News and events

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Credit: Rick Fienberg / TravelQuest International / Wilderness Travel

During this evening’s solar eclipse around 90 to 96% of the Sun will be covered in the UK, but it will do more than create a spectacular sight in the sky.  As the Moon passes in front of the Sun and blocks much of its light for a short period of time, the UK's land surface will briefly respond.  Across the COSMOS-UK national soil moisture monitoring network, we anticipate changes in several of the environmental variables we measure:
 

Solar radiation: the most dramatic change

As the Sun becomes increasingly obscured, the amount of sunlight reaching the ground will decrease sharply, before recovering as the Moon moves away. COSMOS-UK radiation sensors are expected to show this striking feature of the eclipse.
 

Air temperature: a brief cooling effect

Less sunlight means less energy available to warm the Earth's surface.  As a result, air temperatures are expected to fall slightly during the eclipse, though this will vary between sites depending on cloud cover, wind conditions and local landscape.
 

Relative humidity: a small increase

Relative humidity is likely to rise during an eclipse because as air cools, its capacity to hold water vapour decreases.  COSMOS-UK sites may show a temporary increase in humidity that mirrors the temperature decrease.
 

Wind speed: a subtle response

Some COSMOS-UK sites may experience a slight decrease in wind speed as the reduced sunlight causes reduced turbulence in the lower atmosphere, but this change can be difficult to distinguish from normal weather variability.
 

Soil moisture: little immediate change

Soil moisture is not expected to show an immediate response to the eclipse because the event is too short to affect the amount of water stored in the soil.
 

A natural experiment across the UK

The COSMOS-UK network, with 40 sites across the United Kingdom and spanning a wide range of climates, soils and landscapes, provides a unique opportunity to observe how the land and atmosphere respond to a sudden change in sunlight.  For a few hours this evening, the UK will experience a rare natural experiment, and the COSMOS-UK network will be there to measure it.  We will let you know what happens!

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In the last week or so, it has been looking increasingly likely that the Environment Agency would declare a drought for parts of England following series of heatwaves and prolonged period of dry weather.

On the morning of Wednesday 29 July, the declaration came – drought conditions in East Anglia, Hertfordshire and the whole of London, Thames Valley, Hampshire and the Isle of Wight, Devon and Cornwall, the West Midlands, and Wessex, covering Dorset, Somerset, and South Gloucestershire.

By the afternoon, COSMOS-UK Network Operations Manager, Phil Vincent, was doing a piece to camera for Sky News at a COSMOS-UK compound at Sheepdrove Organic Farm in Berkshire. Phil (at 3 mins, 40 secs) describes to Tom Clarke, Sky News Science and Technology Editor, how the COSMOS-UK network measures cosmic rays from space and their interaction with hydrogen nucleii in the soil to derive moisture levels.  Sheepdrove Farm Manager, Simon Bradley-Farmer (at 4 mins, 40 secs) then talks about the challenging impact of the drought conditions on his farm’s cash flow and his ability to reinvest in the farm going forward: “the industry is depressed….in the drought areas in particular”.

For more information about the COSMOS-UK network, please visit the COSMOS-UK website.  For all enquiries, please email CosmosUK@ceh.ac.uk and a member of the team will be in touch.

This dataset contains daily and sub-daily hydrometeorological and soil moisture observations from the COSMOS-UK (cosmic-ray soil moisture) monitoring network from October 2013 to the end of 2025 . These data are from 51 sites across the UK recording a range of hydrometeorological and soil variables.

For the full dataset and supporting documents, please click on the following link: Daily and sub-daily hydrometeorological and soil moisture data (2013-2025) [COSMOS-UK] - EIDC 

Over the past three months, the COSMOS-UK team have been busy making changes to COSMOS-UK’s presence in the south-west of England. 

Sadly, we have had to say goodbye to our site at The Lizard. After 12 years of loyal service, the frequently water-logged ground conditions posed too many problems for site access, maintenance and data reliability. We would like to thank our site hosts – Natural England – for going above and beyond in keeping this site functional despite the conditions.

We have also said goodbye to our site at Tadham Moor, hosted by Natural England too. The site was found to not offer representative soil measurement because of its local conditions (managed flood plain), which are very unusual and not typical of the surrounding areas. Many thanks to the Tadham cows that assisted with the decommissioning process!

On a positive note, the team have successfully installed a new site at Camborne, on ground shared with and hosted by the Met Office. This new site includes the very latest data logger.

We are delighted to maintain such a good presence in the south-west of England, where soil moisture directly affects water resources, agriculture, flood risk, and ecosystem health in a region with variable weather and significant agricultural land use. The presence of a ground-based neutron monitor at the Met Office Camborne weather station also means that the COSMOS-UK team can calibrate its own neutron sensors and support new work the team is doing in the field of space weather research. 

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Thanks to the eddy covariance technique and existing sensors across the network, the UKCEH team have produced sub-daily estimates of sensible heat flux (H), latent heat flux (LE), and evapotranspiration (ET) from 2014 to 2024 for 45 sites across the UK.

This dataset could support applications including evaluating and driving scientific models, comparing measurements across sites and networks, and improving understanding of land-atmosphere interactions relevant to floods, droughts, and water balance studies.

The team encourages users to get in touch with questions, feedback, or observations regarding the dataset. Take a look here: https://doi.org/10.5285/c0b5caf4-c14a-49e8-a720-2401c8d3d135

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Hear UKCEH Micrometeorologist, Dr Jonathan Evans, on BBC Radio 4's Farming Today discuss how the COSMOS-UK cosmic ray neutrons science works to measure soil moisture, soil moisture trends this year and how climate change will impact UK farming in the future.

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UK Centre for Ecology & Hydrology is undertaking a deep dive review, on behalf of NERC, into the National Capability funded long-term environmental terrestrial and freshwater monitoring currently undertaken in the UK. 

This review will help to identify the priorities required for an adaptable and flexible UK environmental monitoring network for the future.

We welcome anyone who is a researcher, practitioner or user of current terrestrial and freshwater monitoring data to complete the survey by 9am Monday 29 September.

The information from this survey will be synthesised and presented to a panel of experts from the UK environmental community. This independently facilitated session will help to build the criteria and vision for the UK environmental monitoring network in the future.

Following the panel session, a report will be presented to NERC to help inform decision making in the future. Please get involved and make your voice heard. Contact nc-uk@ceh.ac.uk if you have any questions.

Soil moisture levels across the COSMOS-UK network have experienced a partial recovery after a very dry period, but some sites, particularly in the South, remain drier than usual.  

Read the full Soil Moisture Summary for July here. 

Soil moisture levels across most of the COSMOS-UK network remained very dry; however, additional rainfall in some northerly and westerly regions resulted in some sites being better than usual. 

 Please click here for the full COSMOS-UK Soil Moisture Summary.

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UKCEH’s soil moisture summary for April 2025 reports that “April soil moisture levels were exceptionally low compared with the long-term averages across many COSMOS-UK sites, continuing the drying trend from the previous month.”  COSMOS-UK is the UK’s national soil moisture monitoring network of 44 sites using cosmic ray neutron sensor technology.  In fact, 11 of the COSMOS-UK sites recorded their lowest April soil moisture on record.

This evidence reiterates the concerns raised by both UKCEH and the Environment Agency earlier this week: what will the driest spring in England since 1961, and the driest start to the year for northern regions in nearly a century, mean for farmers, business and households?

We reached out to a COSMOS-UK site host in one of the worst-affected regions, the East of England, for comment on how the current conditions are affecting their farming operations.

Hugh Mason, independent farm owner hosting the Fincham site, in north-west Norfolk, highlighted how quickly the soil dried out following an extremely wet Autumn and Winter: “Readings in the third week of February showed soil moisture to be extremely wet, historically high for Fincham. By the start of April, it was historically dry and then started setting new levels of dryness through to mid- April.”

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Figure: 2025 soil moisture at Fincham, compared to historic maximum and minimum levels.

At Fincham, oilseed rape, rye, winter wheat, sugar barley, sugar beet and maize are grown on a 6-year rotation on chalky loam and calcareous mineral soil.  The period from April to June is critical for the oilseed rape, wheat and rye crops. At the moment, the exceptionally low rainfall and unusually high temperatures are having a huge impact: “Lack of moisture stops the movement of nutrition from the soil to plant roots and therefore uptake - if you don’t get fed you go hungry”.

There is no irrigation at Fincham which changed its cropping to have less exposed to weather risk at any one moment.  However, other farms in the local area have started irrigating unusually early.

Farmers in drier parts of the UK are having to adapt their farming methods and crop choices in response to the changing climate and impact on soil moisture.

Future increases in soil moisture drought frequency at UK monitoring sites: merging the JULES land model with observations and convection-permitting UK climate projections. Find out more about the paper here. Full paper available at: https://doi.org/10.1088/1748-9326/ad7045.

We are pleased to announce that the latest COSMOS-UK dataset has been released via the Environmental Information Data Centre (EIDC). This contains daily and sub-daily hydrometeorological and soil moisture observations from the COSMOS-UK network from 2013 to 2023 - a full 10-year dataset for some of our sites!  This latest dataset includes updated COSMOS VWC values based on updates to the gamma correction parameter to account for changes in the solar cycle.