Search results for "Clima"
showing 10 items of 6069 documents
Volcanic Plume CO2 Flux Measurements at Mount Etna by Mobile Differential Absorption Lidar
2017
Volcanic eruptions are often preceded by precursory increases in the volcanic carbon dioxide (CO2) flux. Unfortunately, the traditional techniques used to measure volcanic CO2 require near-vent, in situ plume measurements that are potentially hazardous for operators and expose instruments to extreme conditions. To overcome these limitations, the project BRIDGE (BRIDging the gap between Gas Emissions and geophysical observations at active volcanoes) received funding from the European Research Council, with the objective to develop a new generation of volcanic gas sensing instruments, including a novel DIAL-Lidar (Differential Absorption Light Detection and Ranging) for remote (e.g., distal) …
Ultraviolet imaging of volcanic plumes: A new paradigm in volcanology
2017
Ultraviolet imaging has been applied in volcanology over the last ten years or so. This provides considerably higher temporal and spatial resolution volcanic gas emission rate data than available previously, enabling the volcanology community to investigate a range of far faster plume degassing processes than achievable hitherto. To date, this has covered rapid oscillations in passive degassing through conduits and lava lakes, as well as puffing and explosions, facilitating exciting connections to be made for the first time between previously rather separate sub-disciplines of volcanology. Firstly, there has been corroboration between geophysical and degassing datasets at â1 Hz, expeditin…
Lagrangian matches between observations from aircraft, lidar and radar in an orographic warm conveyor belt
2020
Warm conveyor belts (WCBs) are important airstreams in extratropical cyclones, often leading to the formation of intense precipitation and the amplification of upper-level ridges. This study presents a case study that involves aircraft, lidar and radar observations in a WCB ascending from western Europe towards the Baltic Sea during the Hydrological Cycle in the Mediterranean Experiment (HyMeX) and T-NAWDEX-Falcon in October 2012, a preparatory campaign for the THORPEX North Atlantic Waveguide and Downstream Impact Experiment (T-NAWDEX). Trajectories were used to link different observations along the WCB, that is, to establish so-called Lagrangian matches between observations. To this aim, …
Dyvalocca : un projet pour l'étude des nuages bas de saison sèche sur la façade atlantique de l'Afrique centrale et de leur impact bioclimatique sur …
2020
Low-level clouds are key components of the climate but are not well represented in weather and climate models. Recently it has been shown that an extensive low-level cloud cover develops during the June-September main dry season in western equatorial Africa, from the coastal plains of Gabon and Congo-Brazzaville to the inland plateaus downstream of the low-mountain crests. Such a cloudy main dry season is unique in the moist Tropics and is likely to explain the presence of the densest and evergreen forests of Central Africa as evapotranspiration is low and the quality of light is high. The ANR-DFG funded “DYVALOCCA” project will conduct from 2020 to 2022 a field campaign, raise existing in-…
Atmospheric circulation modulates the spatial variability of temperature in the Atlantic-Arctic region
2019
International audience; The Arctic region has experienced significant warming during the past two decades with major implications on the cryosphere. The causes of Arctic amplification are still an open question within the scientific community, attracting recent interest. The goal of this study is to quantify the contribution of atmospheric circulation on temperature variability in the Atlantic–Arctic region at decadal to intra‐annual timescales from 1951 to 2014. Daily 20th Century reanalyses geopotential height anomalies at 500 hPa were clustered into different weather regimes to assess their contribution to observed temperature variability. The results show that in winter, 25% of the warm…
Les types de temps associés aux risques d’inondations et d’érosions en Camargue : éléments de diagnostic et de prospectives pour le 21e siècle (1993-…
2010
Les fortes surcotes marines et les fortes vagues sont les principaux aléas météo-marins associés aux risques de submersion et d’érosion du littoral camarguais. Sur la période 1993-2002, une forte fréquence mensuelle de très hautes surcotes marégraphiques est généralement associée à une forte fréquence de très hautes vagues. Ces deux phénomènes locaux se produisent principalement lorsqu'une dépression autour du Golfe de Gascogne est associée à des hautes pressions sur l’Europe Centrale. La fréquence mensuelle de ce type de temps nous renseigne sur la probabilité d’occurrence de fortes surcotes marégraphiques et vagues en Camargue. Au 21e siècle, la fréquence du type de temps associé aux plus…
Effect of soil management and weed controlm on the diversity and establishment of arbuscular mycorrhizal symbiosis colonisation in Mediterranean clim…
2006
International audience
The influence of ENSO on South Africa winter rainfall
2011
International audience; We analysed the relationship between El Niño Southern Oscillation (ENSO) and South Africa austral winter rainfall using a 682 raingauges daily rainfall database documenting the period 1950-1999. The May, June and July (MJJ) seasonal rainfall amount shows a positive correlation with the Niño3.4 index that becomes significant since the mid 70's. Wet spells properties (length, frequency and intensity) at the raingauge scale indicate that high (low) MJJ seasonal rainfall amounts recorded during El Niño (La Niña) events are the result of longer (shorter) wet spells in the Cape Town area and more (less) frequent wet spells north of 33°S. Wet spells with daily rainfall amou…
Job Resources and Work Engagement: Optimism as Moderator Among Finnish Managers
2014
The aim of the present study was to investigate the moderating role of optimism in the relationship between job resources (organizational climate, job control) and work engagement among Finnish young managers (N = 747). Hierarchical regression analyses showed that both job resources and optimism exerted a positive effect on work engagement and its three dimensions of vigor, dedication, and absorption. The moderation results showed that optimism can diminish the negative impact of low job resources on work engagement. These findings provide evidence to the importance of including personal resources in future research conducted on motivational process. Additionally, these findings provide sig…
The relationship of collective creativity with managerial work and workplace climate in hierarchical and less hierarchical organizations
2023
Collective creativity, managerial work, and workplace climate can influence innovation, organizational learning, and productivity at work. However, little empirical research has examined these factors in everyday work, especially in relation to organizational hierarchies. This study explores the relationships among collective creativity, managerial work, and workplace climate in hierarchical and less hierarchical organizations. A quantitative empirical analysis was conducted using data from a survey of 265 respondents from six Finnish organizations. The findings show that managerial work and workplace climate that focus on building and maintaining trust and highlight empathy, fairness and e…