Sea surface temperature anomalies in the tropical Atlantic Ocean are reexamined to investigate an apparent low-frequency oscillation that has been described as a fluctuating dipole structure with poles north and south of equator node near ITCZ. Using principal components rotated by varimax method simple correlations area-averaged temperatures, we show during 1964–88 interval SST ITCZ not significantly correlated. Therefore, variation, decadal period observed gradient across 1964–88, does...

Dominant spatiotemporal patterns of joint sea surface temperature (SST) and level pressure (SLP) variability in the Atlantic Ocean are identified using a multivariate frequency domain analysis. Five significant bands isolated ranging from quasi biennial to decadal. Two quasi-biennial centered around 2.2- 2.7-yr periods; two interannual 3.5- 4.4-yr fifth band at quasi-decadal is 11.4-yr period. Between 1920 1955, less prominent compared bands. This happens be period when SLP gradually...

The time-space evolution of the El Niño-Southern Oscillation in sea surface temperature (SST) and heat storage upper 400 m (HS400) for Pacific, Indian, Atlantic Oceans is investigated 13 years (1979–1991). EOF rotated (Varimax or VRX) analyses are performed using time series normalized anomalies each ocean separately then global ocean. In Pacific Indian Oceans, two dominant modes both SST H5400 associated with ENSO. For they account 49% total variance mean, while over 35% Ocean, first HS400...

Two distinct low‐frequency fluctuations are suggested from a joint frequency domain analysis of the Pacific Ocean (30°S‐60°N) sea surface temperature (SST) and level pressure (SLP). The lowest signal reveals spatially coherent interdecadal evolution, In‐phase SST SLP anomalies found along subarctic frontal zone (SAFZ). It is symmetric about equator, with tropical peaking near 15° latitudes in eastern Pacific. other decadal evolution. primarily low‐latitude phenomenon. Tropical peak central...

Two common indicators of Atlantic climate variability, viz., the North oscillation (NAO) and cross‐intertropical convergence zone (ITCZ) sea surface temperature (SST) gradient, are examined for their frequency characteristics and, midlatitude‐tropical links. SST anomalies north south ITCZ found to be uncorrelated on all time scales, while level pressure (SLP) fluctuations associated with NAO display a coherent seesaw between Iceland Azores. This out‐of‐phase relationship spans broad range...

Biennial, interannual, and decadal signals in the Pacific basin are observed to share patterns evolution covarying sea surface temperature (SST), 18°C isotherm depth (Z18), zonal wind (ZSW), stress curl (WSC) anomalies from 1955 1999. Each signal has warm SST propagating slowly eastward along equator, generating westerly ZSW their wake. These produce cyclonic WSC off equator which pump baroclinic Rossby waves western/central tropical North Ocean. propagate westward, taking ∼6, ∼12, ∼36...

The disturbance lines which occurred during the three phases of GATE over eastern Atlantic Ocean and West Africa have been identified utilizing excellent data from SMS-1 geostationary satellite. majority these generated decayed land. Genesis predominantly in afternoon land early morning water. They develop to north cloud systems associated with southwest monsoon, where moist layer is shallow overriding dry air favors production downdrafts by evaporation precipitation genesis a large extent...

Interdecadal variability in sea level pressure (SLP) and surface temperature (SST) anomalies the Pacific Ocean was “quasiperiodic” from 1900–91. The coherent of this phenomenon is investigated using gridded observational data turn century (SST SLP) upper ocean heat content (HS) recent two a half decades. nominal cycle atmosphere–ocean variables roughly decades long, but growth decay can happen on shorter timescale (e.g., or so). authors divide full into four phases: An onset phase, during...

The evolution of the El Niño–Southern Oscillation (ENSO) in Indian and western Pacific Oceans is investigated. Observations sea surface temperature (SST), heat storage upper 400 m (HS), zonal wind stress (ZSWS), meridional (MSWS) are mapped monthly onto a 2° latitude–longitude grid over as much (i.e., 40°S–50°N, 40°E–180°) possible for 13-year period (1979–91). This resolution allows upper-ocean variability to be resolved eastern Ocean Timor Sea) Philippine Sea). Time sequences these...

A discrete number of global signals in covarying sea surface temperature (SST) and level pressure (SLP) dominated climate variability from 40°S to 60°N during the 20th Century. They are quasi‐biennial (∼2.2‐year period), interannual (3‐ 7‐year period band), quasi‐decadal (∼11‐year interdecadal (∼17‐year period) signals. joint frequency‐domain analysis SST SLP anomalies over ocean finds these composed mixed standing modes traveling waves that similar pattern evolution. On each scale, wave is...

Introduction High malaria transmission heterogeneity in an urban environment is basically due to the complex distribution of Anopheles larval habitats, sources vectors. Understanding 1) meteorological and ecological factors associated with differential larvae spatio-temporal 2) vectors dynamic, both may lead improving control measures remote sensing high resolution data as key components. In this study a robust operational methodology for entomological predictive risk maps settings...

This paper presents an analysis of the interaction between various variables associated with Rift Valley fever (RVF) such as mosquito vector, available hosts and rainfall distribution. To that end, varying zones potentially occupied by mosquitoes (ZPOM), events pond dynamics, exposure to RVF virus Aedes vexans, were analyzed in Barkedji area Ferlo, Senegal, during 2003 rainy season. Ponds identified remote sensing using a high-resolution SPOT-5 satellite image. Additional data on ponds from...

Monthly mean SLP anomalies are analyzed from the 1958–1997 record covering Mediterranean Basin. From point‐correlation technique, a significant winter anomalous oscillation between North Africa (NA) and West Asia (WA) or NAWA , is identified. Insight into inter‐annual variability of obtained detrended composited patterns. During P/N, positive/negative values index, higher/lower over lower/higher east Caspian Sea displayed respectively. In both cases, maximum gradients found Eastern (EM). P/N...

Ocean climate, environmental and biological conditions vary on several spatio-temporal scales. Besides climate change associated with anthropogenic activity, there is growing evidence of a natural global multi-decadal signal in the ocean–atmosphere–biosphere system. The evolution this thus analyzed during 20th century compared to variability small-pelagic fish landings. It argued that low-frequency ocean environment plankton ecosystems must be modified such populations accordingly. A index...

Climate–environment variability affects the rates of incidence vector-borne and zoonotic diseases is possibly associated with epidemics outbreaks. Over southernmost South America joint spatio-temporal evolution climate–environment analyzed for 1982–2004 period. Detailed mapping normalized difference vegetation index (NDVI) rainfall are then compared to zones preliminary epidemiological reports. A significant quasi-biennial signal (2.2- 2.4-year periods, or QB) NDVI–rainfall revealed. From...

Abstract The aim of this study is to highlight the recent progress in mapping vector‐borne diseases West Africa using modelling and field experiments. Based on climatic indicators, methods have been developed map Rift Valley fever (RVF) malaria risk. Modelling results corroborate that northern Senegal southern Mauritania appear be critical areas for RVF outbreaks epidemic fringe located at edge Sahel. Future projections risk decreases over This related a southward shift potential belt...

Controlling dengue virus transmission mainly involves integrated vector management. Risk maps at appropriate scales can provide valuable information for assessing entomological risk levels. Here, results from a spatio-temporal model of dwellings potentially harboring Aedes aegypti larvae 2009 to 2011 in Tartane (Martinique, French Antilles) using high spatial resolution remote-sensing environmental data and field meteorological are presented. This tele-epidemiology methodology allows...

Abstract. DRIAS (Providing access to Data on French Regionalized climate scenarios and Impacts the environment Adaptation of Societies) is a 2-yr project (2010–2012). It funded by GICC (Management Impact Climate Change) program Ministry Ecology, Sustainable Development, Transportation, Housing (MEDDTL). provide easy regional data products in order facilitate mitigation adaptation studies. The focuses existing projections obtained from national modelling groups such as: IPSL, CERFACS, CNRM....

The spatio‐temporal evolution of Sahelian vegetation is analyzed using the Normalized Difference Vegetation Index (NDVI) obtained from NOAA/AVHRR sensor (1982–2003). Dominant patterns are identified rotated EOFs. While first four modes associated with specific bio‐geo‐climatic conditions in space, significant time scales detected a multi‐tapers method. Three interannual (∼6.2‐, 4.5‐ and 3.6‐year) present third NDVI over western Sahel. A quasi‐biennial scale (∼2.6‐year) second fourth...

A necessary condition for Rift Valley fever (RVF) emergence is the presence of Aedes (Aedimorphus) vexans and Culex (Culex) poicilipes mosquitoes carrying arbovirus responsible infection. This paper presents a detailed mapping in Sahelian region Senegal zones potentially occupied by these (ZPOMs) whose population density directly linked to ecozones vicinity small ponds. The vectors habitats breeding sites have been characterized through an integrated approach combining remote sensing...

Climate and environment vary across many spatio-temporal scales, including the concept of climate change, which impact on ecosystems, vector-borne diseases public health worldwide.To develop a conceptual approach by mapping climatic environmental conditions from space studying their linkages with Rift Valley Fever (RVF) epidemics in Senegal.Ponds mosquitoes could thrive were identified remote sensing using high-resolution SPOT-5 satellite images. Additional data pond dynamics rainfall events...

In the vicinity of Barkedji village (in Ferlo region Senegal), abundance and aggressiveness vector mosquitoes for Rift Valley fever (RVF) are strongly linked to rainfall events associated ponds dynamics. Initially, these results were obtained from spectral analysis high-resolution (~10 m) Spot-5 images, but, as a part French AdaptFVR project, identification free water dynamics within was made with new (down 3-meter pixels), Synthetic Aperture Radar satellite (TerraSAR-X) produced by...