Daily changes in global cloud cover and Earth transits of the heliospheric current sheet

Kniveton, D. R. and Tinsley, B. A. (2004) Daily changes in global cloud cover and Earth transits of the heliospheric current sheet. Journal of Geophysical Research, 109 (D11201). pp. 1-13. ISSN 0148-0227

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Abstract

Changes in cloud cover are found to occur for periods of a few days following Earth transits of the heliospheric current sheet (HCS), provided also that the transits occur in years of high stratospheric aerosol loading. Using global cloud products from the International Satellite Cloud Climatology Project (ISCCP) D1 data series, epoch superposition analyses was made for various samples of HCS events. For the period August 1991 to June 1994 for the stratospheric aerosol loading due to the Pinatubo eruption, the analysis of the data in 30° geomagnetic latitude intervals revealed that cloud anomalies that were significant and negative were located in the southern hemisphere high and middle latitudes, and anomalies that were significant and positive were found in both hemispheres at low latitudes. When the key days in the superposed epoch analysis were determined by minima in the relativistic electron flux, rather than by the HCS crossings, the location of the significant negative anomalies was in the northern high latitudes, and the location of the significant positive anomalies was in middle latitudes in the northern hemisphere. The spatial and temporal patterns of these cloud cover variations are in broad agreement agree with the expected opposite variations at high and low latitudes of the current density (Jz) in the global electric circuit caused by the relativistic electron flux variations, during periods when the aerosol loading has made a large increase in stratospheric resistivity

Item Type: Article
Schools and Departments: School of Global Studies > Geography
Subjects: Q Science > QC Physics
Depositing User: SRO Admin
Date Deposited: 22 Jan 2008
Last Modified: 12 Mar 2017 06:01
URI: http://sro.sussex.ac.uk/id/eprint/1692
Google Scholar:16 Citations

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