Search results for "season"
showing 10 items of 1002 documents
Down-Scaling Modis Vegetation Products with Landsat GAP Filled Surface Reflectance in Google Earth Engine
2020
High spatial resolution vegetation products are fundamental in different fields, such as improving the understanding of crop seasonality at regional scales. Here, two new vegetation products such as the Leaf Area Index (LAI) and the Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) are downscaled at continental scales. A novel HIghly Scalable Temporal Adaptive Reflectance Fusion Model (HIS-TARFM) is used to generate the gap-free time series of Landsat surface reflectance data by fusing MODIS and Landsat reflectance for the contiguous United States. An artificial neural network is trained to capture the relationship between the gap free Landsat surface reflectance and the MODI…
Curve Numbers Seasonal Variation in Mid-Mediterranean Area
2018
AbstractThe curve number (CN) method is a popular technique for estimating a rainstorm event’s direct runoff (Q from its storm depth P). It relies on the parameter CN, a lumped expression of a wate...
The 1430s: a cold period of extraordinary internal climate variability during the early Spörer Minimum with social and economic impacts in north-west…
2016
Changes in climate affected human societies throughout the last millennium. While European cold periods in the 17th and 18th century have been assessed in detail, earlier cold periods received much less attention due to sparse information available. New evidence from proxy archives, historical documentary sources and climate model simulations permit us to provide an interdisciplinary, systematic assessment of an exceptionally cold period in the 15th century. Our assessment includes the role of internal, unforced climate variability and external forcing in shaping extreme climatic conditions and the impacts on and responses of the medieval society in north-western and central Europe. Climate…
Coastal precipitation regimes in Kenya.
1997
Kenya is under the influence of the seasonal reversal of the Indian ocean monsoons. However, its coastal belt, up to about 50 km inland, exhibits original climatic features. Hierarchical clustering...
Spatio-temporal patterns of thermal anomalies and drought over tropical forests driven by recent extreme climatic anomalies
2018
The recent 2015–2016 El Niño (EN) event was considered as strong as the EN in 1997–1998. Given such magnitude, it was expected to result in extreme warming and moisture anomalies in tropical areas. Here we characterize the spatial patterns of temperature anomalies and drought over tropical forests, including tropical South America (Amazonia), Africa and Asia/Indonesia during the 2015–2016 EN event. These spatial patterns of warming and drought are compared with those observed in previous strong EN events (1982–1983 and 1997–1998) and other moderate to strong EN events (e.g. 2004–2005 and 2009–2010). The link between the spatial patterns of drought and sea surface temperature anomalies in th…
Vegetation vulnerability to drought in Spain
2014
[EN] Frequency of climatic extremes like long duration droughts has increased in Spain over the last century.The use of remote sensing observations for monitoring and detecting drought is justified on the basis that vegetation vigor is closely related to moisture condition. We derive satellite estimates of bio-physical variables such as fractional vegetation cover (FVC) from MODIS/EOS and SEVIRI/MSG time series. The study evaluates the strength of temporal relationships between precipitation and vegetation condition at time-lag and cumulative rainfall intervals. From this analysis, it was observed that the climatic disturbances affected both the growing season and the total amount of vegeta…
Climate indices for the Baltic states from principal component analysis
2017
Abstract. We used principal component analysis (PCA) to derive climate indices that describe the main spatial features of the climate in the Baltic states (Estonia, Latvia, and Lithuania). Monthly mean temperature and total precipitation values derived from the ensemble of bias-corrected regional climate models (RCMs) were used. Principal components were derived for the years 1961–1990. The first three components describe 92 % of the variance in the initial data and were chosen as climate indices in further analysis. Spatial patterns of these indices and their correlation with the initial variables were analyzed, and it was detected (based on correlation coefficient between principal compon…
Linking photosynthesis and sun-induced fluorescence at sub-daily to seasonal scales
2018
Abstract Due to its close link to the photosynthetic process, sun-induced chlorophyll fluorescence (F) opens new possibilities to study dynamics of photosynthetic light reactions and to quantify CO2 assimilation rates. Although recent studies show that F is linearly related to gross primary production (GPP) on coarse spatial and temporal scales, it is argued that this relationship may be mainly driven by seasonal changes in absorbed photochemical active radiation (APAR) and less by the plant light use efficiency (LUE). In this work a high-resolution spectrometer was used to continuously measure red and far-red fluorescence and different reflectance indices within a sugar beet field during t…
Intra- and inter-annual uranium concentration variability in a Belizean stalagmite controlled by prior aragonite precipitation: A new tool for recons…
2016
Aragonitic speleothems are increasingly utilised as palaeoclimate archives due to their amenability to high precision U–Th dating. Proxy records from fast-growing aragonitic stalagmites, precisely dated to annual timescales, can allow investigation of climatic events occurring on annual or even sub-annual timescales with minimal chronological uncertainty. However, the behaviour of many trace elements, such as uranium, in aragonitic speleothems has not thus far been as well constrained as in calcitic speleothems. Here, we use uranium concentration shifts measured across primary calcite-to-aragonite mineralogical transitions in speleothems to calculate the distribution coefficient of uranium …
Recreational noise pollution of traditional festivals reduces the juvenile productivity of an avian urban bioindicator.
2021
Noise is a pollutant of emergent concern for ecologists and conservation biologists. Recreational noise pollution, especially unpredictable and intermittent sounds, and its effects on wildlife and biodiversity have been poorly studied. Researchers have paid very little attention to the effect of noisy traditional festivals (fireworks and powder-guns). This study aimed to explore the effect of these recreational activities on the juvenile productivity of an urban avian bioindicator: the house sparrow. We studied five pairs of localities in the Valencia Region (E Spain) with noisy traditional festivals. Each pair was composed of one locality with festivals during the breeding season and the c…