A5084140972- Climate variability and models
- Meteorological Phenomena and Simulations
- Hydrology and Drought Analysis
- Hydrology and Watershed Management Studies
- Flood Risk Assessment and Management
- Precipitation Measurement and Analysis
- Geophysics and Gravity Measurements
- Water resources management and optimization
- Climate change impacts on agriculture
- Atmospheric aerosols and clouds
- Atmospheric chemistry and aerosols
- Oceanographic and Atmospheric Processes
- Solar and Space Plasma Dynamics
- Atmospheric Ozone and Climate
- Water-Energy-Food Nexus Studies
- Tropical and Extratropical Cyclones Research
- Aeolian processes and effects
- Atmospheric and Environmental Gas Dynamics
- Agricultural risk and resilience
- Marine and coastal ecosystems
- Soil Moisture and Remote Sensing
- Sugarcane Cultivation and Processing
- Freshwater macroinvertebrate diversity and ecology
- Fish Ecology and Management Studies
- Astrophysics and Cosmic Phenomena
University of Sussex
2013-2025
Livestock & Meat Commission
2019
Met Office
2018
University College London
1983-2011
UCL Australia
1983-2007
University of Oxford
2000-2001
University of Reading
1990-1992
21st century climate change is projected to result in an intensification of the global hydrological cycle, but there substantial uncertainty how this will impact freshwater availability. A relatively overlooked aspect pertains different methods estimating potential evapotranspiration (PET) respond changing climate. Here we investigate response six PET a 2°C rise mean temperature. All suggest increase associated with warming However, differences signal over 100% are found between methods....
The development of a combined infrared and passive microwave satellite rainfall estimation technique is outlined. Infrared data from geostationary satellites are with polar-orbiting estimates to provide 30-min estimates. Collocated values used generate database, which accessed by cumulative histogram matching approach an temperature–rain-rate relationship. produces initial at 12-km resolution ready be aggregated the user requirements. A 4-month case study over Africa has been chosen compare...
Numerous factors are associated with poverty and underdevelopment in Africa, including climate variability. Rainfall, more generally, implicated directly the United Nations “Millennium Development Goals” to eradicate extreme hunger, reduce child mortality incidence of diseases such as malaria by target date 2015. But, Africa is not currently on meet these goals. We pose a number questions from science perspective aimed at understanding this background: Is there common origin that constrain...
Abstract. We present a comparative analysis of projected impacts climate change on river runoff from two types distributed hydrological model, global model (GHM) and catchment-scale models (CHM). Analyses are conducted for six catchments that in coverage feature strong contrasts spatial scale as well climatic developmental conditions. These include the Liard (Canada), Mekong (SE Asia), Okavango (SW Africa), Rio Grande (Brazil), Xiangxi (China) Harper's Brook (UK). A single GHM (Mac-PDM.09)...
Extremely dry conditions were experienced across most of southern Africa during the austral summer (October–March) 2015/2016, associated with one strongest observed El Niño events in Pacific. Dry peaked early months (October–December) producing intense drought 116‐year historical record, as measured by intensity standardized precipitation index all spatial scales up to sub‐continental. We estimate return period this extreme be greater than 200 years. The interior and eastern parts South...
Abstract The subseasonal-to-seasonal (S2S) predictive time scale, encompassing lead times ranging from 2 weeks to a season, is at the frontier of forecasting science. Forecasts on this scale provide opportunities for enhanced application-focused capabilities complement existing weather and climate services products. There is, however, “knowledge–value” gap, where lack evidence awareness potential socioeconomic benefits S2S forecasts limits their wider uptake. To address here we present first...
The Long-Rains wet season of March–May (MAM) over Kenya in 2018 was one the wettest on record. This paper examines nature, causes, impacts, and predictability rainfall events, considers implications for flood risk management. exceptionally high monthly totals March April resulted from several multi-day heavy episodes, rather than distinct extreme daily events. Three intra-seasonal events particular extensive flooding with loss lives livelihoods, a significant displacement people, major...
Abstract This article pioneers a unique approach to examining generic dry spells, shifting focus from traditional rain‐free period analysis crop‐centric perspective that integrates an anticipatory lens inspired by Impact‐based Forecasting (IbF). Moving beyond analyses of periods, the evaluates these impactful within‐season large‐scale agrometeorologically relevant spells (LARDS) not number days with minimal or no rainfall but their impact—specifically, adequacy root‐zone soil moisture meet...
This paper describes the development of a satellite precipitation algorithm designed to generate rainfall estimates at high spatial and temporal resolutions using combination Tropical Rainfall Measuring Mission (TRMM) radar (PR) data multispectral Geostationary Operational Environmental Satellite (GOES) imagery. Coincident PR measurements were matched with four-band GOES image form training dataset for neural network. Statistical information derived from multiple pixels was each measurement...
There are numerous applications in climatology and hydrology where accurate information at scales smaller than the existing monthly/2.5° products would be invaluable. Here, a new microwave/infrared rainfall algorithm is introduced that combines satellite passive microwave (PMW) infrared (IR) data to account for limitations both types. Rainfall estimates produced high spatial resolution temporal frequency of IR using from PMW data. An IRTb–rain rate relationship, variable space time, derived...
Abstract. This paper assesses the hydrological response to scenarios of climate change in Okavango River catchment Southern Africa. Climate are constructed representing different changes global mean temperature from an ensemble 7 models assessed IPCC AR4. The results show a substantial flow associated with warming 2 °C. However, there is considerable uncertainty sign and magnitude projected between models, implying that not appropriate generalised indicator impact. model patterns...
Summary 1. Flood‐pulsed wetlands make vital contributions to local and global biodiversity. However, the patterns controls of spatial temporal variation in aquatic biodiversity flood‐pulsed are not well understood. We analysed relationship between hydrological regime a large pristine wetland, Okavango Delta, Botswana. 2. Surveys water chemistry, diatoms macroinvertebrates were conducted over seasonal phases flood pulse. Hydrological variables frequency hydroperiod class collated from 16...
Abstract. The impact of climate variability on groundwater storage has received limited attention despite widespread dependence as a resource for drinking water, agriculture and industry. Here, we assess the anomalies that occurred over Southern Africa (SA) East Africa, south Equator (EASE), during major El Niño event 2015–2016, their associated impacts storage, across scales, through analysis in situ piezometry Gravity Recovery Climate Experiment (GRACE) satellite data. At continental...
The lives and livelihoods of people around the world are increasingly threatened by climate-related risks as climate change increases frequency severity high-impact weather. In turn, risk multiple hazards occurring simultaneously grows compound impacts become more likely. World Meteorological Organization (WMO) proposed use multi-hazard impact-based forecasting (IbF) to better anticipate reduce concurrent hazards, but yet, there few operational examples in humanitarian sector. Drought is...
Desert dust, both modern and ancient, is a critical component of the Earth system. Atmospheric dust has important effects on climate by changing atmospheric radiation budget, while deposited influences biogeochemical cycles in oceans land. Dust snow ice decreases its albedo, allowing more light to be trapped at surface, thus increasing rate melt influencing energy budgets river discharge. In human realm, contributes transport allergens pathogens when inhaled can cause or aggravate...
Abstract Equatorial East Africa (EEA) suffers from significant flood risks. These can be mitigated with preemptive action; however, currently available early warnings are limited to a few days’ lead time. Extending using subseasonal climate forecasts could open window for more extensive preparedness activity. However, before these used, the basis of their skill and relevance risk must established. Here we demonstrate that particularly skillful over EEA. Forecasts skillfully anticipate weekly...
The need to assess major infrastructure performance under a changing climate is widely recognized yet rarely practiced, particularly in rapidly growing African economies. Here, we consider high-stakes investments across the water, energy, and food sectors for two river basins transition zone Africa. We integrate detailed interpretation of observed modeled climate-system behavior with hydrological modeling decision-relevant metrics. For Rufiji River Tanzania, projected risks mid-21st century...
The Greater Horn of Africa is prone to extreme climatic conditions, thus, making climate services increasingly important in supporting decision-making processes across a range sensitive sectors. This study aims provide comprehensive review the recent advances, gaps and challenges provision over region, for each components Global Framework Climate Services. explores various milestones that have been achieved toward service delivery. achievements include improvement station network coverage,...
The results of a study to quantify the relationship between cloud cover and short‐term Forbush decreases (FD) galactic cosmic ray flux are presented. Using an extensive record global satellite‐derived products from International Satellite Cloud Climatology Project (ISCCP) D1 data series, epoch superposition analysis sample FD events is conducted. This conducted at range spatial scales global, through 5° geomagnetic latitude bands grid with 2.5° resolution. Resulting anomalies tested for...
We document a strong teleconnection between Central Equatorial African (CEA) rainfall (and Congo River discharge) and the large‐scale circulation over North Atlantic, throughout boreal winter/spring season. Positive anomalies CEA (at interannual multi‐annual timescales) are related to anomalous westerly mid‐tropospheric zonal winds CEA/Atlantic region. These appear be part of coherent structure wind extending polar regions similar that associated with NAO pattern. Idealised model simulations...
Summary The brown locust Locustana pardalina is a major agricultural pest in southern Africa, with populations periodically reaching plague proportions. Management and control would benefit from predictive capacity at seasonal time scales, as yet unavailable. results of study into the dynamics potential predictability Africa are presented here. number districts reporting measures was used proxy for swarming populations. Spectral analysis annual infestations over revealed dominant periodicity...