Search results for "Climate"
showing 10 items of 4934 documents
The onset of the rainy season in Yunnan province, PR China and its significance for agricultural operations
1993
Data of 134 stations located in Yunnan province, PR China were analysed in order to study the temporal and spatial characteristics of the onset of the rainy season and to investigate the consequences for farming operations. Using a precipitation threshold value, a time span of 12 weeks was found for the complete onset of the rainy season, while the range of onset dates varied from 37 days to 155 days. The onset occurred at different places across the province and showed active and break phases due to the interaction of four different branches of the atmospheric circulation. The onset of the growing season, determined by summing up decade precipitation totals, showed the same general pattern…
Ethnographic context and spatial coherence of climate indicators for farming communities : a multi-regional comparative assessment
2015
Accurate seasonal predictions of rainfall may reduce climatic risks that farmers are usually faced with across the tropical and subtropical zones. However, although regional-scale seasonal amounts have regularly been forecasted since 1997/98, the practical use of these seasonal predictions is still limited by myriad factors. This paper synthesizes the main resultsof a multi-disciplinary ethnographic and climatic project (PICREVAT). Its main objective was to seek the climatic information ? beyond the seasonal amounts ? critical for crops, both as an actual constraint to crop yields and as identified by the current and past practices and perceptions of farmers. A second goal was to confront t…
On the projected increase of Sahel rainfall during the late rainy season
2016
Thirteen CMIP5 models are used to analyse changes in climate over the West African monsoon region between the near future (2031–2070 under the RCP4.5 emission scenario), and a control period (1960–1999 under the historical emission scenario), with a focus on the late rainy season. The monsoon circulation is projected to strengthen and to shift northward leading to more rainfall during the Sahelian season. The results show an increase of the Rainfall amounts in September–October and a delay in the monsoon withdrawal. The increased moisture that fuels the rainfall anomalies is associated with an increase in moisture flux convergence and with local moisture recycling. The moisture transport do…
Climate/growth relationships of Brachystegia spiciformis from the miombo woodland in south central Africa
2010
Abstract We present five Brachystegia spiciformis Benth. (BrSp) tree-ring chronologies from the seasonally dry miombo woodland in south central Africa. Between 9 and 34 stem discs were collected from three dry and two wet miombo sites. All samples showed distinct growth rings, which were marked by terminal parenchyma bands. Site chronologies varied in length between 43 and 149 years. An increase in the number of growth ring anomalies in older trees, however, resulted in an increase in dating error and a decrease in between-tree correlations with increase in the chronology length. Annual precipitation variability accounted for some 28% of the common variance in the BrSp chronologies and we f…
Seasonal changes of the infiltration rates in a Mediterranean scrubland on limestone
1997
To investigate the seasonal changes of infiltration rates, measurements by means of simulated rainfall experiments and cylinder infiltrometer were done in a small E–W oriented watershed in Southeast Spain. Data were collected during both the wet seasons (autumn, winter and spring) and the dry season (summer). Infiltration rates were very high in summer, when direct surface runoff is very low. During the wet seasons, the infiltration rates were lower due to the increase in soil moisture. Measurements by means of both ponding as well as simulated rainfall are suitable to study the infiltration process. The former needs more replications, due to the small observation area encompassed for each …
Extreme dry spell detection and climatology over the Mediterranean Basin during the wet season
2016
The E-OBS precipitation gridded data set v.10.0 is used to detect very long dry spell (VLDS) events over the entire Mediterranean Basin for the 1957–2013 period, during the wet season (September to April). The main objective is to characterize these events as climatic objects, in terms of location, spatial extent, duration, and temporal variability. In this study, 76 VLDS events were detected in the Mediterranean Basin and grouped into four spatial patterns: scattered localized (with 25 events), northeast Mediterranean (11 events), West Mediterranean (15 events), and southeast Mediterranean (25 events). Each pattern shows seasonality in events. Most of the scattered localized, northeast, an…
Climate Adjustments over Africa Accompanying the Indian Monsoon Onset
2010
Abstract Rainfall and circulation changes accompanying the Indian monsoon onset are examined, focusing on the African continent and neighboring areas. The Indian Meteorological Department official monsoon onset dates over Kerala (MOK; on average on 1 June) are used. Composites are formed at a pentad (5 days) time scale to compare pre- and postonset conditions. Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) data for 1979–2007 indicate that a substantial rainfall decrease over several parts of Africa is associated with MOK. Significant rainfall anomalies, after removal of the mean seasonal cycle, are found in eastern Africa and the nearby western Indian Ocean. Indian …
Cross-hemispheric transport of central African biomass burning pollutants: implications for downwind ozone production
2010
Pollutant plumes with enhanced concentrations of trace gases and aerosols were observed over the southern coast of West Africa during August 2006 as part of the AMMA wet season field campaign. Plumes were observed both in the mid and upper troposphere. In this study we examined the origin of these pollutant plumes, and their potential to photochemically produce ozone (O<sub>3</sub>) downwind over the Atlantic Ocean. Their possible contribution to the Atlantic O<sub>3</sub> maximum is also discussed. Runs using the BOLAM mesoscale model including biomass burning carbon monoxide (CO) tracers were used to confirm an origin from central African biomass burning fires. The…
Draft Genome Sequence of Actibacterium mucosum KCTC 23349, a Marine Alphaproteobacterium with Complex Ionic Requirements Isolated from Mediterranean …
2014
ABSTRACT Strain R46 (CECT 7668; KCTC 23349), a nomenclatural type of Actibacterium mucosum , was isolated from surface seawater collected at Malvarrosa Beach (Valencia, Spain) in July 2008. The draft genome sequence of strain R46 (approximately 3.72 Mbp) contains 22 scaffolds and 3,619 protein-encoding genes, with a G+C content of 60.8 mol%.