Reflections on the late Cosmoclimatology

Despite over 35 years of constant satellite-based measurements of cloud, reliable evidence of a long-hypothesized link between changes in solar activity and Earth's cloud cover remains elusive. This work examines evidence of a cosmic ray cloud link from a range of sources, including satellite-based cloud measurements and long-term ground-based climatological measurements. The satellite-based studies can be divided into two categories: (1) monthly to decadal timescale analysis and (2) daily timescale epochsuperpositional (composite) analysis. The latter analyses frequently focus on sudden high-magnitude reductions in the cosmic ray flux known as Forbush Decrease events. At present, two long-term independent global satellite cloud datasets are available (ISCCP and MODIS). Although the differences between them are considerable, neither shows evidence of a solar-cloud link at either long or short timescales. Furthermore, reports of observed correlations between solar activity and cloud over the 1983-1995 period are attributed to the chance agreement between solar changes and artificially induced cloud trends. It is possible that the satellite cloud datasets and analysis methods may simply be too insensitive to detect a small solar signal. Evidence from ground-based studies suggests that some weak but statistically significant cosmic ray-cloud relationships may exist at regional scales, involving mechanisms related to the global electric circuit. However, a poor understanding of these mechanisms and their effects on cloud makes the net impacts of such links uncertain. Regardless of this, it is clear that there is no robust evidence of a widespread link between the cosmic ray flux and clouds.

2010

The effect of the Galactic Cosmic Ray (GCR) flux on Earth's climate is highly uncertain. Using a novel sampling approach based around observing periods of significant cloud changes, a statistically robust relationship is identified between short-term GCR flux changes and the most rapid mid-latitude (60 • -30 • N/S) cloud decreases operating over daily timescales; this signal is verified in surface level air temperature (SLAT) reanalysis data. A General Circulation Model (GCM) experiment is used to test the causal relationship of the observed cloud changes to the detected SLAT anomalies. Results indicate that the anomalous cloud changes were responsible for producing the observed SLAT changes, implying that if there is a causal relationship between significant decreases in the rate of GCR flux (∼0.79 GU, where GU denotes a change of 1% of the 11year solar cycle amplitude in four days) and decreases in cloud cover (∼1.9 CU, where CU denotes a change of 1% cloud cover in four days), an increase in SLAT (∼0.05 KU, where KU denotes a temperature change of 1 K in four days) can be expected. The influence of GCRs is clearly distinguishable from changes in solar irradiance and the interplanetary magnetic field. However, the results of the GCM experiment are found to be somewhat limited by the ability of the model to successfully reproduce observed cloud cover. These results provide perhaps the most compelling evidence presented thus far of a GCR-climate relationship. From this analysis we conclude that a GCR-climate relationship is governed by both short-term GCR changes and internal atmospheric precursor conditions.

Pramana, 2010

In this paper, we have provided an overview of cosmic ray effects on terrestrial processes such as electrical properties, global electric circuit, lightning, cloud formation, cloud coverage, atmospheric temperature, space weather phenomena, climate, etc. It is suggested that cosmic rays control short term and long term variation in climate. There are many basic phenomena which need further study and require new and long term data set. Some of these have been pointed out.

Atmospheric Chemistry and Physics, 2010

Aerosol particles affect the Earth's radiative balance by directly scattering and absorbing solar radiation and, indirectly, through their activation into cloud droplets. Both effects are known with considerable uncertainty only, and translate into even bigger uncertainties in future climate predictions. More than a decade ago, variations in galactic 5 cosmic rays were suggested to closely correlate with variations in atmospheric cloud cover and therefore constitute a driving force behind aerosol-cloud-climate interactions. Later, the enhancement of atmospheric aerosol particle formation by ions generated from cosmic rays was proposed as a physical mechanism explaining this correlation. Here, we report unique observations on atmospheric aerosol formation based on mea-10 surements at the SMEAR II station, Finland, over a solar cycle (years 1996-2008) that shed new light on these presumed relationships. Our analysis shows that none of the quantities related to aerosol formation correlates with the cosmic ray-induced ionisation intensity (CRII). We also examined the contribution of ions to new particle formation on the basis of novel ground-based and airborne observations. A consistent 15 result is that ion-induced formation contributes typically less than 10% to the number of new particles, which would explain the missing correlation between CRII and aerosol formation. Our main conclusion is that galactic cosmic rays appear to play a minor role for atmospheric aerosol formation, and so for the connected aerosol-climate effects as well.

Geophysical Research Letters, 1999

High energy cosmic rays may influence the formation of clouds, and thus can have an impact on weather and climate. Cosmic rays in the solar wind are incident on the magnetosphere boundary and are then transmitted through the magnetosphere and atmosphere to reach the upper troposphere. The flux to the troposphere will depend both on the intensity and spectrum of the cosmic rays at the outer boundary of the magnetosphere (magnetopause) and on the configuration of the magnetosphere through which they propagate. Both the incident flux and the magnetospheric transmission have changed systematically during this century due to systematic changes in the solar wind. We show that, early in the century the region of the troposphere open to cosmic ray precipitation was usually confined to a relatively small high-latitude region. As the century progressed there was a systematic increase in the size of this region by over 7". We suggest that these changes contributed to climate change during the last 100 years.

The purpose of this paper is to show the public solar cosmic raysirradiated the early solar system after its birth five billion years (5 Ga) ago, still do, and influence Earth’s climate today.Cosmic rays are one of many ways the Sun’s pulsar core maintains invisible contact with atoms, lives and planets in the solar system. Cosmic rays produce tracks of ion pairs (charge separation) on traversing Earth’s atmosphere. The attractive force of water vapor condensation into water droplets along ion tracks produces electrically charged clouds, rain, lightening and thunder asfrequent reminders a solarpulsar controls human destiny.

Eos, Transactions American Geophysical Union, 2004

Journal of Geophysical Research: Atmospheres, 2001

Based on a 16-year observation period (1980-1995), it was claimed recently that Earth's climate was linked to variations in the flux of cosmic rays penetrating into the atmosphere via their postulated effect on global cloud cover. Data from three independent studies yie.ld information relevant to the ongoing discussion of the likelihood of the existence of such a hnk. (1) Model calculations show that the relative change in the ion production rate from a solar maximum to a solar minimum is of the same order as, or even greater than, the corresponding change in global cloud cover. (2) However, the smoothed combined flux of 10 Be and 36 Cl at Summit, Greenland, from 20-60 kyr B.P. (proportional to the geomagnetically modulated cosmic ray flux) is unrelated to the corresponding 8 18 0 and CH4 data (interpreted as supraregional climate proxies). (3) Furthermore, although a comparison of the incoming neutron flux with cloud cover in Switzerlan.d over the last 5 decades shows a significant correlation at times during the 1980s and 1990s, this does not occur during the rest of the period.

Journal of Atmospheric and Solar-Terrestrial Physics, 2009

The cause of the correlation of low cloud cover with the sunspot cycle, and the associated cosmic ray intensity, is still the subject of controversy. Insofar as 'clouds' come in different types with, doubtless, different sensitivities to the cloud condensation nuclei (charged or otherwise) it is useful to search for differences in the correlation between cloud types. Here, we examine the major cloud components: stratiform and cumuliform, the latter with its much higher upthrust velocities being expected to be less efficient as cosmic ray induced cloud generation. No difference is found between the two types of cloud, in the sense that there is no dependence on the fraction of cloud of stratiform type for the various parameters studied. This result is true over the Globe as a whole and as a function of cosmic ray cutoff rigidity. Once more there is no support for the cosmic ray hypothesis for cloud modulation. There is no obvious implication for the alternative hypotheses of solar irradiance modulation, but this is probably still the more likely.

International Journal of Astrobiology, 2020

Motivated by the occurrence of a moderately nearby supernova near the beginning of the Pleistocene, possibly as part of a long-term series beginning in the Miocene, we investigated whether nitrate rainout resulting from the atmospheric ionization of enhanced cosmic ray flux could have, through its fertilizer effect, initiated carbon dioxide drawdown. Such a drawdown could possibly reduce the greenhouse effect and induce the climate change that led to the Pleistocene glaciations. We estimate that the nitrogen flux enhancement onto the surface from an event at 50 pc would be of order 10%, probably too small for dramatic changes. We estimate deposition of iron (another potential fertilizer) and find it is also too small to be significant. There are also competing effects of opposite sign, including muon irradiation and reduction in photosynthetic yield caused by UV increase from stratospheric ozone layer depletion, leading to an ambiguous result. However, if the atmospheric ionization ...