scholarly journals Long-time spatio-temporal variations in anchovy (Engraulis ringens) biological traits off northern Chile: an adaptive response to long-term environmental change?

2018 ◽  
Vol 75 (6) ◽  
pp. 1908-1923 ◽  
Author(s):  
Cristian M Canales ◽  
Nicolás A Adasme ◽  
Luis A Cubillos ◽  
Maria Jose Cuevas ◽  
Nazareth Sánchez
Keyword(s):  
Environmental Change ◽  
Adaptive Response ◽  
Temporal Variations ◽  
Biological Traits ◽  
Northern Chile ◽  
Long Time ◽  
Engraulis Ringens ◽  
Spatio Temporal

Long-term dynamics of natural populations of Schistosoma mansoni among Rattus rattus in patchy environment

Parasitology ◽  
1992 ◽  
Vol 104 (2) ◽  
pp. 291-298 ◽  
Author(s):  
A. Théron ◽  
J. P. Pointier ◽  
S. Morand ◽  
D. Imbert-Establet ◽  
G. Borel
Keyword(s):  
Schistosoma Mansoni ◽  
Rattus Rattus ◽  
Natural Populations ◽  
Ecological Factors ◽  
Temporal Variations ◽  
Distribution Analysis ◽  
Patchy Environment ◽  
Human Parasite ◽  
Spatio Temporal

SUMMARYDynamics of natural populations of Schistosoma mansoni were studied during 8 consecutive years among Rattus rattus populations from 8 transmission sites of the marshy forest focus of Guadeloupe (French West Indies). The schistosome population is over-dispersed (k = 0·119) within the murine hosts and ecological factors linked to the patchy environment may be responsible for such aggregated distribution. Analysis of the spatio-temporal variations in prevalences, intensities and abundances showed limited variations of the infection during the 8 years at the level of the whole parasite population but great spatial heterogeneity at the level of local schistosome populations. Inter-populational genetic variability linked to the degree of adaptation of this human parasite to the murine host may explain differences in transmission dynamics between the local populations of S. mansoni.

scholarly journals Spatio-Temporal Mapping of Multi-Satellite Observed Column Atmospheric CO2 Using Precision-Weighted Kriging Method

2020 ◽  
Vol 12 (3) ◽  
pp. 576 ◽  
Author(s):  
Zhonghua He ◽  
Liping Lei ◽  
Yuhui Zhang ◽  
Mengya Sheng ◽  
Changjiang Wu ◽  
...  
Keyword(s):  
Temporal Variations ◽  
Atmospheric Co2 ◽  
Total Carbon ◽  
Kriging Method ◽  
Good Reliability ◽  
Potential Applications ◽  
Satellite Sensors ◽  
Spatio Temporal ◽  
Atmospheric Co2 Concentrations

Column-averaged dry air mole fraction of atmospheric CO2 (XCO2), obtained by multiple satellite observations since 2003 such as ENVISAT/SCIAMACHY, GOSAT, and OCO-2 satellite, is valuable for understanding the spatio-temporal variations of atmospheric CO2 concentrations which are related to carbon uptake and emissions. In order to construct long-term spatio-temporal continuous XCO2 from multiple satellites with different temporal and spatial periods of observations, we developed a precision-weighted spatio-temporal kriging method for integrating and mapping multi-satellite observed XCO2. The approach integrated XCO2 from different sensors considering differences in vertical sensitivity, overpass time, the field of view, repeat cycle and measurement precision. We produced globally mapped XCO2 (GM-XCO2) with spatial/temporal resolution of 1 × 1 degree every eight days from 2003 to 2016 with corresponding data precision and interpolation uncertainty in each grid. The predicted GM-XCO2 precision improved in most grids compared with conventional spatio-temporal kriging results, especially during the satellites overlapping period (0.3–0.5 ppm). The method showed good reliability with R2 of 0.97 from cross-validation. GM-XCO2 showed good accuracy with a standard deviation of bias from total carbon column observing network (TCCON) measurements of 1.05 ppm. This method has potential applications for integrating and mapping XCO2 or other similar datasets observed from multiple satellite sensors. The resulting GM-XCO2 product may be also used in different carbon cycle research applications with different precision requirements.

Spatial and temporal variations of seismicity during the Maurienne swarm (French Alps): short- and long-term migrations and b-value dependence with depth

2021 ◽  
Author(s):  
Riccardo Minetto ◽  
Agnès Hemlstetter ◽  
Philippe Guéguen ◽  
Mickaël Langlais
Keyword(s):  
Template Matching ◽  
B Value ◽  
Temporal Variations ◽  
Fault System ◽  
Double Difference ◽  
French Alps ◽  
Vertical Fault ◽  
Spatio Temporal ◽  
The One

<p>We analyse the spatio-temporal variations of the seismicity recorded during the Maurienne swarm. The Maurienne swarm occurred between 2017 and 2018 in the French Alps in the central part of the external crystalline massif of Belledonne. This massif extends for more than 120km in N30 direction, it is bounded to the west by the wide topographic depression of the Isère valley and the Combe de Savoie, and it is crosscut by the Maurienne valley.  The location and the 3D shape of the seismic swarm are consistent with an outcroping N80 vertical fault zone. The seismic activity is interpreted as a result of the reactivation of this inherited vertical fault system. The largest event had a magnitude of 3.5.</p><p><br>We used a catalog of 58000 events that were detected using template-matching and relocated with a double-difference method.  <br>We show that the swarm is characterised by short-term (days) and long-term (months) migrations that may be related to the presence of fluids. <br>We also observe that the b-value decreases with depth and we discuss how this variation may due to shallow fault systems whose geometry differs from the one of the main fault system. <br>Part of the events occurred when only one station was active. This study shows that, by grouping earthquakes into groups of similar events (clusters), it is possible to study spatio-temporal variations in such conditions.</p>

scholarly journals Contrasting large fire regimes in the French Mediterranean

2018 ◽  
Author(s):  
Anne Ganteaume ◽  
Renaud Barbero
Keyword(s):  
Fire Suppression ◽  
Sharp Decrease ◽  
Weather Conditions ◽  
Fire Regimes ◽  
Temporal Variations ◽  
Burned Area ◽  
Prone Area ◽  
Large Fires ◽  
Spatio Temporal

Abstract. In the French Mediterranean, large fires have significant socio-economic and environmental impacts. We used a long-term geo-referenced fire time series (1958–2017) to analyze spatio-temporal variations of large fires (LF; ≥ 100 ha) throughout a fire-prone area of this region. This area was impacted in some locations up to 5 or 6 times by recurrent LF and 21 % of the total area burned by LF occurred on a surface that previously burned in the past. We found distinct patterns between the East and the West of the study area, the former experiencing fewer LF but of a larger extent compared to the latter, with an average time of occurrence between LF exceeding 4000 ha  50 years, respectively. This longitudinal gradient in LF extent contrasts with what was expected from mean fire weather conditions strongly decreasing eastwards but is consistent with larger fuel cover in the East. The temporal variation of LF, featuring a sharp decrease in both frequency and burned area in the early 1990s, highlighted the efficiency of fire suppression and prevention, reinforced at that time. However, the LF outbreak in 2003 due to the exceptional heat wave remains of major concern in the context of climate change.

scholarly journals Benchmarking an operational hydrological model for providing seasonal forecasts in Sweden

2021 ◽  
Vol 25 (3) ◽  
pp. 1189-1209
Author(s):  
Marc Girons Lopez ◽  
Louise Crochemore ◽  
Ilias G. Pechlivanidis
Keyword(s):  
Hydrological Model ◽  
Temporal Variations ◽  
Forecast Skill ◽  
Added Value ◽  
Streamflow Prediction ◽  
Seasonal Forecasts ◽  
The Future ◽  
Spatio Temporal ◽  
Forecasting And Warning

Abstract. Probabilistic seasonal forecasts are important for many water-intensive activities requiring long-term planning. Among the different techniques used for seasonal forecasting, the ensemble streamflow prediction (ESP) approach has long been employed due to the singular dependence on past meteorological records. The Swedish Meteorological and Hydrological Institute is currently extending the use of long-range forecasts within its operational warning service, which requires a thorough analysis of the suitability and applicability of different methods with the national S-HYPE hydrological model. To this end, we aim to evaluate the skill of ESP forecasts over 39 493 catchments in Sweden, understand their spatio-temporal patterns, and explore the main hydrological processes driving forecast skill. We found that ESP forecasts are generally skilful for most of the country up to 3 months into the future but that large spatio-temporal variations exist. Forecasts are most skilful during the winter months in northern Sweden, except for the highly regulated hydropower-producing rivers. The relationships between forecast skill and 15 different hydrological signatures show that forecasts are most skilful for slow-reacting, baseflow-dominated catchments and least skilful for flashy catchments. Finally, we show that forecast skill patterns can be spatially clustered in seven unique regions with similar hydrological behaviour. Overall, these results contribute to identifying in which areas and seasons and how long into the future ESP hydrological forecasts provide an added value, not only for the national forecasting and warning service, but also, most importantly, for guiding decision-making in critical services such as hydropower management and risk reduction.

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