Point discharge is an electrical process which occurs naturally in Earth’s atmosphere. Like lightning, it has been observed both directly and indirectly for centuries. Several of the milestone investigations in atmospheric electricity have arisen through measuring point discharge. This work gives a history of various investigations involving the phenomenon and explains its central role in developments in atmospheric electricity.

Eskdalemuir Observatory opened in 1908, sited remotely for magnetically quiet conditions. Continuous atmospheric potential gradient (PG) recordings began in 1911, using a Kelvin water dropper electrograph. Notable scientists who worked with atmospheric electricity at Eskdalemuir include Lewis Fry Richardson and Gordon Dobson. The PG measurements continued until 1981. The methodologies employed are described to help interpret the monthly data now digitally available.

Lerwick Observatory in Shetland has recently celebrated its centenary. Measurements of atmospheric electricity were made at the site between 1925 and 1984. The instruments and equipment used for this are discussed and the value of the measurements obtained assessed. A major aspect of the atmospheric electricity work was explaining the dramatic changes which followed the nuclear weapons test period. Although less well known, there are strong parallels with the discovery of the ozone hole.

Weather balloons are released every day around the world to obtain the latest atmospheric data for weather forecasting. Expanding the range of sensors they carry can make 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.

A network of Rayleigh lidars have been used to infer the upper-stratosphere temperature bias in ECMWF ERA-5 and ERA-Interim reanalyses during 1990–2017. Results show that ERA-Interim exhibits a cold bias of −3 to −4 K between 10 and 1 hPa. Comparisons with ERA-5 found a smaller bias of 1 K which varies between cold and warm between 10 and 3 hPa, indicating a good thermal representation of the atmosphere to 3 hPa. These biases must be accounted for in stratospheric studies using these reanalyses.