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Determining the Sun's Deep Meridional Flow Speed Using Active Latitude Drift Rates Since 1874Dynamo models that incorporate a deep meridional return flow indicate that this flow regulates both the period and the amplitude of the sunspot cycle. We recently examined the equatorward drift of the active latitudes (as given by the centroid of the sunspot areas in each hemisphere) and found evidence supporting this view. In those studies we fit the equatorward drift in each hemisphere for each sunspot cycle with a simple parabola - giving us a drift rate and its deceleration for each hemisphere/cycle. Here we analyze the same data (the Royal Greenwich Observatory/JSAF/NOAA daily active region summaries) to determine the drift rates in each hemisphere on a yearly basis (rotation-by- rotation measurements smoothed to remove high frequencies) and fit them with a simple model for the meridional flow that provides the meridional flow speed as a function of latitude and time from 1874 to 2005. These flow speeds can be used to test dynamo models - some of which have predictive capabilities.
Document ID
20050182056
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Hathaway, David H.
(National Space Science and Technology Center Huntsville, AL, United States)
Wilson, Robert M.
(National Space Science and Technology Center Huntsville, AL, United States)
Date Acquired
August 23, 2013
Publication Date
January 1, 2005
Subject Category
Astronomy
Meeting Information
Meeting: American Geophysical Union General Assembly
Location: New Orleans, LA
Country: United States
Start Date: May 23, 2005
End Date: May 27, 2005
Sponsors: American Geophysical Union
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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