Meteorological research unit
Surface and balloon-borne meteorological observations and research to improve process parameterizations in the Unified Model.
The Meteorological Research Unit (MRU) is located at Cardington, Bedfordshire, UK. There has been meteorological research and observational work based at Cardington since the 1920s, from early research, through routine BALTHUM (BALloon Temperature and HUMidity) observations during the 1940s and balloon-borne turbulence research since the 1970s. Today, the facility has a wide variety of research grade meteorological equipment, including surface, sub-surface, mast-mounted, balloon-borne, small unmanned aircraft borne, remote sensing and radiosonde instruments. Research campaigns are conducted both on site and, during field campaigns, at remote locations throughout the UK and internationally. Topics studied include boundary layer cloud and fog, stable boundary layers, flow over hills and urban meteorology.
Quantities measured include wind and turbulence, temperature and humidity, radiation, visibility, aerosols, clouds, fog, soil temperature and moisture content. Data are logged continuously and processed data from the site are made available through the Centre for Environmental Data Analysis (CEDA). The surface site data record stretches back to 1998.
Additional on-site activities include instrument and platform development, and trials. Recent examples include a dewmeter, to measure dew and fog droplet deposition, a portable weather station, specially adapted for monitoring fog, and a small fleet of SUAs (small unmanned aircraft), enabling us to monitor and visualize conditions in the lower atmosphere. Our SUAs incorporate a bespoke data logging and transmission system, developed in-house, that is fully independent of aircraft platform.
Field campaigns are run for durations of between a few weeks up to more than a year, and may include deployment at multiple sites. We are able to deploy a number of comprehensive observational sites or “supersites”, similar in capability to our main site at Cardington. We also use a mobile radiosonde and doppler LiDAR (Light Detection and Ranging) facility, which can be deployed rapidly during periods of interest.
Improve understanding of meteorological processes in the boundary layer, including surface processes and high impact weather such as fog, visibility and freezing temperatures
Direct validation and development of high resolution numerical models, focusing on specific NWP [Numerical Weather Prediction] issues
Emphasis is on small scale processes relevant to the latest generation of high resolution models
Current research projects
SOFOG3D (SOuth west FOGs 3D experiment): MRU is currently participating in the SOFOG3D experiment. SOFOG3D is an initiative proposed by Meteo France, designed as a follow on from the LANFEX campaign. It will study the behaviour of various types of fog over a mesoscale network of a few km, located to the south-east of Bordeaux, France. The six month observational campaign, starting Autumn 2019, will collect data in this fog-prone region to both improve our understanding of fog processes, and provide a reference dataset for comparison with, and development of, high-resolution numerical weather prediction models, including large eddy simulation models. An MRU supersite will be deployed.
LIAISE (Land surface Interactions with the Atmosphere over the Iberian Semi-arid Environment]) will exploit observations of the land surface, hydrological and lower atmospheric processes and make use of state of the art land surface models to obtain a better understanding and model representation of land/atmosphere interactions across a range of timescales. An MRU supersite will be part of a network of observation sites deployed by European project partners. The observational campaign is located in the Ebro valley in North East Spain.
LANFEX (Local And Non-local Fog EXperiment): MRU has been analysing the data from this recent field experiment based in a valley system in the Welsh Borders region. The purpose of the experiment was to study the formation and evolution of fog in a range of valley and hill top sites. Using the terrain as a natural laboratory, we investigated whether slight differences in conditions at the various sites affected the formation of fog, examining and comparing these differing conditions to improve our understanding of the interaction of processes affecting fog. Five supersites, as well as additional smaller fog monitoring stations were deployed in this region. During the campaign, additional observations (IOPs [intense observing periods]), were taken using our mobile radiosonde and tethered balloon facilities, during weather conditions of particular interest. Using modelling and data analysis, we have developed new insight into the processes involved in the initial formation and subsequent deepening of radiation fogs. This experiment has been a collaboration with APP (Atmospheric Processes and Parametrizations), Meteo France, Leeds University, Manchester University and the University of East Anglia.
Aerosol and visibility studies: Routine aerosol and visibility observations are made at Cardington. These have been used to construct a neural network visibility predictor, which has been shown to improve prediction of visibility at the Cardington site. Further work aims to extend the study to other sites, such as airports, throughout the UK.
Stratocumulus cloud studies: The break up of stratocumulus cloud is important for the forecasting of sunny versus cloudy weather. Field trials are performed across East Anglia to better understand the development and break up of stratocumulus cloud over land, to improve the modelling of these processes.
Specialist Instrument Capability
Dewmeter: A dewmeter has been developed to measure dewfall and fog-droplet deposition. This is a portable and easily deployable device to measure total deposition of dew and fog-droplets with good sensitivity. Different natural and artificial grass surfaces can be used for collection, allowing for a variety of experiments to be performed.
Mobile Radiosonde and LiDAR [acronym] facility: MRU [acronym] has converted a van into a mobile radiosonde facility, enabling measurement of atmospheric profiles of temperature, humidity and winds from a wide variety of locations. The van is also fitted with a doppler LiDAR [acronym], enabling measurement of atmospheric turbulence, cloud properties and volcanic ash.
Tethered balloon facility: MRU tethered balloon facility flies kite balloons with both standard and specialist meteorological instruments attached to the cable at a range of heights, enabling us to perform profiles or take measurements at constant altitude. Specialist instruments we can fly include a cloud droplet probe, measuring the size distribution of cloud and fog droplets, and an array of in-house turbulence probes, measuring 3D turbulence at 20Hz.
Current development projects
SUA activities: MRU operates SUAs in both fixed wing and multi-copter form. The recent rapid advances in SUA [acronym] technology, and the availability of appropriate sensors, offer the opportunity to acquire valuable atmospheric information that is unattainable using conventional techniques. Our main platform is a hexa-copter with a take-off weight of 7 kg and typical flight times of 20 minutes. It can hover at fixed locations and perform vertical profiles to an altitude of 500m, making it well suited for fog and stable-boundary layer studies. Our fixed-wing SUA has a 1.8 m wingspan and is capable of acquiring data to an altitude of 5000 feet, within Cardington’s own restricted airspace. SUAs can be programmed to fly autonomously and complete complex flight patterns without direct input from the pilot. Our SUAs carry our miniaturised data logging and transmission system. This is designed to operate independently of aircraft platform, thus making it easily transferable between aircraft.