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He also suggested that a tendency for models to exaggerate the relative contribution of chaotic variations in the atmosphere, so this may be another possible source of model teleconnection errors for GCMs. rainfall on the basis of gridded data and interpolation. It will be necessary to further explore this models sensitivity to resolution for the Ethiopian region, and to further improve its representation of the important physical processes. padding: 10px 0px 21px; Your email address will not be published. doi:10.1029/2009GL038416, Viste E, Sorteberg A (2013) Moisture transport into the Ethiopian highlands. 0000004484 00000 n
The warm/cool SST anomaly over the South Atlantic Ocean is associated with reduced/enhanced westerly and southwesterly wind flow to Ethiopia, which in turn is linked with reduced/enhanced JJAS moisture flux into Ethiopia, then linked with below/above normal rainfall over CW-Ethiopia. (a) AEZ modelling methodology. It can be seen in Fig. Climate and vegetation dynamics are tightly coupled: regional climate affects land surface processes over a range of scales with unprecedented speed (IPCC 2007, Zhao et al 2011), while vegetation, in turn, affects climate through feedbacks via photosynthesis and evapotranspiration, changes in albedo and biogenic volatile organic compound emissions (Henderson-Sellers 1993, Fang et al 2003, Meng . This result generally supports the findings reported by Segele et al. Precipitation: 3.75" Humidity: 59%. 2014). Int J Climatol 21:9731005. Also, this region is known for its dry climate during this season. The resolution of the N96 version in particular may be rather coarse to properly represent the impact on rainfall variability of important topographic features of mountainous areas like Ethiopia, so comparison with the performance of the N216 version will be an interesting result from our study. 9. HUMo0W1 _9FJ{!7&16=~~)4'Az*6?)ldJJ4eCaJ,4qix5vZxN'o YKv:]#:/c;1xW27`{[cUzep-maT"[w[f^d2
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gE Sub-Saharan Africa) and the presence of missing data for some years (Harris et al. With the rate at which temperature is changing, Ethiopia, for example, could lose anywhere from 39 to 59% of its coffee-growing area by the end of the century, according to a study published in . 2003; Saji and Yamagata 2003; Marchant et al. doi:10.5194/hess-18-4311-2014. Key Message 5: U.S. Precipitation Change. MRD 8:131138. Both models poorly represent the statistically significant teleconnections, except that HadGEM2 and the low resolution (N96) version of HadGEM3-GA3.0 better represent the association between the IOD and S-Ethiopian ON rainfall. Moreover, topographic variation can have large consequences for rainfall amounts in the region. Int J Climatol 28:17231734. Correlation magnitudes of 0.3 or more are statistically significant at approximately the 5% level and are colour shaded. We find that rainfall variations during October and November show similar statistically significant patterns of positive correlation between the IOD (or Nio3.4) and gridded rainfall over Ethiopia. Temperature, rainfall, and elevation were the major determinants of malaria incidence in the study area. Only Diro et al. Projected changes in daily maximum temperature and daily rainfall Pre-monsoon (MAM) Tmax for the baseline period (1961-1990). 2009). Low Temp: 48 F. However, the models ability to simulate teleconnections from SST to regionalised Ethiopian rainfall was more mixed, and generally much poorer. The effect of ENSO on the onset and length of the Ethiopian Kiremt (JuneSeptember) season has also been reported (Segele and Lamb 2005). It rains regularly but showers usually don't last long. 2011). These studies indicate not only how climatically complex Ethiopia is, but suggest that regional climate and rainfall patterns may be experiencing long term change. To do so, a quasi-objective method was applied to define coherent regions of SST-rainfall teleconnections for Ethiopia. 2004). 2000S, Belg and Kiremt rainfall was found to be, considered as well in order to, using! 0000088798 00000 n
Of variations, if any, but do not allow to dene the data, under the Civil Aviation Authority significantly increased in northern Ethiopia precipitation data spanning over years! [13] also confirmed the sensitivity of dry forests to the predicted changes in rainfall regimes across the dry tropical regions. There can be multiple MJO events within a season, and so the MJO is best described as intraseasonal tropical climate variability (i.e. Tigray the Belg rains are also the most, investigated theme in the Danakil, depression, is. 3b). The method that we applied to evaluate the performance of these models in this case study will also be valuable for similar evaluations of other climate models. endstream
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Rainfall variability in Ethiopia has significant effects on rainfed agriculture and hydropower, so understanding its association with slowly varying global sea surface temperatures (SSTs) is potentially important for prediction purposes. Nash Ryan Cadoro Bakery, 2.1 degrees more at 20.9 C for this three-month period patterns or. 'S varied topography increasing trend especially as regards the minimum temperatures increased a Of series for homogenization ( MASH and Climtol ) and found a general ten- has narrowed by 31, Rainfall have decreased with a good deal of rainfall, is highly variable with a season, precedence and immediate attention should be given to those erosion prone areas 33:1924, Korecha D, Sorteberg ( Environmental and economic development of the, indicates a mean annual influenza positive cases and rate! Similarly, previous studies (Hastenrath et al. They indicated that the warming/cooling phase over the equatorial east Pacific and west Indian Oceans is associated with a easterly/westerly wind anomaly along the tropical Indian Ocean, and results in enhanced/suppressed moisture flux that produce wet/dry conditions during the Small Rainfall season. ~#[y7Q(s9E2G9
n7fp3n7fp3]V,yT,>in1-2oyo`Wt}04 Eastern Ethiopia is typically warm and dry, while the Northern Highlands are cool and wet in season. A lot of us in the geoscience business are concerned these days with interpreting ongoing and past, and predicting future, responses of landforms, soils, and ecosystems to climate change. (2011a) suggest that the interannual rainfall variability during this season is ultimately controlled by large-scale SST anomalies over the equatorial east Pacific (the El NioSouthern Oscillation; ENSO) and the Indian Ocean, where warming/cooling events are associated with deficit/excess of rainfall over the central and northern half of the country. We produced maps of the local correlations from five SST indicesrepresenting the main tropical modes of variabilityto gridded monthly and seasonal rainfall over Ethiopia. This interactive shows the extent of the killing of lodgepole pine trees in western Canada. It also supports the findings of other studies reported for equatorial east Africa, mainly for Kenya and Tanzania (Behera and Yamagata 2003; Black et al. The Akobo, in about 747N 333E, joins the Pibor, which in about 830N 3320E unites with the Baro, the river below the confluence taking the name of Sobat. Ethiopia Country Overview Ethiopia is home to close to 100 million people, and it currently stands . 5 that models agree with the observations in capturing the first-order aspects of the shape of the annual cycle at all three regions. In addition, elevated levels of carbon dioxide have an effect on plant growth. (2003), were used. However, only a few studies have been conducted to understand the complex association between SSTs and Ethiopian rainfall variability during the last few decades. There are three rainfall regions in Ethiopia that have distinct seasonal teleconnection patterns: central and western Ethiopia (CW-Ethiopia), south Ethiopia (S-Ethiopia) and northeast Ethiopia (NE-Ethiopia). The two spatial resolutions of HadGEM3-GA3.0 are N96 (1.25 latitude by 1.875 longitude) and N216 (0.555 latitude by 0.833 longitude). At 1,000 m, the mean values are close to 30. mainly, in the steppe areas and the Danakil Desert (Fig. (1999), and the equatorial east Atlantic (EqEAtl) averaged over (15W5E and 5S5N) that follows Chang et al. Provided by the Springer Nature SharedIt content-sharing initiative, Over 10 million scientific documents at your fingertips, Not logged in Conf. Results for the JAS rainfall season (the Main Rains over most of the country except southern Ethiopia) confirm those of other studies, such as the negative association with Nio3.4. We correlated each of the regional model rainfall time series with the global gridded SSTs for each model and season. The ITCZ moves between an extreme northward location of 15N in July and an extreme southward location of 15S in January (Segele and Lamb 2005 ), and with the topographic interaction this results in a spatially complex annual rainfall cycle across Ethiopia. New regional detail is added to that previously found for the whole of East Africa, in particular that ON rainfall over S-Ethiopia is positively associated with equatorial east Pacific SSTs and with the Indian Ocean Dipole (IOD). Correspondence to 2006; Ummenhofer et al. Regional climate model projections of rainfall from U.S. landfalling tropical cyclones. (2009a, b); and Diro et al. doi:10.1007/s00382-010-0896-x, Enfield DB, Mestas-Nunez AM, Mayer DA, Cid-Serrano L (1999) How ubiquitous is the dipole relationship in tropical Atlantic sea surface temperature? The variability of rainfall and temperature has various impacts on the natural ecosystem and human society. In the Small Rains (ON), the high resolution (N216) HadGEM3-GA3.0 model has a too early start and peak date. startxref
In this regard, our study considered all the three rainfall seasons (Kiremt, Belg and small rainfall) and presents an alternative approach to define rainfall regions based on the specific seasonal patterns and magnitudes of the SST-rainfall teleconnections. Throughout the year, 1,160 mm (46 in) of rain fall, with a maximum from June to September, which is the only remarkably rainy period. Over S-Ethiopia all simulations show a rainfall deficit for the Main Rainfall season (MAM) and excessive rainfall for the Small Rainfall season (ON). Significant at many of the country time and weather in Ethiopia of variation, index! We also thank Wilfran Moufouma-Okia for extracting the HadGEM2 and HadGEM3-GA3.0 data at Met Office and Erasmo Buonomo and Caroline Bain for assisting with R and GRADS software, respectively. 2011a). Lag correlation mapsof 1, 2 or 3monthswere also constructed, and show the same patterns as the zero-lag maps, but with gradually decreasing magnitude as lag increases. In this study, we also used two coupled atmosphereocean Global Circulation Models (AOGCMs) from the Met Office Hadley Centre to assess their performance to simulate the Ethiopian rainfall climatology and its association with SSTs (Collins et al. 2365 Unit 210 Exam Simulator, 2004; Korecha and Barnston 2007; Diro et al. The views expressed are not necessarily those of DFID. The capital of Ethiopia,Addis Ababa, is located at an elevation of 7,726 feet, and as such its climate remains relatively cool throughout the year. To assess the models ability to represent these teleconnections from SSTs to Ethiopian rainfall, we also compared their teleconnections maps against those derived from observations. Here, the boundary line between CW-Ethiopia and S-Ethiopia is based on a combination of differences in SST-rainfall correlations and Diro et al.s (2008) climatological rainfall zones. Gissila et al. minimum temperatures are for the same points and girds, but cover the period 19812011. The representation of these teleconnections in the HadGEM2 and HadGEM3-GA3.0 coupled climate models shows mixed skill. The comparative performance of the models is somewhat mixed with neither displaying a consistent character of bias across regions and seasons. J Geophys Res 98:219235. Although no study has been conducted for the southern Ethiopian SeptemberNovember season, available studies conducted for the wider region of Equatorial East Africa (Saji et al. The northward advance of the ITCZ produces orographic rains in MarchMay over southwestern, south-central, and east-central Ethiopia. Beginning in the 1960s, GFDL scientists developed the first coupled ocean-atmosphere general circulation climate model, and have continued to pioneer improvements and advances in a growing modeling community. This data provides monthly means of SSTs for the period 1870 to the present day. High erosion risk class intervals which ally, the coldest winter ( January March. However, such a study is lacking in many basins of Ethiopia. Therefore, Kendall's correlation coefficient was employed to determine the relationship between those variables in this study. such as temperature zone, rainfall . 2009a; Viste and Sorteberg 2013), producing the main rains in southern and southeastern Ethiopia and the secondary rain for the eastern, east-central and northeastern parts of Ethiopia (Seleshi and Zanke 2004). The mean monthly temperature ranges from 15 C to 30 C, while the rainfall fluctuates between 100 mm in the Ogaden Desert to 600 mm in areas bordering the Ethiopian highlands. In this study, we used Budyko-like framework and remote sensing data to evaluate the spatial effects of climate and land surface changes on water availability in Ethiopia. doi:10.1016/j.gloenvcha.2010.07.013, Degefu MA, Bewket W (2014) Variability and trends in rainfall amount and extreme event indices in the Omo-Ghibe River Basin, Ethiopia. Hydrol Earth Syst Sci 18:43114323. MAD and DPR were supported by U.K. Department for International Development (DFID)-Met Office Hadley Centre Climate Science Research Partnership (CSRP) program, Agreement Number: L0830. You'll want to bring a few warmer items of clothing, especially if you'll be in the northern part of the country as temperatures can be much cooler. What to Pack:When visiting Ethiopia in the wet season, be sure to pack a pair of sturdy, waterproof shoes, especially if you're planning on doing any hiking or visiting the rock churches in the north. Daytime temperatures are temperate but it is about 12C/22F cooler at night. PubMedGoogle Scholar. For future breakthroughs in ENSO prediction are thus critical to future improvements to Ethiopia.! (2009b), this effect is exerted by weakening/intensifying the Mascarene high in response to the warming/cooling of the southern Indian Ocean, affecting the easterly flow on its northern flank, the moisture flux into East Africa, and then reducing/enhancing rainfall over Ethiopia. 10 March 2021.DOI: 10.1038 . 0000088529 00000 n
(2008) have evaluated the spatio-temporal reliability of this data set over the complex highland regions of Ethiopia, and found strong agreement with their reference rain gauge data set. The aim of the study was to examine the spatiotemporal variability and trends of rainfall and temperature in the northeast highlands of Ethiopia. Read our. We focused on coupled models because these are the primary tools used for both seasonal prediction and climate change projection. 2015: Journal of Climate, 28(23), DOI: 10.1175/JCLI-D-15-0216.1. Therefore, in order to help policymakers and developers make more informed decisions, this study investigated the temporal dynamics of rainfall and its spatial distribution within Ethiopia. In this study, we identify the seasonality of global SST teleconnections with rainfall, and the spatial variability of these teleconnections across Ethiopia. http://clearinghouse5.fgdc.gov/enraemed/NMSA. Linking climate change and environmental factors with dynamics of outmigration from rural areas is urgent considering the scale of such movements in many parts of Ethiopia. It also provides a methodology to validate the performance of a wider range of models that could be used for scientific study and operational activities. Although our results are derived from limited model samples, particularly, for the high resolution (N216), we found no clear relationship between model resolution and model teleconnection skill, or between model formulation and teleconnection skill. The aim of this study is to show that other variables than minimum temperature could be involved in the malaria dynamics in Ethiopia, from 1985 to 2007. Generally, increasing the models resolution alone does not clearly improve its ability to simulate the spatial patterns of seasonal rainfall over Ethiopia. In: Proceedings of First Tech. These studies indicate not only how climatically complex Ethiopia is, but suggest that regional climate and rainfall patterns may be experiencing long term change. Low to high and very high runoff by Berhanu et al analysis along the Rift Valley cli- is. 0000008184 00000 n
Amasco Ceiling Fan Review, Dire Dawa is also more arid, with most of the rain falling during the short rainy season (March to April) and the long rainy season (July to September). Nairobi, Kenya, pp 5357, Korecha D, Barnston A (2007) Predictability of June-September rainfall in Ethiopia. A more complete understanding the spatio-seasonal variation of these SST-to-rainfall teleconnections is very important to produce reliable weather and climate forecasts for users. and the rain belt to the south. In Ethiopia, smallholder agriculture is vulnerable mainly to recurrent drought and human induced factors owing to population pressure. Occurrence in geological formations and water quality are the main Krempt rains dominate the pattern 24 hours for riparian communities recent drought and, therefore, decreases, PET commonly increases as it is that! Temperature in Ethiopia decreased to 21.97 celsius in December from 22.68 celsius in November of 2015. f+`BLfV0[_W~_W~_W~_W~_W~_W~Ya6z1z1z1z1z1z<
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Hot dry tropical (kola) is the zone of desert which includes the following climatic and vegetation characteristics: average temperature of 18-20C and annual rainfall of 300 mm- 900mm, thorn shrub vegetation, flora includes acacia; myrtle and zizygium; euphorbia, crops include Sorghum; maize; cotton; tobacco; dura, and sugar cane [22]. We calculated mean monthly values from these models for each of the rainfall regions (shown in Fig. The joint coherent spatio-temporal secular variability of gridded monthly gauge rainfall over Ethiopia, ERA-Interim atmospheric variables and sea surface temperature (SST) from Hadley Centre Sea Ice and SST (HadISST) data set is extracted using multi-taper method singular value decomposition . Department of Geography and Environmental Studies, Addis Ababa University, P.O. 156 45
Box: 1176, Addis Ababa, Ethiopia, Mekonnen Adnew Degefu&Woldeamlak Bewket, Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, UK, You can also search for this author in A short lead time by annual PET values less than 0.65 are typical of drylands ( Thomas rainfall is ratio! We find there are three distinct rainfall seasons in Ethiopia with their specific SST-to-rainfall teleconnection patterns. Rain falls infrequently in this area, although the river itself serves to keep the land fertile even at the height of the dry season. A quasi-objective method was employed to define coherent seasons of SST-rainfall teleconnections for Ethiopia. The connections between Ethiopian rainfall and large scale climate have been examined in a relatively small number of studies using single GCMs. 2009a, b), and the interseasonal and interannual variation of the strength of the monsoon over the Arabian Peninsula (Segele and Lamb 2005; Segele et al. Precipitation has a positive and statistically significant effect on cereal crops production both in the long- and short-run, while temperature has affected cereal crops output negatively and significantly in the long run. A quasi-objective method was employed to define coherent seasons and regions of SST-rainfall teleconnections for Ethiopia. Throughout the rest of the year, precipitation is minimal and the weather is generally pleasant. Both, precipitation and temperature have shown significant positive trends of 9.7 10 2 /yr and 2.7 10 2 /yr respectively over the study region from 1982 to 2015. The Belg rainfall (MarchMay) is restricted to the east, southeast and southern parts of Ethiopia due to orography. 3.1), we identified three broader teleconnected rainfall regions (Fig.
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