space weather

Investigation of the physical mechanism of the formation and evolution of equatorial plasma bubbles during a moderate storm on September 17, 2021

whawkins — Wed, 06 Dec 2023 16:34:59 +0000

Investigation of the physical mechanism of the formation and evolution of equatorial plasma bubbles during a moderate storm on September 17, 2021 whawkins Wed, 12/06/2023 - 09:34

Author:

whawkins

Dec 6, 2023

GOLD Namx on September 16-17, 2021. Left panels show the observations on the night of September 16th, while right panels show the observations on the night of September 17th. The red dotted lines represent the magnetic dip equator.

Space Weather: We investigate in detail the occurrence and evolution of ionospheric equatorial plasma bubbles (EPBs) during a moderate storm on September 17th, 2021, using Global-scale Observation of the Limb and Disk (GOLD) observations and Whole Atmosphere Community Climate Model-eXtended (WACCM-X) simulations. GOLD observations show that there were no EPBs on September 16th before the storm but EPBs occurred after the storm commencement on September 17th. The EPBs extended to ~ 30° magnetic latitude. A diagnostic analysis of WACCM-X simulations reveals that the rapid enhancement of prompt penetration electric fields (PPEFs) after the sudden storm commencement is the main reason that triggered the occurrence of the EPBs. Further quantitative analysis shows that vertical plasma drifts, which are enhanced by the PPEF, played a dominant role in strengthening the Rayleigh-Taylor instability, leading to the occurrence of the EPBs and the large latitudinal extension of the EPBs to ~ 30° magnetic latitude during the night of September 17th.

Thermospheric Density Perturbations Produced by Traveling Atmospheric Disturbances during August 2005 Storm

whawkins — Fri, 16 Dec 2022 19:44:31 +0000

Thermospheric Density Perturbations Produced by Traveling Atmospheric Disturbances during August 2005 Storm whawkins Fri, 12/16/2022 - 12:44

Author:

whawkins

Dec 16, 2022

During geomagnetic storms, increased activity within the geospace environment causes large scale plasma convection to occur and electrons to precipitate into the upper atmosphere. The enhanced heating of the thermosphere by the plasma convection and electron precipitation can produce large perturbations in the neutral density. These neutral density perturbations propagate away from their point of origin, oftentimes traveling to the equator and into the other hemisphere. Here, simulation results using a high resolution coupled geospace model that includes a magnetosphere, inner magnetosphere, ionosphere, and thermosphere model show that neutral density perturbations generated in one hemisphere can propagate far enough to interact with those in the other hemisphere. The intersection of two or more perturbations produce regions of larger neutral density perturbations. The high resolution coupled geospace model performs significantly better than the standalone model when compared to observations of neutral density by low altitude spacecraft. A significant fraction of the observed neutral density perturbations is captured by the coupled model, especially those at low latitudes. Proper simulation and understanding of storm-time neutral density perturbations is imperative to space weather prediction as neutral density perturbations can greatly affect satellite drag.

Snapshots that follow the neutral density perturbation observed by CHAMP (star) and GRACE (circle) at low latitude at 13:20 UT. The approximate location of the wavefront for TADs that intersect near CHAMP’s position at 13:20 UT are indicated by a line white line for the northern hemisphere and black line for the southern hemisphere.

The Ionospheric Connection Explorer - Prime Mission Review

whawkins — Fri, 16 Dec 2022 19:00:21 +0000

The Ionospheric Connection Explorer - Prime Mission Review whawkins Fri, 12/16/2022 - 12:00

Author:

whawkins

Dec 16, 2022

The two-year prime mission of the NASA Ionospheric Connection Explorer (ICON) is complete. The baseline operational and scientific objectives have been met and exceeded, as detailed in this report. In October of 2019, ICON was launched into an orbit that provides its instruments the capability to provide near-continuous measurements of the densest plasma in Earth's space environment. Through collection of a key set of in-situ and remote sensing measurements that are, by virtue of a detailed mission design, uniquely comparable, ICON provides for new investigations of the mechanisms that control the behavior of the ionosphere-thermosphere system under both geomagnetically quiet and active conditions. In a two-year period that included a deep solar minimum, ICON has elucidated a number of remarkable effects of influences of the lower and middle atmosphere in the ionosphere. The observatory is now moving into a period of elevated solar activity that will dramatically rebalance the impacts of lower and upper atmospheric drivers on the ionosphere.

TIEGCM vertical ExB drift over the 2 year period at the top with lower atmospheric tidal forcing at the TIEGCM lower boundary based on ICON observations and bottom with no tidal forcing at the lower boundary.

Pronounced suppression and X-pattern merging of equatorial ionization anomalies after the 2022 Tonga volcano eruption

whawkins — Fri, 16 Dec 2022 18:47:19 +0000

Pronounced suppression and X-pattern merging of equatorial ionization anomalies after the 2022 Tonga volcano eruption whawkins Fri, 12/16/2022 - 11:47

Author:

whawkins

Dec 16, 2022

Following the 2022 Tonga Volcano eruption, dramatic suppression and deformation of the equatorial ionization anomaly (EIA) crests occurred in the American sector ∼14,000 km away from the epicenter. The EIA crests variations and associated ionosphere-thermosphere disturbances were investigated using Global Navigation Satellite System (GNSS) total electron content (TEC) data, Global-scale Observations of the Limb and Disk (GOLD) ultraviolet images, Ionospheric Connection Explorer (ICON) wind data, and ionosonde observations. The main results are as follows: (1) Following the eastward passage of expected eruption-induced atmospheric disturbances, daytime EIA crests, especially the southern one, showed severe suppression of more than 10 TECU and collapsed equatorward over 10◦ latitudes, forming a single band of enhanced density near the geomagnetic equator around 15–17 UT, (2) Evening EIA crests experienced a drastic deformation around 22 UT, forming a unique X-pattern in a limited longitudinal area between 20–40◦W. (3) Thermospheric zonal winds showed long-lasting quasi-periodic fluctuations between ±200 m/s for 7–8 hours after the passage of volcano-induced Lamb waves. The EIA suppression and X-pattern merging was consistent with a westward equatorial zonal dynamo electric field induced by the strong zonal wind oscillation with westward reversal.

(a–c) ICON MIGHTI track and corresponding zonal wind and meridional wind profiles between 20:48–21:16 UT on 15 January 2022. The iso-distance circles away from the Tonga eruption epicenter are shown in black lines. The blue circle in (a) is the estimated wavefront location of volcano-induced Lamb waves. (d–l) Combined GNSS TEC and GOLD OI 135.6-nm radiance maps in successive disk scan during 20:40–23:55 UT. The dip equator and meridional field lines are shown in cyan.

Thermospheric Neutral Density Variation during the "SpaceX" Storm: Implications from Physics-based Whole Geospace Modeling

whawkins — Wed, 23 Nov 2022 18:32:53 +0000

Thermospheric Neutral Density Variation during the "SpaceX" Storm: Implications from Physics-based Whole Geospace Modeling whawkins Wed, 11/23/2022 - 11:32

Author:

whawkins

Nov 23, 2022

Space Weather—Dong Lin, Wenbin Wang, Katherine Garcia-Sage, Jia Yue, Viacheslav Merkin, Joseph McInerney, Kevin Pham, Kareem Sorathia

Neutral density variations along the Starlink orbit calculated by (a) MAGE, (b) TIEGCM, (c) DTM-2012, and (d) NRLMSIS 2.0. (e) Relative variations of neutral density based on the values on February 1 at the same UT and location. (f) Starlink altitude. (g) The Ap index used to drive NRLMSIS 2.0.

On February 3, 2022, 40 Starlink satellites were launched by the SpaceX Corporation when a moderate geomagnetic storm occurred, followed by another storm on February 4. The storm activities have been regarded as the culprit for the loss of the Starlink satellites afterwards. Although strong geomagnetic storms are well-known to be able to increase the neutral atmospheric mass density so as to satellite drag in the thermosphere where many space vehicles are orbiting around the Earth, a not-so-strong storm was not expected to bring such huge impacts based on engineering design evaluation using empirical atmospheric density models. This study compares the performance of a state-of-the-art physics-based, fully coupled whole geospace model and empirical models in predicting the neutral mass density variation in the thermosphere. It turns out that the physics-based model is more accurate in capturing the magnitude of storm enhancement of neutral density. It also resolves the gradual recovery process even though it is not reflected in some geomagnetic indices that are used to drive the empirical models. Using such first-principles whole geospace model is suggested as a necessary step in future space weather applications.

2022 Space Weather Summer School

whawkins — Tue, 30 Aug 2022 15:45:48 +0000

2022 Space Weather Summer School whawkins Tue, 08/30/2022 - 09:45

Author:

whawkins

Aug 30, 2022

FYI, we will not be holding a Space Weather Summer School in 2023. We hope to resume in 2024.

HAO held the latest in a series of successful Space Weather Summer Schools in Boulder, Colorado during the last 2 weeks of July. This unique educational workshop brought together 31 students mainly from the United States along with two students from abroad. Lecturers included experts in solar physics, solar wind, magnetsophere, and ionosphere-thermosphere in order to provide the students with a comprehensive background of the complete space weather system. In addition to lectures on the physics of the system, students learned from experts at the Space Weather Prediction Center about the challenges in making accurate space weather forecasts. Specialists provided an understanding of how space weather processes turn into impacts in human systems such as the power grid. Each day of the school included a computer-based laboratory exercise that let the students get hands-on experience with the models used to simulate space weather. HAO was pleased to once again provide students with an informative, comprehensive, and well well-appreciated introduction to space weather.

SWSS 2022 Group Photograph

The Multiscale Atmosphere-Geospace Environment (MAGE) model

kolinski — Mon, 11 Jul 2022 21:20:33 +0000

The Multiscale Atmosphere-Geospace Environment (MAGE) model kolinski Mon, 07/11/2022 - 15:20

2023 UCAR/NCAR Summer Program: Heliophysics

kolinski — Mon, 04 Apr 2022 17:30:32 +0000

2023 UCAR/NCAR Summer Program: Heliophysics kolinski Mon, 04/04/2022 - 11:30

Author:

kolinski

Apr 4, 2022

Boulder Space Weather Summer School (website)

Hosted by HAO/NCAR and Sponsored by NSF

Application Deadline: FYI, we will not be holding a Space Weather Summer School in 2023. We hope to resume in 2024.

When/Where:

Who: Graduate students starting their research careers in space physics as well as selected undergraduate students interested in exploring the topic.

Theme: The physics of space weather and its impacts on the space environment, space craft, astronauts and ground based systems. Deepen your conceptual understanding of space weather and the physics behind using fundamental physics principles, spacecraft and ground based data, and model results. Learn from leading researchers in the field and experts in forecasting space weather. Meet other students working in the field.

Description: The Boulder Space Weather Summer School (SWSS) is a two-week program, funded by NSF and hosted by HAO, that gives students a comprehensive introduction to the science of space weather: what it is, what it does, and what can be done about it.

Heliophysics Summer School (website)

Hosted by UCAR/CPAESS and Sponsored by NASA

Application Deadline: 3 March 2023

When/Where: Remote phase from July 17–21, 2023 and an in-person phase from August 7–11, 2023 / Boulder, CO

Who: Advanced graduate students and postdoctoral researchers who want to broaden their understanding of fundamental processes across all disciplines of heliophysics.

Theme: Connecting the Heliosphere: Using Global Models to Connect In-situ and Remote Sensing Data Throughout the Heliosphere.

Description: During this two-week NASA funded summer school hosted by UCAR, participants will:

dive into physics connecting global models to remote and in-situ measurements,
learn from leading experts in the field,
use prototype visualizations tools to recreate data from a spacecraft flying through the magnetosphere,
connect with other early career researchers.

Heliophysics relies on the data collected through in-situ instruments on spacecraft—such as Solar Probe, MMS, and DMSP—to provide point measurements, remote-sensing observations such as solar imagery from SDO and DKIST, and measurements of the upper atmosphere and space environment from ground-based radar and the GOLD spacecraft. Global models allow us to bridge the gap between these measurements and understand the implications for the whole system. This Summer School will explore the various types of models (global MHD, kinetic, and general circulation) across all the domains of heliophysics (solar, heliosphere, magnetosphere, and thermosphere/ionosphere) and their relationship to observations.

For more information and to apply

3rd Eddy Cross Disciplinary Symposium 2022

kolinski — Fri, 04 Mar 2022 16:23:44 +0000

3rd Eddy Cross Disciplinary Symposium 2022 kolinski Fri, 03/04/2022 - 09:23

A New Coronagraph for Mauna Loa

kolinski — Wed, 01 Dec 2021 21:36:31 +0000

A New Coronagraph for Mauna Loa kolinski Wed, 12/01/2021 - 14:36

Author:

kolinski

Dec 1, 2021

NCAR's High Altitude Observatory (HAO) will be installing a new white light coronagraph at the Mauna Loa Solar Observatory (MLSO) in Hawaii in August of this year (2013). A coronagraph is an instrument designed to mimic a total solar eclipse, which occurs when the moon completely occults the solar disk. The new coronagraph, known as K-cor, was designed by HAO engineers and scientists, along with two engineering consultants. K-cor will replace the 1-D scanning coronameter at Mauna Loa known as the Mk4. K-cor will provide a factor of ten improvement in speed and signal-to-noise as well as significant advancements in calibration accuracy and reliability.

It is specially designed to acquire images of the lowest region of the very faint, hot solar atmosphere known as the corona. With a field-of-view of 1.05 to 3.0 solar radii, and a time cadence of 15 seconds, the K-cor will provide unprecedented white light imaging for studying the birth and evolution of coronal mass ejections (CMEs). CMEs are dramatic eruptions in the solar atmosphere that hurl millions of tons of magnetized plasma into the solar wind that can create severe space weather at Earth and throughout the heliosphere. High time cadence images of the low corona provide crucial observations for understanding the formation of CMEs and CME-driven shocks in the solar wind.

A sequence of coronal images from Mk4 showing a CME erupting through the corona in May 2001.

Electrical engineer, Brandon Larson, and Technician Rob Graves install the K-cor center section onto the solar spar at the NCAR Mesa Lab in Boulder.

K-cor has been successfully deployed to the HAO solar spar in Boulder, Colorado. The deployment required careful alignment of the optical systems beginning with the installation of the primary objective lens near the front of the telescope. The objective lens is bombarded by light from the solar surface, which is a million times brighter than the faint corona. The lens must be nearly free of scratches, striations and any blemishes that will cause light to scatter and overwhelm the faint signal coming from the corona.

K-cor occulter

The back end of the K-cor instrument contains the occulter, filters, polarization modulator, lenses and cameras. The system is carefully designed to filter out all unwanted light and capture the all-important polarized light scattered by the electrons in the Sun’s corona. If the corona were not polarized it would not be possible with current technologies to observe it in white light from the ground except during a total solar eclipse. The white object at center left in the image is the K-cor occulter, illuminated by, and blocking, the bright light from the solar surface.

K-cor system testing at the Mesa spar by project manager Scott Sewell and electrical engineer Brandon Larson.

K-cor is undergoing spar testing before it is fully deployed to the Mauna Loa spar in August. The pristine skies at MLSO provide the ideal sky conditions needed to observe the faint corona. HAO engineers and scientists will work with the Mauna Loa observers (Allen Stueben, Ben Berkey, Greg Rose and Lisa Waters) to complete the installation at MLSO by September.

K-cor instrument scientist Alfred de Wijn inspects the calibration optics at the Mesa spar in Boulder.

Following installation at the Mauna Loa spar, K-cor will begin routine observations of the corona. Final checks on data calibration by HAO scientists, led by Alfred deWijn (pictured at left,) will be completed and cross-checked to space-based coronagraph observations to ensure the community receives highest quality dataset. All K-cor observations will be provided via the Mauna Loa website.

K-Cor H-alpha image

An image of the solar corona taken with the K-cor in a neutral emission line of hydrogen known as H-alpha. The dark circle is the projection of the occulter obscuring the solar disk. The two bright features are dense, cool objects known as prominences which may play a key role in the dynamical processes that result in CME formation.

space weather

Investigation of the physical mechanism of the formation and evolution of equatorial plasma bubbles during a moderate storm on September 17, 2021

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Thermospheric Density Perturbations Produced by Traveling Atmospheric Disturbances during August 2005 Storm

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The Ionospheric Connection Explorer - Prime Mission Review

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Pronounced suppression and X-pattern merging of equatorial ionization anomalies after the 2022 Tonga volcano eruption

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Thermospheric Neutral Density Variation during the "SpaceX" Storm: Implications from Physics-based Whole Geospace Modeling

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2022 Space Weather Summer School

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The Multiscale Atmosphere-Geospace Environment (MAGE) model

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2023 UCAR/NCAR Summer Program: Heliophysics

Boulder Space Weather Summer School (website)

Heliophysics Summer School (website)

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3rd Eddy Cross Disciplinary Symposium 2022

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A New Coronagraph for Mauna Loa

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