Search results for "reanalysis"
showing 10 items of 13 documents
Denboratik kausara: -nez gero kausazko lokailuaren garapenaz
2019
LABURPENA Lan honetan -nez gero atzizki multzoaren garapena dugu aztergai, lehen testuetatik hasi eta gaurdaino. Denbora lokailuetatik sortu diren beste kausazko lokailu asko bezala, -nez gero batez ere mintza-ekintzak eta antzekoak justifikatzeko erabiltzen da. Hala ere, kausa neutroagoak adierazteko ere erabiltzen da. Gaztelaniaz ez bezala, menpeko perpausaren kokagunea ez da aldatu azken mendeotan eta funtzio informatiboan ere ez dugu aldakuntza handirik ikusten. Sumatzen dugun garapen nagusia da beharbada edukizko kausazko neutroetan maizago erabiltzeko joera. Oro har, -nez gero kausazko menderagailuak, gazt. ya que-rekin baino, antz handiagoa du fr. puisque eta ing. since lokailuekin. …
Wave energy assessment in Sicily (Italy)
2015
Abstract This research presents an estimation of wave energy potential in Sicily (Italy) carried out using both buoy wave measurements from Rete Ondametrica Nazionale (RON), the Italian Government wave buoy network, and wave parameter data by ERA-INTERIM, a recent meteorological reanalysis project of the European Centre for Medium-Range Weather Forecasts (ECMWF). Starting from these offshore data, we first identified the western part of Sicily as the area with a higher availability of offshore wave energy; subsequently, we selected a study area in the western part of the south coast and assessed the nearshore potential energy by performing propagation using a spectral model (SWAN). The near…
Droughts Over Amazonia in 2005, 2010, and 2015: A Cloud Cover Perspective
2018
Amazon forests experienced recent severe droughts in an anomalous short period induced by different mechanisms and had different length periods and spatial patterns. Droughts of 2005 and 2010 were attributed to anomalous Sea Surface Temperature (SST) over the Tropical North Atlantic (TNA) during the dry season, but the 2010 drought was more severe and remained for a longer period because it was also induced in late 2009 by a moderate to strong El Niño (EN). Drought in 2015 led to unprecedented warming and extreme soil moisture deficits over some regions, and it was attributed to a very strong EN. Several studies analyzed these drought events regarding different climatic factors such as anom…
Trends in column integrated water vapour over Europe from 1973 to 2003
2010
The spatial and temporal variations of atmospheric precipitable water (PW) content anomalies were analysed over Europe from 1973 to 2003 using daily data (0000 and 1200 UTC) from National Center of Environmental Prediction and National Center of Atmospheric Research Reanalysis project (NCEP-1) and in situ radiosonde data. Mann–Kendall trend tests were applied to long-term PW time series. Technology changes influence PW radiosonde trends, although these are in agreement with NCEP-1 trends. Over the south of the Iberian Peninsula, trends are negative and statistically significant ( 0.04 mm year−1; p < 0.05). Seasonal trends revealed negative and significant trends over the Iberian Peninsula f…
Evaluation of the ERA5 reanalysis-based Universal Thermal Climate Index on mortality data in Europe
2021
Air temperature has been the most commonly used exposure metric in assessing relationships between thermal stress and mortality. Lack of the high-quality meteorological station data necessary to adequately characterize the thermal environment has been one of the main limitations for the use of more complex thermal indices. Global climate reanalyses may provide an ideal platform to overcome this limitation and define complex heat and cold stress conditions anywhere in the world. In this study, we explored the potential of the Universal Thermal Climate Index (UTCI) based on ERA5 – the latest global climate reanalysis from the European Centre for Medium-Range Weather Forecasts (ECMWF) – as a h…
Seasonal evolution of boundary layer heat content in the West African monsoon from the NCEP/NCAR reanalysis (1968-1998)
2000
Using the National Center for Environmental Prediction (NCEP)/National Centre for Atmospheric Research (NCAR) dataset over the period 1968–1998, the basic relationships between July and September monsoon circulation variations over West Africa and monthly meridional distribution of moist static energy (MSE) content in the boundary layer are portrayed. Wet minus dry stratified analyses relative to Sudan–Sahel rainfall show that particular April–June meridional patterns of near-surface MSE contents, south of 10°N, could control the amplitude and timing of the monsoon rainy season. Relative to the driest July–September situations, the wettest ones have been, on average, preceded by delayed but…
Comparing the use of ERA5 reanalysis dataset and ground-based agrometeorological data under different climates and topography in Italy
2022
Study region: The study region is represented by seven irrigation districts distributed under different climate and topography conditions in Italy. Study focus: This study explores the reliability and consistency of the global ERA5 single levels and ERA5-Land reanalysis datasets in predicting the main agrometeorological estimates commonly used for crop water requirements calculation. In particular, the reanalysis data was compared, variable-by-variable (e.g., solar radiation, R; air temperature, T; relative humidity, RH; wind speed, u; reference evapotranspiration, ET), with in situ agrometeorological observations obtained from 66 automatic weather stations (2008–2020). In addition, the pre…
Intercomparison of remote-sensing based evapotranspiration algorithms over amazonian forests
2019
Abstract Evapotranspiration (ET) is considered a key variable in the understanding of the Amazonian tropical forests and their response to climate change. Remote-Sensing (RS) based evapotranspiration models are presented as a feasible means in order to provide accurate spatially-distributed ET estimates over this region. In this work, the performance of four commonly used ET RS models was evaluated over Amazonia using Moderate Resolution Imaging Spectroradiometer (MODIS) data. RS models included i) Priestley-Taylor Jet Propulsion Laboratory (PT-JPL), ii) Penman-Monteith MODIS operative parametrization (PM-Mu), iii) Surface Energy Balance System (SEBS), and iv) Satellite Application Facility…
Etude diagnostique de nouvelles données climatiques : les réanalyses. Exemples d'application aux précipitations en Afrique tropicale
2000
This study establishes an objective diagnosis of NCEP/NCAR reanalysis data reliability over tropical Africa at intra-seasonal to interannuel space scale. The reanalysis data are an original database available over 1958-1998 period which combines observations and atmospheric model outputs and allows us to better understand global scale atmospheric dynamics. The study of data reliability allows us to identify a great number of recommendations for using them. Over tropical Africa, the homogeneous period which should be extracted goes from 1968 to 1998. Before this year, reanalysed datasets should be used with greatest caution. However, during this period, the SMWDA, a statistical method used t…
Evapotranspiration simulations in ISIMIP2a-Evaluation of spatio-temporal characteristics with a comprehensive ensemble of independent datasets
2018
Actual land evapotranspiration (ET) is a key component of the global hydrological cycle and anessential variable determining the evolution of hydrological extreme events under different climate change scenarios. However, recently available ET products show persistent uncertainties thatare impeding a precise attribution of human-induced climate change. Here, we aim at comparing arange of independent global monthly land ET estimates with historical model simulations from theglobal water, agriculture, and biomes sectors participating in the second phase of the Inter-SectoralImpact Model Intercomparison Project (ISIMIP2a). Among the independent estimates, we use theEartH2Observe Tier-1 dataset …