Douglas J. Parker

Douglas J. Parker
University of Leeds · School of Earth and Environment

About

140
Publications
20,087
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
6,508
Citations
Introduction
Douglas J. Parker currently works at the School of Earth and Environment, University of Leeds. Douglas does research in Meteorology.
Additional affiliations
February 1997 - present
University of Leeds
Position
  • Professor of Meteorology

Publications

Publications (140)
Article
Full-text available
On September 1st 2009 an extreme high-impact weather event occurred in Burkina Faso that had significant impacts upon the capital city Ouagadougou and its inhabitants. Subsequent reporting and research has however not focused on the contributing socio-economic and hydrological factors and the role of global warming and climatic change remains uncer...
Article
Full-text available
In tropical convective climates, where numerical weather prediction of rainfall has high uncertainty, nowcasting provides essential alerts of extreme events several hours ahead. In principle, short-term prediction of intense convective storms could benefit from knowledge of the slowly-evolving land surface state in regions where soil moisture contr...
Article
The ability to predict heavy rain and floods in Africa is urgently needed to reduce the socioeconomic costs of these events, and increase resilience as climate changes. Numerical weather prediction in this region is challenging and attention is being drawn to observationally-based methods of providing short-term nowcasts (up to ∼6 hours lead time)....
Article
Full-text available
The ‘silent revolution’ of numerical weather prediction (NWP) has led to significant social benefits and billions of dollars in economic benefits to mid-latitude countries, however the level of benefit in sub-Saharan Africa has been very limited, despite the potential to save lives, improve livelihoods, protect property and infrastructure and boost...
Article
Full-text available
Two techniques are presented for characterisation of cloud‐feeding coherent boundary layer structures through analysis of large‐eddy simulations of shallow cumulus clouds, contrasting conditions with and without ambient shear. The first technique is a generalisation of the two‐point correlation function, where the correlation length‐scale as well a...
Article
Full-text available
Due to associated hydrological risks, there is an urgent need to provide plausible quantified changes in future extreme rainfall rates. Convection-permitting (CP) climate simulations represent a major advance in capturing extreme rainfall and its sensitivities to atmospheric changes under global warming. However, they are computationally costly, li...
Article
The Indian monsoon is a seasonal large‐scale circulation system with complex dynamical and thermodynamic interactions. The physical processes are not fully understood. In particular, the mechanisms that control the propagation of the monsoon onset across the Indian continent, against the mid‐level wind field, are debated. The Indian monsoon is poor...
Article
Full-text available
Africa is poised for a revolution in the quality and relevance of weather predictions, with potential for great benefits in terms of human and economic security. This revolution will be driven by recent international progress in nowcasting, numerical weather prediction, theoretical tropical dynamics and forecast communication, but will depend on su...
Article
Full-text available
There is a huge opportunity for the African continent to benefit from the ‘silent revolution’ in weather forecasting that has been realised in the mid-latitudes throughout the twentieth century. While there are tremendous societal and economic benefits from advancing the science behind weather forecasting in sub-Saharan Africa, there are also signi...
Article
Full-text available
The high frequency of intense convective storms means there is a great demand to improve predictions of high‐impact weather across Africa. The low skill of numerical weather prediction over Africa, even for short lead times highlights the need to deliver nowcasting based on satellite data. The Global Challenges Research Fund African SWIFT (Science...
Article
Full-text available
A coherent synoptic sequence, mostly over North Africa, is identified whereby an upper‐level midlatitude trough (in November‐March) excites several days of quasi‐stationary near‐surface warming across the Sahara, leading to rainfall events over northern Congo (NC), and perturbed weather more widely. Ahead of NC rainfall events, composite sequences...
Book
FRENCH ABSTRACT Météorologie de l’Afrique de l’Ouest tropicale : Le manuel du prévisionniste présente les bases scientifiques et la prévision du temps pour une région importante des tropiques. En faisant la relation entre les théories les plus récentes et la pratique de la prévision, ce livre constitue une documentation unique pour la formation des...
Article
Full-text available
Current climate precipitation and temperature extremes have been identified by decision makers in West Africa among the more impactful weather events causing lasting socio-economic damage. In this article, we use a plausible future-climate scenario (RCP 8.5) for the end of the 21st Century to explore the relative commonness of such extremes under g...
Preprint
Full-text available
This paper presents two techniques for characterisation of cloud-feeding coherent boundary layer structures through analysis of large-eddy simulations of shallow cumulus clouds, contrasting conditions with and without ambient shear. The first technique is a generalisation of the two-point correlation function where the correlation length-scale as w...
Article
Full-text available
Extreme rainfall is expected to increase under climate change carrying potential socio-economic risks. However, the magnitude of increase is uncertain. Over recent decades, extreme storms over the West African Sahel have increased in frequency with increased vertical wind shear shown to be a cause. Drier mid-levels, stronger cold pools, and increas...
Article
Meteorology of Tropical West Africa: The Forecasters' Handbook is set to change the way forecasters, researchers and students learn about tropical meteorology and will serve to drive demand for new forecasting tools. Bridging the gap between rapidly moving scientific research and specific forecasting tools, Meteorology of Tropical West Africa: The...
Article
Full-text available
The INCOMPASS field campaign combines airborne and ground measurements of the 2016 Indian monsoon, towards the ultimate goal of better predicting monsoon rainfall. The monsoon supplies the majority of water in South Asia, but forecasting from days to the season ahead is limited by large, rapidly developing errors in model parametrizations. The lack...
Article
The Met Office Unified Model (MetUM) is known to produce too little total rainfall on average over India during the Monsoon period, when assessed for multi-year climate simulations. We investigate how quickly this dry bias appears by assessing the 5-day operational forecasts produced by the MetUM for six different years. It is found that the MetUM...
Article
Full-text available
Convection-permitting models perform better at representing the diurnal cycle and the intermittency of convective rainfall over land than parameterized-convection models. However, most of the previous model assessments have been from an Eulerian point of view, while key impacts of the rainfall depend on a storm-relative perspective of the system li...
Article
Full-text available
This paper presents a land‐atmosphere case study for a single day during monsoon onset, incorporating data from a research aircraft, satellite products and model outputs. The unique aircraft observations reveal temperature and humidity contrasts of up to 5 K and 4 gkg‐1 in the planetary boundary layer induced by spatial variations in soil moisture....
Article
The ascent of a moist thermal is used to test a recently developed essentially Lagrangian model for simulating moist convection. In this Moist‐Parcel‐In‐Cell (MPIC) model, a number of parcels are used to represent the flow in each grid cell. This has the advantage that the parcels provide an efficient and explicit representation of subgrid scale fl...
Article
Full-text available
Mesoscale Convective Systems (MCSs) produce some of the most intense rainfall on the planet, and their response to climate variability and change is rather uncertain. Under global warming, increased water vapour is expected to intensify the most extreme rain events and enhance flood frequency. However, MCS dynamics are also sensitive to other atmos...
Article
Cold pool outflows have been shown from both observations and convection-permitting models to be a dominant source of dust emissions (“haboobs”) in the summertime Sahel and Sahara, and to cause dust uplift over deserts across the world. In this paper Met Office Large Eddy Model (LEM) simulations, which resolve the turbulence within the cold-pools m...
Article
Monsoon depressions (MDs) bring substantial monsoon rainfall to northern and central India. These events usually form over the Bay of Bengal and travel across northern India toward Pakistan. Using European Centre for Medium-Range Weather Forecasting Interim Reanalysis, an MD tracking algorithm, and an objective identification method, we find that a...
Article
Full-text available
An objective tracking algorithm is used to characterise the three-dimensional structure of African Easterly Waves (AEWs) in ERA-Interim reanalysis and a Met Office Unified Model (UM) simulation. A special focus is dedicated to the coupling of dynamical aspects of the wave and moist convection. The relation between baroclinic features of the wave an...
Article
Full-text available
For the remote Sahara, the Earth's largest dust source, there has always been a near-absence of data for evaluating models. Here, new observations from the Fennec project are used along with Sahelian data from the African Monsoon Multidisciplinary Analysis (AMMA) to give an unprecedented evaluation of dust-generating winds in the European Centre fo...
Article
Herein we describe a promising alternative approach to modelling moist convection and cloud development in the atmosphere. Rather than using a conventional grid‐based approach, we use Lagrangian ‘parcels’ to represent key dynamical and thermodynamical variables. In the prototype model considered, parcels carry vorticity, mass, specific humidity, an...
Article
The hydrological cycle is expected to intensify under global warming¹, with studies reporting more frequent extreme rain events in many regions of the world²³⁴, and predicting increases in future flood frequency⁵. Such early, predominantly mid-latitude observations are essential because of shortcomings within climate models in their depiction of co...
Chapter
This chapter presents a consensus of current thinking on synoptic weather systems in West Africa. It focuses on discussing the synoptic circulations that occur within the West Africa region, encompassing scales of a few thousand kilometres, and on timescales of 1-10 days. The chapter begins by presenting synoptic features on the continental scale,...
Chapter
To help forecasters in West Africa with the difficult task of numerical weather prediction, a conceptual framework was developed and tested in 2006, during the Specific Observation Period of the African Monsoon and Multidisciplinary Analyses (AMMA) project. The framework adopts an object-oriented approach to forecasting based on available conceptua...
Chapter
This chapter describes the prediction of seasonal timescale events such as seasonal means; its focus will be forecasts of 1-6 months ahead. Seasonal predictability tends to be evident on larger scales; therefore, much of the chapter discusses predictability for the three regions, including Sahel, Soudan, and Guinea coast. Most of the literature on...
Chapter
This chapter shows that the unique characteristics of convection over West Africa can be explained in terms of the semi-arid climatic conditions that prevail in the region. Predicting convection is one of the most important and, at the same time, most difficult tasks facing the forecaster. The chapter summarizes the factors and diagnostics that sho...
Chapter
This chapter considers a set of challenges in weather forecasting for specific geographic locations, such as a particular village, town or airport. It describes some basic principles that relating to the offshore environment. The diurnal pattern of the surface energy balance is the primary control on local weather conditions in West Africa. There i...
Chapter
This chapter focuses on the nowcasting of convective storms and associated hazards. The nowcast process begins when the forecaster first assesses the synoptic and mesoscale weather pattern, and continues to evolve, ideally, with continuous monitoring of the local high-resolution observations. The chapter presents general methods and tools used for...
Article
Full-text available
In common with many global models, the Met Office Unified Model (MetUM) climate simulations show large errors in Indian summer monsoon rainfall, with a wet bias over the equatorial Indian Ocean, a dry bias over India, and with too weak low-level flow into India. The representation of moist convection is a dominant source of error in global models,...
Article
Full-text available
Over monsoon regions, such as the Indian Subcontinent, the local onset of persistent rainfall is a crucial event in the annual climate for agricultural planning. Recent work suggested that local onset dates are spatially coherent to a practical level over West Africa; a similar assessment is undertaken here for the Indian Subcontinent. Areas of coh...
Article
From May to July 2016, as part of the INCOMPASS project, the Facility for Airborne Atmospheric Measurements (FAAM, jointly funded by the Met Office and NERC) BAe-146 research aircraft travelled to India to record key aspects of the Indian summer monsoon onset and evolution (Turner et al., 2016). As part of the planning for the campaign, partners in...
Article
Full-text available
The advance of the onset of the Indian monsoon is here explained in terms of a balance between the low-level monsoon flow and an over-running intrusion of mid-tropospheric dry air. The monsoon advances, over a period of about 6 weeks, from the south of the country to the northwest. Given that the low-level monsoon winds are westerly or southwesterl...
Article
Full-text available
The summertime Sahara heat low (SHL) is a key component of the West African monsoon (WAM) system. Considerable uncertainty remains over the relative roles of water vapour and dust aerosols in controlling the radiation budget over the Sahara and therefore our ability to explain variability and trends in the SHL, and in turn, the WAM. Here, new obser...
Article
Full-text available
Accurate prediction of the commencement of local rainfall over West Africa can provide vital information for local stakeholders and regional planners. However, in comparison with analysis of the regional onset of the West African Monsoon, the spatial variability of the local monsoon onset has not been extensively explored. One of the main reasons b...
Article
Full-text available
State-of-the-art regional climate model simulations that are able to resolve key mesoscale circulations are used, for the first time, to understand the interaction between the large-scale convective environment of the MJO and processes governing the strong diurnal cycle over the islands of the Maritime Continent (MC). Convection is sustained in the...
Article
Full-text available
Cold pools are integral components of squall-line mesoscale convective systems and the West African monsoon, but are poorly represented in operational global models. Observations of 38 cold pools made at Niamey, Niger, during the 2006 African Monsoon Multidisciplinary Analysis (AMMA) campaign (1 June-30 September 2006), are used to generate a seaso...
Research
Full-text available
Presentation on the differences in onset definitions for the West African Monsoon. Presentation was given at the Would Weather Open Science Conference in Montreal, Canada, August 2014.
Article
Full-text available
The Fennec climate programme aims to improve understanding of the Saharan climate system through a synergy of observations and modelling. We present a description of the Fennec airborne observations during 2011 and 2012 over the remote Sahara (Mauritania and Mali) and the advances in the understanding of mineral dust and boundary layer processes th...
Article
Full-text available
The summertime Sahara Heat Low (SHL) is a key component of the West African Monsoon (WAM) system. Considerable uncertainty remains over the relative roles of water vapour and dust aerosols in controlling the radiation budget over the Sahara and therefore our ability to explain variability and trends in the SHL, and in turn, the WAM. Here, new obser...
Article
Weather and climate model simulations of the West African Monsoon (WAM) have generally poor representation of the rainfall distribution and monsoon circulation because key processes, such as clouds and convection, are poorly characterized. The vertical distribution of cloud and precipitation during the WAM are evaluated in Met Office Unified Model...
Article
We present a characterization of the Saharan heat low (SHL) based on dropsonde observations made on 22 June 2011 by two simultaneously flying aircraft during the Fennec project. The observations are used to identify moisture transport pathways and to validate the UK Met Office limited area model for northern Africa (Africa-LAM). The observations ca...
Article
Full-text available
Global climate and weather models are a key tool for the prediction of future crop productivity, but they all rely on parameterizations of atmospheric convection, which often produce significant biases in rainfall characteristics over the tropics. The authors evaluate the impact of these biases by driving the General Large Area Model for annual cro...
Article
We present a characterization of the Saharan heat low (SHL) based on dropsonde observations made on 22 June 2011 by two simultaneously flying aircraft during the Fennec project. The observations are used to identify moisture transport pathways and to validate the UK Met Office limited area model for northern Africa (Africa-LAM). The observations ca...
Article
As weather and climate models move towards higher resolution, there is growing excitement about potential future improvements in the understanding and prediction of atmospheric convection and its interaction with larger-scale phenomena. A meeting in January 2013 in Dartington, Devon was convened to address the best way to maximise these improvement...
Article
Full-text available
The turbulent structure and growth of the remote Saharan atmospheric boundary layer (ABL) is described with in situ radiosonde and aircraft measurements and a large-eddy simulation model. A month of radiosonde data from June 2011 provides a mean profile of the midday Saharan ABL, which is characterized by a well-mixed convective boundary layer, cap...
Article
Links between convergence and convection are poor in global models and poor representation of convection is the source of many model biases in the tropics. State-of-the-art convection-permitting simulations allow us to analyse realistic convection statistically. Analysis of fractal dimension is used to show that in convection-permitting simulations...
Article
The first size-resolved airborne measurements of dust fluxes and the first dust flux measurements from the central Sahara are presented and compared with a parameterization by Kok [2011a]. High frequency measurements of dust size distribution were obtained from 0.16-300 µm diameter and eddy covariance fluxes were derived. This is more than an order...
Article
The first size-resolved airborne measurements of dust fluxes and the first dust flux measurements from the central Sahara are presented and compared with a parameterization by Kok (2011a). High-frequency measurements of dust size distribution were obtained from 0.16 to 300 μm diameter, and eddy covariance fluxes were derived. This is more than an o...
Article
As weather and climate models move towards higher resolution, there is growing excitement about potential future improvements in the understanding and prediction of atmospheric convection and its interaction with larger-scale phenomena. A meeting in January 2013 in Dartington, Devon was convened to address the best way to maximise these improvement...
Article
[1] A suite of 40-day UK Met Office Unified Model simulations over West Africa during summer 2006 are analysed to investigate the causes of biases in the position of the rainbelt and to understand the role of convection in the regional water budget. The simulations include climate, global operational and limited-area runs (grid-spacings from 1.5 to...
Article
Full-text available
[1] Feedback between soil moisture and precipitation influence climate variability in semiarid regions. However, serious concerns exist about the ability of coarse-scale global atmospheric models to depict one key aspect of the feedback loop, namely the sensitivity of daytime convection to soil moisture. Here we compare regional simulations using a...
Article
A mesoscale convective system (MCS) case study was observed over northeast Mali as part of the African Monsoon Multidisciplinary Analysis (AMMA) on 31 July 2006. Observations of this case suggest that the soil-moisture heterogeneity and atmospheric gravity waves emitted from a ‘parent’ MCS were important trigger mechanisms for this system. This stu...