Juri Toomre
Address: Prof. Juri Toomre, JILA, and Department of
Astrophysical and Planetary Sciences, University of Colorado, Boulder
CO 80309-0440, USA
E-mail: jtoomre@jila.colorado.edu or jtoomre@solarz.colorado.edu
Phone: (303) 492-7854 (office); (303) 443-3310 (home);
(303) 907-9316 (mobile)
Fax: (303) 492-5235 (JILA fax)
Biographical Sketch:
Toomre received B.Sc. and M.Sc. degrees from the Massachusetts
Institute of Technology in aeronautics and astronautics in 1963, and
then went to England as a Marshall Scholar to receive a Ph.D. from
Trinity College, University of Cambridge in applied mathematics and theoretical
physics in
1967. He joined the New York University mathematics faculty in 1969, and
then in 1972 came to the University of Colorado as an associate professor.
Since 1975 Toomre has been a professor of astrophysics in
APS
(Department of Astrophysical and Planetary Sciences) and a fellow of
JILA
(formerly the Joint Institute for Laboratory Astrophysics),
University of Colorado, Boulder.
Research and Teaching Emphasis:
Toomre's research and teaching centers on astrophysical fluid dynamics
(AFD), with particular emphasis on nonlinear theories for compressible
convection in stars, and in studying nonlinear dynamical systems
exhibiting multiple bifurcations and chaos. He is particularly
interested in topics where theoretical work related to fluid dynamics
can be challenged and tested by observation and experiment. He is
active in turbulence theory and simulation, with extensive experience
in the use of vector supercomputers, massively parallel machines,
high-speed networks, archival storage systems, and major visualization
systems. Toomre's teaching spans graduate courses in basic fluid
dynamics, waves and instabilities, nonlinear dynamical systems,
geophysical and astrophysical fluid turbulence, magnetohydrodynamics,
mathematical methods, computational mathematics and simulations, and a
variety of courses in general astronomy. Toomre in
Spring 2014 taught the undergraduate course
ASTR 1040-010
Accelerated Intro Astronomy 2: Stars & Galaxies, and in Spring 2015 he
is teaching the graduate course
ASTR 5540 Intro to Fluid Dynamics.
Toomre is PI (with other Co-Is) on the NASA Heliophysics Theory Program (HTP)
effort to study turbulent solar convection coupled to rotation and magnetic
fields, and thus the sun's dynamo processes. Toomre has sustained interests in
helioseismology, using observations of the frequency-splitting of five-minute
oscillations of the sun to search for subphotospheric flows, large-scale
structures and differential rotation in the convection zone; inverse theory has
been developed to interpret the data. The Global Oscillations Network Project
(GONG) is using six ground-based
Doppler imaging instruments to obtain nearly uninterrupted observations of solar
oscillations. These are complemented by major observations from space. Toomre
has been a Co-I on the helioseismology SOI-MDI Doppler imaging experiment onboard the
SOHO spacecraft, still positioned at the L1 Lagrangian point
(SOI-MDI Project on SOHO) , and
is a Co-I on the Helioseismic Magnetic Imager (HMI) with four-fold higher
resolution onboard the (launched in Feb 2010) Solar Dynamics Observatory (SDO)
in tilted geosynchronous orbit (HMI
Project on SDO).
Other theoretical work includes nonlinear instabilities of shear flows;
double-diffusive convection exhibiting traveling waves and chaos;
internal gravity waves both in the solar atmosphere and in its deep
core; penetrative convection in the nuclear-burning cores of rotating A and B-type
stars and in the outer convective envelope of the sun; core dynamos building
super-equipartition magnetic fields in the cores of B-type stars; and early work
on the modeling of interacting galaxies that yield a rich assembly of
bridges and tails.
Professional Activities:
Toomre has served on the central committee of Astro2010, the most
recent decadal survey of astronomy and astrophysics ("New Worlds, New Horizons
in Astronomy and Astrophysics''). He has served on the NSF Astronomy
Portfolio Review that completed its work in Aug 2012 ("Advancing Astronomy in
the Coming Decade: Opportunities and Challenges"). He has chaired the AURA
Decadal Steering committee to provide commentary on investments and thrusts
to be made in UVOIR astronomy. Toomre has been chair of the scientific advisory
committee to GONG (Global Oscillation Network Group), the major ground-based
observational project in helioseismology. He has served on the Solar and Heliospheric
Physics panel for the NAS (2001-2002) decadal study of Solar and Space Physics
("The Sun to the Earth - and Beyond").
Toomre has been vice-chair of the Solar Observatory Council (SOC) of AURA with
oversight for the National Solar Observatory, and has been member and chair of
the Space Telescope Institute Council (STIC, which has oversight for STScI)
for three intensive years following the launch of the Hubble Space Telescope.
Recent Selected Publications:
-
``Three-dimensional spherical simulations of solar convection: I.
Differential rotation achieved with laminar and turbulent states'',
Astrophys. J., 532, 593-612 (2000), with M.S. Miesch,
J.R. Elliott, T.L. Clune, G.A. Glatzmaier, P.A. Gilman.
-
``Dynamic variations at the base of the solar convection zone'',
Science, 287, 2456--2460 (2000), with R. Howe, J.
Christensen-Dalsgaard, F. Hill, R.W. Komm, R.M. Larsen, J. Schou, M.J.
Thompson.
-
``Deeply penetrating banded zonal flows in the solar convection zone'',
Astrophys. J., 533, L163-L166 (2000), with R. Howe, J.
Christense-Dalsgaard, F. Hill, R.W. Komm, R.M. Larsen, J. Schou, M.J.
Thompson.
-
``Turbulent solar convection and its coupling with rotation: The effect
of Prandtl number and thermal boundary conditions on the resulting
differential rotation'', Astrophys. J., 533, 546-556
(2000), with J.R. Elliott, M.S. Miesch.
-
``Solar shear flows deduced from helioseismic dense-pack samplings of
ring diagrams'', Solar Phys., 192, 335-350 (2000), with
D.A. Haber, B.W. Hindman, R.S. Bogart, M.J. Thompson, F. Hill.
-
``Transport and storage of magnetic fields in turbulent penetrative
convection'', Astrophys. J., 549, 1183-1203 (2001), with S.M.
Tobias, N.H. Brummell, T. Clune.
-
``Penetration and overshooting in turbulent compressible convection'',
Astrophys. J., 570, 825-854 (2002), with N.H. Brummell, T. Clune.
-
``Turbulent convection under the influence of rotation: Sustaining a
strong differential rotation'', Astrophys. J., 570, 865-885 (2002), with
A.S. Brun.
-
``Evolving submerged meridional circulation cells within the upper
convection zone revealed by ring-diagram analysis'', Astrophys. J.,
570, 855-864, (2002), with D.A. Haber, B.W. Hindman, R.S. Bogart, R.M. Larsen,
F. Hill.
-
``Solar multiscale convection and rotation gradients studied in shallow
spherical shells'', Astrophys. J., 581, 1356-1374 (2002), with M.L. DeRosa,
P.A. Gilman.
-
``Order amidst turbulence'', Science, 296, 64-65 (2002).
-
``The internal rotation of the Sun'', Ann. Rev. Astron. Astrophys., 41,
599-643 (2003), with M.J. Thompson, J. Christensen-Dalsgaard, M.S. Miesch.
-
``Overview: Where do we stand with helioseismology?'', Proc. SOHO 12/GONG+
2002, Local and Global Helioseismology: The Present and Future, ESA SP-517,
3-14 (2003).
-
``Bridges between helioseismology and models of convection zone
dynamics'', in Stellar Astrophysical Fluid Dynamics, eds. M.J. Thompson,
J. Christensen-Dalsgaard, 299-314 (2003), (Cambridge Univ. Press).
-
``Simulations of core convection in rotating A-type stars: Differential
rotation and overshooting'', Astrophys. J., 601, 512-529 (2004), with
M.K. Browning, A.S. Brun.
-
``The spectrum of solar supergranulation: Multiple nonwave components'',
Astrophys. J., 608, 1156-1166 (2004), with M.P. Rast, J.P. Lisle.
-
``Persistent north-south alignment of the solar supergranulation'',
Astrophys. J., 608, 1167-1174 (2004), with J.P. Lisle, M.P. Rast.
-
``Comparison of solar subsurface flows assessed by ring and
time-distance analyses'', Astrophys. J., 613, 1253-1262 (2004), with
B.W. Hindman, L. Gizon, T.L. Duvall, Jr., D.A. Haber.
-
``Global-scale turbulent convection and magnetic dynamo action in the
solar envelope'', Astrophys. J., 614, 1073-1098 (2004), with A.S. Brun,
M.S. Miesch.
-
``Evolution of solar supergranulation'', Astrophys. J., 616, 1242-1260
(2004), with M.L. DeRosa.
-
``Simulations of core convection in rotating A-type stars: Magnetic
dynamo action'', Astrophys. J., 629, 461-481 (2005), with A.S. Brun,
M.K. Browning.
-
``Solar differential rotation influenced by latitudinal entropy variations
in the tachocline'', Astrophys. J., 641, 618-625 (2006), with M.S. Miesch,
A.S. Brun.
-
``Dynamo action in the solar convection zone and tachocline: Pumping and
organization of toroidal fields'', Astrophys. J., 648, L157-L160 (2006),
with M.K. Browning, M.S. Miesch, A.S. Brun.
-
``Helioseismically determined near-surface flows underlying a quiescent
filament'', Astrophys. J., 653, 725-732 (2006), with B.W. Hindman, D.A.
Haber.
-
``Rapid rotation, active nests of convection and global-scale flows in
solar-like star'', Astron. Nachr., 328, 1002-1005 (2007), with B.P. Brown,
M.K. Browning, A.S. Brun, M.S. Miesch.
-
``Temporal variations in solar rotation at the bottom of the convection
zone: The current status'', Advances Space Res., 40, 915-918 (2007), with
R. Howe, J. Christensen-Dalsgaard, F. Hill, R. Komm, J. Schou, M.J.
Thompson.
-
``Challenges of magnetism in the turbulent Sun'', in Convection in Astrophysics,
IAU Symp. 239, ed. F. Kupka et al., Cambridge UP, 488-493 (2007), with
A.S. Brun, M.S. Miesch.
-
``Structure and evolution of giant cells in global models of solar convection'',
Astrophys. J., 673, 557-575 (2008), with M.S. Miesch, A.S. Brun, M. DeRosa.
-
``Rapidly rotating suns and active nests of convection'', Astrophys. J., 689,
1354-1372 (2008), with M.K. Browning, A.S. Brun, M.S. Miesch.
-
``Subsurface circulations within active regions'', Astrophys. J., 698, 1749-1760
(2009), with B.W. Hindman, D.A. Haber.
-
``Turbulence, magnetism and shear in stellar interiors'', Ann. Rev. Fluid Mech.,
41, 317-345, [online appendix also on ``Tachocline confinement, 6pp] (2009),
with M.S. Miesch.
-
``Effects of fossil magnetic fields on convective core dynamos in A-type
stars'', Astrophys. J., 705, 1000-1018 (2009), with N.A. Featherstone,
M.K. Browning, A.S. Brun.
-
``Persistent magnetic wreaths in a rapidly rotating sun'', Astrophys. J., 711,
424-438 (2010), with B.P. Brown, M.K. Browning, A.S. Brun, M.S. Miesch.
-
``Magnetic cycles in a convective dynamo simulation of a young solar-type star'',
Astrophys. J., 731: 69 (19pp) (2011), with B.P. Brown, M.S. Miesch, M.K. Browning,
A.S. Brun.
-
``Modeling the dynamical coupling of solar convection with the radiative interior'',
Astrophys. J., 742: 79 (22 pp) (2011), with A.S. Brun, M.S. Miesch.
-
``Buoyant magnetic loops in a global dynamo simulation of a young sun'',
Astrophys. J. Lett., 739: L38 (5pp) (2011), with N.J. Nelson, B.P. Brown,
A.S. Brun, M.S. Miesch.
-
``New Era in 3-D modeling of convection and magnetic dynamos in stellar envelopes
and cores'', in `Progress in Solar/Stellar Physics with Helio- and Asteroseismology',
ASP Conf. Ser., Vol. 462, 331-344 (2012), with K.C. Augustson, B.P. Brown,
M.K. Browning, A.S. Brun, N.A. Featherstone, M.S. Miesch.
-
``Effects of granulation upon large-scale convection'', in `Hinode-3: The 3rd
Hinode Science Meeting', ASP Conf. Ser., Vol 454, 13-17 (2012), with N.E.
Hurlburt, M.L. DeRosa, K.C. Augustson.
-
``Convection and differential rotation in F-type stars'', Astrophys. J., 756: 169
(23pp) (2012), with K.C. Augustson, B.P. Brown, A.S. Brun, M.S. Miesch.
-
``Magnetic wreaths and cycles in convective dynamos'', Astrophys. J., 762: 73
(20 pp) (2013), with N.J. Nelson, B.P. Brown, A.S. Brun, M.S. Miesch.
-
``Dynamo action and magnetic cycles in F-type stars'', Astrophys. J., 777: 153
(22 pp) (2013), with K.C. Augustson, B.P. Brown, A.S. Brun, M.S. Miesch.
-
``Center-to-lim velocity systematics in ring-diagram analysis'', in `Fifty Years of
Seismology of the Sun and Stars'', ASP Conf. Ser., Vol. 478, 199-204 (2013),
with B.J. Greer, B.W. Hindman,
-
``Buoyant magnetic loops generated by convective dynamo action'', Solar Phys., 289,
441-458 (18 pp) (2014), with N.J. Nelson, B.P. Brown, A.S. Brun, M.S. Miesch.
-
``Multi-ridge fitting for ring-diagram helioseismology'', Solar Phys., 289,
2823-2843 (21 pp) (2014), with B.J. Greer, B.W. Hindman.
-
``Convective dynamo simulation with a grand minimum'', in `18th Cambridge Workshop
on Cool Stars, Stellar Systems, and the Sun'', Proc. Lowell Observ., (15pp), (2014),
arXiv:1503:04225, with K.C. Augustson, A.S. Brun, M.S. Miesch.
-
``Grand minima and equatorward propagation in a cycling stellar convective dynamo'',
Astrophys. J., in review (24 pp) (2014), arXiv:1410.6547, with K.C. Augustson,
A.S. Brun, M.S. Miesch.
-
``Helioseismic imaging of fast convective flows throughout the near-surface shear
layer'', Astrophys. J. Lett., in press (2015), arXiv:1504.00699, with B.J. Greer,
B.W. Hindman, N.A. Featherstone.
Means Toward A Happier Life: