The ongoing sea level rise is a big concern in the context of present climatic change. The study of past sea level observations is of great importance in describing sea level variations. This work describes the rescue and analysis of a previously unrecognised 12-year record of sea level heights, measured at Trieste in the late 18th century. Besides having historical value, the data were found to be consistent, although undocumented technical issues limited the scientific conclusions.

The Liverpool Tidal Institute's (LTI) 100th anniversary was in 2019, and it acquired a reputation using tide prediction machines (TPMs). We describe the principles of a TPM, how many were made and Doodson's method to determine harmonic constants from tidal data to predict the tides. Although only three TPMs were used at the LTI, Doodson oversaw the design and manufacture of several others. We show how the UK, and Doodson particularly, played a central role in this area of science.

This article argues that the configuration of the Pontus Euxinus (the Black Sea), as described in Ptolemy's Geography, can be satisfactorily explained as a result of fitting contradictory pieces of information together that were inherited from earlier geographers, under the assumption that his sources were similar to those that have come down to us. The method is based on comparison of Ptolemy's data with the other ancient sources, revealing conspicuous similarities and differences between them.

The Széchenyi István Geophysical Observatory, also known as the Nagycenk Geophysical Observatory (NCK), is the only measurement site in Hungary where atmospheric electricity (AE) measurements have been made continuously since 1961. Quasi-continuous records of electrical potential gradient (PG) and Schumann resonances (SRs) from NCK are among the longest time series of their kind in Europe. This paper commemorates the efforts of people who established and managed AE measurements at NCK.

The German Geophysical Society was founded in 1922 as the Deutsche Seismologische Vereinigung. One of the 24 founders of this society was Karl Friedrich Almstedt. Born in 1891 and deceased in 1964, Almstedt represents a generation of academics and scientists who grew up during the decline of the European empires, experiencing the devastations of the two World Wars and the cruelties of the Nazi era as well as the resurrection of academic and cultural life in post-war Germany.

A graphical record of a cruciform appearance in the night sky and possible lunar-halo display of 806 CE in the Anglo-Saxon Chronicle is philologically traced back to mid-ninth-century continental manuscripts, and a probable observational site is identified as around Sens in France. Possible lunar halos are examined by numerical ray tracing. Cruciform halos are shown to be faint and rare and thus notable. Halos from physically credible cloud ice crystals reproduce the manuscript renditions.

A brief history of the development of the Leith atmosphere model (LAM) by Chuck Leith around 1960 is presented. It is argued that the LAM was the first model that could reasonably be considered a comprehensive atmospheric general circulation model. The LAM was notable in that it had a representation of the hydrological cycle including prognostic cloud fields. The LAM left almost no footprint on the journal literature, but LAM simulations were published in pioneering computer animations.

This paper reviews Michael Rycroft's career as part of his 80th birthday celebrations in terms of the social and structural changes in international science. His contributions to research, teaching, and management across solar–terrestrial and ionospheric physics, and atmospheric and space science are also discussed. The paper is based on primary sources combined with the recollections of colleagues.

The Pakistan Space Weather Centre (PSWC) was inaugurated on 20 August 2018, but its long history dates back to the 1950s. SUPARCO was established as the national space agency in 1961 and, along with other projects, started ionospheric and geomagnetic monitoring and research in the country. The milestones achieved in the discipline of space weather are mentioned that subsequently resulted in the establishment of PSWC. It is anticipated that PSWC will act as a Regional Warning Center in future.

This paper outlines the establishment of the Liverpool Tidal Institute in 1919. There is a particular focus on early patrons and supporters, in the context of both previous tidal research on the accuracy of predictions and debates about the involvement of state actors in science at the end of the First World War. It shows that industrial support was crucial to the early tidal institute, which adds to debates about patronage in the history of modern physical oceanography in Britain and beyond.

The International Geophysical Year (IGY) of 1957–1958 was one of the most significant scientific events of the 20th century that marked the beginning of the Space Age. IGY united efforts of scientists from 67 countries for comprehensive study of our planet. The scientific program included multidisciplinary activity on all the continents, in the oceans, in the air, and in space. This article gives a brief overview of the history of the IGY organization and its main achievements.

Researching, compiling and analysing geophysical ideas and measurements in historical periods will contribute to the historical development of earth science. Also, this is important for geophysicists working on time-dependent (historical) data and revealing the physical properties of the earth. This paper focuses on the earth and its sciences (with concepts, ideas and measurements) in classical Islamic science in the Ottoman Empire and the evolution of these thoughts and concepts.

Carl Friedrich Gauss (1777–1855) was one of the most eminent scientists of all time. He was born in Brunswick, and from 1807 until his death, he was director of the Göttingen Astronomical Observatory, where he made world-famous and lasting contributions. In his honour, and to preserve his memory, the Gauss Society was founded in Göttingen in 1962. The present paper aims to give nonspecialists a brief introduction into the life and works of Gauss and a brief history of the Gauss Society.

The early 20th century voyages of the Carnegie – a floating geophysical observatory – revealed the daily rhythm of atmospheric electricity. Combined with ideas from Nobel Prize winner C. T. R. Wilson, the Carnegie curve helped answer a fundamental question, from the time of Benjamin Franklin, about the origin of Earth's negative charge. The Carnegie curve still provides an importance reference variation, and the original data, explored further here, have new relevance to geophysical change.

Tides from the Moon and Sun change the force of gravity. Pendulum clocks that use pendula are affected by this, but the resulting time errors are less than a millisecond over a day. These errors were measured by a few precision pendulum clocks between 1929 (the first data showing tidal gravity signals) and 1985. This paper shows the original results of each measurement and also compares these with simulations using modern tidal models.