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Alexandre Ramos   Dr.  Post Doctoral Researcher 
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Alexandre Ramos published an article in December 2018.
Top co-authors See all
José Vaquero

224 shared publications

Instituto Universitario de Investigación del Agua, Cambio Climático y Sostenibilidad (IACYS), Universidad de Extremadura, Badajoz, Spain

Ricardo M. Trigo

201 shared publications

Instituto Geofísico do Infante D. Luiz (IGIDL), Universidade de Lisboa, Ed C8, Piso 6, 1749-016, Rua da Escola Politécnica nº 58, 1250-102 Lisboa, Lisbon, PORTUGAL

Luis Gimeno

143 shared publications

Environmental Physics Laboratory (EPhysLab), Facultade de Ciencias, Universidad de Vigo, Ourense 32004, Spain

Raquel Nieto

119 shared publications

Environmental Physics Laboratory (EPhysLab), Facultade de Ciencias, Universidad de Vigo, Ourense 32004, Spain

José Luís Zêzere

56 shared publications

Institute of Geography and Spatial Planning – Universidade de Lisboa, Rua Branca Edmée Marques, Cidade Universitária, Lisbon, Portugal

56
Publications
87
Reads
19
Downloads
292
Citations
Publication Record
Distribution of Articles published per year 
(2008 - 2018)
Total number of journals
published in
 
29
 
Publications See all
Article 1 Read 0 Citations Atmospheric Rivers over the Arctic: Lagrangian Characterisation of Their Moisture Sources Marta Vázquez, Iago Algarra, Jorge Eiras-Barca, Alexandre M.... Published: 26 December 2018
Water, doi: 10.3390/w11010041
DOI See at publisher website ABS Show/hide abstract
In recent years, the Arctic has become a subject of special interest due to the drastic effect of climate change over the region. Despite that there are several mechanisms that influence the Arctic region; some recent studies have suggested significant influences of moisture transport over the observed loss of sea ice. Moisture transport can affect the region in different ways: direct precipitation over the region, radiative effect from the cloud cover and through the release of latent heat. Atmospheric rivers (ARs) represent one of the main events involved in moisture transport from the tropics to the mid-latitudes and despite having been shown especially relevant on the northward advection, their effect over the Arctic has not been deeply investigated. The aim of this work was to establish the groundwork for future studies about the effect of ARs linked to moisture transport over the Arctic region. For this purpose, an automated algorithm was used to identify regions of maximum AR occurrence over the Arctic. This was done by analysing the number of AR detections every month over a band of 10° of latitude centred on 60° N. The Lagrangian model FLEXPART was used to find the areas where the ARs take their moisture to the Arctic. Using this model, the anomalous moisture contribution to these baroclinic structures was analysed taking into account only the dates of AR occurrence. From the results, it appears that the main moisture sources for AR events extend over the North Atlantic and North Pacific oceans; moreover, the local input of moisture over the region of maximum AR occurrence seems to be especially relevant. In general terms, moisture comes from major evaporative areas over the western part of the oceanic regions in the band between 30° and 40° N for most months in the year, showing a continental origin in the summer months. This behaviour agrees with the climatological moisture transport into the Arctic determined in previous studies. However, in special association with AR events, an intensification of local moisture uptake is observed over the area of maximum AR activity and nearby. The study of the origin of this moisture and associated anomalies for Arctic ARs is an important step in the analysis of the effect of these structures on the Arctic environment.
Article 1 Read 2 Citations The ‘Day Zero’ Cape Town drought and the poleward migration of moisture corridors Pedro M Sousa, Ross C Blamey, Chris J C Reason, Alexandre M.... Published: 17 December 2018
Environmental Research Letters, doi: 10.1088/1748-9326/aaebc7
DOI See at publisher website ABS Show/hide abstract
Since 2015 the greater Cape Town area (~3.7 million people) has been experiencing the worst drought of the last century. The combined effect of this prolonged dry period with an ever-growing demand for water culminated in the widely publicized "Day Zero" water crisis. Here we show how: i) consecutive significant decreases in rainfall during the last three winters led to the current water crisis; ii) the 2015-2017 record breaking drought was driven by a poleward shift of the Southern Hemisphere moisture corridor; iii) a displacement of the jet-stream and South Atlantic storm-track has imposed significantly drier conditions to this region. Decreasing local rainfall trends are consistent with an expansion of the semi-permanent South Atlantic High Pressure, and reflected in the prevalence of the positive phase of the Southern Annular Mode. Large-scale forcing mechanisms reveal the intensification and migration of subtropical anticyclones towards the mid-latitudes, highlighting the link between these circulation responses and the record warm years during 2015-2017 at the global scale.
Article 0 Reads 0 Citations Assessing the Use of Satellite-Based Estimates and High-Resolution Precipitation Datasets for the Study of Extreme Preci... Riccardo Hénin, Margarida L. R. Liberato, Alexandre M. Ramos... Published: 19 November 2018
Water, doi: 10.3390/w10111688
DOI See at publisher website ABS Show/hide abstract
An assessment of daily accumulated precipitation during extreme precipitation events (EPEs) occurring over the period 2000–2008 in the Iberian Peninsula (IP) is presented. Different sources for precipitation data, namely ERA-Interim and ERA5 reanalysis by the European Centre for Medium-Range Weather Forecast (ECMWF) and Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA), both in near-real-time and post-real-time releases, are compared with the best ground-based high-resolution (0.2° × 0.2°) gridded precipitation dataset available for the IP (IB02). In this study, accuracy metrics are analysed for different quartiles of daily precipitation amounts, and additional insights are provided for a subset of EPEs extracted from an objective ranking of extreme precipitation during the extended winter period (October to March) over the IP. Results show that both reanalysis and multi-satellite datasets overestimate (underestimate) daily precipitation sums for the least (most) extreme events over the IP. In addition, it is shown that the TRMM TMPA precipitation estimates from the near-real-time product may be considered for EPEs assessment over these latitudes. Finally, it is found that the new ERA5 reanalysis accounts for large improvements over ERA-Interim and it also outperforms the satellite-based datasets.
Article 0 Reads 0 Citations Earlier awareness of extreme winter precipitation across the western Iberian Peninsula David A. Lavers, David S. Richardson, Alexandre M. Ramos, Er... Published: 24 September 2018
Meteorological Applications, doi: 10.1002/met.1727
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Extreme winter precipitation across the western Iberian Peninsula is frequently connected to atmospheric rivers, which are bands of intense water vapour transport (integrated vapour transport, IVT). Recent research over Western Europe has shown that by using the IVT forecasts in the form of the extreme forecast index (EFI), a tool that identifies anomalous conditions, it is possible to provide earlier awareness of extreme precipitation events than by using the precipitation EFI directly. The aim of the present paper is to assess these findings further by identifying the regions of Iberia where such IVT forecasts are skilful and for what lead times. Employing the EFI on the European Centre for Medium‐Range Weather Forecasts (ECMWF) Integrated Forecasting System ensemble for winters 2015/2016 and 2016/2017 and using high‐density daily surface precipitation observations, the IVT EFI is shown to have slightly more skill (than the precipitation EFI) in discriminating extreme precipitation anomalies across the western Iberian Peninsula (Portugal and northwestern Spain) from forecast day 11 onwards. The reasoning is that the higher IVT predictability means that the IVT EFI is more able to detect the approximate location of extreme events at earlier lead times than the precipitation EFI. In contrast, for shorter forecast lead times, the precipitation EFI is more skilful. Also, when considering the entire Iberian Peninsula, the precipitation EFI is more skilful and more appropriate to monitor for potential extremes even at longer lead times.
Article 0 Reads 2 Citations From Amazonia to southern Africa: atmospheric moisture transport through low-level jets and atmospheric rivers Alexandre M. Ramos, Ross C. Blamey, Iago Algarra, Raquel Nie... Published: 18 September 2018
Annals of the New York Academy of Sciences, doi: 10.1111/nyas.13960
DOI See at publisher website
Article 1 Read 1 Citation Assigning precipitation to mid-latitudes fronts on sub-daily scales in the North Atlantic and European sector: Climatolo... Riccardo Hénin, Alexandre M. Ramos, Sebastian Schemm, Célia ... Published: 04 September 2018
International Journal of Climatology, doi: 10.1002/joc.5808
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