Atmospheric Electricity Activities of the Institute for Atmospheric Environmental Research

Reiter, R.

doi:10.1007/978-3-642-85294-7_124

Cited by 33 publications

(42 citation statements)

References 11 publications

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“…Concerning Saharan dust, more than a two-fold reduction of atmospheric conductivity within SD layers was observed by Gringel and Mühleisen (1978). The electric field within an SD layer at a 3 km high Alpine peak exceeded fair weather value by a factor of about two, while the current density remained approximately constant (Reiter, 1992). The influence of neutral aerosols on the electric field is a consequence of small ion scavenging by the atmospheric particles (Fuchs, 1963;Hoppel and Frick, 1986;Brazenor and Harrison, 2005).…”

Section: Atmospheric Electric Fieldmentioning

confidence: 94%

Alignment of atmospheric mineral dust due to electric field

et al. 2007

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Abstract. Optical polarimetry observations on La Palma, Canary Islands, during a Saharan dust episode show dichroic extinction indicating the presence of vertically aligned particles in the atmosphere. Modelling of the extinction together with particle orientation indicates that the alignment could have been due to an electric field of the order of 2 kV/m. Two alternative mechanisms for the origin of the field are examined: the effect of reduced atmospheric conductivity and charging of the dust layer, the latter effect being a more likely candidate. It is concluded that partial alignment may be a common feature of Saharan dust layers. The modelling indicates that the alignment can significantly alter dust optical depth. This "Venetian blind effect" may have decreased optical thickness in the vertical direction by as much as 10% for the case reported here. It is also possible that the alignment and the electric field modify dust transport.

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Section: Atmospheric Electric Fieldmentioning

confidence: 94%

Alignment of atmospheric mineral dust due to electric field

et al. 2007

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“…They did not find any clear relationship between the two. When high-latitude data were included, the correlations were even weaker than otherwise, despite the fact that cosmic ray ionization is largest at high latitude [Reiter, 1992]. Kernthaler et al [1999] further found an increase in high cloud cover during a period of decreasing cosmic ray flux.…”

Section: Introductionmentioning

confidence: 89%

“…Estimates of the relative significance of these two forcings vary, but recent studies by Lean [1997] suggested an alternative global warming mechanism through a proposed coupling between galactic cosmic rays and clouds. Solar activity and galactic cosmic ray flux are inversely related [Reiter, 1992], meaning In order to check the validity of the cosmic-raycloud-climate hypothesis we have carefully investigated data sets for global cloud coverage, i.e., data from the International Satellite Cloud Climatology Project (IS-CCP) [Rossow and $chiffer, 1991;1999] Recently, Kernthaler et al [1999] related ISCCP data for different cloud types (high, midlevel, and low) to galactic cosmic ray flux for the period 1985 through 1988. They did not find any clear relationship between the two.…”

Section: Introductionmentioning

confidence: 99%

Is there a cosmic ray signal in recent variations in global cloudiness and cloud radiative forcing?

Kristjánsson¹,

Kristiansen²

2000

J. Geophys. Res.

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Abstract. In order to evaluate a recent hypothesis of a coupling between galactic cosmic rays, clouds, and climate we have investigated temporal variations in global cloudiness and radiative fluxes at the top of the atmosphere. For this purpose wo h•.vo •.qocl tho ho.qt nvnilnhlo g!ob•l clntn .•ot•, i.e., thoso •f tho lntornational Satellite Cloud Climatology Project (ISCCP) and the Earth Radiation Budget Experiment (ERBE), respectively. Both globally and over midlatitude oceans only, we find a decrease in total cloud coverage between 1986 and 1990 of 2%, while between 1990 and 1993 there is a slightly smaller decrease. When the results are related to temporal variations in cosmic ray activity, we do not find support for a coupling between cosmic rays, total cloudiness, and radiative forcing of climate. A possible exception is low marine clouds at midlatitudes, characterized by few cloud condensation nuclei and a large net cooling effect, but no physical mechanism is known which might explain a connection between cosmic rays and low clouds. The net radiative effect of clouds during the period 1985-1989 shows an enhanced cooling effect despite a reduction in both total and low cloud cover. This contradicts the simple relationship between cloud cover and radiation assumed in the cosmicray-cloud-climate hypothesis. The interpretation of the results is rendered difficult by the short time series of ISCCP and ERBE data and by uncertainties concerning instrument calibrations and changes of satellites. When a 43-year time series of synoptic observations over sea is related to cosmic rays over the same period, a weak, negative correlation is found.

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“…The transport and deposition of H 2 SO 4 vapor are also taken into account in the model. The global ionization rates due to cosmic rays are calculated based on the schemes given in Usoskin and Kovaltsov (2006) and the contribution of radioactive materials from soil to ionization rates is parameterized based on the profiles given in Reiter (1992). We run the GEOS-Chem coupled with nucleation module for one year from 07/01/2001 to 06/30/2002.…”

Section: Simulations and Comparisons With Observationsmentioning

confidence: 99%

Ion-mediated nucleation as an important global source of tropospheric aerosols

et al. 2008

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Abstract. Aerosol nucleation events have been observed at a variety of locations worldwide, and may have significant climatic and health implications. While ions have long been suggested as favorable nucleation embryos, their significance as a global source of particles has remained uncertain. Here, an ion-mediated nucleation (IMN) mechanism, which incorporates new thermodynamic data and physical algorithms, has been integrated into a global chemical transport model (GEOS-Chem) to study ion-mediated particle formation in the global troposphere. The simulated annual mean results have been compared to a comprehensive set of data relevant to particle nucleation around the globe. We show that predicted annual spatial patterns of particle formation agree reasonably well with land-, ship-, and aircraft-based observations. Our simulations show that, globally, IMN in the boundary layer is largely confined to two broad latitude belts: one in the northern hemisphere (∼20 • N-70 • N), and one in the southern hemisphere (∼30 • S-90 • S). In the middle latitude boundary layer over continents, the annual mean IMN rates are generally above 10 4 cm −3 day −1 , with some hot spots reaching 10 5 cm −3 day −1 . The zonally-averaged vertical distribution of IMN rates indicates that IMN is significant in the tropical upper troposphere, the entire middle latitude troposphere, and over Antarctica. Comparing the relative strengths of particle sources due to IMN and due to primary particle emissions demonstrates that IMN is significant on a global scale. Further research is needed to reduce modeling uncertainties and to understand the ultimate contribution of freshly nucleated particles to the abundance of cloud condensation nuclei.

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Atmospheric Electricity Activities of the Institute for Atmospheric Environmental Research

Cited by 33 publications

References 11 publications

Alignment of atmospheric mineral dust due to electric field

Alignment of atmospheric mineral dust due to electric field

Is there a cosmic ray signal in recent variations in global cloudiness and cloud radiative forcing?

Ion-mediated nucleation as an important global source of tropospheric aerosols

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