Results 251 to 260 of about 2,754,875 (281)

Differential solar rotation depends on solar activity

Nature, 1979
SUNSPOTS have long been used as tracers to determine the rotation rate of the Sun. Scheiner1 noted 250 years ago that low-latitude sunspots rotate more rapidly than those at high latitude (‘differential rotation’). In a recent review, Howard2 stressed the limitations of the sunspot technique for determining rotation rate and differential rotation, as ...
D. H. CLARK, B. D. YALLOP, S. RICHARD, B. EMERSON, P. J. RUDD   +4 more
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Solar radiation and solar differential rotation

Solar Physics, 1988
Areas of sunspots and their positions taken from the Greenwich Photoheliographic Results (1874–1976) and typical intensities of the umbrae and penumbrae are used to calculate daily values of the solar flux at a wavelength of about 500 nm. Using overlapping time series of 512 days each solar rotation periods are determined by Fourier transformation. The
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Study of the Periodicities of the Solar Differential Rotation

Astrophysics, 2020
Data on solar hydrogen filaments obtained at the Abastumani Astrophysical Observatory during solar activity cycles 19-22 are used to study the characteristic periods of the solar differential rotation. In addition to the known 11-year period of solar activity, a quasi-biennial periodicity was revealed for the rotation rates of hydrogen filaments and a ...
D. Japaridze, G. Dumbadze, G. Ramishvili, B. Chargeishvili   +3 more
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A model of solar differential rotation

Solar Physics, 1991
An axisymmetric model for the Sun's differential rotation based upon a mechanism for angular momentum transport by compressible convection is developed. Convective heat transport is also considered. The model is simplified by the neglect of meridional circulation and radiative heat transport but is otherwise a self-consistent one because no adjustable ...
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Differential rotation of solar filaments

Solar Physics, 1974
The latitudinal component of solar differential rotation and the possibility of a radial component are discussed and compared to the observed rotational velocities of solar filaments. The author's values of rotational rate versus heliographic latitude for 100 points in the solar atmosphere derived from 17 quiescent filaments are shown to be comparable
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Models of solar differential rotation

Geophysical & Astrophysical Fluid Dynamics, 1982
Abstract Models of a differentially rotating compressible convection zone are calculated, considering the inertial forces in the poloidal components of the equations of motion. Two driving mechanisms have been considered: latitude dependent heat transport and anisotropic viscosity.
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Differential rotation of the solar electron corona

Solar Physics, 1969
Autocorrelation analyses of K-coronameter observations made at Haleakala and Mauna Loa, Hawaii, during 1964–1967 have established average yearly rotation rates of coronal features as a function of latitude and height above the limb. At low latitudes the corona was found to rotate at the same rate as sunspots but at higher latitudes was consistently ...
Richard T. Hansen, Shirley F. Hansen, Harold G. Loomis   +2 more
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22-Year Periodicity in the Solar Differential Rotation

International Astronomical Union Colloquium, 2000
AbstractUsing the data on sunspot groups compiled during 1879–1975, we determined variations in the differential rotation coefficientsAandBduring the solar cycle. The variation in the equatorial rotation rateAis found to be significant only in the odd numbered cycles, with an amplitude ∼ 0.01μrads−1.
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Models of solar differential rotation

1984
o-.rr rcdels give the deperrdence of the angular velocity at the Sunis equator on the depth of the convecÈion zcne. In order to drive differential rotation we ccnsidered two different rnechanisxns: latirude depe:rience of the n:xj"ng length and the anisoircpy of :ie turbulent viscosity.
Pidatella, Rosa Maria, Stix, M., Belvedere, G., Paternò. L.   +3 more
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The solar differential rotation from the eightteenth solar cycle

Astrophysics and Space Science, 1982
The sidereal daily rotation of the Sun, ζ(φ), depends on the data used. From an appropriate selection of the data — sunspots with regular motion — it is found that ζ(φ)=14.31–2.70 sin2 φ, where φ denotes the heliographic latitude. Moreover, it seems that there is a variation, of the order of 3%, with the solar activity.
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