Next Solar Cycle: up to 50% stronger; up to 1 year late!

Date: Mon Mar 06 2006 - 14:18:20 EST

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    Thought this might be of 
    interest to our group, especially since
    it would imply that satellites (especially LEOs) might be pushed toward 
    reentry at a much faster rate.
    -- joe rao  
    2006-5 FOR IMMEDIATE RELEASE: March 6, 2006
    Scientists Issue Unprecedented Forecast of Next Sunspot Cycle
    Teleconference Today (see end of release for details)
    David Hosansky, NCAR Media Relations
    Mausumi Dikpati, NCAR High Altitude Observatory
    Peter Gilman, NCAR High Altitude Observatory
    BOULDER—The next sunspot cycle will be 30-50% stronger than the last one
    and begin as much as a year late, according to a breakthrough forecast
    using a computer model of solar dynamics developed by scientists at the
    National Center for Atmospheric Research (NCAR). Predicting the Sun's
    cycles accurately, years in advance, will help societies plan for active
    bouts of solar storms, which can slow satellite orbits, disrupt
    communications, and bring down power systems.
    The scientists have confidence in the forecast because, in a series of
    test runs, the newly developed model simulated the strength of the past
    eight solar cycles with more than 98% accuracy. The forecasts are
    generated, in part, by tracking the subsurface movements of the sunspot
    remnants of the previous two solar cycles. The team is publishing its
    forecast in the current issue of Geophysical Research Letters.
    “Our model has demonstrated the necessary skill to be used as a
    forecasting tool,” says NCAR scientist Mausumi Dikpati, the leader of
    the forecast team at NCAR’s High Altitude Observatory that also includes
    Peter Gilman and Giuliana de Toma.
    -----Understanding the cycles -----
    The Sun goes through approximately 11-year cycles, from peak storm
    activity to quiet and back again. Solar scientists have tracked them for
    some time without being able to predict their relative intensity or timing.
    Forecasting the cycle may help society anticipate solar storms, which
    can disrupt communications and power systems and affect the orbits of
    satellites. The storms are linked to twisted magnetic fields in the Sun
    that suddenly snap and release tremendous amounts of energy. They tend
    to occur near dark regions of concentrated magnetic fields, known as
    The NCAR team’s computer model, known as the Predictive Flux-transport
    Dynamo Model, draws on research by NCAR scientists indicating that the
    evolution of sunspots is caused by a current of plasma, or electrified
    gas, that circulates between the Sun's equator and its poles over a
    period of 17 to 22 years. This current acts like a conveyor belt of
    The sunspot process begins with tightly concentrated magnetic field
    lines in the solar convection zone (the outermost layer of the Sun’s
    interior). The field lines rise to the surface at low latitudes and form
    bipolar sunspots, which are regions of concentrated magnetic fields.
    When these sunspots decay, they imprint the moving plasma with a type of
    magnetic signature. As the plasma nears the poles, it sinks about
    200,000 kilometers (124,000 miles) back into the convection zone and
    starts returning toward the equator at a speed of about one meter (three
    feet) per second or slower. The increasingly concentrated fields become
    stretched and twisted by the internal rotation of the Sun as they near
    the equator, gradually becoming less stable than the surrounding plasma.
    This eventually causes coiled-up magnetic field lines to rise up, tear
    through the Sun's surface, and create new sunspots.
    The subsurface plasma flow used in the model has been verified with the
    relatively new technique of helioseismology, based on observations from
    both NSF– and NASA–supported instruments. This technique tracks sound
    waves reverberating inside the Sun to reveal details about the interior,
    much as a doctor might use an ultrasound to see inside a patient.
    -----Predicting Cycles 24 and 25 -----
    The Predictive Flux-transport Dynamo Model is enabling NCAR scientists
    to predict that the next solar cycle, known as Cycle 24, will produce
    sunspots across an area slightly larger than 2.5% of the visible surface
    of the Sun. The scientists expect the cycle to begin in late 2007 or
    early 2008, which is about 6 to 12 months later than a cycle would
    normally start. Cycle 24 is likely to reach its peak about 2012.
    By analyzing recent solar cycles, the scientists also hope to forecast
    sunspot activity two solar cycles, or 22 years, into the future. The
    NCAR team is planning in the next year to issue a forecast of Cycle 25,
    which will peak in the early 2020s.
    “This is a significant breakthrough with important applications,
    especially for satellite-dependent sectors of society,” explains NCAR
    scientist Peter Gilman.
    The NCAR team received funding from the National Science Foundation and
    NASA’s Living with a Star program. NCAR’S primary sponsor is the
    National Science Foundation. Opinions, findings, conclusions, or
    recommendations expressed in this publication do not necessarily reflect
    the views of the National Science Foundation.
                          -The End-
    Notes to Editors:
    Reporters only may contact David Hosansky ( or Harvey
    Leifert ( to obtain a copy of the paper, "Predicting
    the strength of solar cycle 24 using a flux-transport 3 dynamo-based
    tool," Mausumi Dikpati, Giuliana de Toma, and Peter A. Gilman,
    Geophysical Research Letters, Vol. 33, doi:10.1029/2005GL025221, 2006.
    -----Monday Teleconference-----
    NCAR, in partnership with NASA and the National Science Foundation, will
    present the findings during a media teleconference today at 1 p.m.
    Eastern Standard Time (11 a.m. Mountain Time). Reporters should call
    (888) 677-1822 or (210) 234-0001 and provide the passcode "Solar." At
    the start of the briefing, images and graphics supporting the conference
    will be posted on the Web at:
    Participants in the teleconference will be:
    - Richard Behnke: director, NSF Upper Atmospheric Research Section,
    Arlington, Va.
    - Madhulika Guhathakurta: Living With a Star lead program scientist,
    NASA Headquarters, Washington, D.C.
    - Mausumi Dikpati: scientist, NCAR’s High Altitude Observatory, Boulder,
    - Joseph Kunches: chief, Forecast and Analysis Branch, National Oceanic
    & Atmospheric Administration's Space Environment Center, Boulder, Colo.
    - David Hathaway: Solar astronomer, NASA's Marshall Space Flight Center,
    Huntsville, Ala.
    Find this press release and images on the Web at
    Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive:

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