E-Print Archive

There are 4524 abstracts currently viewable.


Advanced Search
Main Page Add New E-Print Submitter
News Help/FAQ About Preferences
Manage Key Phrase
Catastrophic cooling of impulsively heated coronal loops View all abstracts by submitter

Cesar A. Mendoza-Briceno   Submitted: 2004-11-01 03:57

The physical mechanisms that cause the heating of the solar corona are still far from being completely understood. However, recent highly-resolved observations with the current solar missions have thrown clear evidence for frequent and very localized heating events near the chromosphere, which may be responsible for the observable high temperatures of the coronal plasma. In this paper, we perform one-dimensional hydrodynamic simulations of the evolution of a hypothetical loop model undergoing impulsive heating through the release of localized Gaussian energy pulses near the loop's footpoints.We find that when a discrete number of randomly spaced pulses is released, the loop heats up and stays at coronal temperatures for the whole duration of the impulsive heating stage provided that the elapsing time between successive heat injections is lesssim 215 s. For elapsing times longer than this critical value, coronal temperatures can no longer be maintained at the loop apex in spite of continued impulsive heating. As a result, the loop apex cools down catastrophically well below the initial state, reaching chromospheric temperatures (sim 104 K) and leading to the typical hot-cool temperature profile characteristic of a cool condensation. For a large number of pulses (up to sim 1000) having a fully random spatio-temporal distribution, the variation of the temperature along the loop is highly sensitive to the spatial distribution of the heating. As long as the heating concentrates more and more at the loop's footpoints, the temperature variation is seen to make a transition from that of a uniformly heated loop to a flat, isothermal profile along the loop length. Concentration of the heating at the footpoints also results in the more frequent appearance of rapid and significant depressions of the apex temperature during the loop evolution, most of them ranging from sim 1.5 imes 106 to sim 104 K and lasting from about 3 to 10 minutes. This behavior bears a tight relation with the strong variability of coronal loops inferred from {it SOHO} observations in active regions of the solar atmosphere.

Authors: Cesar A. Mendoza-Briceno, Leonardo Di G. Sigalotti & Robert Erdelyi

Publication Status: ApJ, 2005, 624, 1080-1092 (in press)
Last Modified: 2005-05-09 03:18
Go to main E-Print page  Quasi-Periodicity in global solar radio flux at metric wavelengths during Noise Storms  Catastrophic cooling of impulsively heated coronal loops  Edit Entry  Download Preprint  Delete Entry 

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
Coronal seismology by slow waves in non-adiabatic conditions
Exploring the Ideal MHD Quasi-Modes of a Plasma Interface with a Thick Nonuniform Transition
Changes of Magnetic Energy and Helicity in Solar Active Regions from Major Flares
Spectroscopic and Imaging Observations of Spatially Extended Magnetic Reconnection in the Splitting of a Solar Filament Structure
The Universality of Power Law Slopes in the Solar Photosphere and Transition Region Observed with HMI and IRIS
Turbulence and Anomalous Resistivity inside Near-Earth Magnetic Clouds
On the specific energy and pressure in near-Earth magnetic clouds
Solar Energetic Particle Event Associated with the 2012 July 23 Extreme Solar Storm
Investigation of Energetic Particle Release Using Multi-point Imaging and In Situ Observations
Shock Properties and Associated Characteristics of Solar Energetic Particles in the 2017 September 10 GLE event
Dimensionality of Solar Magnetic Reconnection
Microwave Perspective on Magnetic Breakout Eruption
Effects of Coronal Density and Magnetic Field Distributions on a Global Solar EUV Wave
Multi-spacecraft Observations of the Coronal and Interplanetary Evolution of a Solar Eruption Associated with Two Active Regions
Sun-to-Earth Characteristics of the 2012 July 12 Coronal Mass Ejection and Associated Geo-effectiveness
The effect of nanoflare flows on EUV spectral lines
On some features of the solar proton event on 2021 October 28 GLE73
The role and contribution of magnetic fields, characterized via their magnetic flux, to the statistical structuring of the solar atmosphere
Do periods of decayless kink oscillations of solar coronal loops depend on noise?
Automatic detection technique for solar filament oscillations in GONG data

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

© 2000-2020 Solar Physics Group - Montana State University