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The summer of 2022 was particularly notable for the prolonged and extensive hot and dry conditions experienced across the UK. The resultant 2022 drought had widespread impacts and prompted much discussion about the continuing vulnerability of the UK to drought, particularly in the context of anthropogenic warming. Here, we briefly describe the evolution of the drought before focusing on the severity of rainfall, river flow, soil moisture and groundwater level deficits from summer 2022, placing the event into a historical context and addressing the impacts of the drought. We also consider whether the 2022 drought is part of a long-term trend towards increasing drought severity.

The COSMOS-UK network delivers high quality continuous near real-time monitoring of soil moisture and meteorological variables across the whole of the UK, at 48 long-term field-monitoring locations, from 2013 ongoing. UKCEH operate the network on behalf of the Natural Environment Research Council (NERC), as part of their National Capability programme, for the benefit of the national academic research community and the private sector. Research grade datasets are publically available for comparison with EO products as a ground based calibration and validation (Cal/Val) network. A range of in situ data are available, focusing on large area (0.1 km2) soil moisture measurements using Cosmic Ray Neutron Sensors (CRNS), as well as point soil moisture measurements at various soil depths; and when applicable the CRNS is used to derive snow water equivalent. Phenology camera imagery is processed to provide greenness products, cropping patterns, and other vegetation and land use changes; upwelling longwave radiation measurements can be related to land surface temperatures in addition to soil temperature profiles from near surface to 50 cm soil depth. Shortwave radiometers give albedo and cloudiness. Sonic anemometers not only provide wind speed and direction, but are also processed to give sensible heat fluxes, and evapotranspiration is estimated as the residual of the land surface energy balance using net radiation and soil heat flux measurements. The suite of data is an invaluable resource in testing EO products, primarily for SAR and other combined EO soil moisture products, and with great potential for further Cal/Val applications.

Backward Brillouin scattering in whispering-gallery-mode micro-resonators offers an exciting avenue to pursue both classical and quantum optomechanics applications. Our team-the Quantum Measurement Lab-together with our collaborators, are currently utilizing this regime and the favourable properties it affords for non-Gaussian motional state preparation of the acoustic field. In particular, the high mechanical frequencies, and low optical absorption and heating provide a promising route to overcome current hindrances within optomechanics. Three of our recent experimental results in this area include: (i) Brillouin optomechanical strong coupling, (ii) single-phonon addition or subtraction to a thermal state of the acoustic field, and (iii) performing phase-space tomography of non-Gaussian states generated by single- and multi-phonon subtraction. This SPIE presentation will cover these three results, what they enable, and the broader direction of our lab including the prospects of this platform for quantum-memory applications.

Chapter 2. Whilst infrastructure projects have often focused on improving the supply of water for agriculture, there has been much less focus on managing or reducing the agricultural water demand. The net effect of increasing supply, without managing demand, is that agricultural water (and energy) consumption increases, without necessarily increasing food production. Improved agricultural Water Use Efficiency (WUE) can help address this issue, as well as contributing to reducing the pressures on water resources (NITI Aayog 2019). This chapter outlines how recent improvements in large area measurement of soil moisture and the availability of high-resolution Soil Moisture Deficit information at a fine scale can provide actionable guidance to farmers. Practical methods, demonstrated in farm pilot studies, to manage irrigation demand are discussed, along with considerations of efficient irrigation methods, with the objective of improving WUE.

The COSMOS-UK observation network has been providing field-scale soil moisture and hydrometeorological measurements across the UK since 2013. At the time of publication a total of 51 COSMOS-UK sites have been established, each delivering high-temporal resolution data in near-real time. Each site utilizes a cosmic-ray neutron sensor, which counts epithermal neutrons at the land surface. These measurements are used to derive field-scale near-surface soil water content, which can provide unique insight for science, industry, and agriculture by filling a scale gap between localized point soil moisture and large-scale satellite soil moisture datasets. Additional soil physics and meteorological measurements are made by the COSMOS-UK network including precipitation, air temperature, relative humidity, barometric pressure, soil heat flux, wind speed and direction, and components of incoming and outgoing radiation. These near-real-time observational data can be used to improve the performance of hydrological models, validate remote sensing products, improve hydro-meteorological forecasting, and underpin applications across a range of other scientific fields. The most recent version of the COSMOS-UK dataset is publically available at https://doi.org/10.5285/b5c190e4-e35d-40ea-8fbe-598da03a1185 (Stanley et al., 2021).

This dataset contains daily and sub-daily hydrometeorological and soil observations from COSMOS-UK (cosmic-ray soil moisture) monitoring network from October 2013 to the end of 2019. These data are from 51 sites across the UK recording a range of hydrometeorological and soil variables.

A new generalised data acquisition and processing tool has been developed for COSMOS soil moisture sensor data in order to detect space weather events.

This dataset contains daily and sub-daily hydrometeorological and soil observations from COSMOS-UK (cosmic-ray soil moisture) monitoring network from October 2013 to the end of 2018. These data are from 50 sites across the UK recording a range of hydrometeorological and soil variables. Each site in the network records the following hydrometeorological and soil data at 30 minute resolution: Radiation (short wave, long wave and net), precipitation, atmospheric pressure, air temperature, wind speed and direction, humidity, soil heat flux, and soil temperature and volumetric water content (VWC), measured by point senors at various depths. Each site hosts a cosmic-ray sensing probe; a novel sensor technology which counts fast neutrons in the surrounding atmosphere. In combination with the recorded hydrometeorological data, neutron counts are used to derive VWC over a field scale (COSMOS VWC), at two temporal resolutions (hourly and daily). The presence of snow leads to erroneously high measurements of COSMOS VWC due to all the extra water in the surrounding area. Included in the daily data are indications of snow days, on which, the COSMOS VWC are adjusted and the snow water equivalent (SWE) is given. The potential evapotranspiration (PE), derived from recorded hydrometeorological and soil are also included at daily resolution. Two levels of quality control are carried out, firstly data is run through a series of automated checks, such as range tests and spike tests, and then all data is manually inspected each week where any other faults are picked up, including sensor faults or connection issues. Quality control flags are provided for all recorded (30 minute) data, indicating the reason for any missing data.

The COSMOS-UK User Guide is a comprehensive guide to the data collected by COSMOS-UK, including the near-real time soil moisture data derived from counts of neutrons derived from cosmic rays. The User Guide contains: i) information about the sites, their locations and other metadata; ii) details of the instruments deployed at each site; iii) background information about the cosmic ray neutron counter which is used to derive soil moisture within a 12 hectare footprint; and iv) descriptions of data and information products that are available from COSMOS-UK.