Search results for "Teleconnection"
showing 10 items of 38 documents
Influences of synoptic situation and teleconnections on fog-water collection in the Mediterranean Iberian Peninsula, 2003-2012
2019
Fog-water collection has been widely analysed for its quantification and potential uses; however, there are few studies assessing the synoptic conditions and large-scale teleconnection patterns that affect its occurrence. Focusing on the Mediterranean Iberian Peninsula, this work aims to analyse the synoptic patterns, both at surface level and 850 hPa geopotential height, that most likely to favour fog-water collection, and to quantify the relationship between fog-water collection and the NAOi (North Atlantic Oscillation index), MOi (Mediterranean Oscillation index) as well as WeMOi (Western Mediterranean Oscillation index) teleconnection patterns. For this purpose, daily fog-water observat…
Climate of the Mediterranean
2012
This chapter considers a set of issues related to the synoptic climatology of the Mediterranean region (MR). The main Northern Hemisphere teleconnections affecting the MR and their role on temperature, precipitation, and atmospheric cyclones are described. The characteristics of the cyclones in the MR are presented. The role of teleconnections and atmospheric regimes on temperature and precipitation is discussed. The content includes extremes of temperature, precipitation, wind, and storminess (considering also marine aspects such as waves and storm surges).
Interacción entre el Monzón de África Occidental y el clima Mediterráneo en verano: Artículo de revisión
2014
Although in the framework of the global climate research the Mediterranean climate variability and the West African Monsoon (WAM) dynamics have been considered for a long time as “passive” systems, i.e., prone to the influence of large scale ocean and atmospheric variability, over the last decade many studies have been dedicated to the WAM-Mediterranean interaction and the active role of these climate systems has been highlighted. This article presents the WAM-Mediterranean teleconnection through an overview of the recent literature, describing the observational evidences and the dynamical mechanisms underlying this climate teleconnection. The influence of the Mediterranean Sea thermal anom…
June-september rainfall in north-eastern Africa and atmospheric signals over the tropics: A zonal perspective
1995
The connection between rainfall in northeast Africa (Djibouti, Eritrea, Ethiopia, Kenya, Somalia, Sudan, and Uganda) and various atmospheric indicators from the tropics have been investigated for the northern summer season. Variables used include zonal wind at 700 hPa and 200 hPa, sea-level pressure, and rainfall over other tropical areas, for the period 1951–1988. Strong significant correlations are shown with the Southern Oscillation and the components of the Walker cell in the Pacific Ocean. Droughts in the Ethiopia-Uganda area are associated with El Nino events and, moreover, with above normal pressure and droughts over India. Other significant relationships exist with the African monso…
Rainfall Anomalies in the Source Region of the Nile and Their Connection with the Indian Summer Monsoon
1997
Abstract In light of the droughts and subsequent food crises that have plagued the Ethiopia–Sudan region in the course of its history, and especially during the last 3 decades, the author examines both the interannual and intraseasonal variabilities of the July–September rains and compares them to the Indian summer monsoon. Regional rainfall indexes for the region stretching from Eritrea to Lake Victoria are computed using seasonal totals for the period 1901–88. Daily data for 1982–88 are also considered. Though all these regions are only partly affected by the Indian monsoon cross-equatorial flow and although they are separated from India by an extensive dry belt (Red Sea, Somalia, west Ar…
The Stationarity of Lead-Lag Teleconnections with East Africa Rainfall and its Incidence on Seasonal Predictability
2001
East Africa experiences large interannual rainfall variations, which can lead to severe droughts, as in 1984 in Ethiopia, or extensive flooding, as in 1997 in Somalia and Kenya. In the last 15 years, significant advances have been made in relating these variations to large-scale ocean-atmosphere anomalies, of which those associated to ENSO (El Nino Southern Oscillation) come first. The additional importance of sea-surface variations in the Tropical Atlantic and Indian Oceans is becoming established. Although 20th century East African precipitation series did not experience decadal-scale trends as significant as those found in the sahelian belt, the correlation with ENSO, the Indian monsoon …
Interaction between the West African Monsoon and the summer Mediterranean climate: An overview.
2013
15 pages; International audience; Although in the framework of the global climate research the Mediterranean climate variability andthe West African Monsoon (WAM) dynamics have been considered for a long time as “passive”systems, i.e., prone to the influence of large scale ocean and atmospheric variability, over the lastdecade many studies have been dedicated to the WAM-Mediterranean interaction and the active roleof these climate systems has been highlighted. This article presents the WAM-Mediterraneanteleconnection through an overview of the recent literature, describing the observational evidencesand the dynamical mechanisms underlying this climate teleconnection. The influence of the Me…
Precipitation pattern in the Baltic countries under the influence of large-scale atmospheric circulation and local landscape factors
2010
The main objectives of the study are to analyse the mean precipitation pattern in the Baltic countries (Estonia, Latvia, Lithuania) and the influence of local landscape factors on it, to derive a regionalization, i.e. select regions having coherent fluctuations in precipitation, and to analyse relationships between precipitation and characteristics of the large-scale atmospheric circulation. Monthly precipitation data from 123 stations in the Baltic countries from 1966 to 2005 are analysed in relation to 52 landscape variables and 13 circulation variables. The landscape variables characterize landscape around the meteorological stations: land cover, land surface elevation, distance from the…
What Drove Past Teleconnections?
2003
Ice core records from Greenland and Antarctica and sediment records from the world9s oceans have shown that over the past 100,000 years, climate has varied substantially across the globe. In his Perspective, Sirocko asks what drove these--sometimes very rapid--climate oscillations. He highlights the report of Burns et al., whose monsoon record from the Indian Ocean shows strong similarities with ice core records from Greenland. Sirocko argues that the large areas of homogeneous sea surface temperature in the cold circum-Antarctic current and in the warm-water masses of the low latitudes must have played an important role in linking climate forcing between distant parts of the world. The muc…
Inter-Relationships Between Groundnut Yield in Senegal, Interannual Rainfall Variability and Sea-Surface Temperatures
1999
Groundnut production strongly contributes to Senegal’s economy. Interannual variations of groundnut yield for the country as a whole, and their relationship with rainfall amounts, are examined for the 31-yr period 1960–1990. It is shown that on that scale, and after removing decadal trends, almost half of the variance is explained by rainfall variability, especially that of the early part of the rainy season (July–August). Given the high spatial coherence of seasonal rainfall in the region, teleconnections with global- and regional-scale climate dynamics, including sea-surface temperatures, are assessed. Though some features are similar to the rest of the Sahel, others are more specific, su…