Recent  

Most measurements of air temperature and humidity originate from Stevenson-type thermometer screens, which can produce erroneous measurements in light winds owing to insufficient ventilation of the in-screen sensors. A field experiment to measure airflow within a Stevenson screen found mean airflow to be only 0.2 m s⁻¹, well below the 1 m s⁻¹ minimum normally assumed, and only 7 % of 10 m mean wind speeds. Implications for air temperature and humidity measurement uncertainties are discussed.

Sensors capable of measuring rapid fluctuations are important to improve our understanding of environmental processes. Many sensors are unable to do this, due to their reliance on the transfer of the measured property, for instance a gas, across a semi-permeable barrier. We have developed a mathematical tool which enables the retrieval of fast response signals from sensors with this type of sensor design.

We present an experiment intended to enable extremely low-noise magnetic field measurements. We manufactured fluxgate magnetometer cores using two metal alloys, two geometries, two foil thicknesses, and six different heat treatments and compared the resulting material properties, power consumption, and magnetic noise. Our results suggest that thinner foils, potentially using a new copper alloy, manufactured into continuous racetrack washers may provide excellent performance in fluxgate sensors.

Using an underwater buoyancy powered autonomous glider, we collected profiles of temperature and salinity from the ocean NE of Barbados. Most of the temperature and salinity profiles contained staircase like structures of alternating constant values and large gradients. We wrote an algorithm to identify these staircases. We hypothesise that these staircases are prevented from forming where background gradients in temperature and salinity are too great.

Weather balloons are released every day around the world, to obtain up to date atmospheric data for weather forecasting. Expanding the range of sensors they carry can make measurements of additional quantities available, such as for atmospheric turbulence, cloud electricity, energetic particles from space and, in emergency situations, volcanic ash or radioactivity. An adaptable system has been developed to provide these and other measurements, without interfering with the core weather data.

When radio waves from our Galaxy enter the Earth's atmosphere, they are absorbed by electrons in the upper atmosphere. It was thought that by measuring the amount of absorption, it would allow the height of these electrons in the atmosphere to be determined. If so, this would have significance for future instrument design. However, this paper demonstrates that it is not possible to do this, but it does explain how multiple-frequency measurements can nevertheless be useful.