Research Highlights

Recent numerical simulations and observations of sunspots show a significant amount of opposite polarity magnetic fields within the sunspot penumbra. Most of the opposite polarity fields are associated with convective downflows.

We have analyzed 33 cavities observed between 2012 and 2018, from solar activity maximum to minimum. For each cavity we applied a differential emission measure method to obtain both a temperature distribution and a value of the average temperature.

Storm-induced ionospheric density variations are a major concern of near-Earth space environment as they could drastically disrupt satellite navigation and telecommunication systems. Although ionospheric disturbances such as traveling ionospheric disturbances (TIDs) and storm enhanced density (SED) are commonly observed during geomagnetic storms, accurate specification of these phenomena remains a great challenge for geospace models.

This work reveals the pathway through which the lower atmosphere impacts the ionosphere weather at mid and low latitudes. An interesting ionospheric phenomena at low to mid-latitudes is the development of the so-called equatorial plasma bubbles (EPBs)--the rapid depletion of plasma density during night time.

The ionosphere is different from one day to the next, even under geomagnetic and solar quiet condition. The vertical E×B drift at the geomagnetic equator is a key parameter that influences the state of the ionosphere and atmosphere. In this paper, we study the quiet-time day-to-day variability of the equatorial vertical E×B drift by ROCSAT-1 observations and the Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension (WACCM-X) v2.1 simulations.

We examine spectropolarimetric data from the CoMP instrument, acquired during the evolution of the September 10th 2017 X8.2 solar flare on the western solar limb. CoMP captured linearly polarized light from two emission lines of Fe XIII at 1074.7 and 1079.8 nm, from 1.03 to 1.5 solar radii. We focus here on the hot plasma-sheet lying above the bright flare loops and beneath the ejected CME.

The Earth’s atmosphere is coupled at high latitude to the magnetosphere. This is a crucial region since energy is put into the upper atmosphere of Earth and is redistributed globally. Numerical models such as general circulation models (GCMs) simulate the effects of the high latitude energy input on the thermosphere-ionosphere system.

GOLD measurements provide the first observational proof of model predictions that the break up of the stratospheric polar vortex changes the composition of the thermosphere.

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.