Zachary Atheru's research while affiliated with Igad Climate Prediction and Applications Centre and other places

Publications (15)

Preprint
Full-text available
Extreme Rainfall is crucial for Crop production and food security in Eastern Africa. This paper seeks to investigate the changes and variability in wet days and dry spells over the IGAD region. Data used are Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS). Several statistical methods and wet days and dry spells thresholds at...
Preprint
Rainfall Onset Dates (ROD), Rainfall Cessation Dates (RCD) and Length of rainy Season (LRS) are crucial for Crop production and food security in Eastern Africa yet scantily documented. This paper seeks to investigate the spatial patterns of these parameters. Data used are Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) and N...
Article
Full-text available
A significant proportion of the population in Sub-Saharan Africa are vulnerable to extreme climatic conditions, hence there is a high demand for climate information. In response to this need, the Global Challenges Research Fund African Science for Weather Information and Forecasting Techniques has been undertaking a two-year testbed to co-produce t...
Article
Full-text available
Timing of the rainy season is essential for a number of climate sensitive sectors over Eastern Africa. This is particularly true for the agricultural sector, where most activities depend on both the spatial and temporal distribution of rainfall throughout the season. Using a combination of observational and reanalysis datasets, the present study in...
Article
Full-text available
Ethiopia and South Sudan contain several population centers and important ecosystems that depend on July–August rainfall. Here we use two models to understand current and future rainfall: the first ever pan-African numerical model of climate change with explicit convection and a parameterized model that resembles a typical regional climate model at...
Article
Full-text available
Abstract We analyze the potential effect of global warming levels (GWLs) of 1.5 ◦C and 2 ◦C above pre-industrial levels (1861−1890) on mean temperature and precipitation as well as intra-seasonal precipitation extremes over the Greater Horn of Africa. We used a large, 25-member regional climate model ensemble from the Coordinated Regional Downscal...
Article
Full-text available
For the first time in serveral years, the El Nino-Southern Oscillation did not dominate regional climate conditions around the globe. A weak La Ni a dissipated to ENSOneutral conditions by spring, and while El Nino appeared to be emerging during summer, this phase never fully developed as sea surface temperatures in the eastern conditions. Neverthe...
Article
Full-text available
Large-scale climate patterns influenced temperature and weather patterns around the globe in 2011. In particular, a moderate-to-strong La Nina at the beginning of the year dissipated during boreal spring but reemerged during fall. The phenomenon contributed to historical droughts in East Africa, the southern United States, and northern Mexico, as w...
Article
Full-text available
Several large-scale climate patterns influenced climate conditions and weather patterns across the globe during 2010. The transition from a warm El Niño phase at the beginning of the year to a cool La Niña phase by July contributed to many notable events, ranging from record wetness across much of Australia to historically low Eastern Pacific basin...
Article
Full-text available
Several large-scale climate patterns influenced climate conditions and weather patterns across the globe during 2010. The transition from a warm El Nino phase at the beginning of the year to a cool La Nina phase by July contributed to many notable events, ranging from record wetness across much of Australia to historically low Eastern Pacific basin...
Article
Full-text available
Several large-scale climate patterns influenced climate conditions and weather patterns across the globe during 2010. The transition from a warm El Nino phase at the beginning of the year to a cool La Nina phase by July contributed to many notable events, ranging from record wetness across much of Australia to historically low Eastern Pacific basin...

Citations

... connections found between the interannual variability of SSTs and the GHA rainy seasons in observations, models with WIOSSTs and IODs that are too strong may be expected to have rainy seasons that are biased wet, or dry for models with WIOSSTs and IODs that are too weak. Connections between SSTs and the timing of the rainy seasons are more tenuous-forecast skill is connected more to atmospheric variables (e.g., MacLeod (2018))-but a recent study has connected onset variability in the short rains to SST anomalies in the Indian Ocean (Gudoshava et al. 2022). ...
... Rare freezing rain-snow events and snowfall were observed in many areas along the northern coast of the Mediterranean Sea. More than 800 people died as a result of the disaster in Eastern Europe alone (Blunden et al. 2013). In 2008, China's freezing rain and snow events caused serious losses, with 107 deaths and direct economic losses amounted to 111.9 billion CNY (Cheng et al. 2011). ...
... When decreasing horizontal grid spacing to about 4 km or less, deep convection is crudely resolved by the model and the parametrization of this process can be switched off (Prein et al. 2015). Recent Convection-Permitting (CP) model simulations over East Africa have shown to substantially improve model performance for rainfall intensity, rainfall diurnal cycle, storm propagation and dry spells ( Van de Walle et al. 2020;Finney et al. 2019Finney et al. , 2020aJackson et al. 2020;Senior et al. 2021;Misiani et al. 2020;Woodhams et al. 2018)). Moreover, Van de Walle et al. (2020) found a much better representation of top-of-atmosphere radiation in their COSMO-CLM CP model simulation compared to the CORDEX-Africa COSMO-CLM simulations (Kothe et al. 2014) and linked this both to higher resolution and to the improved microphysics (2-moment scheme). ...
... There are a considerable number of de nitions and thresholds for calculating wet days and dry spells patterns in the Literature. In most cases, these de nitions and thresholds produce different wet/dry days and spells even when applied to the same observation or gridded dataset (e. (Gudoshava et al., 2020a). All these methods observed limitation regarding number of rainy days within threshold of total rainfall amount, seasonal extremes indices and probability of exceeding de ned wet days and dry spells. ...
... The primary difference from Figure 3a is the V-shaped pattern of negative (often significant) correlation in the western Pacific, especially at the apex of the V. A similar pattern has been found in previous studies examining the role of western Pacific SSTs in the LR drying trend (Funk et al., 2018(Funk et al., , 2019Funk & Hoell, 2015;Lyon & DeWitt, 2012). Comparing the distributions suggests that the relationship of western Pacific SSTs with EA rainfall totals is more independent of the MJO. ...
... Previous studies have demonstrated the importance of body reserves built up at the spring stopover sites for reproductive success (Black et al., 1991;Ebbinge and Spaans, 1995;Madsen, 1995), and as capital breeders these reserves become vital especially when the green-up at the breeding ground is later than normal. The 2012 May and early June temperature at the breeding grounds on Svalbard was one of the coolest observed after the turn of the millennium (Iden et al., 2012a(Iden et al., , 2012bOverland et al., 2012). This resulted in belated snow and ground ice melt (Vickers et al., 2020), and hence delayed onset of spring also at the breeding grounds. ...
... The GBM region experiences relatively few tropical cyclones compared with other terrestrial basins: the number of named storms in the North Indian Ocean for 1980-2009 was only seven per cent of the global total (Knapp et al. 2010;Diamond and Trewin 2011). However, the large coastal population around the Bay of Bengal means that the impact of cyclone-induced storm surge can be very large. ...
... The three park units in this study are underlain by permafrost, or material that is continually at or below 0 °C for at least two consecutive years [15]. Warming temperatures lead to a deepening of the annual active layer (e.g., the layer that warms above freezing in the summer and re-freezes in the winter), permafrost thaw as this layer deepens, and eventually thermokarst formation with irregular soil subsidence. ...
... Globally, there was an increase in the annual percentage of area with droughts over the period 1902−2008 (Wang et al., 2014). Since 1970, the intensity and duration of droughts has increased and the area affected by droughts has increased (Burke et al., 2006;Blunden et al., 2011). In fact, it is thought that the 2018−2020 drought in Central Europe was likely the worst in 2000 years (Büntgen et al., 2021). ...
... The Pacific Ocean-originating weather patterns, El Niño and La Niña, have both been indicted as two of the drivers (and not causes) of climate change (Blunden et al., 2011). El Niño and La Niña describe the warming and cooling phases, respectively, of the El Niño Southern Oscillation (ENSO), which is a cyclical weather pattern that influences temperature, humidity, rainfall and winds across the globe (Wang et al., 2017). ...