Magnetic Rossby waves in the solar tachocline and Rieger-type periodicities
arXiv:0911.4591 · doi:10.1088/0004-637X/709/2/749
Abstract
Apart from the 11-year solar cycle, another periodicity around 155-160 days was discovered during solar cycle 21 in high energy solar flares, and its presence in sunspot areas and strong magnetic flux has been also reported. This periodicity has an elusive and enigmatic character, since it usually appears only near the maxima of solar cycles, and seems to be related with a periodic emergence of strong magnetic flux at the solar surface. Therefore, it is probably connected with the tachocline, a thin layer located near the base of the solar convection zone, where strong dynamo magnetic field is stored. We study the dynamics of Rossby waves in the tachocline in the presence of a toroidal magnetic field and latitudinal differential rotation. Our analysis shows that the magnetic Rossby waves are generally unstable and that the growth rates are sensitive to the magnetic field strength and to the latitudinal differential rotation parameters. Variation of the differential rotation and the magnetic field strength throughout the solar cycle enhance the growth rate of a particular harmonic in the upper part of the tachocline around the maximum of the solar cycle. This harmonic is symmetric with respect to the equator and has a period of 155-160 days. A rapid increase of the wave amplitude could give place to a magnetic flux emergence leading to observed periodicities in solar activity indicators related with magnetic flux.
34 pages, 5 figures, accepted in ApJ
References in corpus (4)
Cited by in corpus (41)
- Solar cycle prediction
- Solar Cycle Prediction
- Quasi-biennial oscillations in the solar tachocline caused by magnetic Rossby wave instabilities
- Rieger-type periodicity during solar cycles 14-24: estimation of dynamo magnetic field strength in the solar interior
- North-south asymmetry in Rieger-type periodicity during solar cycles 19-23
- Double-peaks of the solar cycle: An explanation from a dynamo model
- Equatorial magnetohydrodynamic shallow water waves in the solar tachocline
- Starspot activity and rotation of the planet-hosting star Kepler-17
- An Analysis of Apparent r-Mode Oscillations in Solar Activity, the Solar Diameter, the Solar Neutrino Flux, and Nuclear Decay Rates, with Implications Concerning the Solar Internal Structure and Rotation, and Neutrino Processes
- Long-term variation in the Sun's activity caused by magnetic Rossby waves in the tachocline
- Magneto-Rossby waves in the solar tachocline and the annual variations in solar activity
- Rossby waves and polar spots in rapidly rotating stars: Implications for stellar wind evolution
- Properties of solar Rossby waves from normal mode coupling and characterizing its systematics
- The planetary theory of solar activity variability: a review
- Midterm Periodicity Analysis of the Mount Wilson Magnetic Indices Using the Synchrosqueezing Transform
- Power Spectrum Analysis of LMSU (Lomonosov Moscow State University) Nuclear Decay-Rate Data: Further Indication of r-Mode Oscillations in an Inner Solar Tachocline
- Influence of the Solar Global Magnetic Field Structure Evolution on CMEs
- Indications of r-mode Oscillations in SOHO/MDI Solar Radius Measurements
- Stellar activity and rotation of the planet host Kepler-17 from long-term space-borne photometry
- On Midrange Periodicities in Solar Radio Flux and Sunspot Areas
- Temporal evolutions and quasi-periodic variations present in the sunspot number and group sunspot area data measured at Kodaikanal Observatory for solar cycles 14 to 24
- Further Evidence Suggestive of a Solar Influence on Nuclear Decay Rates
- Searching for star-planet magnetic interaction in CoRoT observations
- Tidally Forced Planetary Waves in the Tachocline of Solar-like Stars
- The Super-Alfvénic Rotational Instability in accretion disks about black holes
- Power-law Distribution of Solar-Cycle Modulated Coronal Jets
- Rieger-type periodicity in the total irradiance of the Sun as a star during solar cycles 23-24
- Rossby modes in slowly rotating stars: depth dependence in distorted polytropes with uniform rotation
- Looking for granulation and periodicity imprints in the sunspot time series
- Anomalies in Radioactive Decay Rates: A Bibliography of Measurements and Theory
- Spicules Intensity Oscillations in SOT/HINODE Observations
- Spatio-Temporal Evolution and North-South Asymmetry of Quasi-Biennial Oscillations in the Coronal Fe XIV Emission
- Potential vorticity dynamics in the framework of disk shallow-water theory: II. Mixed Barotropic-Baroclinic Instability
- Rossby waves on stellar equatorial beta-planes: uniformly rotating radiative stars
- Convectively coupled equatorial trapped waves in stars and planets
- Scaler rates from the Pierre Auger Observatory: a new proxy of solar activity
- Stellar activity, differential rotation, and exoplanets
- Two-dimensional ideal magnetohydrodynamic waves on a rotating sphere under a non-Malkus field: I. Continuous spectrum and its ray-theoretical interpretation
- Current state of the modelling of photospheric activity
- Analysis of Short-term Solar Activity Variability and Estimating the Timings of the Next Enhanced Bursts
- Thermomagnetic Ettingshausen-Nernst effect in tachocline, magnetic reconnection phenomenon in lower layers, axion mechanism of solar luminosity variations, coronal heating problem solution and mechanism of ADM variations around BH