Compiled from the Foundation for the Study of Cycles archive (Cycles — A Monthly Report / Cycle Magazine, vols. 1950–1955)

Who He Was

Sir David Brunt appears in these pages as "an Englishman" — the archive gives no further biographical detail beyond his nationality and his output, which tells you something about how the Foundation typically treated its cited authorities: they were interested in the data, not the person. He is referenced repeatedly as one of the primary authorities on cyclic behavior in European weather, cited in the same breath as Sir William Beveridge, H. H. Clayton, and E. Brückner — the core figures of early-20th-century climatic periodicity research.

The Core Work: The 1927 Study

The archive's central reference point is:

"David Brunt, an Englishman, published in 1927 an exhaustive study tracing some 34 different weather rhythms, with durations of from less than two years up."

This 1927 study is treated as one of the foundational surveys of the field — a systematic hunt through European weather records for recurring periodicities, using harmonic analysis of rainfall, temperature, and atmospheric pressure across twelve European cities with records extending back at least a century.

A more detailed passage in the 1953 volume elaborates:

"The right-hand side of Figure 57 compares Beveridge's cycles with those found by Brunt in an elaborate harmonic analysis of rainfall, temperature, and atmospheric pressure in twelve European cities where records for at least a century are available... In addition to the 28 cycles shown here, Brunt describes 16 more with a length of less than 2 years."

So Brunt's total catalogue of identified weather rhythms ran to roughly 44+ distinct periodicities once the sub-2-year cycles are included — an extraordinarily granular harmonic decomposition for the era.

Specific Cycle Lengths Attributed to Brunt

The archive credits Brunt with isolating several specific periodicities that recur throughout the Foundation's cross-comparisons with other researchers' work:

• ~22.4 years — a rhythm in European weather, later cross-referenced by Dewey's colleagues against the ~22.3-year sunspot polarity-reversal cycle found by C. N. Anderson

• 7.50 years — a climatic rhythm, closely bracketed by H. P. Gillette's 7.47-year drought-based figure and Beveridge's 7.42-year figure. The Foundation treated this convergence as significant enough to flag repeatedly

• 8.16 years — found in Brunt's century-long study of European weather, sitting alongside a cluster of independently-derived "~8-year" cycles from Dinsmore Alter (8.1 yrs, sunspots), H. H. Clayton (8.1 yrs), Beveridge (8.05 yrs, wheat prices), and A. E. Douglass (8.2 yrs, tree rings)

How the Foundation Used Brunt's Work

Edward Dewey and his colleagues treated Brunt primarily as a cross-validation source — a way of checking whether a cycle length found in one dataset (say, wheat prices, or sunspots, or animal populations) also showed up independently in Brunt's European weather record. The logic, explicit throughout the archive, was that a cycle appearing across unrelated phenomena was much harder to dismiss as a statistical artifact than one found in a single series.

The Foundation's summary comparison (Figure 57, December 1953 report) explicitly overlaid Beveridge's wheat-price cycles against Brunt's weather cycles and found points of convergence near 3½, 5, 8, 9½, and 35 years — treating agreement between an economic historian (Beveridge) and a meteorologist (Brunt) as meaningful corroboration of an underlying cyclic force.

Brunt in Context: The Wider Circle

Brunt doesn't stand alone in this literature. The names that recur alongside him — and that may be worth their own entries for your forum — include:

• Sir William Beveridge — wheat price and rainfall cycles in Western Europe (1500–1869)

• E. Brückner — the 35-year "Brückner cycle" in European weather (1891), tracing back to an observation by Sir Francis Bacon

• H. H. Clayton — barometric pressure cycles from Siberia to Calcutta

• H. P. Gillette — drought-based climatic rhythms

• A. E. Douglass — tree-ring dendrochronology and cyclic analysis

• C. E. P. Brooks — Nile flood cycles

• C. N. Anderson — sunspot cycle analysis (Bell System Technical Journal)

Given your interest in surfacing lesser-known figures for the forum, several of these — particularly Brückner and Gillette — appear to have done foundational work that's largely forgotten today, much like Brunt himself.

Note on Sourcing

All citations above are drawn directly from the Foundation for the Study of Cycles' own publications (1952–1953 volumes currently in the project). The Foundation's own footnoted reference for Brunt's original work does not give a full bibliographic citation in the passages captured here — if you want the exact title of the 1927 study, that would need tracking down externally (likely Periodicities in European Weather, Royal Society, 1927 — worth verifying independently before publishing).

Unfortunately the study of climate has become very politicised and scientific considerations are sometimes forgotten as people attack each other. This forum does not allow abuse, name calling and the like, and expects people to only report scientific facts. Terms like “climate denier” and “climate alarmist” are abusive, so please use terms that the people themselves would be happy with. All views are welcomed and valued if they come with observations of climate variables, correlations and the like.

If all else fails, we can talk about the weather. :-)

First published: 2024

Brief summary

Uses 20 years of hourly global satellite precipitation data (IMERG) with hierarchical clustering to map worldwide patterns in the ~24-hour diurnal precipitation cycle.

Article

Clustering the Diurnal Cycle of Precipitation Using Global Satellite Data is a peer-reviewed journal article published by Geophysical Research Letters (AGU) in 2024. It uses 20 years of hourly global satellite precipitation data (IMERG) with hierarchical clustering to map worldwide patterns in the ~24-hour diurnal precipitation cycle.

Period ~24 hours (diurnal). The data source is IMERG satellite precipitation dataset 2001-2020, hourly resolution. It also considers global maps/clustering as visual output. This gives the cycle claim a specific numerical and evidential setting rather than presenting periodicity only as a visual impression.

The article reports the following result: This study uses IMERG as the primary data source, combined with hierarchical clustering, to analyse the diurnal cycle of precipitation amount, frequency, and intensity globally. The interpretation is strongest when it survives proxy uncertainty, model choice, dating error and comparison with established solar, orbital and ocean-atmosphere forcing.

For cycles researchers, the article brings together diurnal precipitation cycle, satellite rainfall, imerg data, hierarchical clustering. It is relevant to climate-cycle research because observed periodicities may arise from orbital forcing, solar variability, ocean-atmosphere dynamics or internal stochastic behaviour.

Because it is a peer-reviewed journal article, the article is a strong starting point for discussion in the Climate & Weather forum, although its conclusions should still be compared with later replications and updated datasets.

Source details and credits

• Source / publisher: Geophysical Research Letters (AGU)
• Source type: Peer-reviewed journal article
• URL type: WWW
• Credits: Geophysical Research Letters (AGU)
• URL: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2024GL111513

First published: 2024

Brief summary

Textbook chapter explaining orbital climate cycles from 23,000-100,000 years, plus a highly stable 405,000-year eccentricity cycle used for dating ancient sediments.

Article

Climate Cycles (book chapter) - Milankovitch and 405-kyr Earth-Sun Cycle is a peer-reviewed textbook published by Springer Nature (book chapter) in 2024. It is a textbook chapter explaining orbital climate cycles from 23,000-100,000 years, plus a highly stable 405,000-year eccentricity cycle used for dating ancient sediments.

The analysis focuses on 23,000-100,000 years (precession/obliquity/eccentricity), and 405,000-year long eccentricity cycle stable over hundreds of millions of years. This gives the cycle claim a specific numerical and evidential setting rather than presenting periodicity only as a visual impression.

The article reports the following result: The three most important orbital cycles have periods ranging from 23,000 to 100,000 years. One very long Earth-Sun cycle, with a period of 405,000 years, has been consistent for several hundred million years. The interpretation is strongest when it survives proxy uncertainty, model choice, dating error and comparison with established solar, orbital and ocean-atmosphere forcing.

For cycles researchers, the article brings together milankovitch cycles, 405-kyr eccentricity cycle, orbital climate forcing, astrochronology. It is relevant to climate-cycle research because observed periodicities may arise from orbital forcing, solar variability, ocean-atmosphere dynamics or internal stochastic behaviour.

Because it is a peer-reviewed textbook, the article is a strong starting point for discussion in the Climate & Weather forum, although its conclusions should still be compared with later replications and updated datasets.

Source details and credits

• Source / publisher: Springer Nature (book chapter)
• Source type: Peer-reviewed textbook
• URL type: WWW
• Credits: Springer Nature (book chapter)
• URL: https://link.springer.com/chapter/10.1007/978-3-031-82869-0_9

First published: 2023

Brief summary

General reference on Earth's orbital cycles (eccentricity, obliquity, axial precession) and their role in ice age timing, including the unresolved '100 kyr problem'.

Article

Milankovitch Cycles (overview) is an encyclopedic / general reference published by Wikipedia (hosted via Harvard course page) in 2023. It presents a general reference on Earth's orbital cycles (eccentricity, obliquity, axial precession) and their role in ice age timing, including the unresolved '100 kyr problem'.

The analysis focuses on 41 kyr (obliquity), ~100 kyr (eccentricity, dominant in last 1 Myr). It also considers notes shift from 41 kyr to 100 kyr dominant mode ~1 Myr ago, cause unresolved. This gives the cycle claim a specific numerical and evidential setting rather than presenting periodicity only as a visual impression.

The article reports the following result: Some researchers interpret climate records of the last million years as showing a single spectral peak at 100 ka periodicity. From 1-3 million years ago climate had a dominant mode matching the 41 ka obliquity cycle; after 1 million years ago this changed to 100 ka. The interpretation is strongest when it survives proxy uncertainty, model choice, dating error and comparison with established solar, orbital and ocean-atmosphere forcing.

For cycles researchers, the article brings together milankovitch cycles, orbital eccentricity, obliquity, axial precession. It is relevant to climate-cycle research because observed periodicities may arise from orbital forcing, solar variability, ocean-atmosphere dynamics or internal stochastic behaviour.

Because this is an encyclopedic / general reference, it is best used as an accessible introduction or perspective rather than as conclusive evidence. Forum discussion should follow its references back to the primary data and original research wherever possible.

Source details and credits

• Source / publisher: Wikipedia (hosted via Harvard course page)
• Source type: Encyclopedic / general reference
• URL type: PDF
• Credits: Wikipedia (hosted via Harvard course page)
• URL: https://courses.seas.harvard.edu/climate/eli/Courses/EPS281r/Sources/Glacial-cycles/Milankovitch-cycles-Wikipedia.pdf

First published: 2022

Brief summary

Review of astronomically-derived solar activity cycles (9.1, 10.5, 20, 60, 115, 981-year) linked to planetary orbital configurations, used in a semi-empirical climate model.

Article

The Planetary Theory of Solar Activity Variability: A Review is a preprint / review article published by arXiv (Scafetta) in 2022. It reviews astronomically-derived solar activity cycles (9.1, 10.5, 20, 60, 115, 981-year) linked to planetary orbital configurations, used in a semi-empirical climate model.

Multiple periods stated: 9.1, 10.46, 10.5, 20, 60, 115, and 981 years. It also considers ties solar/climate cycles to planetary orbital resonances. This gives the cycle claim a specific numerical and evidential setting rather than presenting periodicity only as a visual impression.

The article reports the following result: The planetary theory links solar activity cycles to orbital invariant inequalities among Venus, Earth, Jupiter and Saturn, and underlies a semi-empirical climate model incorporating cycles from 9.1 to 981 years. The interpretation is strongest when it survives proxy uncertainty, model choice, dating error and comparison with established solar, orbital and ocean-atmosphere forcing.

For cycles researchers, the article brings together planetary theory, solar activity variability, orbital resonances, climate cycles. It is relevant to climate-cycle research because observed periodicities may arise from orbital forcing, solar variability, ocean-atmosphere dynamics or internal stochastic behaviour.

Because it is a preprint / review article, the work should be read alongside later peer-reviewed publications and independent replications. It remains useful because the proposed cycle, dataset and analytical approach are stated clearly enough to be scrutinised.

Source details and credits

• Source / publisher: arXiv (Scafetta)
• Source type: Preprint / review article
• URL type: PDF
• Credits: arXiv (Scafetta)
• URL: https://arxiv.org/pdf/2208.09293

First published: 2021

Brief summary

Uses Slow Feature Analysis on global proxy temperature records to identify intrinsic oscillations from ~60 to ~1000 years, separated by a gap from Milankovitch-scale (20,000+ year) forcing.

Article

On Time Scales of Intrinsic Oscillations in the Climate System is a peer-reviewed journal article published by Entropy (MDPI) via PMC in 2021. It uses Slow Feature Analysis on global proxy temperature records to identify intrinsic oscillations from ~60 to ~1000 years, separated by a gap from Milankovitch-scale (20,000+ year) forcing.

The analysis focuses on 60-1000 years (intrinsic), gap 1000-20,000 yr, then 20,000-100,000 yr (external/Milankovitch). It also considers power spectrum P vs log(T) graph described. This gives the cycle claim a specific numerical and evidential setting rather than presenting periodicity only as a visual impression.

Proxy temperature data records are analysed using Slow Feature Analysis. the authors report intrinsic climatic oscillations with periods ranging from ~60 years to ~1000 years, separated by a gap from longer Milankovitch-forced periodicities. The interpretation is strongest when it survives proxy uncertainty, model choice, dating error and comparison with established solar, orbital and ocean-atmosphere forcing.

For cycles researchers, the article brings together climate timescales, intrinsic oscillations, slow feature analysis, proxy temperatures. It is relevant to climate-cycle research because observed periodicities may arise from orbital forcing, solar variability, ocean-atmosphere dynamics or internal stochastic behaviour.

Because it is a peer-reviewed journal article, the article is a strong starting point for discussion in the Climate & Weather forum, although its conclusions should still be compared with later replications and updated datasets.

Source details and credits

• Source / publisher: Entropy (MDPI) via PMC
• Source type: Peer-reviewed journal article
• URL type: WWW
• Credits: Entropy (MDPI) via PMC
• URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8070030/

First published: 2021

Brief summary

Analysis of observational data and a large climate model (CESM) finds Earth's climate has intrinsic 11-year and 3.5-year oscillations, out of sync with the solar cycle.

Article

Earth's Climate System Fluctuates in 11-Year and 3.5-Year Cycles is a peer-reviewed published by Climate Dynamics / EurekAlert in 2021. It analyses observational data and a large climate model (CESM) and finds Earth's climate has intrinsic 11-year and 3.5-year oscillations, out of sync with the solar cycle.

Peer-reviewed study published in Climate Dynamics (Feliks, Small & Ghil). It also considers period ~11 yr and ~3.5 yr. It also considers based on two observational datasets + climate model. This gives the cycle claim a specific numerical and evidential setting rather than presenting periodicity only as a visual impression.

The article reports the following result: The Earth's global climate system fluctuates in 11-year and 3.5-year cycles. An analysis of observational data and a large climate model finds Earth's 11-year cycle is out of sync with solar fluctuations, refuting claims of major solar effects on recent climate evolution. The interpretation is strongest when it survives proxy uncertainty, model choice, dating error and comparison with established solar, orbital and ocean-atmosphere forcing.

For cycles researchers, the article brings together intrinsic climate oscillations, 11-year cycle, 3.5-year cycle, climate modelling. It is relevant to climate-cycle research because observed periodicities may arise from orbital forcing, solar variability, ocean-atmosphere dynamics or internal stochastic behaviour.

Because it is a peer-reviewed, the article is a strong starting point for discussion in the Climate & Weather forum, although its conclusions should still be compared with later replications and updated datasets.

Source details and credits

• Source / publisher: Climate Dynamics / EurekAlert
• Source type: Peer-reviewed (journal summary)
• URL type: WWW
• Credits: Climate Dynamics / EurekAlert
• URL: https://www.eurekalert.org/news-releases/927831

First published: 2018

Brief summary

Uses Lomb-Scargle periodogram to detect periodicities in tropical rainfall onset/cessation, referencing known atmospheric cycles: QBO (2-3 yr), ENSO (5-7 yr), sunspot (10-15 yr), AMO (30 yr).

Article

modelling Onset and Cessation of Tropical Rainfall: Spectral Analysis of Seasonal Cycles is a preprint published by arXiv in 2018. It uses Lomb-Scargle periodogram to detect periodicities in tropical rainfall onset/cessation, referencing known atmospheric cycles: QBO (2-3 yr), ENSO (5-7 yr), sunspot (10-15 yr), AMO (30 yr).

The analysis focuses on 2-3 years (QBO), 5-7 years (ENSO), 10-15 years (sunspot), 30 years (AMO). It also considers methodology paper using Lomb-Scargle periodogram on unevenly sampled data. This gives the cycle claim a specific numerical and evidential setting rather than presenting periodicity only as a visual impression.

The article reports the following result: Atmospheric and climatic data show several periodicities such as the Quasi-Biennial Oscillation (2-3 years), El-Nino Southern Oscillation (5-7 years), Sunspot cycles (10-15 years) and Atlantic Multi-Decadal Oscillation (30 years). The interpretation is strongest when it survives proxy uncertainty, model choice, dating error and comparison with established solar, orbital and ocean-atmosphere forcing.

For cycles researchers, the article brings together tropical rainfall cycles, lomb-scargle periodogram, enso, qbo. It is relevant to climate-cycle research because observed periodicities may arise from orbital forcing, solar variability, ocean-atmosphere dynamics or internal stochastic behaviour.

Because it is a preprint, the work should be read alongside later peer-reviewed publications and independent replications. It remains useful because the proposed cycle, dataset and analytical approach are stated clearly enough to be scrutinised.

Source details and credits

• Source / publisher: arXiv
• Source type: Preprint
• URL type: PDF
• Credits: arXiv
• URL: https://arxiv.org/pdf/1811.09677

First published: 2014

Brief summary

Sediment pollen and varve record from East Asia reveals a ~500-year climate cycle nearly in phase with solar activity and Greenland temperature, with a further ~250-year cool-phase component.

Article

500-Year Climate Cycles Stacking of Recent Centennial Warming (East Asian Pollen Record) is a peer-reviewed journal article published by Scientific Reports (Nature) in 2014. It focuses on sediment pollen and varve record from East Asia reveals a ~500-year climate cycle nearly in phase with solar activity and Greenland temperature, with a further ~250-year cool-phase component.

The analysis focuses on ~500 years and ~250 years. The data source is varved lake sediment core, dated via 137Cs/210Pb radionuclide measurement. This gives the cycle claim a specific numerical and evidential setting rather than presenting periodicity only as a visual impression.

The article reports the following result: A ~500-year periodic change was almost in phase with solar activity and Greenland temperature change. This periodic climate change may reduce the man-made warming trend in the next two centuries in East Asia. The interpretation is strongest when it survives proxy uncertainty, model choice, dating error and comparison with established solar, orbital and ocean-atmosphere forcing.

For cycles researchers, the article brings together 500-year climate cycle, pollen records, solar activity, east asian climate. It is relevant to climate-cycle research because observed periodicities may arise from orbital forcing, solar variability, ocean-atmosphere dynamics or internal stochastic behaviour.

Because it is a peer-reviewed journal article, the article is a strong starting point for discussion in the Climate & Weather forum, although its conclusions should still be compared with later replications and updated datasets.

Source details and credits

• Source / publisher: Scientific Reports (Nature)
• Source type: Peer-reviewed journal article
• URL type: WWW
• Credits: Scientific Reports (Nature)
• URL: https://www.nature.com/articles/srep03611