George Otieno

Igad Climate Prediction and Applications Centre | ICPAC · CLIMATE MODELLING AND DIAGNOSTICS

The Horn of Africa drylands (HAD) are among the most vulnerable regions to hydroclimatic extremes. The two rainfall seasons — long and short rains — exhibit high intraseasonal and interannual variability. Accurately simulating the long and short rains has proven to be a significant challenge for the current generation of weather forecast and climat...

There is growing recognition of the multiple benefits of co-production for forecast producers, researchers and users in terms of increasing understanding of the skill, decision-relevance, uptake and use of forecasts. This policy brief identifies lessons learnt from two operational research projects, African SWIFT and ForPAc, on pathways for embeddi...

The lives and livelihoods of people around the world are increasingly threatened by climate-related risks as climate change increases the frequency and severity of high-impact weather. In turn, the risk of multiple hazards occurring simultaneously grows and compound impacts become more likely. The World Meteorological Organization (WMO) proposed th...

Drought and food security crises heighten risks to lives and livelihoods in East Africa. In recent years, a shift towards acting in advance of such events has gained momentum, notably among the humanitarian and development community. This shift is premised on tools that link climate forecasts with pre-agreed actions and funding, known as Forecast-b...

Reliable information on the likelihood of drought is of crucial importance in agricultural planning and humanitarian decision-making. Acting based upon probabilistic forecasts of drought, rather than responding to prevailing drought conditions, has the potential to save lives, livelihoods and resources, but is accompanied by the risk of acting in v...

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...

The suitability of a weather research and forecasting model in simulating mean rainfall, number of rainy days (NRDs), intensity of rainy days and their frequencies is investigated over East Africa for selected wet years. Physical cumulus parameterizations using Kain–Fritsch (KF), Kain–Fritsch with a moisture advection-based trigger function (KFT),...

cumulus parameterization over East Africa Extreme Rainfall

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 Downscaling Experi...

The aim of this study was to determine suitability zones of future banana growth under a changing climate to guide the design of future adaptation options in the banana sub-sector of Uganda. The study used high resolution (~1 km) data on combined bioclimatic variables (rainfall and temperature) to map suitability zones of the banana crop while the...

Variations in weather and climate have a significant impact on rain-fed banana yields in East Africa. This study examined empirical linkages between banana yields and variations in rainfall and temperature over Uganda for the historical period (1971-2009) using time series moments, correlation and regression analysis. The Food and Agriculture Organ...

The October to December (OND) is a major rainfall season over the Greater Horn of Africa (GHA) with strong El Niño Southern Oscillations (ENSO) signals and high rainfall variability leading to drought and floods. One of the major efforts to address these climate extreme challenges is the use of the Global Producing Centers (GPCs) models for seasona...

Arid and semi-­‐arid regions are characterized by insufficient rainfall to sustain agricultural production. The rains are erratic and often come in a few heavy storms of short duration resulting in high run-­‐off , instead of replenishing the ground water. Protective vegetation cover is sparse and there is very little moisture for the most parts of...

The October to December (OND) is a major rainfall season over the Greater Horn of Africa (GHA) with strong El Niño Southern Oscillations (ENSO) signals and high rainfall variability leading to drought and floods. One of the major efforts to address these climate extreme challenges is the use of the Global Producing Centers (GPCs) models for seasona...

Abstract: Current rapid deterioration of air quality in most urban can be majorly attributed to ongoing urbanization. This study simulates air pollutant dispersal over Nairobi city using Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model, considering a case for emission of Total Suspended Particles (TSP) into the environment. T...

The spatial distribution of rainfall anomalies of the observed models output during extreme events showed that the ensemble model was able to simulate El-Niño (1997) and La-Niña (2000) years. The ensemble models did not show good skill in capturing the magnitude of the extreme events. The skill of the ensemble model was higher than that for the mem...

Current rapid deterioration of air quality in most urban can be majorly attributed to ongoing urbanization. This study simulates air pollutant dispersal over Nairobi city using Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model, considering a case for emission of Total Suspended Particles (TSP) into the environment. The wind cl...