E-Print Archive

There are 4102 abstracts currently viewable.


Search:

Advanced Search
Options
Main Page Add New E-Print Submitter
Information
Feedback
News Help/FAQ About Preferences
Manage Key Phrase
Notification
The origin of the reversed granulation in the solar photosphere View all abstracts by submitter

Mark Chun Ming Cheung   Submitted: 2006-12-20 17:30

We study the structure and reveal the physical nature of the reversed granulation pattern in the solar photosphere by means of 3-dimensional radiative hydrodynamics simulations. We used the MURaM code to obtain a realistic model of the near-surface layers of the convection zone and the photosphere. The pattern of horizontal temperature fluctuations at the base of the photosphere consists of relatively hot granular cells bounded by the cooler intergranular downflow network. With increasing height in the photosphere, the amplitude of the temperature fluctuations diminishes. At a height of z=130-140 km in the photosphere, the pattern of horizontal temperature fluctuations reverses so that granular regions become relatively cool compared to the intergranular network. Detailed analysis of the trajectories of fluid elements through the photosphere reveal that the motion of the fluid is non-adiabatic, owing to strong radiative cooling when approaching the surface of optical depth unity followed by reheating by the radiation field from below. The temperature structure of the photosphere results from the competition between expansion of rising fluid elements and radiative heating. The former acts to lower the temperature of the fluid whereas the latter acts to increase it towards the radiative equilibrium temperature with a net entropy gain. After the fluid overturns and descends towards the convection zone, radiative energy loss again decreases the entropy of the fluid. Radiative heating and cooling of fluid elements that penetrate into the photosphere and overturn do not occur in equal amounts. The imbalance in the cumulative heating and cooling of these fluid elements is responsible for the reversal of temperature fluctuations with respect to height in the photosphere.

Authors: M. C. C. Cheung, M. Schuessler, F. Moreno-Insertis
Projects: None

Publication Status: Astronomy & Astrophysics, in press.
Last Modified: 2006-12-21 09:54
Go to main E-Print page  Characteristics of Solar Flare Hard X-ray Emissions: Observations and Models  An optimization principle for the computation of MHD equilibria in the solar corona  Edit Entry  Download Preprint  Delete Entry 

Key
Go to main E-Print pageGo to main E-Print page.
Previous AbstractPrevious Abstract.
Next AbstractNext Abstract.
Download PreprintDownload Preprint.
Submitter's HomepageSubmitters Homepage.
Edit EntryEdit Entry.
View All Abstracts By SubmitterView all abstracts by submitter.
Delete AbstractDelete abstract.

Latest Entries
Three-dimensional Density Structure of a Solar Coronal Streamer Observed by SOHO/LASCO and STEREO/COR2 in Quadrature
Modelling Mg II During Solar Flares, I: Partial Frequency Redistribution, Opacity, and Coronal Irradiation
The Birth of a Jet-driven Twin CME and Its Deflection from Remote Magnetic Fields
On the Origin of Solar Torsional Oscillations and Extended Solar Cycle
What Sets the Magnetic Field Strength and Cycle Period in Solar-type Stars?
Stereoscopic Observations of an Erupting Mini-filament Driven Two-Sided-Loop Jet and the Applications for Diagnosing Filament Magnetic field
Dynamic Processes of the Moreton Wave on 2014 March 29
Shock Heating Energy of Umbral Flashes Measured with Integral Field Unit Spectroscopy
Stealth Coronal Mass Ejections from Active Regions
Coronal Loop Scaling Laws for Various Forms of Parallel Heat Conduction
Structure of the transition region and the low corona from TRACE and SDO observations near the limb
Quantifying the relationship between Moreton-Ramsey waves and "EIT waves" using observations of 4 homologous wave events
Formation of quasi-periodic slow magnetoacoustic wave trains by the heating/cooling misbalance
Fundamental Transverse Vibrations of the Active Region Solar Corona
Damping of slow magnetoacoustic oscillations by the misbalance between heating and cooling processes in the solar corona
Magnetic helicity and eruptivity in active region 12673
Impulsive coronal heating from large-scale magnetic rearrangements: from IRIS to SDO/AIA
Probing the effect of cadence on the estimates of photospheric energy and helicity injections in eruptive active region NOAA AR 11158
The birth of a coronal mass ejection
Oscillations of the baseline of solar magnetic field and solar irradiance on a millennial timescale

Related Pages
MSU Solar Physics.
Max Millennium Science Mail Archive.
Max Millennium Message of the Day Mail Archive.
Max Millennium Flare Catalog

Archive Maintainer
Alisdair Davey



© 2003 Solar Physics Group - Montana State University