A5036665617- Meteorological Phenomena and Simulations
- Atmospheric aerosols and clouds
- Wind and Air Flow Studies
- Climate variability and models
- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Ionosphere and magnetosphere dynamics
- Plant Water Relations and Carbon Dynamics
- Aeolian processes and effects
- Precipitation Measurement and Analysis
- Solar and Space Plasma Dynamics
- Tropical and Extratropical Cyclones Research
- Cryospheric studies and observations
- Geology and Paleoclimatology Research
- Climate change and permafrost
- Fluid Dynamics and Turbulent Flows
- Ocean Waves and Remote Sensing
- Aerospace Engineering and Energy Systems
- Radiative Heat Transfer Studies
- Solar Radiation and Photovoltaics
- Aerospace and Aviation Technology
- Air Traffic Management and Optimization
- Botany, Ecology, and Taxonomy Studies
- Vehicle emissions and performance
Met Office
2013-2024
Exeter Hospital
2024
University of Bedfordshire
2024
Phillips Exeter Academy
2019-2021
University of Alabama in Huntsville
2013
University of Exeter
2011
Indiana Department of Natural Resources
2009
University of Wales
1993-1996
Aberystwyth University
1991-1995
Abstract A prognostic cloud fraction and condensate scheme has been developed for the Met Office Unified Model. This is designed to replace currently used in weather forecast climate simulations, which liquid water content are calculated diagnostically. Such a overprescribes links between fraction, vapour contents. By contrast, our new (PC2) calculates increments variables of liquid, ice total fractions, as result each physical process represented model. (Ice already prognostically.) paper...
Abstract. We analyse the development of a radiation fog event and its gradual transition from optically thin in stable boundary layer to well-mixed thick fog. A comparison observations detailed large-eddy simulation demonstrate that aerosol growth activation is key process determining onset adiabatic Weak turbulence low supersaturations lead particles which can significantly affect visibility but do not interact with long-wave radiation, allowing atmosphere remain stable. Only when...
Abstract Fog is a high-impact weather phenomenon affecting human activity, including aviation, transport, and health. Its prediction longstanding issue for forecast models. The success of depends on complex interactions among various meteorological topographical parameters; even very small changes in some these can determine the difference between thick fog good visibility. This makes one most challenging goals numerical prediction. Local Nonlocal Experiment (LANFEX) an attempt to improve...
Irrigation in semi-arid regions induces thermal heterogeneity across a range of spatial scales that impacts the partitioning energy at surface, development atmospheric boundary layer, and bidirectional interactions between atmosphere surface. In this analysis, we use data from Land Surface Interactions with Atmosphere Iberian Semi-Arid Environment (LIAISE) experiment combined coupled land–atmosphere model to understand role irrigation-induced, on surface fluxes consequently, diurnal...
Abstract Three mechanisms are discussed associated with cut‐off‐low (COL) systems which can transfer stratospheric air into the troposphere. These are: (i) convective erosion of tropopause, (ii) tropopause by turbulence a jet stream, and (iii) folding around flank COL. case studies presented examine first two these processes provide evidence that stratosphere‐troposphere exchange (STE) had occurred. Furthermore, results suggest periodic reintensification some COLs cause all to recur or be...
Abstract A prognostic cloud fraction and condensate scheme (PC2) has been developed for the Met Office Unified Model. companion paper discussed motivation a new described its formulation in detail. In this we describe results of climate model simulations, concentrating on mechanisms by which predicted change between Control scheme. We demonstrate that detrainment from convection directly into large scale, as parametrized PC2 scheme, produces improved simulations deep tropical cloud. also...
Abstract. Land surface models (LSMs) need to be able simulate realistically the dynamics of permafrost and frozen ground. In this paper we evaluate performance LSM JULES (Joint UK Environment Simulator), stand-alone version land scheme used in Hadley Centre climate models, simulating large-scale distribution permafrost. particular look at how well model is seasonal thaw depth or active layer thickness (ALT). We performed a number experiments driven by observation-based datasets. Visually...
Abstract A 100 m resolution simulation of radiation fog observed during the Local And Non‐local Fog EXperiment (LANFEX) was performed over Shropshire hills (UK) in order to understand impact local circulation on valley formation. The model correctly resolves all valleys and their different geometries, associated dynamical features, conditions between measurement sites. Passage stratocumulus night led dissipation gave opportunity study two formation stages. In narrow valleys, formed at floor...
Abstract A relationship is derived between absolute vorticity in the lower stratosphere and total‐ozone column. This shows that reversible deformations to flow on synoptic scales or smaller (such as trough/ridge patterns) cause perturbations total ozone which depend amplitude depth of anomaly. Examples are presented showing excellent correspondence charts, even mesoscales. Grid correlations show at least half variance related variations just above tropopause. Some applications...
During stable nighttime periods, large variations in temperature and visibility often occur over short distances regions of only moderate topography. These are great practical significance yet pose major forecasting challenges because a lack detailed understanding the processes involved crucial topographic not resolved current forecast models. This paper describes field numerical modeling campaign, Cold-Air Pooling Experiment (COLPEX), which addresses many issues. The observational campaign...
Abstract The Convective Precipitation Experiment (COPE) was a joint U.K.–U.S. field campaign held during the summer of 2013 in southwest peninsula England, designed to study convective clouds that produce heavy rain leading flash floods. form along convergence lines develop regularly as result topography. Major floods have occurred past, most famously at Boscastle 2004. It has been suggested much produced by warm processes, similar some United States. overarching goal COPE is improve...
Abstract The numerical weather prediction (NWP) of fog remains a challenge, with accurate forecasts relying on the representation many interacting physical processes. recent Local And Non‐local Fog EXperiment (LANFEX) has generated detailed observational dataset, creating unique opportunity to assess NWP events. We evaluate performance operational and research configurations Met Office Unified Model (MetUM) three horizontal grid lengths, 1.5 km 333 100 m, in simulating four LANFEX case...
Abstract A tropopause fold developed to the west of British Isles on western flank a trough in 300 mb flow 6 October 1990. Radiosonde ascents over Europe showed very dry stable layers beneath jet stream potential temperature range 310‐315 K. These were evident profiles from 12h 00h 8 October. The European Centre for Medium‐range Weather Forecasts (ECMWF) model assimilations examined this period determine how well they represented radiosonde observations. Good agreement was found, especially...
Forecasting and modelling fog formation, development, dissipation is a significant challenge. Fog dynamics involve subtle interactions between small‐scale turbulence, radiative transfer microphysics. Recent studies have highlighted the role of aerosol related cloud microphysical properties in evolution fog. In this article, we investigate using very high‐resolution large eddy simulations coupled with newly developed multi‐moment microphysics scheme (CASIM), which has been designed to model...
Abstract The purpose of the Tropical Air–Sea Propagation Study (TAPS), which was conducted during November–December 2013, to gather coordinated atmospheric and radio frequency (RF) data, offshore northeastern Australia, in order address question how well wave propagation can be predicted a clear-air, tropical, littoral maritime environment. Spatiotemporal variations vertical gradients conserved thermodynamic variables found surface layers, mixing entrainment layers have potential bend or...
Despite the impact it has on human activity, particularly transport, accurate forecasting of fog remains a major challenge for numerical weather prediction models. The complex interaction between various physical processes, many which are parametrised and highly sensitive to small changes, is one key reasons poor forecasts. One models predicting structure boundary layer, often undergoes transition from statically stable weakly unstable during life cycle event. recent local non‐local...
Abstract The database presented in this study has been acquired during the SOuth west FOGs 3D (SOFOG3D) experiment for processes study. This international campaign led by Météo-France winter 2019–2020 aimed at deploying a unique network of both situ and remote sensing measurements order to document spatial temporal variabilities fog events. To support scientific objective but also conduct first data assimilation experiments within French convective scale model AROME, an un-precedented 8...
Abstract Observations of boundary‐layer‐humidity probability‐distributions made with the Meteorological Office tethered‐balloon facility have been derived from nine representative days between 1996 and 1999. Measurements include those at several heights simultaneously. Four types distribution defined, including skewed multimodal types. These analysed on scales relevant to sub‐grid parametrizations. functions fitted observations their accuracy in predicting cloud fraction assessed. It was...