Solar irradiance, cosmic rays and cloudiness over daily timescales

Laken, Benjamin A.; Čalogović, Jaša

doi:10.1029/2011gl049764

Cited by 15 publications

(17 citation statements)

References 40 publications

(46 reference statements)

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“…Throughout this work we will frequently use the cloud data as an anomaly equivalent to A i described in Section 1, with units of %. We again note that the analysis presented here is not meant as a serious test for the hypothesized CRcloud link, for which other similar studies exist (e.g., Laken & Č alogović 2011), but rather is presented for demonstration purposes.…”

Section: Working From the Example Of The Hypothesized Cosmic Ray -Clomentioning

confidence: 99%

“…However, despite extensive research in this area, clear conclusions regarding the validity of a solar-climate link from composite studies have yet to be drawn. Instead, the numerous composite analyses have produced widely conflicting results: some studies have shown positive statistical associations between the CR flux and cloud properties (e.g., Tinsley & Deen 1991;Pudovkin & Veretenenko 1995;Todd & Kniveton 2001, 2004Kniveton 2004;Harrison & Stephenson 2006;Svensmark et al 2009Svensmark et al , 2012Dragić et al 2011Dragić et al , 2013Harrison et al 2011;Okike & Collier 2011), while others find no clearly significant relationships (e.g., Lam & Rodger 2002;Kristjánsson et al 2008;Sloan & Wolfendale 2008;Laken et al 2009;Laken & Č alogović 2011;Laken et al 2012a;Č alogović et al 2010), or even identify significant correlations of a negative sign (e.g., Wang et al 2006;Troshichev et al 2008). We suggest that these ambiguities may result from seemingly minor methodological differences between the composites (e.g., relating to the filtering or normalization of data), which are capable of producing widely divergent results.…”

Section: Introductionmentioning

confidence: 99%

“…While the composite approach appears straightforward, inconsistencies in the design, creation, and evaluation of composites can strongly affect the conclusions of composites studies and are the focus of this paper. Numerous composite studies have been published within the field of solar-terrestrial physics, relating to a hypothesized connection between small changes in solar activity and the Earth's atmosphere (e.g., Tinsley et al 1989;Tinsley & Deen 1991;Pudovkin & Veretenenko 1995;Stozhkov et al 1995;Egorova et al 2000;Fedulina & Laštovička 2001;Todd & Kniveton 2001, 2004Kniveton 2004;Harrison & Stephenson 2006;Bondur et al 2008;Kristjánsson et al 2008;Sloan & Wolfendale 2008;Troshichev et al 2008;Svensmark et al 2009;Dragić et al 2011;Harrison et al 2011;Laken & Č alogović 2011;Okike & Collier 2011;Laken et al 2012a;Mironova et al 2012;Svensmark et al 2012;Artamonova & Veretenenko 2011;Dragić et al 2013). However, despite extensive research in this area, clear conclusions regarding the validity of a solar-climate link from composite studies have yet to be drawn.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Composite analysis with Monte Carlo methods: an example with cosmic rays and clouds

Laken

Čalogović

2013

J. Space Weather Space Clim.

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The composite (superposed epoch) analysis technique has been frequently employed to examine a hypothesized link between solar activity and the Earth's atmosphere, often through an investigation of Forbush decrease (Fd) events (sudden high-magnitude decreases in the flux cosmic rays impinging on the upper-atmosphere lasting up to several days). This technique is useful for isolating low-amplitude signals within data where background variability would otherwise obscure detection. The application of composite analyses to investigate the possible impacts of Fd events involves a statistical examination of time-dependent atmospheric responses to Fds often from aerosol and/or cloud datasets. Despite the publication of numerous results within this field, clear conclusions have yet to be drawn and much ambiguity and disagreement still remain. In this paper, we argue that the conflicting findings of composite studies within this field relate to methodological differences in the manner in which the composites have been constructed and analyzed. Working from an example, we show how a composite may be objectively constructed to maximize signal detection, robustly identify statistical significance, and quantify the lower-limit uncertainty related to hypothesis testing. Additionally, we also demonstrate how a seemingly significant false positive may be obtained from non-significant data by minor alterations to methodological approaches.

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Section: Working From the Example Of The Hypothesized Cosmic Ray -Clomentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Composite analysis with Monte Carlo methods: an example with cosmic rays and clouds

Laken

Čalogović

2013

J. Space Weather Space Clim.

View full text Add to dashboard Cite

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“…In this study, cloud measurements were taken from the International Satellite Cloud Climatology Project (ISCCP) (Rossow and Schiffer 1999). Data from this project have been widely utilized for studying the possibility of a relationship between solar activity and cloud cover (e.g., Pallé and Butler 2000;Todd and Kniveton 2001;Kristjánsson et al 2002;Laut 2003;Marsh and Svensmark 2003;Kristjánsson et al 2004;Č alogović et al 2010;Laken et al 2010Laken et al , 2011. Data from this project have been widely utilized for studying the possibility of a relationship between solar activity and cloud cover (e.g., Pallé and Butler 2000;Todd and Kniveton 2001;Kristjánsson et al 2002;Laut 2003;Marsh and Svensmark 2003;Kristjánsson et al 2004;Č alogović et al 2010;Laken et al 2010Laken et al , 2011.…”

Section: Introductionmentioning

confidence: 99%

A Decade of the Moderate Resolution Imaging Spectroradiometer: Is a Solar–Cloud Link Detectable?

2012

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Based on the results of decadal correlation studies between the International Satellite Cloud Climatology Project-detected cloud anomalies and the galactic cosmic ray (GCR) flux, it has been suggested that a relationship exists between solar activity and cloud cover. If valid, such a relationship could have important implications for scientists' understanding of recent climate change. In this work, an analysis of the first decade of Moderate Resolution Imaging Spectroradiometer (MODIS)-detected cloud anomalies are presented, and the data at global and local geographical resolutions to total solar irradiance (TSI), GCR variations, and the multivariate El Niñ o-Southern Oscillation index are compared. The study identifies no statistically significant correlations between cloud anomalies and TSI/GCR variations, and concludes that solar-related variability is not a primary driver of monthly to annual MODIS cloud variability. The authors observe a net increase in cloud detected by MODIS over the past decade of ;0.58%, arising from a combination of a reduction in highto midlevel cloud (20.31%) and an increase in low-level cloud (0.89%); these long-term changes may be largely attributed to ENSO-induced cloud variability.

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“…Others find no change in global cloud cover during FD (Č alogović et al 2010;Laken & Č alogović 2011).…”

Section: Introductionmentioning

confidence: 99%

Investigating a solar influence on cloud cover using the North American Regional Reanalysis data

Krahenbuhl

2015

J. Space Weather Space Clim.

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The controversial connection between cosmic rays, solar activity, and cloud cover is investigated using a climatological reconstructed reanalysis product: the North American Regional Reanalysis which provides high-resolution, low, mid-level, high, and total cloud cover data over a Lambert conformal conic projection permitting land/ocean discrimination. Pearson's product-moment regional correlations were obtained between monthly cloud cover data and solar variability indicators, cosmic ray neutron monitors, several climatological indices, including the Atlantic Multidecadal Oscillation (AMO), and between cloud layers. Regions of the mid-latitude oceans exhibited a positive correlation with cosmic ray flux. Additionally, this maritime low cloud cover exhibits the only failed correlation significance with other altitudes. The cross correlation reveals that cloud cover is positively correlated everywhere but for ocean low cloud cover, supporting the unique response of the marine layer. The results of this investigation suggest that with the assumption that solar forcing does impact cloud cover, measurements of solar activity exhibits a slightly higher correlation than GCRs. The only instance where GCRs exhibit a positive regional correlation with cloud cover is for maritime low clouds. The AMO exerts the greatest control of cloud cover in the NARR domain.

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Solar irradiance, cosmic rays and cloudiness over daily timescales

Cited by 15 publications

References 40 publications

Composite analysis with Monte Carlo methods: an example with cosmic rays and clouds

Composite analysis with Monte Carlo methods: an example with cosmic rays and clouds

A Decade of the Moderate Resolution Imaging Spectroradiometer: Is a Solar–Cloud Link Detectable?

Investigating a solar influence on cloud cover using the North American Regional Reanalysis data

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