Lead Research Organisation: University of Manchester
Department Name: Earth Atmospheric and Env Sciences


An understanding of cloud properties is highly desirable due to the role of clouds on precipitation formation and the global energy balance. The presence of liquid water in clouds is associated with clouds which are highly reflective with respect to incoming sunlight. The validation of numerical weather and climate models is key to understanding the deficiencies and strengths of the current generation of models.

While in-situ observations of various meteorological and compositional parameters are routinely collected at multiple sites from various platforms, there are no routine in-situ observations of cloud properties. Remote sensing data (e.g. radar) is commonly used to validate the numerical model cloud products. However, the data from remote sensing techniques requires inverting in order to obtain useful information on clouds. These data inversions are in need of validation against observations as the small number of in-situ/remote sensing inter-comparisons performed to date have highlight major discrepancies.

We propose the development of a new low cost, lightweight, low power liquid water sensor suitable for operational use on weather balloons. Data from the sensor could be used to initialise numerical models to improve weather forecasts, validate climate/weather models, validate remote sensing retrievals, and monitor the state of the climate. Other applications of the sensor include real time fog monitoring and fog forecast validation. The sensor could also be deployed on Unmanned Aerial Systems to obtain observations from low cost platforms operating in hazardous environments.

There are three distinct activities within the project:
(1) Design
(2) Testing and Characterisation
(3) Engage with potential end users and industry

Design: We will develop a miniaturised sensor based on the PVM-100A (Particle Volume Monitor). The PVM-100A was made by Gerber Scientific Inc, in the 1990s, but is no longer available to buy. The PVM-100A is not suitable for operational use on weather balloons in its current form due to its cost, size, weight and power consumption. Owing to the high sensitivity of the PVM-100A design, miniaturisation and modernization of the PVM-100A system components would results in a high performance, low cost bulk sensor suitable for operation use on weather balloons. Modern opto-electronic and electrical components have far greater stability, efficiency and sensitivity than those from the early 1990s, meaning the use of modern low cost components is a viable option. Novel design features will also be incorporated to simplify instrument construction and to develop Intellectual Property. The investigator team has been using PVM technology for over 20 years.

Testing and Characterisation: The new sensor will be tested in a cloud chamber based at the University of Manchester. These tests will be conducted in a variety of laboratory conditions to assess instrument performance. The influence of parameters such as ambient temperature, cloud water content, and cloud droplet effective radius will be tested.

Engage with potential end users and industry : The new sensor will be integrated with a standard radiosonde package. Potentially interested end users and commercial bodies will be invited to attend demonstration activities at the Manchester cloud chamber.

Planned Impact

Beneficiary: National weather agencies (e.g. UK Met Office)
Uptake of the sensor will allow low cost monitoring of cloud properties. This can lead to improved weather forecasts, as cloud properties measured by the new technology can be assimilated to create improved initial conditions and remote sensing retrievals. Data from the sensors can also be used in forecast validation, by identifying deficiencies in the cloud and fog forecast schemes. This can lead to improve forecasts of cloud and fog, which benefits society. Economic impacts are also generated via improved hazard forecasting accuracy (floods, fog).

Beneficiary: UK Small/Medium Business
Commercialisation of a low cost sensor for cloud/fog liquid water monitoring could lead to significant wealth/job creation. Radiosondes provide essential data on the vertical structure of the atmosphere, and the data from them which drives numerical weather forecast models. A low cost cloud sensor could be used in conjunction with a radiosonde to provide additional information on the state of the atmosphere, improving forecasts. The commercial potential of a low cost cloud sensor is large, given the number of radiosonde launches which occur every day. The National Weather Service in the USA launches 70,000 radiosondes per year. Globally, over 400,000 radiosondes are launched every year.


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Description The prototype sensor was developed and tested in a variety of conditions. Unfortunately the sensor had some undesirable responses to the input, which lead to uncertainty in the output. Further modifications and testing are required but unfortunately funding has expired.
Exploitation Route More funding needed (~6 months PDRA) to further develop the prototype sensor to improve response to input.
Sectors Environment