NCAR High Altitude Observatory

The Effect of Small-Scale Magnetic Structures on Inferred Solar Continuum Brightness

Graph depicting average intensity of magnetic structures as a function of width (a) and equivalent radius (b)
Monday, December 3, 2018

Solar irradiance models indicate that irradiance variations are dominated by changes in disk-coverage of magnetic structures, whose brightness is thought to be determined by their size and average magnetic flux density.

The Extended Solar Cycle: Muddying the Waters of Solar/Stellar Dynamo Modeling Or Providing Crucial Observational

Graph depicting extended solar cycles
Monday, December 3, 2018

In 1844 Schwabe discovered that the number of sunspots increased and decreased over a period of about 11 years, that variation became known as the sunspot cycle.

The long-term trends of nocturnal mesopause temperature and altitude revealed by the Na lidar observations between 1990 and 2018 at mid-latitude

Graph showing WACCM-X (2.0) simulated summer temperature profiles of year 1974 and year 2003
Sunday, December 2, 2018

The nighttime mesopause, marking the boundary of mesosphere and thermosphere and having the coldest atmospheric temperature, is formed mainly by the combination of radiative cooling by CO2, and the adiabatic flow in the Mesosphere and Lower Thermosphere.

Pitch angle scattering of energetic electrons by bursty bulk flows (BBFs)

Pitch angle scattering of electrons in high resolution LFM fields
Tuesday, November 13, 2018

Mary Hudson and others have studied field line curvature scattering by the magnetic field structure associated with Bursty Bulk Flows (BBFs), using simulated output fields from the Lyon‐Fedder‐Mobarry (LFM) global magnetohydrodynamic (MHD) code for specified solar wind input.

The eruption of a prominence carrying coronal flux rope forward synthesis of the magnetic field strength measurement by COSMOS

(a) The inferred line-of-sight (LOS) magnetic field B_LOS obtained from the forward synthesis of the circular polarization signal from the MHD model data at a time during the quasi-static phase of the flux rope; (b) The same as (a) but only show the pixels of the measured B_LOS with sufficient signal to noise ratio; (c) The axial field strength in the mid cross-section of the flux rope; (d) The 3D field lines of the coronal magnetic field as view
Tuesday, November 13, 2018

From a magnetohydrodynamic (MHD) simulation of the eruption of a prominence hosting coronal flux rope, Yuhong Fan and others carry out forward synthesis of the circular polarization signal (Stokes V signal) of the FeXIII emission line at 1074.7 nm produced by the MHD model.

On the variability of the semidiurnal solar and lunar tides of the equatorial electrojet (EEJ)

Plot showing EEJ obtained from Huancayo and Fuquene observatories
Friday, November 9, 2018

The variabilities of the semidiurnal solar and lunar tides of the equatorial electrojet (EEJ) are investigated during the 2003, 2006, 2009 and 2013 major sudden stratospheric warming (SSW) events in this study.

Transport of Internetwork Magnetic Flux Elements in the Solar Photosphere

Graph of displacement probability distributions
Tuesday, October 23, 2018

The motions of small-scale magnetic flux elements in the solar photosphere can provide some measure of the Lagrangian properties of the convective flow.

MLSO Honors the Sun at AstroDay West

Radio dish

On October 6th, the MLSO staff participated in AstroDay 2018, an educational outreach event coordinated by the Mauna Kea Observatories. 3,000 people attended. This was the second occurrence of this event, located in Kailua-Kona, on the west side of Hawaii Island.

Characterization of Cameras for the COSMO K-Coronagraph

Digital image sensors
Thursday, October 11, 2018

Digital image sensors are ubiquitous in astronomical instrumentation and it is well known that they suffer from issues that must be corrected for data to be scientifically useful.


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