Research Highlights

Research Highlights

A selection of highlights culled from publications by HAO staff.

Selected swirling events

Multiwavelength High-resolution Observations of Chromospheric Swirls in the Quiet Sun

We report observations of small-scale swirls seen in the solar chromosphere. They are typically 2 Mm in diameter and last around 10 minutes. Using spectropolarimetric observations obtained by the CRisp Imaging Spectro- Polarimeter at the Swedish 1 m Solar Telescope, we identify and study a set of swirls in chromospheric Ca II 8542 Å and Hα lines as well as in the photospheric Fe I line.

HIWIND thermospheric winds

HIWIND Observation of Summer Season Polar Cap Thermospheric Winds

HIWIND (High altitude Interferometer WIND experiment) is a balloon borne Fabry Perot interferometer (FPI) for daytime thermospheric wind observations. In this paper, we examine the summer polar cap thermospheric winds observed by HIWIND with the RISR-C (Resolute Incoherent Scatter Radar-Canada) observed ion drifts and electron densities.

SW2 amplitude in neutral temperature

On the importance of interactive ozone chemistry in Earth-System models for studying MLT tidal changes during sudden stratospheric warmings

We use the CESM2-WACCM, to study the importance of ozone in the vertical coupling between lower and upper atmosphere during SSWs. During SSWs, the build-up of stratospheric ozone concentrations at tropical latitudes and its increased asymmetrical distribution carries the potential to affect the generation of migrating and non-migrating semidiurnal solar tides.

Seasonally averaged data for the CaII“S-index” and for the average magnitudes of the Strömgrenbplusy filters are shown for the star 18 Sco

Sun-Like Stars Shed Light on Solar Climate Forcing

Recently published, precise stellar photometry of 72 Sun-like stars obtained at the Fairborn Observatory between 1993 and 2017 is used to set limits on the solar forcing of Earth’s atmosphere of ±4.5 W m−2 since 1750. This compares with the +2.2 ± 1.1 W m−2 IPCC estimate for anthropogenic forcing.

Accuracy of temperature estimates in the measurement update step for four different assimilated observations

Upper atmosphere radiance data assimilation: A feasibility study for GOLD far ultraviolet observations

Availability of far ultraviolet observations of Earth’s dayglow by the NASA Global-scale Observations of the Limb and Disk (GOLD) mission presents an unparalleled opportunity for upper atmosphere radiance data assimilation.

Differences in the monthly mean temperature from the long-term average over three WACCM realizations

Interhemispheric Coupling Mechanisms in the Middle Atmosphere of WACCM6

Simulations with the Community Earth System Model 2 using the Whole Atmosphere Community Climate Model configuration, known as CESM2(WACCM6), show evidence of dynamical coupling from the high latitudes of the winter middle atmosphere to the tropics and the middle and high latitudes of the summer hemisphere.