This page contains a variety of useful and interesting climate-related pdf files presenting reports, studies, and data. The individual files written by a variety of authors and presented here under the fair use doctrine may be accessed by clicking on the hyperlink. Most of these files are in PDF format, but you may encounter the occasional file in some other format. If you have difficulty accessing a file, please leave a comment or email the webmaster at the address listed in the Contact page. These documents are in random order.
This summary of the Systematic Problems in the Four “National Assessments” of Climate Change Impacts on the United States was authored by Patrick Michaels. He concludes that
“The four “National Assessments” of climate change impacts on the United States have dramatically overstated the effects of our changing climate, in large part because the climate models used have systematic biases coupled with over-estimates of the expected changes in lower atmospheric radiation resulting from human activities.”
This as yet unpublished journal article by van Wijngaarden and Happer establishes that CO2, N2O, and H2O are saturated with respect to their infrared absorption capacity and can be expected to produce little or no additional heating with respect to their concentration doubling.
This article by Ross McKitrick and John Christy has been accepted for publication in Earth and Space Sciences. The article compares output from 38 CMIP6 climate models with data from 4 sets of satellite data, 4 sets of rawinsonde data, and 4 sets of reanalysis surface data. As in their CMIP5 comparison, this study shows that the IPCC models continue to overpredict the warming.
Chapter 7 of Tucker Carlson’s 2018 book, Ship of Fools, is about environmentalism in this country. It is being provided here, because it is accurate, interesting, pertinent to this web site, and overall well done. Ship of Fools is available in both hard cover and Kindle format on Amazon.com and most book stores.
This November 2019 journal style article by vanWijngaarden and Happer shows that methane, in the amount currently being released to the atmosphere will increase global temperature by only 0.012 C/yr. Consequently, suggestions to take expensive steps to mitigate the release of methane appear to be unwarranted.
This paper, Proof Sun Causes Global Warming by Dr. Roger Higgs, presents 29 bullet points that the sun and not CO2 causes global warming. Read for an excellent summary.
“The State of the Climate-2019” by Ole Humlum was published by the Global Warming Policy Foundation (GWPF) as Report 42 with a 2020 copyright and it reports the state of the climate as of 2019. It is being provided here under the Fair Use Doctrine. Ole Humlum is former Professor of Physical Geography at the University Centre in Svalbard, Norway, and Emeritus Professor of Physical Geography, University of Oslo, Norway.
The Scientific Case for Vacating the EPA’s Carbon Dioxide Endangerment Finding is discussed by Patrick Michaels and Kevin Dayaratna in this PDF report.
“The EPA’s carbon dioxide endangerment finding is based on climate models which research has shown to be fundamentally flawed, providing no justifiable basis for enacting climate policies.”
They say that all prospective climatic impacts in the Endangerment Finding are generated by computer models that made systematic and dramatic errors over the climatically critical tropics. They say that new research comparing that which has been observed to what is forecast finds that warming in this century will be modest and near the lowest extreme of the ranges given by the United Nations.
The authors conclude that the constellation of unreliable models, poor scientific practice, and exaggerated estimates of the Social Cost of Carbon argue consistently and cogently for the endangerment finding to be reopened and then vacated.
This book by Alan Longhurst is titled “Doubt and Certainty in Science” and was intended to be an objective evaluation of the evidence supporting and not supporting climate change. In an attempt to ensure its objectivity, Longhurst did his best to steer clear of web sites promoting one view or the other. Nevertheless, he did speak to several experts in the field in the course of writing this book. Longhurst based his book on over 600 peer-reviewed scientific papers. [Note: Some of us might conclude that since “peer-review” tended to evolve into “pal-review” over the past 20 or 30 years, this would tend to bias the book in favor of the alarmist views.] Regarding any unwarranted certainty in the debate, Longhurst commented,
“While I am aware that the general opinion of the relevant scientific community is that no further debate is necessary after five successive assessments by the IPCC I suggest that this is premature because these conclusions concern topics that have not yet been properly addressed by that body, and so should be accorded status in a continuing debate concerning the influence of anthropogenic effects on regional climates . . .”
He then goes on to list some conclusions he has drawn regarding the uncertainty of the data.
The affect of water vapor and clouds on air temperature is discussed by Bernie McCune in this short report about the use of a Normal Incidence Pyrheliometer (NIP) to study these effects at the White Sands Missile Range Solar Furnace.
If you think you know a lot about so-called “renewable energy” and the problems associated with establishing a significant percentage (not to mention total) energy system based on it, you might want to think again and then take a look at this comprehensive study and report by Mark Mills.
Oreskes, Harvard and the Destruction of Scientific Revolutions by Bradley Keyes ridicules the “97%” claim by the scientifically illiterate Oreskes with very amusing and sarcastic arguments. We highly recommend this very entertaining read.
Dr. Rex Fleming reviews carbon dioxide and climate change and concludes that global temperatures are unrelated to increasing CO2 concentrations and that the catastrophic anthropogenic global warming hypothesis is unfounded in this peer reviewed journal article entitled, “An updated review about carbon dioxide and climate change,” Environmental Earth Sciences (2018) 77:262. He concludes that “The results of this review point to the extreme value of CO2 to all life forms, but no role of CO2 in any signifcant change of the Earth’s climate.
This July 2019 Policy Brief by Heartland’s Joe Bass discusses the question “Should EPA Reverse Its Endangerment Finding on Greenhouse Gases?” Since scientific rigor was lacking and EPA policies were not followed by the Obama administration in the creation of the endangerment finding, Bass obviously thinks that the answer to this question is a resounding “Yes!” Take a look at this brief to see if you agree with him.
Tornadogenisis in Supercell Storms by Robert Davies-Jones, National Severe Storms Laboratory, NOAA,
Norman, Oklahoma. In this undated paper, Davies-Jones argues that the big unknown in supercell tornado genesis is how rotation develops next to the ground. He reviews several plausible mechanisms for this second stage of tornado genesis.
Hal Lewis’ letter of resignation from the American Physical Society written around 2010.
Henrik Svensmark discusses the Sun’s Role in Climate Change in this Global Warming Policy Foundation Report (GWPF Report 33) published in 2019. He discusses the good progress in understanding the solar influence on climate and in particular the many scientific studies that have shown how changes in solar activity have impacted climate over the entire Holocene period (approximately the last 10,000 years). An important scientific task was to quantify the solar impact on climate. Over the eleven-year solar cycle, the energy that enters the Earth’s system is of the order of 1.0-1.5 W/m2. This is nearly an order of magnitude larger than what would be expected from solar irradiance alone, and this suggests that solar activity is getting amplified by some atmospheric process. He also discusses the three main theories that have been proposed to explain the solar-climate link. They are solar ultraviolet changes, atmospheric-electric-filed effect on cloud cover, and cloud changes produced by solar-modulated galactic cosmic rays. He found that the studies strongly suggest that the solar impact on climate change is much larger than the “official consensus” suggests.
Myron Ebell, Director, Center for Energy and Environment with the Competitive Enterprise Institute recently forwarded this newspaper article for publication by up to 20 newspapers including the Los Angeles Times in which he proposes a “Critical Review of Climate Science by Skeptical Experts” . Simply, getting a letter such as this the public exposure it deserves would be a major step forward in the open discussion and debate of climate science, something that has been severely lacking.
Myron Ebell, Director, Center for Energy and Environment and Marlo Lewis, Senior Fellow, both with the Competitive Enterprise Institute recently forwarded this letter to President Trump asking him to create by executive order a President’s Commission on Climate Security to be headed by scientist Will Happer. The letter was signed by a large number of organizations and individuals who support the formation of this commission and who feel an independent look at climate change is necessary to resolve the numerous biases and errors in many of the current studies of the subject and the faulty models used to predict future global temperatures.
The Charney Report. Back around the time the International Panel on Climate Change (IPCC) was formed, an ad hoc study group on carbon dioxide and climate headed by MIT’s Jule Charney examined the prospect of human-caused CO2 affecting climate change, and in July 1979 they published a report: Carbon Dioxide and Climate – A scientific Assessment that describes their findings. In the report, they introduced a couple of parameters to help define the effects of carbon dioxide on average global temperatures. The two parameters described in their report are Equivalent Climate Sensitivity (ECS) and Transient Climate Response (TCR). This report provides an excellent introduction into anthropogenic global warming and the substantial beginning of climate activism.
The much discussed and impractical “Green New Deal” sponsored by freshman congresswoman Alexandria Ocasio-Cortez proposes (among many other things) a conversion to 100% clean and renewable energy within 10 years of the 2020 election; i.e. by 2030. The original, unmodified Green New Deal proposal is available for viewing at this link.
Michael Crichton presentation titled “Aliens Create Global Warming” given at Caltech Michelin Center on 27 January 2003. While the title of this presentation may sound a bit whimsical the presentation is quite serious and a very worthwhile read.
US State Department recommendations to IPCC Working Group 1 (1995)
Climate Impact of Increasing Carbon Dioxide by James Hansen, et. al. is an increasingly hard to find paper published by Science in 1981 (Sci. 28 Aug 1981, Vol. 213, No. 4511. This paper contains plots of temperature measurements that have since undergone significant modifications to hide the 30-year cooling trend from the early 1940s to the late 1960s to early 1970s. See the temperatures prior to this modification in this journal article by one of the original climate alarmists, James Hansen.
The correlation between the 11-year sunspot cycle and sea surface temperatures is examined by George C. Reid in this 1991 JGR article. This article is as relevant today as it was when it was written.
J. Ray Bates discusses the deficiencies in the IPCC’s Special Report on 1.5 Degrees in this paper published by the Global Warming Policy Foundation. Specifically, he presents compelling evidence that
the SR1.5 report is deficient in three regards:
• It departs from the IPCC (2013) Fifth Assessment in the direction of an increased sense
of planetary emergency without giving rigorous scientific reasons for doing so.
• Crucial research evidence, accumulated since the IPCC Fifth Assessment (2013), significantly reduces the prospect of a looming emergency. This evidence has not been
taken into account; nor is it even referred to in the SR1.5 report.
• The disturbing revelation of the widespread practice of ‘tuning’ climate models to
achieve desired results, disclosed since the Fifth Assessment, has not been referred
Nir Shaviv comments with a Statement letter to the committee (on the Environment, Nature Conservation and Nuclear Safety, Deutscher Bundestag) discussion on “COP24 in Katowice – Another milestone for global climate protection.” He points out the lack of evidence for catastrophic climate change caused by carbon dioxide or that humans are responsible for significant climate change. He also discusses the contrary evidence that climate sensitivity to increasing carbon dioxide is high. He points out evidence indicating it is low. He demolishes the appeal to authority (the 97% claim) regarding scientists’ opinions on climate, and he presents many other arguments against the anthropogenic climate change claims.
Carbon starvation in glacial trees recovered from the La Breah tar pits, Southern California, Joy K. Ward et. al., pnas Vol 102, No. 3, January 18, 2005. Dr Joy Ward writes of CO2 starvation with her analysis from the La Brea Tar Pits in Los Angeles on the starvation of Junipers during the depth of the last ice age. Patrick Moore (see below) puts this in the context of a long time series of <CO2> and how burning of fossil fuels may have had a dramatic positive impact on plant and animal life on Earth.
The Positive Impact of Human CO2 Emissions on the Survival of Life on Earth, by Patrick Moore, PhD., March 2015. Patrick Moore has taken the <CO2> geologic time series and has explained it in a cogent and easy to understand manner. He uses many of the same graphics and ideas Bob Endlich has used and puts them together to make a convincing argument that mankind’s use of fossil fuels may have staved off the calamity of plant starvation, even death, because of the conversion of atmospheric CO2 into limestone, dolomite, chalk and shells of marine animals, which has reduced atmospheric <CO2> to near starvation concentrations.
The 2018 Annual GWPF Lecture: Global Warming for the Two Cultures provides a lecture by Richard Lindzen on two cultures in which one is considered to be highly educated but is limited in the area of science while the other has a much deeper and complete under standing of science. “While some might maintain that ignorance of physics does not impact political ability, it most certainly impacts the ability of non-scientific politicians to deal with nominally science-based issues. The gap in understanding is also an invitation to malicious exploitation. Given the democratic necessity for non-scientists to take positions on scientific problems, belief and faith inevitably replace understanding, though trivially oversimplified false narratives serve to reassure the non-scientists that they are not totally without scientific ‘understanding.’ The issue of global warming offers numerous examples of all of this. I would like to begin this lecture with an attempt to force the scientists in the audience
to come to grips with the actual nature of the climate system, and to help the motivated non-scientists in this audience who may be in Snow’s ‘one in ten’ to move beyond the trivial oversimplifications.”
NIST Calibration Uncertainties of Liquid-in-Glass Thermometers over Range from -20C to 400 C by C. D. Vaughn and G. F. Strause. Abstract: The National Institute of Standards and Technology (NIST) Industrial Thermometer Calibration Laboratory (ITCL) is responsible for calibrating several different types of industrial thermometers. One of those types is a liquid-in-glass (LiG) thermometer, which includes both mercury (partial and total immersion) and organic (total immersion) filled models. Over the past two years, improvements in both calibration equipment and software used in the ITCL has led to a new assessment of the uncertainties assigned to the calibration of LiG thermometers covering the temperature range from -20 C to 400 C. In total, 18 thermometers from three different manufacturers, six of which were mercury-filled partial immersion, 12 of which are mercury-filled total immersion, and two of which are organic-filled total immersion models, were used for determination of LiG thermometer calibration uncertainties over the range from -20 C to 400 C in the NIST ITCL.
The Levelized Cost of Energy (LCOE-E) from existing generation sources represents a crucial piece of information that has been missing from the electricity policy discussion. The LCOE-E data and framework introduced in this report offer policymakers a powerful tool as they make decisions affecting the cost of electricity in the U.S. The cost of electricity from existing energy production facilities that have not reached end of life is always less than the cost from new facilities of the same type and especially of new types. According to this report “the LCOE-E framework allows for cost comparisons that are relevant for today’s energy policymakers. For example, when all known costs are accurately included in the LCOE calculations, we find that existing coal ($39.9), nuclear ($29.1), and hydroelectric resources ($35.4) are about one-third of the cost of new wind resources ($107.4) on average and one-fourth of the cost of new PV solar resources ($140.3). By increasing the transparency of the costs associated with policies favoring new resources over existing conventional resources, we hope to inform policymakers with the best available data and raise the level of the electricity policy debate. “
The Solar Value Cliff represents the percentage of total energy production from photo voltaic methods beyond which any further increase would be detrimental to the total energy production. According to this report, “Solar power is reaching a steep drop-off point beyond which additional solar production contributes no additional capacity to the grid, and indeed begins to actively harm the grid’s reliability and economics. This paper dubs the phenomenon the solar value cliff. ” This study shows that the solar value cliff occurs when solar energy production exceeds 5 percent of the total energy production.
“Global models underestimate large decadal declining and rising water storage trends relative to GRACE satellite data” by Bridget R. Scanlon et.al. [ do a comprehensive comparison of decadal trends (2002–2014) in land water storage from seven global models (WGHM, PCR-GLOBWB, GLDAS NOAH, MOSAIC, VIC, CLM, and CLSM) to trends from three Gravity Recovery and Climate Experiment (GRACE) satellite solutions in 186 river basins (∼60% of global land area). Their comparative analysis shows that the climate models compare poorly with the measurements.
B. M. Smirnov from the Joint Institute for High Temperatures, Izhorskaya 13/19, Moscow 125412, Russia presents some results of his research in his 2 May 2018 article in the J. Phys. D: Appl. Phys. 51 214004 titled, “Collision and radiative processes in emission of atmospheric carbon dioxide.” From his abstract: “The line-by-line method gives the change of the global temperature (0.4 ± 0.1) K as a result of doubling the carbon dioxide concentration. The contribution to the global temperature change due to anthropogenic injection of carbon dioxide in the atmosphere, i.e. resulted from combustion of fossil fuels, is approximately 0.02 K now.”
If you have ever encountered the argument that global cooling alarmism in the 1970s never happened, you might want to take a look at this article published by Popular Technology.net. It contains a lengthy but incomplete list of articles published in scientific magazines, news papers, and other media during the 1970s. Most of the articles in the list have been linked to the magazine or other media and may be accessed by clicking on the link.
This article by Ross McKitrick says that greenhouse gases may not have as strong of an effect on global temperatures as has been estimated by those pushing the catostrophic, anthropogenic, global warming hypothesis. One of the most important numbers in the world goes by the catchy title of Equilibrium Climate Sensitivity, or ECS. It is a measure of how much the climate responds to greenhouse gases. More formally, it is defined as the increase, in degrees Celsius, of average temperatures around the world, after doubling the amount of carbon dioxide1 in the atmosphere and allowing the atmosphere and the oceans to adjust fully to the change. The reason it’s important is that it is the ultimate justification for governmental policies to fight climate change.
Richard Lindzen is the author of a paper presented at a National Academy of Science colloquium held November 13–15, 1995, at the National Academy of Sciences, Irvine, CA.. The paper was subsequently published in the August 1997 issue of the Proc. Natl. Acad. Sci. USA Vol. 94, pp. 8335–8342, August 1997. The title of the paper is “Can increasing carbon dioxide cause climate change?” The main thrust of this paper pertains to climate sensitivity and how it affects model errors and uncertainties. Dr. Lindzen also discusses how to measure climate sensitivity.
In this relatively brief commentary titled “Alternate Power” from 21 June 2018 by CASF member, Bernie McCune, Bernie talks about the problems, economics, and misinformation regarding the use of alternative energy sources. After reading an article in the WSJ about how recent spending on renewable electrical energy projects (mostly wind and photovoltaic) is outpacing spending on regular energy base load projects (coal, nuke and natural gas) Bernie dug into the story a little more since the economics of this activity seemed highly questionable. In his commentary, he describes what he found.
This peer reviewed article by Lewis and Curry will be published in the Journal of Climate in 2018. The paper entitled “The impact of recent forcing and ocean heat uptake data on estimates of climate sensitivity” concludes that equilibrium climate sensitivity (ECS) used by the IPCC modelers are significantly overestimated. The paper provided here is in the manuscript form (content wise) that was submitted in April 2018 for publication. It is possible some minor changes might be made prior to publication.
Richard Lindzen 1997 paper on climate sensitivity to a doubling of CO2. He finds it to be less than 1 degree Celsius and nowhere near the IPCC estimates of as much as 4.5 degrees Celsius.
Steve McIntyre’s 2008 Presentation to Ohio State University – This is a transcript of McIntyre’s presentation entitled: How do we “know” that 1998 was the warmest year of the millennium?
2014 Ex-NASA Team Report – Bounding GHG Climate Sensitivity for Use in Regulatory Decisions
Global Climate Anomaly 1940-1942 – Bronnimann – This is an article describing an unusual El Nino event during WWII.
Wikipedia’s Climate Doctor – Lawrence Solomon, Financial Post, Dec. 19, 2009. How (the climate doctor) rewrote 5,428 climate articles in an attempt to suppress the truth about global warming.
Multi-decadal Tendencies by Joseph D’Aleo and Dr. Don Easterbrook.
Environmental Movement by Walter Williams. Here’s how wrong past environmental predictions have been. Excellent article!
Bounding GHG Climate Sensitivity for Use in Regulatory Decisions – The Right Climate Stuff Research Team. Lead Author: Harold H. Doiron, PhD. The purpose of this report is to provide a rigorous scientific basis for official comments to be submitted to the Office of Management and Budget (OMB) by The Right Climate Stuff (TRCS) Research Team in response to OMB’s official request for comments on the overall approach for computing Social Cost of Carbon (SCC).
The long sunspot cycle 23 predicts a significant temperature decrease in cycle 24 – by Jan-Erik Solheim, et. al., Journal of Atmospheric and Solar-Terrestrial Physics · February 2012. “ . . . a significant negative trend is found between the length of a [sun spot] cycle and the temperature in the next cycle.”
Catastrophe Denied by Warren Meyer, who operates the web site “climate-skeptic.com,” provides a very detailed analysis of climate change. He prepared this analysis for the skeptic’s side for a number of debates in which he had participated.
Several simple Climate Models (Compared) are examined and their output is compared with the measurements and with the projections of the IPCC global climate models. Briefing by Bernie McCune.
This file contains some background information on Ed Caryl’s natural cycles model.
This file contains some background information on David Evan’s model. Who are you going to believe? The government climate scientists or the data?
Ed Caryl provides some additional thoughts on natural cycles in this file.
Girma Orssengo takes apart the IPCC climate projections and replaces them with those from his own model that are much more realistic.
A Powerpoint briefing on Examining the Hypothesis by Bob Endlich.
Bob’s Method for Plotting CO2 and Temperature in Time Series in Excel.
A Major Deception on Global Warming by Frederick Seitz. A Wall Street Journal Op Ed piece.
Wallace III, D’Aleo, and Idso examine the many problems with the validity of the NOAA, NASA, HADCRUT data and the validity of the EPA’s Carbon Dioxide endangerment finding.
Clive James provides a detailed critique of the mass media and their coverage of climate change.
A Powerpoint briefing on the costs and benefits of alternative energy sources entitled “21st Century Snake Oil” by Bob Endlich.
The First Decade of the New Century: A Cooling Trend for Most of Alaska, G. Wendler, L. Chen and B. Moore, The Open Atmospheric Science Journal, 2012, 6, 111-116.111. During the first decade of the 21st century most of Alaska experienced a cooling shift, modifying the long-term warming trend, which has been about twice the global change up to this time. All of Alaska cooled with the exception of Northern Regions. This trend was caused by a change in sign of the Pacific Decadal Oscillation (PDO), which became dominantly negative, weakening the Aleutian Low.
Captain T. A. (Ike) Kiefer discusses why the US should reject biofuels as a part of a rational national security energy strategy. Published by Waterloo Institute for Complexity and Innovation.
Dr. Roy Spencer presents A Guide to Understanding Global Temperatures in this pdf booklet.
A few Mayors and Governors plan to continue on their own with the Paris Climate Accord. Such decisions are unwise according to this Heritage Foundation article.
A Robust Test on Warming Trend and Precipitable Water Vapor Content is examined in this Geophysical Research Letters article. The IPCC models generally assume that global relative humidity remains on average constant so that when temperatures rise the amount of precipitable water vapor in the atmosphere increases. This study has found that this is not the case.
Natural climate variability part 1 – Observations versus Model Predictions are discussed in this International Journal of Heat and Technology article. Most climate-change-informed people are aware that the models fail when compared to actual observations except, perhaps, when the models have been adjusted after the observations have become available. This paper provides the details of those failures.
Natural climate variability part 2 – Interpretation of the post-2000 temperature standstill is discussed in this International Journal of Heat and Technology article. They show that when the effects of the 2015-2016 el nino is removed from the data, the temperature standstill continues.
Climate Change’s Rational Optimist – Matt Ridley by Julie Kelley. Matt Ridley is a self-described “luke warmer,” but is called a “denier” by climate pessimists.
This is a Microsoft Power Point presentation saved as a pdf file. The Power Point version had a number slides containing short video clips relating to a critique of an Al Gore presentation on climate change. Those videos do not function in the pdf version.
At the end of the presentation is a list of more than 20,000 individuals with various degrees in the physical sciences who have signed the Oregon Petition disagreeing with the catastrophic, anthropogenic global warming hypothesis and the Kyoto protocol. The petition reads as follows:
“We urge the United States government to reject the global warming agreement that was written in Kyoto, Japan in December, 1997, and any other similar proposals. The proposed limits on greenhouse gases would harm the environment, hinder the advance of science and technology, and damage the health and welfare of mankind.
There is no convincing scientific evidence that human release of carbon dioxide, methane, or other greenhouse gases is causing or will, in the foreseeable future, cause catastrophic heating of the Earth’s atmosphere and disruption of the Earth’s climate. Moreover, there is substantial scientific evidence that increases in atmospheric carbon dioxide produce many beneficial effects upon the natural plant and animal environments of the Earth.”
This PDF contains a series of graphs displaying various elements in the North Atlantic. These graphs were produced by Kenneth Richard from the No Tricks Zone blog. The graphs illustrate that there has been no significant warming in the North Atlantic, which directly contradicts the claims made by the data deniers pushing the catastrophic anthropogenic climate change hypothesis.
Those pushing the human-caused, catastrophic climate change hypothesis have long held that human use of fossil fuels is the primary cause of global increases in atmospheric carbon dioxide since the beginning of the industrial revolution. In recent decades careful records have been kept regarding the amount of carbon dioxide that has been released to the atmosphere through the burning of fossil fuels. Consequently, there should be a correlation between the amount of carbon dioxide emissions by human activity and the increase in global carbon dioxide. This study of emissions versus global CO2 concentrations by Jamal Munshi shows that this is not the case and that there is no significant correlation between the two sets of data. In other words, the IPCC carbon budget is flawed, and the climate alarmist’s hypothesis has once again been shown to be questionable at best.
Influence of solar system oscillation on the variability of total solar irradi-ance is discussed in this research paper published in New Astronomy.