24 research outputs found
Alteração climática dos Ãndices de estabilidade na Peninsula Iberica
Mestrado em Meteorologia e Oceanografia FÃsicaEste trabalho tem como objetivo a comparação da intensidade,
frequência e distribuição de um conjunto de Ãndices de estabilidade
atmosférica simulados entre o clima histórico (1986-2005) e um cenário
climático (2081-2100) na PenÃnsula Ibérica. Considerou-se o cenário de
emissão de gases RCP8.5. Estes Ãndices avaliam a instabilidade
atmosférica que é um elemento fundamental e percursor no
desenvolvimento de tempestades. Através dos seus valores limite, é
possÃvel estimar alterações na probabilidade de ocorrência de eventos
extremos que se poderão desenvolver no clima futuro, relativamente ao
histórico. Primeiro, utilizou-se um conjunto de simulações do WRF com
dois forçamentos: reanálises do ERA-Interim e um modelo do Max
Planck Institute. De seguida, foram calculados diferentes Ãndices de
estabilidade. A validação do modelo consistiu no cálculo das médias
sazonais, da sua diferença e das respetivas PDFs dos Ãndices simulados
pelo WRF-MPI e WRF-ERA. Verifica-se uma sobrestimação do CAPE,
SHR6km (vento de corte) e SWEAT simulados pelo WRF-MPI. No
entanto, nos campos dos Ãndices simulados pelos dois forçamentos para
o perÃodo histórico, verifica-se que os padrões espaciais são
semelhantes apesar das diferenças na intensidade. Como as alterações
climáticas dos Ãndices são avaliadas através de diferenças, estas
discrepâncias não invalidam a utilização do modelo no futuro.
Posteriormente foram estudadas as alterações climáticas dos Ãndices
através da comparação entre o clima histórico e futuro. Estima-se um
aumento da intensidade do CAPE e uma diminuição (aumento) da
frequência de eventos com intensidade reduzida (elevada). Estas
alterações são robustas no verão e outono. Também é esperado um
aumento da intensidade do SHR6km na primavera e inverno tal como
da frequência de SHR6km elevado nestas estações e uma redução da
intensidade e da frequência de eventos com SHR6km elevado nas
restantes. Haverá um possÃvel aumento robusto da intensidade do
SWEAT no verão e outono, bem como da frequência destes valores.
Concluindo, será provável um aumento da frequência dos ambientes
favoráveis ao desenvolvimento de tempestades, devido a uma maior
intensidade e probabilidade de ocorrência de valores extremos do CAPE
e do SWEAT. No entanto, a redução do SHR6km, poderá diminuir a
organização das tempestades e o seu tempo de vida.The purpose of this study is to compare the intensity, frequency and
distribution of several atmospheric stability indices simulated between
the historical climate (1986-2005) and a climate scenario (2081-2100) in
the Iberian Peninsula. It was considered the gases emission scenario
RCP8.5. These indices evaluate the atmospheric instability which is a
basic and precursor ingredient needed for thunderstorm development.
By using their threat values, it is possible to estimate the changes in the
occurrence probability of extreme events which may develop in the
future climate, relatively to the historical. First, it was used a WRF
simulation ensemble driven by two forcings: ERA-Interim reanalysis and
a Max Planck Institute model. Then, it was calculated a group of different
stability indices. The model validation consisted on the calculus of the
seasonal means, their differences and the respective PDFs of the indices
simulated by WRF-MPI and WRF-ERA. It is verified an overestimation of
CAPE, SHR6km (wind shear) and SWEAT simulated by WRF-MPI.
However, in the indices fields simulated by both forcings, for the
historical period, it is verified that the spatial patterns are similar,
although differences in intensity. As the climate changes are evaluated
by differences, these discrepancies don’t invalidate the model utilization
in the future. Afterwards it was studied the climate changes of the
indices by comparing the historical and future climate. In the future, it is
estimated an increase of CAPE intensity and a decrease (increase) of the
frequency of events with low (high) intensity. These changes are robust
in the summer and autumn. It is also expected an increase of SHR6km
intensity in spring and winter, just as of high SHR6km frequency in those
seasons and a decrease of intensity and frequency of events with high
SHR6km on the other seasons. There will be a robust increase of SWEAT
intensity in the summer and autumn, as well as the frequency of those
values. Concluding, it will probably occur an increase of the frequency of
favorable environments to the development of thunderstorms, due to
the increase of the intensity and occurrence probability of extreme CAPE
and SWEAT values. However, the decrease of SHR6km, may reduce the
thunderstorms organization and their lifetime
Atmospheric Rivers over the Arctic with the ICON model
The Arctic climate changes faster than the ones of other regions, but the relative role of the individual feedback mechanisms contributing to Arctic amplification is still unclear. Atmospheric Rivers (ARs) are narrow and transient river-style moisture flows arriving from the sub-polar regions. The integrated water vapour transport associated with ARs can explain up to 70% of the precipitation variance north of 70N. However, there are still uncertainties regarding the specific role and the impact of ARs on the Arctic climate variability. For the first time, the high-resolution ICON modelling framework is used over the Arctic region (from 13 km down to ca. 2 km) to investigate processes related with anomalous moisture transport into the Arctic. Based on a case study for Svalbard, the representation of the atmospheric circulation and the spatio-temporal structure of water vapour, temperature, and precipitation and snowfall within the limited-area mode (LAM) of the ICON model is assessed. The impact on the surface energy budget will be calculated
Atmospheric rivers and associated precipitation patterns during the ACLOUD/PASCAL campaigns near Svalbard (May-June 2017): case studies using observations, reanalyses, and a regional climate model
Recently, a significant increase in the atmospheric moisture content has been documented over the Arctic, where both local contributions and poleward moisture transport from lower latitudes can play a role. This study focuses on the anomalous moisture transport events confined to long and narrow corridors, known as atmospheric rivers (ARs), which are expected to have a strong influence on Arctic moisture amounts, precipitation, and the energy budget. During two concerted intensive measurement campaigns – Arctic CLoud Observations Using airborne measurements during polar Day (ACLOUD) and the Physical feedbacks of Arctic planetary boundary layer, Sea ice, Cloud and AerosoL (PASCAL) – that took place at and near Svalbard, three high-water-vapour-transport events were identified as ARs, based on two tracking algorithms: the 30 May event, the 6 June event, and the 9 June 2017 event. We explore the temporal and spatial evolution of the events identified as ARs and the associated precipitation patterns in detail using measurements from the French (Polar Institute Paul Emile Victor) and German (Alfred Wegener Institute for Polar and Marine Research) Arctic Research Base (AWIPEV) in Ny-Ålesund, satellite-borne measurements, several reanalysis products (the European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA) Interim (ERA-Interim); the ERA5 reanalysis; the Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2); the Climate Forecast System version 2 (CFSv2); and the Japanese 55-Year Reanalysis (JRA-55)), and the HIRHAM regional climate model version 5 (HIRHAM5). Results show that the tracking algorithms detected the events differently, which is partly due to differences in the spatial and temporal resolution as well as differences in the criteria used in the tracking algorithms. The first event extended from western Siberia to Svalbard, caused mixed-phase precipitation, and was associated with a retreat of the sea-ice edge. The second event, 1 week later, had a similar trajectory, and most precipitation occurred as rain, although mixed-phase precipitation or only snowfall occurred in some areas, mainly over the coast of north-eastern Greenland and the north-east of Iceland, and no differences were noted in the sea-ice edge. The third event showed a different pathway extending from the north-eastern Atlantic towards Greenland before turning south-eastward and reaching Svalbard. This last AR caused high precipitation amounts on the east coast of Greenland in the form of rain and snow and showed no precipitation in the Svalbard region. The vertical profiles of specific humidity show layers of enhanced moisture that were concurrent with dry layers during the first two events and that were not captured by all of the reanalysis datasets, whereas the HIRHAM5 model misrepresented humidity at all vertical levels. There was an increase in wind speed with height during the first and last events, whereas there were no major changes in the wind speed during the second event. The accuracy of the representation of wind speed by the reanalyses and the model depended on the event. The objective of this paper was to build knowledge from detailed AR case studies, with the purpose of performing long-term analysis. Thus, we adapted a regional AR detection algorithm to the Arctic and analysed how well it identified ARs, we used different datasets (observational, reanalyses, and model) and identified the most suitable dataset, and we analysed the evolution of the ARs and their impacts in terms of precipitation. This study shows the importance of the Atlantic and Siberian pathways of ARs during spring and beginning of summer in the Arctic; the significance of the AR-associated strong heat increase, moisture increase, and precipitation phase transition; and the requirement for high-spatio-temporal-resolution datasets when studying these intense short-duration events
Ozone effects on Douro vineyards under climate change
Tropospheric ozone (O3) levels in southern Europe have an increasing tendency, in close
relation with the higher incidence of hot summers and heatwaves. Given that O3 is one of the most
damaging pollutants for vegetation, known to affect productivity and quality of crops, it is necessary
to develop more rigorous and consistent methods of risk assessment that consider climate change
conditions. Studying the O3 deposition over the Douro Demarcated Region (DDR), which is one of
the most productive wine areas in Portugal, and assessing its potential effects under a climate change
scenario, was the purpose of this study. To that end, the chemical transport model CHIMERE, with
a spatial resolution of 1 km2, fed by meteorological data from the WRF model, was applied for a
recent past climate (2003 to 2005) and future mid-term (2049 and 2064) and long-term (2096 and 2097)
scenarios. Simulations for future climate were performed considering: (i) only the climate change
effect, and (ii) the effect of climate change together with future air pollutant emissions. The assessment
of the potential damage in terms of wine productivity and quality (sugar content) was performed
through analysis of O3 deposition and the application of concentration–response functions, based on
AOT40 values. Modeling results show that a reduction in emission of O3 precursors can successfully
decrease AOT40 levels in the DDR, but it is not enough to accomplish the European Commission
target value for the protection of vegetation. If the emissions remain constant, the exposure–response
functions indicate that, in the long-term, AOT40 levels could worsen wine productivity and quality.The authors wish to thank the financial support of FEDER through the COMPETE Program
and the national funds from FCT—Science and Technology Portuguese Foundation for financing the
DOUROZONE project (PTDC/AAG-MAA/3335/2014; POCI-01-0145-FEDER-016778). Thanks is
also due for the financial support to the PhD grant of A. Ascenso (SFRH/BD/136875/2018). Thanks
is due to FCT/MCTES for the financial support to CESAM (UIDP/50017/2020+UIDB/50017/2020),
through national fundsinfo:eu-repo/semantics/publishedVersio
Climate change potential effects on grapevine bioclimatic indices: a case study for the Portuguese demarcated Douro Region (Portugal)
In this work, bioclimatic parameters and indices relevant to the grapevine are estimated for the years 2000 (recent-pat), 2049 (medium-term future) and 2097 (long-term future), based on very high resolution (1 km × 1 km) MPI-WRF RCP8.5 climate simulations. The selected parameters and indices are the mean temperature during the grapevine growing season period (April to October, Tgs), the cumulative rainfall during the grapevine growing season period (Pgs), the Winkler index (WI), the Huglin heliothermic index (HI), the night cold index (CI) and the dryness index (DI). In general, a significant increase in mean temperature during the grapevine growing season period is observed, together with a significant decrease in precipitation. The recent-past WI is associated with the production of high-quality wines; the higher values predicted for the future represent intensive production of wines of intermediate quality. The HI shows the passage of a grapevine growing region considered as temperate-warm to a warm category of higher helio-thermicity. The recent-past CI indicates very cool conditions (associated with quality wines), while in the future there is a tendency for temperate or warmer nights. Finally, DI indicates an increase in water stress considered already high under the recent-past climate conditions. These results point to an increased climatic stress on the Douro region wine production and increased vulnerability of its vine varieties, providing evidence to support strategies aimed to preserve the high-quality wines in the region and their typicality in a sustainable way.The authors wish to thank the financial support of the
DOUROZONE project (PTDC/AAG-MAA/3335/2014; POCI-
01-0145-FEDER-016778) through the Project 3599 – Promoting
the scientific production and the technological development,
and thematic networks (3599-PPCDT) and through
FEDER, and the national funds from FCT-Science and
Technology Portuguese Foundation for the doctoral grants of Blanco-Ward, D. (SFRH/BD/139193/2018) and Silveira, C. (SFRH/BD/112343/2015). Thanks, are also due for the financial
support to CESAM (UID/AMB/50017 - POCI-01-0145-FEDER-
007638), to FCT/MEC through national funds (PIDDAC), and
the co-funding by the FEDER, within the PT2020 Partnership
Agreement and Compete 2020.info:eu-repo/semantics/publishedVersio
Analysis of climate change indices in relation to wine production: a case study in the Douro region (Portugal)
Climate change is of major relevance to wine production as most of the wine-growing regions of
the world, in particular the Douro region, are located within relatively narrow latitudinal bands with average
growing season temperatures limited to 13–21◦C. This study focuses on the incidence of climate variables and
indices that are relevant both for climate change detection and for grape production with particular emphasis
on extreme events (e.g. cold waves, storms, heat waves). Dynamical downscaling ofMPI-ESM-LR global data
forced with RCP8.5 climatic scenario is performed with the Weather Research and Forecast (WRF) model to
a regional scale including the Douro valley of Portugal for recent-past (1986–2005) and future periods (2046–
2065; 2081–2100). The number, duration and intensity of events are superimposed over critical phenological
phases of the vine (dormancy, bud burst, flowering, v´eraison, and maturity) in order to assess their positive
or negative implications on wine production in the region. An assessment on the statistical significance of
climatic indices, their differences between the recent-past and the future scenarios and the potential impact
on wine production is performed. Preliminary results indicate increased climatic stress on the Douro region
wine production and increased vulnerability of its vine varieties. These results will provide evidence for future
strategies aimed to preserve the high-quality wines in the region and their typicality in a sustainable way.The authors wish to thank the financial support of the DOUROZONE project (PTDC/AAG-MAA/3335/2014; POCI- 01-0145-FEDER-016778) through the Project 3599 – Promoting the scientific production and the technological development, and thematic networks (3599-PPCDT) and through FEDER.info:eu-repo/semantics/publishedVersio
Grapevine bioclimatic indices in relation to climate change: a case study in the Portuguese Douro Demarcated Region
Climate change is of major relevance to wine production as most of the wine-growing regions of the world, in
particular the Douro region, are located within relatively narrow latitudinal bands with average growing season temperatures limited to 13-21ºC. This study focuses on the temporal variability of three grapevine bioclimatic indices, which are commonly used as part of the Geoviticulture Multicriteria Climatic Classification System (MCC) to classify the climate of wine producing regions worldwide. Dynamical downscaling of MPI-ESM-LR global data forced with RCP8.5 climatic scenario is performed with the Weather Research and Forecast (WRF) model to a regional scale including the Douro valley of Portugal for recent-past (1986-2005) and future periods (2046-2065; 2081-2100). Results indicate significant shifts towards warmer and dryer conditions during
the growing season and higher night temperatures during the grape ripening period. An assessment on the statistical significance of the differences between the recent-past and the future scenarios and the potential impact on wine production in the study area is performed. These results will provide evidence for future strategies aimed to preserve the high-quality wines in the region and their typicality in a sustainable way.The authors wish to thank the financial support of the
DOUROZONE project (PTDC/AAG-MAA/3335/2014; POCI-
01-0145-FEDER-016778) through the Project 3599 –
Promoting the scientific production and the technological
development, and thematic networks (3599-PPCDT) and
through FEDER, and the national funds from FCT – Science
and Technology Portuguese Foundation for the doc grant of C.
Silveira (SFRH/BD/112343/2015).info:eu-repo/semantics/publishedVersio
A systematic assessment of water vapor products in the Arctic: from instantaneous measurements to monthly means
Water vapor is an important component in the water and energy cycle of the Arctic. Especially in light of Arctic amplification, changes in water vapor are of high interest but are difficult to observe due to the data sparsity of the region. The ACLOUD/PASCAL campaigns performed in May/June 2017 in the Arctic North Atlantic sector offers the opportunity to investigate the quality of various satellite and reanalysis products. Compared to reference measurements at R/V Polarstern frozen into the ice (around 82∘ N, 10∘ E) and at Ny-Ålesund, the integrated water vapor (IWV) from Infrared Atmospheric Sounding Interferometer (IASI) L2PPFv6 shows the best performance among all satellite products. Using all radiosonde stations within the region indicates some differences that might relate to different radiosonde types used. Atmospheric river events can cause rapid IWV changes by more than a factor of 2 in the Arctic. Despite the relatively dense sampling by polar-orbiting satellites, daily means can deviate by up to 50 % due to strong spatio-temporal IWV variability. For monthly mean values, this weather-induced variability cancels out, but systematic differences dominate, which particularly appear over different surface types, e.g., ocean and sea ice. In the data-sparse central Arctic north of 84∘ N, strong differences of 30 % in IWV monthly means between satellite products occur in the month of June, which likely result from the difficulties in considering the complex and changing surface characteristics of the melting ice within the retrieval algorithms. There is hope that the detailed surface characterization performed as part of the recently finished Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) will foster the improvement of future retrieval algorithms
Climate change impact on a wine-producing region using a dynamical downscaling approach: Climate parameters, bioclimatic indices and extreme indices
Climate change is of major relevance to wine production as most of the winegrowing
regions of the world are located within relatively narrow latitudinal bands
with average growing-season temperatures (GSTs) limited to 13–21 C. This study
focuses on the incidence of climate variables and indices that are relevant both for
climate change assessment and for grape production, with emphasis on grapevine
bioclimatic indices and extreme events (e.g., cold waves, storms, heatwaves).
Dynamical downscaling of European Reanalysis-Interim and Max Planck Institute
Earth System low-resolution global simulations forced with a Representative Concentration
Pathway 8.5 (RCP8.5) greenhouse gas emission scenario was performed
with the Weather Research and Forecast (WRF) model to a regional scale including
the Douro Valley of Portugal for recent-past (1986–2005) and future periods
(2046–2065, 2081–2100). The number, duration and intensity of events were superimposed
over critical phenological phases estimated by using a specific local
grapevine varietal phenological model in order to assess their positive or negative
implications for wine production in the region. An assessment of the relevance of
climate parameters and indices and their progression in recent-past and future climate
scenarios with regard to the potential impact on wine production was performed.
Results indicate a positive relation between higher growing-season heat
accumulations and greater vintage yields. A moderate incidence of very hot days
(daily maximum temperature above 35 C) and drought from pre-véraison phenological
conditions have a positive association with vintage ratings. However, the
mid- and long-term WRF-MPI RCP8.5 future climate scenarios reveal shifts to
warmer and drier conditions, with the mean GST not remaining within range for
quality wine production in the long-term future climate scenario. These results indicate
potential impacts that suggest a range of strategies to maintain wine production
and quality in the region.The authors wish to thank the DOUROZONE project
(PTDC/AAG-MAA/3335/2014; POCI-01-0145-FEDER-
016778) for financial support through Project 3599 – Promoting
the Scientific Production and the Technological
Development, and Thematic Networks (3599-PPCDT) – and
through FEDER, and the national funds from FCT-Science
and Technology Portuguese Foundation for the doctoral
grant of D. Blanco-Ward (SFRH/BD/139193/2018). Thanks
are also due for the financial support to CESAM
(UID/AMB/50017 - POCI-01-0145-FEDER-007638), to
FCT/MEC through national funds, and the co-funding by
FEDER within the PT2020 Partnership Agreement and
Compete 2020.info:eu-repo/semantics/publishedVersio
Climate Change Projections of Extreme Temperatures for the Iberian Peninsula
The comprehensive characterization of heat waves and extreme hot days is fundamental for policymakers due to its vast implications for human health. This study evaluates extreme temperature changes over the Iberian Peninsula for the present climate and future projections, considering extreme temperature indices, cold/heat waves, and a recovery factor, using the Weather Research and Forecasting model. The projected temperatures show an increase of over 6 °C. An increase in the number of summer days and tropical nights and a decrease in frost days is expected. The number of heat waves and their duration and intensity are expected to increase. The number of heat wave days are expected to increase, with much of the average summer season being under heat wave conditions. The recovery factor is expected to decrease. Cold spells are projected to decrease in terms of number, intensity, duration, and number of spell days, whereas the recovery factor is expected to increase. Heat wave analysis was combined with maximum temperature thresholds to isolate extreme heat waves. The results show an increase in extreme heat wave days, with regions experiencing over 10 heat wave days with maximum temperature surpassing 45 °C for the long-term future