (1727–1799). Climatic Change. 2021; 165 (1-2):1-20.

Chicago/Turabian Style

Maria João Alcoforado; Luís Pedro Silva; Inês Amorim; Marcelo Fragoso; João Carlos Garcia. 2021. "Historical floods of the Douro River in Porto, Portugal (1727–1799)." Climatic Change 165, no. 1-2: 1-20.

Research article
Published: 13 August 2020 in International Journal of Disaster Risk Reduction
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This research quantifies and compares the material damage caused by flooding resulting from the two most extreme rainfall events of the 21st century in two Portuguese regions, using insurance data: the Lisbon Metropolitan Area (LMA) and Madeira Island. During the 2000-2011 period, 24% of the claims and 40% of the payouts in the LMA were caused by the February 2008 event. In Madeira, the February 2010 event represented 50% of the claims and 88% of the payouts. The maximum rainfall values during the 2010 event more than doubling those recorded during the 2008 event. The steep slopes of the Madeira’s drainage basins exacerbate the potential for flooding to cause damage. Peak discharges are higher and occur earlier than in the LMA’s basins. Flash floods are the most important type of flooding in Madeira, unlike what occurs in the LMA, where urban flooding is most prevailent. The greater destructive capacity of flash floods, the higher magnitude of the triggering rainfall during the 2010 event and the higher flooding susceptibility of the Madeira’s drainage basins justify the greatest material damage. The lower education levels and economic power of the Madeira’s population may affect the capacity to purchase insurance and can explain the lower number of insurance policies, contributing for a higher vulnerability to flooding. The obtained results represent an important knowledge regarding flooding in Portugal for spatial planning, risk management and insurance companies.

ACS Style

Miguel Leal; Marcelo Fragoso; Sérgio Lopes; Eusébio Reis. Material damage caused by high-magnitude rainfall based on insurance data: Comparing two flooding events in the Lisbon Metropolitan Area and Madeira Island, Portugal. International Journal of Disaster Risk Reduction 2020, 51, 101806 .

AMA Style

Miguel Leal, Marcelo Fragoso, Sérgio Lopes, Eusébio Reis. Material damage caused by high-magnitude rainfall based on insurance data: Comparing two flooding events in the Lisbon Metropolitan Area and Madeira Island, Portugal. International Journal of Disaster Risk Reduction. 2020; 51 ():101806.

Chicago/Turabian Style

Miguel Leal; Marcelo Fragoso; Sérgio Lopes; Eusébio Reis. 2020. "Material damage caused by high-magnitude rainfall based on insurance data: Comparing two flooding events in the Lisbon Metropolitan Area and Madeira Island, Portugal." International Journal of Disaster Risk Reduction 51, no. : 101806.

Journal article
Published: 08 August 2020 in Atmosphere
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Urbanized hot spots incorporate a great diversity of microclimates dependent, among other factors, on local meteorological conditions. Until today, detailed analysis of the combination of climatic variables at local scale are very scarce in urban areas. Thus, there is an urgent need to produce a Local Weather Type (LWT) classification that allows to exhaustively distinguish different urban thermal patterns. In this study, hourly data from air temperature, wind speed and direction, accumulated precipitation, cloud cover and specific humidity (2009–2018) were integrated in a cluster analysis (K-means) in order to produce a LWT classification for Lisbon’s urban area. This dataset was divided by daytime and nighttime and thermal periods, which were generated considering the annual cycle of air temperatures. Therefore, eight LWT sets were generated. Results show that N and NW LWT are quite frequent throughout the year, with a moderate speed (daily average of 4–6 m/s). In contrast, the frequency of rainy LWT is considerably lower, especially in summer (below 10%). Moreover, during this season the moisture content of the air masses is higher, particularly at night. This methodology will allow deepening the knowledge about the multiple Urban Heat Island (UHI) patterns in Lisbon.

ACS Style

Cláudia Reis; António Lopes; Ezequiel Correia; Marcelo Fragoso. Local Weather Types by Thermal Periods: Deepening the Knowledge about Lisbon’s Urban Climate. Atmosphere 2020, 11, 840 .

AMA Style

Cláudia Reis, António Lopes, Ezequiel Correia, Marcelo Fragoso. Local Weather Types by Thermal Periods: Deepening the Knowledge about Lisbon’s Urban Climate. Atmosphere. 2020; 11 (8):840.

Chicago/Turabian Style

Cláudia Reis; António Lopes; Ezequiel Correia; Marcelo Fragoso. 2020. "Local Weather Types by Thermal Periods: Deepening the Knowledge about Lisbon’s Urban Climate." Atmosphere 11, no. 8: 840.

Journal article
Published: 15 January 2020 in Atmosphere
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The article presents new information on the spatial distribution of intense rainfall and a new map of susceptibility to the formation of mass movements in the mountainous streams of the municipality of Funchal, the capital of the Autonomous Region of Madeira, an archipelago of Portugal. The methodology that was adopted is based on the spatial analysis of weighted overlap of variables, with influence in the occurrence of hydro-geomorphological processes that are at the origin of catastrophic events, marked by the mobilization of solid material towards and along the fluvial channels. Intense precipitations are effectively the main triggering factor of mass movements, which is why their statistical characteristics and local contrasts are analyzed, to integrate this layer of information into the new susceptibility assessment model of mass movements produced in this article. This type of spatialized information is of strategic importance to support the planning of urban expansion, which requires a land use management practice in accordance with the existing risk in the Madeira Island.

ACS Style

Sérgio Lopes; Marcelo Fragoso; António Lopes. Heavy Rainfall Events and Mass Movements in the Funchal Area (Madeira, Portugal): Spatial Analysis and Susceptibility Assessment. Atmosphere 2020, 11, 104 .

AMA Style

Sérgio Lopes, Marcelo Fragoso, António Lopes. Heavy Rainfall Events and Mass Movements in the Funchal Area (Madeira, Portugal): Spatial Analysis and Susceptibility Assessment. Atmosphere. 2020; 11 (1):104.

Chicago/Turabian Style

Sérgio Lopes; Marcelo Fragoso; António Lopes. 2020. "Heavy Rainfall Events and Mass Movements in the Funchal Area (Madeira, Portugal): Spatial Analysis and Susceptibility Assessment." Atmosphere 11, no. 1: 104.

Articles
Published: 18 April 2019 in Hydrological Sciences Journal
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This research aims to understand how insurance, rainfall, land cover and urban flooding are related and how these variables influenced the material damages in the Lisbon Metropolitan Area (LMA) during the 2000–2011 period. Correlation coefficients show strong relationships between built-up areas and claims (0.94) and payouts (0.88). Despite no significant relationships being found between rainfall and the amount of material damages per event, three likelihood levels of flooding were determined for hourly rainfall. Unlike the studied period, the number of claims and their spatial distribution during the 2008 extreme rainfall event were strongly dependent on rainfall. Flooding related to the old watercourses assumed greater importance during this extreme event, recovering a more natural/ancient hydrologic behaviour. In the LMA, the greatest material damages were the result of high-magnitude/low-probability rainfall events. Still, lower magnitude events can trigger numerous claims in heavily built-up areas, but they are hardly capable of producing large material damages.

ACS Style

Miguel Leal; Inês Boavida-Portugal; Marcelo Fragoso; Catarina Ramos. How much does an extreme rainfall event cost? Material damage and relationships between insurance, rainfall, land cover and urban flooding. Hydrological Sciences Journal 2019, 64, 673 -689.

AMA Style

Miguel Leal, Inês Boavida-Portugal, Marcelo Fragoso, Catarina Ramos. How much does an extreme rainfall event cost? Material damage and relationships between insurance, rainfall, land cover and urban flooding. Hydrological Sciences Journal. 2019; 64 (6):673-689.

Chicago/Turabian Style

Miguel Leal; Inês Boavida-Portugal; Marcelo Fragoso; Catarina Ramos. 2019. "How much does an extreme rainfall event cost? Material damage and relationships between insurance, rainfall, land cover and urban flooding." Hydrological Sciences Journal 64, no. 6: 673-689.

Original paper
Published: 18 October 2018 in Theoretical and Applied Climatology
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Recent and future changes in precipitation extremes over Portugal were studied. Trends in selected precipitation indices were calculated on a seasonal scale for the period of 1950–2003. Considering the same indices, this study also assessed possible changes under future climatic conditions (2046–2065). Furthermore, trends and projections for the future were evaluated using a single/unified index of extreme precipitation susceptibility (EPSI). The results revealed statistically significant drying trends in spring, mainly in northern and central Portugal, while weak wetting trends were detected in autumn. The EPSI trends also depicted a decrease of extreme precipitation in spring over central Portugal and a slight increase in autumn over northern Portugal and nearby Lisbon. On the other hand, climate change projections revealed a decrease in precipitation, mainly over northwestern Portugal, whereas the contribution of extreme precipitation to total precipitation is expected to increase, mostly in southern Portugal. The maximum number of consecutive dry days (CDD) is also projected to increase throughout Portugal. EPSI showed enhanced susceptibility for most Portuguese municipalities, which may be associated with increased vulnerability to flash floods. Climate change projections by municipality for both EPSI and CDD are an important decision support tool for civil protection and for risk management in Portugal.

ACS Style

Mónica Santos; André Fonseca; Marcelo Fragoso; João Carlos Andrade dos Santos. Recent and future changes of precipitation extremes in mainland Portugal. Theoretical and Applied Climatology 2018, 137, 1305 -1319.

AMA Style

Mónica Santos, André Fonseca, Marcelo Fragoso, João Carlos Andrade dos Santos. Recent and future changes of precipitation extremes in mainland Portugal. Theoretical and Applied Climatology. 2018; 137 (1-2):1305-1319.

Chicago/Turabian Style

Mónica Santos; André Fonseca; Marcelo Fragoso; João Carlos Andrade dos Santos. 2018. "Recent and future changes of precipitation extremes in mainland Portugal." Theoretical and Applied Climatology 137, no. 1-2: 1305-1319.

Research article
Published: 27 August 2018 in International Journal of Climatology
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A renewed interest in historical droughts is due to the current climate change issues and also to the recent extreme drought of 2017 in Portugal. This work aims to lengthen the historical drought series and help improve projections for the future. The main droughts of the 18th century in mainland Portugal were identified using mostly direct documentary sources: individual (poems, letters, memoirs, manuscripts and printed newspapers) and institutional (ecclesiastical and administrative), as well as accounts of Pro pluvia ceremonies and processions. All the records had been assembled in the KlimHist database (http://clima.ul.pt/Klimhist-project).A summary statistical analysis of the drought evidence including its impacts was performed to assess its temporal distribution and geographical incidence. A strong precipitation variability was detected, which, similar to the present times, hardly presents trends in long series. The main years of drought during the 18th century in Portugal are highlighted, particularly the severe and long‐lasting 1737–38 and 1753–54 droughts that, together with their atmospheric causes, were studied in detail. There are more drought records for Southern Portugal (SP) than for Northern Portugal (NP). It was also observed that spring March, April and May (MAM) and winter December, January and February (DJF) drought evidence are more frequent in SP, whereas in NP there are more records concerning summer June, July and August (JJA). The results obtained agree with those of others of the Iberian Peninsula (IP). Despite Portugal being a small country, our results confirm the existence of an important climatic boundary between the NP and the SP with different precipitation variability.

ACS Style

Marcelo Fragoso; Maria Da Graça Carraça; Maria Joao Alcoforado. Droughts in Portugal in the 18th century: A study based on newly found documentary data. International Journal of Climatology 2018, 38, 5522 -5541.

AMA Style

Marcelo Fragoso, Maria Da Graça Carraça, Maria Joao Alcoforado. Droughts in Portugal in the 18th century: A study based on newly found documentary data. International Journal of Climatology. 2018; 38 (15):5522-5541.

Chicago/Turabian Style

Marcelo Fragoso; Maria Da Graça Carraça; Maria Joao Alcoforado. 2018. "Droughts in Portugal in the 18th century: A study based on newly found documentary data." International Journal of Climatology 38, no. 15: 5522-5541.

Original paper
Published: 17 January 2018 in Natural Hazards
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Floods are a major natural hazard, with vast implications over a wide range of socio-economic activities. A harmonized post-flood classification is critical for a better understanding of this hazard, by providing homogeneous flood catalogues for future research on triggering mechanisms. We apply a flood severity index (FSI) to damaging floods in Northern Portugal over a 152-year period (1865–2016) and identify the most critical areas to flood occurrences. The index is a damage-based post-event assessment tool, which includes five categories ranging from minor flooding (1) to catastrophic flooding (5). FSI is applied to a historical damaging flood database with 2318 occurrences. In Northern Portugal, serious floods (3) are the most frequent typology, while catastrophic floods are typically river floods occurring in the Douro basin. Overall, damaging flood occurrences are favoured by the positive phase of the East Atlantic pattern and by the negative phase of the North Atlantic Oscillation. Furthermore, the north-western areas reveal higher concentrations of damaging flood occurrences, mainly due to higher population density, higher precipitation values and more flood plain areas. In particular, 48% of all occurrences are concentrated in the Porto Metropolitan Area, mainly the Porto city centre and nearby riverside areas of the Douro River. High-population density and heavily urbanized areas lead to greater exposure to flood risk, whereas the most peripheral municipalities, with large agricultural/forested areas, show much lower numbers of damaging floods. FSI is tool to communicate the magnitude of the flood risk and is, therefore, of foremost relevance to civil protection and risk management.

ACS Style

Mónica Santos; Marcelo Fragoso; João A. Santos. Damaging flood severity assessment in Northern Portugal over more than 150 years (1865–2016). Natural Hazards 2018, 91, 983 -1002.

AMA Style

Mónica Santos, Marcelo Fragoso, João A. Santos. Damaging flood severity assessment in Northern Portugal over more than 150 years (1865–2016). Natural Hazards. 2018; 91 (3):983-1002.

Chicago/Turabian Style

Mónica Santos; Marcelo Fragoso; João A. Santos. 2018. "Damaging flood severity assessment in Northern Portugal over more than 150 years (1865–2016)." Natural Hazards 91, no. 3: 983-1002.

Review article
Published: 08 July 2017 in Applied Geography
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The present study aims to identify regions of extreme precipitation in mainland Portugal and to create a single index of extreme precipitation susceptibility (EPSI). For this purpose, twelve extreme precipitation indices were selected from the Expert Team on Climate Change Detection and Indices between 1950 and 2003. By considering only six extreme precipitation indices: R×1day, R×5day, SDII, R20, CWD and R95PTOT for the 10-year return period, between 1950 and 2003, the EPSI was developed to both annual data and meteorological season. The regionalization of extreme precipitation in Portugal were determined using a principal component analysis in T-mode. The results, show three spatial regions obtained from PCA. The three regions were analyzed separate. In the annual EPSI, the highest susceptibility areas are the mountainous regions in northern (e.g. Gerês, Peneda, Alvão, Marão and Montesinho) and central Portugal (e.g. Serra da Estrela), as well as in the Algarve (southern Portugal). Conversely, the lower susceptibility classes are in municipalities of the northeast, Alentejo and along the central-western coast. The results of EPSI show similar results in autumn and winter. In spring, however, the high susceptibility class increases in the Lisbon region and in the Sado Basin. In summer, there is an increase in susceptibility in the northeast, while susceptibility is low over much of Alentejo and Algarve, where precipitation is neglectful. This work presents a first attempt to implement this type of index for mainland Portugal. The first results are very promising, showing a consistent representation of the overall spatial distribution of extreme precipitation susceptibility. The combination of this information by municipalities can be of foremost relevance to civil protection and risk management.

ACS Style

Mónica Santos; Marcelo Fragoso; João A. Santos. Regionalization and susceptibility assessment to daily precipitation extremes in mainland Portugal. Applied Geography 2017, 86, 128 -138.

AMA Style

Mónica Santos, Marcelo Fragoso, João A. Santos. Regionalization and susceptibility assessment to daily precipitation extremes in mainland Portugal. Applied Geography. 2017; 86 ():128-138.

Chicago/Turabian Style

Mónica Santos; Marcelo Fragoso; João A. Santos. 2017. "Regionalization and susceptibility assessment to daily precipitation extremes in mainland Portugal." Applied Geography 86, no. : 128-138.

Article
Published: 12 March 2017 in International Journal of Climatology
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The present study aims to investigate how large-scale atmospheric circulation may influence flash floods in Portugal. For this purpose, weather types (WTs) in a northeastern North Atlantic sector are used and flash floods between 1950 and 2003 were identified in six hydrographic basins: three in the north of Portugal and another three in the south of Portugal. An adapted methodology for flash flood detection on daily discharges is applied. A total of 131 flash floods were detected: 35 in the northern basins and 96 in the southern basins. WTs are identified using the National Oceanic and Atmospheric Administration 20th Century Reanalysis V2. The sea level pressure composites for flash flood days by WT reveal the large-scale atmospheric patterns underlying their occurrence. The results show that the cyclonic (C) type was strongly associated with flash flood days in the northern basins. The C type pattern features deep low pressure systems north of Iberia, much stronger than average for this WT. For the southern basins, the C type still shows the highest relevance for flood occurrence, but to a lesser extent, since the easterly wind (E) and dual anticyclonic (AA) types also acquire some importance. The flash flood-inducing AA-type events are characterized by atypical largely zonal troughs extending towards Portugal. The flash flood-inducing E type events hint at the occurrence of anomalously strong cut-off low pressure systems over southern Portugal. Although the significance of these systems to precipitation in Portugal was addressed in previous studies, a systematized assessment of their role on flash flood occurrences is herein provided for the first time. The presented flash flood detection methodology can be applied to other regions where hourly flow discharge data are not available, thus being an alternative to the more conventional detection algorithms.

ACS Style

Mónica Santos; João Carlos Andrade dos Santos; Marcelo Fragoso. Atmospheric driving mechanisms of flash floods in Portugal. International Journal of Climatology 2017, 37, 671 -680.

AMA Style

Mónica Santos, João Carlos Andrade dos Santos, Marcelo Fragoso. Atmospheric driving mechanisms of flash floods in Portugal. International Journal of Climatology. 2017; 37 ():671-680.

Chicago/Turabian Style

Mónica Santos; João Carlos Andrade dos Santos; Marcelo Fragoso. 2017. "Atmospheric driving mechanisms of flash floods in Portugal." International Journal of Climatology 37, no. : 671-680.

Journal article
Published: 31 August 2016 in Water
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Thresholds based on critical combinations of amount/duration of precipitation and flood events were estimated for the Corgo hydrographic basin, in northern Portugal. Thirty-one flood events in the Corgo basin were identified between 1865 and 2011 from a database of hydrometeorological disasters in Portugal. The minimum, maximum, and pre-warning thresholds that define the boundaries for flood occurrence were determined. The results show that the ratio between the total number of floods and precipitation events exceeding the minimum threshold denotes a relatively low probability of successful forecasting. This result may be due to the reduced number of flooding events in the floods database, which only include floods that caused damage as reported by the media. The estimated maximum threshold is not adequate for use in floods, since the majority of true positives are below this limit. However, and more interestingly, the retrospective verification of the estimated thresholds suggests that the minimum and pre-warning thresholds are well adjusted. Therefore, the application of these precipitation thresholds may contribute to minimize possible situations of pre-crisis or immediate crisis by reducing the flood consequences and the resources involved in emergency response to flood events.

ACS Style

Mónica Santos; Marcelo Fragoso. Precipitation Thresholds for Triggering Floods in the Corgo Basin, Portugal. Water 2016, 8, 376 .

AMA Style

Mónica Santos, Marcelo Fragoso. Precipitation Thresholds for Triggering Floods in the Corgo Basin, Portugal. Water. 2016; 8 (9):376.

Chicago/Turabian Style

Mónica Santos; Marcelo Fragoso. 2016. "Precipitation Thresholds for Triggering Floods in the Corgo Basin, Portugal." Water 8, no. 9: 376.

Journal article
Published: 22 October 2015 in Journal of Hydrology
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A long time series of damaging flood records in Northern Portugal for 1871–2011, gathered from a large number of documentary sources, is analyzed. The relationships between damaging floods (DFs) and relevant circulation weather types (CWTs) are also assessed. The DFs database has 1861 records and CWTs are identified using the 20th century reanalysis dataset v2. A coefficient of effectiveness (CE) is calculated for each weather type in order to assess DF–CWT relationships. Furthermore, conditions in the 10 days preceding a DF outbreak, type of flood and season were taken into account in CE calculations. The DF occurrences were responsible for 186 killed people, 59 injured, 29 missing, 1873 displaced and 15,924 homeless people. The monthly frequencies each CWT show that anticyclonic (A) and easterly wind (E) types are prevalent in winter, whereas R tends to prevail in the summer half of the year. However, the results show that the cyclonic (C) type has a positive frequency with DF occurrence (i.e. anomalously frequent), both on the DF day and on the nine previous days. The C type is commonly associated with southwesterly flow and unsettled weather conditions over Portugal, which are favorable to rain-generating mechanisms. The results also highlight some seasonal variation: in autumn, winter and spring, the C type is largely related to DFs, while the A and E types acquire higher preponderance in the summer. In effect, the latter two CWTs may trigger thunderstorms and heavy precipitation episodes in the Douro River catchment in summer.

ACS Style

Mónica Santos; J.A. Santos; M. Fragoso. Historical damaging flood records for 1871–2011 in Northern Portugal and underlying atmospheric forcings. Journal of Hydrology 2015, 530, 591 -603.

AMA Style

Mónica Santos, J.A. Santos, M. Fragoso. Historical damaging flood records for 1871–2011 in Northern Portugal and underlying atmospheric forcings. Journal of Hydrology. 2015; 530 ():591-603.

Chicago/Turabian Style

Mónica Santos; J.A. Santos; M. Fragoso. 2015. "Historical damaging flood records for 1871–2011 in Northern Portugal and underlying atmospheric forcings." Journal of Hydrology 530, no. : 591-603.

Journal article
Published: 20 October 2015 in Climate Research
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The final stage of the Little Ice Age in Europe was characterized by strong climatic variability. New documentary sources containing information referring to weather and climate are used in this study to reconstruct and to describe climate conditions in Portugal during the 18th century, mainly in the 1780s. Indexation of documentary data concerning hydric and thermal conditions was based on C. Pfister’s methodology and early instrumental data (1780s and 1790s) were used to verify the reconstruction. Precipitation and temperature were highly variable throughout the 18th century: an alternation of extremely hot to extremely cold months was found. Very cold years occurred mostly in the first 2 decades of the 18th century, but several other cold winters were also detected. Precipitation information is far more frequent than for temperature, and allowed yearly and seasonal indexations. The highest variability was detected in the 1730s and the 1780s. The early 1780s were very dry: during the winter and spring of 1781 and the spring of 1782 several drought episodes occurred, as confirmed by ‘pro-pluvia’ rogations. In contrast, heavy precipitation prevailed from 1784 onwards. The year 1786 was the rainiest in Portugal, triggering floods in northwestern and central Portugal. The year of 1788 was extremely wet and rainfall caused floods along the largest rivers: Douro, Mondego and Tagus. A storm that struck north - western Iberia between 23 and 24 February 1788 is analyzed in detailKLIMHIST: Reconstruction and model simulations of past climate in Portugal using documentary and early instrumental sources (17th-19th century) (PTDC/AAC-CLI/119078/2010

ACS Style

M Fragoso; David Marques; João Carlos Andrade dos Santos; Maria Joao Alcoforado; Inês Amorim; João Garcia; Luís Pedro Silva; Mdf Nunes. Climatic extremes in Portugal in the 1780s based on documentary and instrumental records. Climate Research 2015, 66, 141 -159.

AMA Style

M Fragoso, David Marques, João Carlos Andrade dos Santos, Maria Joao Alcoforado, Inês Amorim, João Garcia, Luís Pedro Silva, Mdf Nunes. Climatic extremes in Portugal in the 1780s based on documentary and instrumental records. Climate Research. 2015; 66 (2):141-159.

Chicago/Turabian Style

M Fragoso; David Marques; João Carlos Andrade dos Santos; Maria Joao Alcoforado; Inês Amorim; João Garcia; Luís Pedro Silva; Mdf Nunes. 2015. "Climatic extremes in Portugal in the 1780s based on documentary and instrumental records." Climate Research 66, no. 2: 141-159.

Journal article
Published: 26 January 2015 in Finisterra
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ACS Style

Paulo Canário; Marcelo Fragoso; Carla Mora; Helena Nogueira. Environmental conditions and childhood asthma in Lisbon. An exploratory analysis for autumn thunderstorm. Finisterra 2015, 49, 1 .

AMA Style

Paulo Canário, Marcelo Fragoso, Carla Mora, Helena Nogueira. Environmental conditions and childhood asthma in Lisbon. An exploratory analysis for autumn thunderstorm. Finisterra. 2015; 49 (98):1.

Chicago/Turabian Style

Paulo Canário; Marcelo Fragoso; Carla Mora; Helena Nogueira. 2015. "Environmental conditions and childhood asthma in Lisbon. An exploratory analysis for autumn thunderstorm." Finisterra 49, no. 98: 1.

Journal article
Published: 01 September 2013 in Atmospheric Research
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This study focuses on the spatial and temporal variability of selected extreme precipitation indices in Northern Portugal. Data were collected in the period of 1950–2000 from 39 meteorological and gauge stations. Tests of homogeneity (e.g., Pettit, SNHT, Buishand and Von Neumann tests) were performed for all the data collected from the gauge series, in order to identify and select the useful series to time variability analysis. Four extreme precipitation indices were investigated: total precipitation in wet days, with daily precipitation ≥1 mm (PRCPTOT); number of days with precipitation amount ≥ 30 mm (R30mm); the maximum 5 day precipitation amount (R×5day); and total precipitation amount ≥ 95th percentile (R95p). The Mann–Kendall non-parametric test was applied to detect long term (1950–2000) trends in the aforementioned indices of extremes. Annual and seasonal trends were analyzed in this study. The results showed a decrease in extreme precipitation indices during annual scale, spring, winter and summer but showed a slight increase during autumn. For most series, there is no statistically significant trend in the parameters of extreme precipitation analyzed. Out of all of the indices examined, only three rain-gauges showed significant trends on annual scale. On a seasonal timescale, extreme precipitation indices tended to decrease in winter, spring and summer in more than 80% of the precipitation series. The opposite was observed in autumn in which the four indices studied showed that more than 70% of the series had a positive trend. However, only 15% of the series showed a significant trend in winter, 46% in spring, only 2% in summer and 4% in autumn.info:eu-repo/semantics/publishedVersio

ACS Style

Mónica Santos; Marcelo Fragoso. Precipitation variability in Northern Portugal: Data homogeneity assessment and trends in extreme precipitation indices. Atmospheric Research 2013, 131, 34 -45.

AMA Style

Mónica Santos, Marcelo Fragoso. Precipitation variability in Northern Portugal: Data homogeneity assessment and trends in extreme precipitation indices. Atmospheric Research. 2013; 131 ():34-45.

Chicago/Turabian Style

Mónica Santos; Marcelo Fragoso. 2013. "Precipitation variability in Northern Portugal: Data homogeneity assessment and trends in extreme precipitation indices." Atmospheric Research 131, no. : 34-45.

Journal article
Published: 07 May 2013 in Atmospheric Research
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The present study employs a dataset of cloud-to-ground discharges over Portugal, collected by the Portuguese lightning detection network in the period of 2003–2009, to identify dynamically coherent lightning regimes in Portugal and to implement a statistical–dynamical modeling of the daily discharges over the country. For this purpose, the high-resolution MERRA reanalysis is used. Three lightning regimes are then identified for Portugal: WREG, WREM and SREG. WREG is a typical cold-core cut-off low. WREM is connected to strong frontal systems driven by remote low pressure systems at higher latitudes over the North Atlantic. SREG is a combination of an inverted trough and a mid-tropospheric cold-core nearby Portugal. The statistical–dynamical modeling is based on logistic regressions (statistical component) developed for each regime separately (dynamical component). It is shown that the strength of the lightning activity (either strong or weak) for each regime is consistently modeled by a set of suitable dynamical predictors (65–70% of efficiency). The difference of the equivalent potential temperature in the 700–500 hPa layer is the best predictor for the three regimes, while the best 4-layer lifted index is still important for all regimes, but with much weaker significance. Six other predictors are more suitable for a specific regime. For the purpose of validating the modeling approach, a regional-scale climate model simulation is carried out under a very intense lightning episode.

ACS Style

J.F. Sousa; M. Fragoso; S. Mendes; J. Corte-Real; J.A. Santos. Statistical–dynamical modeling of the cloud-to-ground lightning activity in Portugal. Atmospheric Research 2013, 132-133, 46 -64.

AMA Style

J.F. Sousa, M. Fragoso, S. Mendes, J. Corte-Real, J.A. Santos. Statistical–dynamical modeling of the cloud-to-ground lightning activity in Portugal. Atmospheric Research. 2013; 132-133 ():46-64.

Chicago/Turabian Style

J.F. Sousa; M. Fragoso; S. Mendes; J. Corte-Real; J.A. Santos. 2013. "Statistical–dynamical modeling of the cloud-to-ground lightning activity in Portugal." Atmospheric Research 132-133, no. : 46-64.

Journal article
Published: 01 December 2012 in Territorium
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No dia 23 de Dezembro de 2009 a região Oeste foi atingida por uma tempestade extratropical com ventos muito fortes (as rajadas foram superiores a 140 km/h), que derrubaram torres de alta tensão (provocando cortes no abastecimento de energia) e árvores. As consequências mais gravosas ocorreram nos distritos de Lisboa, Leiria e Santarém. As quedas de árvores constituíram a maior parte das ocorrências observadas, sendo por isso necessário e urgente proceder-se à realização de inventários sobre o estado fitossanitário das árvores em ambiente urbano.

ACS Style

Antonio Lopes; Marcelo Fragoso. Tempestade de 23 de dezembro de 2009. Causas meteorológicas e impactes na Região Oeste de Portugal continental. Territorium 2012, 23 -31.

AMA Style

Antonio Lopes, Marcelo Fragoso. Tempestade de 23 de dezembro de 2009. Causas meteorológicas e impactes na Região Oeste de Portugal continental. Territorium. 2012; (19):23-31.

Chicago/Turabian Style

Antonio Lopes; Marcelo Fragoso. 2012. "Tempestade de 23 de dezembro de 2009. Causas meteorológicas e impactes na Região Oeste de Portugal continental." Territorium , no. 19: 23-31.

Journal article
Published: 23 March 2012 in Natural Hazards and Earth System Sciences
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This study aims to characterise the rainfall exceptionality and the meteorological context of the 20 February 2010 flash-floods in Madeira (Portugal). Daily and hourly precipitation records from the available rain-gauge station networks are evaluated in order to reconstitute the temporal evolution of the rainstorm, as its geographic incidence, contributing to understand the flash-flood dynamics and the type and spatial distribution of the associated impacts. The exceptionality of the rainstorm is further confirmed by the return period associated with the daily precipitation registered at the two long-term record stations, with 146.9 mm observed in the city of Funchal and 333.8 mm on the mountain top, corresponding to an estimated return period of approximately 290 yr and 90 yr, respectively. Furthermore, the synoptic associated situation responsible for the flash-floods is analysed using different sources of information, e.g., weather charts, reanalysis data, Meteosat images and radiosounding data, with the focus on two main issues: (1) the dynamical conditions that promoted such anomalous humidity availability over the Madeira region on 20 February 2010 and (2) the uplift mechanism that induced deep convection activity.

ACS Style

M. Fragoso; Ricardo Trigo; Joaquim G. Pinto; S. Lopes; António Lopes; S. Ulbrich; C. Magro. The 20 February 2010 Madeira flash-floods: synoptic analysis and extreme rainfall assessment. Natural Hazards and Earth System Sciences 2012, 12, 715 -730.

AMA Style

M. Fragoso, Ricardo Trigo, Joaquim G. Pinto, S. Lopes, António Lopes, S. Ulbrich, C. Magro. The 20 February 2010 Madeira flash-floods: synoptic analysis and extreme rainfall assessment. Natural Hazards and Earth System Sciences. 2012; 12 (3):715-730.

Chicago/Turabian Style

M. Fragoso; Ricardo Trigo; Joaquim G. Pinto; S. Lopes; António Lopes; S. Ulbrich; C. Magro. 2012. "The 20 February 2010 Madeira flash-floods: synoptic analysis and extreme rainfall assessment." Natural Hazards and Earth System Sciences 12, no. 3: 715-730.