Abstract Sudden stratospheric warmings (SSWs) are impressive fluid dynamical events in which large and rapid temperature increases the winter polar stratosphere ( ∼ 10–50 km) associated with a complete reversal of climatological wintertime westerly winds. SSWs caused by breaking planetary‐scale waves that propagate upwards from troposphere. During an SSW, vortex breaks down, accompanied descent warming air latitudes, mirrored ascent cooling above warming. The column affect tropospheric...

Abstract Key developments have been made to the NCAR Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension (WACCM‐X). Among them, most important are self‐consistent solution of global electrodynamics, transport O + in F‐region. Other include time‐dependent electron/ion temperatures, metastable chemistry, high‐cadence solar EUV capability. Additional thermospheric components improvements momentum energy equation solvers account for variable mean molecular mass...

Observations of the Global Positioning System (GPS) total electron content (TEC) are used to study coupling between 2009 sudden stratospheric warming (SSW) and ionospheric perturbations. The observations reveal both migrating nonmigrating perturbations semidiurnal tide in equatorial ionization anomaly crest region that associated with changes electric fields induced by tidal dynamo. In particular, a significant enhancement is observed westward propagating zonal wavenumber 1 ( SW 1) GPS TEC...

Abstract For the first time a mesoscale‐resolving whole atmosphere general circulation model has been developed, using National Center for Atmospheric Research Whole Atmosphere Community Climate Model with ∼0.25° horizontal resolution and 0.1 scale height vertical above middle stratosphere (higher below). This is made possible by high accuracy scalability of spectral element dynamical core from High‐Order Method Modeling Environment. simulated January–February period, latitude‐height...

Numerical simulations are performed for a sudden stratosphere warming (SSW) under different atmospheric tide and planetary wave forcing conditions to investigate the tidal variability in mesosphere lower thermosphere (MLT). The influence of tides MLT on generating perturbations low latitude ionosphere is also investigated. Significant changes found occur migrating semidiurnal solar ( S W 2) lunar M as well westward propagating nonmigrating with zonal number 1 1). mean atmosphere that during...

Whole Atmosphere Community Climate Model (WACCM) simulations are used to investigate solar and lunar tide changes in the mesosphere lower thermosphere (MLT) that occur response sudden stratosphere warmings (SSWs). The average tidal is demonstrated based on 23 moderate strong Northern Hemisphere SSWs. migrating semidiurnal enhanced globally during SSWs, with largest enhancements (∼60–70%) occurring at mid high latitudes Hemisphere. Enhancements ( SW 2) also up an altitude of 120 km. Above...

High above Earth’s surface, air temperatures occasionally increase suddenly, producing widespread effects on weather, chemistry, and telecommunications.

Abstract Launched in 2006, the Formosa Satellite Mission 3–Constellation Observing System for Meteorology, Ionosphere and Climate (FORMOSAT-3/COSMIC) was first constellation of microsatellites carrying global positioning system (GPS) radio occultation (RO) receivers. Radio is an active remote sensing technique that provides valuable information on vertical variations electron density ionosphere, temperature, pressure, water vapor stratosphere troposphere. COSMIC has demonstrated great value...

The present study compares simulations of the 2009 sudden stratospheric warming (SSW) from four different whole atmosphere models. models included in comparison are Ground‐to‐topside model Atmosphere and Ionosphere for Aeronomy, Hamburg Model Neutral Ionized Atmosphere, Whole Model, Community Climate Extended version (WACCM‐X). focuses on zonal mean, planetary wave, tidal variability middle upper during SSW. constrained lower atmosphere, simulated mean wave is thus similar up to ∼1 hPa (50...

The joint Taiwan-United States FORMOSAT-3/COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate) mission, hereafter called COSMIC, is the first satellite constellation dedicated to remotely sense Earth's atmosphere ionosphere using a technique Global Positioning (GPS) radio occultation (RO). occultations yield abundant information about neutral atmospheric temperature moisture as well space weather estimates of slant total electron content, density profiles, an...

The solar-wind magnetosphere interaction primarily occurs at altitudes where the dipole component of Earth’s magnetic field is dominating. disturbances that are created in this propagate along lines and interact with ionosphere–thermosphere system. At ionospheric altitudes, deviates significantly from a dipole. North–South asymmetries imply magnetosphere–ionosphere–thermosphere (M–I–T) coupling different two hemispheres. In paper we review primary differences polar latitudes, consequences...

Abstract The ability to perform data assimilation in the Whole Atmosphere Community Climate Model eXtended version (WACCMX) is implemented using Data Assimilation Research Testbed (DART) ensemble adjustment Kalman filter. Results are presented demonstrating that WACCMX+DART analysis fields reproduce middle and upper atmosphere variability during 2009 major sudden stratospheric warming (SSW) event. Compared specified dynamics WACCMX, which constrains meteorology by nudging toward an external...

Abstract We conduct observational and modeling studies of thermospheric composition responses to weak geomagnetic activity (nongeomagnetic storms). found that the O N 2 column density ratio (∑O/N ) in part Northern Hemisphere measured by Global‐scale Observations Limb Disk (GOLD) exhibited large long‐lived depletions during May June 2019. The reached 30% quiet time values, extended equatorward 10°N lasted more than 10 hr. Furthermore, numerical simulation results are similar these...

Abstract Prediction systems to enable Earth system predictability research on the subseasonal time scale have been developed with Community System Model, version 2 (CESM2) using two configurations that differ in their atmospheric components. One uses Atmosphere 6 (CAM6) its top near 40 km, referred as CESM2(CAM6). The other employs Whole Climate (WACCM6) whose extends ∼140 and it includes fully interactive tropospheric stratospheric chemistry [CESM2(WACCM6)]. Both are utilized carry out...

Abstract To investigate ionosphere variability during the 2009 sudden stratosphere warming (SSW), we present simulation results that combine Whole Atmosphere Community Climate Model Extended version and thermosphere‐ionosphere‐mesosphere electrodynamics general circulation model (TIME‐GCM). The simulations reveal notable enhancements in both migrating semidiurnal solar ( S W 2) lunar (M 2 ) tides SSW. M amplitudes reach ∼50 m s −1 ∼40 , respectively, zonal wind at E region altitudes....

Abstract In recent years there have been a series of reported ground‐ and satellite‐based observations lunar tide signatures in the equatorial low latitude ionosphere/thermosphere around sudden stratospheric warming (SSW) events. This lower atmosphere/ionosphere coupling has suggested to be via E region dynamo. this work we present results analyzing 6 hourly upper mesospheric winds from specular meteor radars over midlatitude (54°N) station high (69°N) station. Instead correlating our with...

Transient loss of lock is one the key space weather effects on Global Navigation Satellite System (GNSS). Based Constellation Observing for Meteorology, Ionosphere, and Climate Positioning (GPS) radio occultation (RO) observations during 2007–2011, we have analyzed signal cycle slip (CS) occurrence comprehensively its correlation to ionospheric phenomena such as sporadic E (Es), equatorial F region irregularity (EFI), ionization anomaly (EIA). The high vertical resolution RO enables us...

Abstract The NCAR Whole Atmosphere Community Climate Model (WACCM) is used to investigate the dynamical influence of lower and middle atmosphere on upper mesosphere thermosphere. In simulations using a methodology adapted from “specified dynamics” (nudged) version model, horizontal winds temperature over part vertical range are relaxed toward results previous simulation that serves as true simulation, equivalent meteorological analysis. mesosphere, magnitude divergence constrained depends...

Abstract New ionosphere and electrodynamics modules have been incorporated in the thermosphere eXtension of Whole Atmosphere Community Climate Model (WACCM‐X), order to self‐consistently simulate coupled atmosphere‐ionosphere system. The first specified dynamics WACCM‐X v.2.0 results are compared with several data sets, Thermosphere‐Ionosphere‐Electrodynamics General Circulation (TIE‐GCM), during deep solar minimum year. Comparisons Thermosphere Ionosphere Mesosphere Energetics Dynamics...

Abstract Observations from the recently launched Global‐Scale of Limb and Disk (GOLD) instrument on geostationary SES‐14 communications satellite reveal a substantial response mean state thermosphere to Sudden Stratospheric Warming (SSW) event in early January 2019. The observed O/N column density depletion more than 10% starts at onset SSW, maximizes time stratospheric wind reversal, recovers toward end SSW. A connection between SSW thermospheric composition was previously predicted by...

Abstract We conducted observational and modeling studies of thermospheric composition ionospheric total electron content (TEC) variations during two geomagnetically quiet periods (maximum Kp = 1.7) at solar minimum. Daytime O N 2 column density ratio (∑O/N ) observed by Global‐scale Observations the Limb Disk TEC from a network ground‐based Global Navigation Satellites System receivers both exhibited large (∼30% reference values) long‐lived (5–11 h) day‐to‐day in roughly same mid‐latitude...

The Constellation Observing System for Meteorology, Ionosphere, and Climate 2 (COSMIC-2) mission was launched into a low-inclination (24°) orbit on June 25, 2019. Six satellites, each with an advanced Tri-GNSS Radio-Occultation Receiver (TGRS), provide global uniform data coverage of the equatorial region several thousand electron density profiles daily. COSMIC-2 profiles, specifically derived ionospheric F2 peak parameters, are properly validated in this study reliable “truth” observations....

Abstract We report a new ionosphere phenomenon: Equatorial ionization anomaly (EIA) discontinuity (EIAD), based on OI 135.6 nm radiance observations from the Global Observations of Limb and Disk (GOLD), ground‐based total electron content maps in‐situ ion density data Constellation Observing System for Meteorology, Ionosphere, Climate‐2. The EIAD occurs when EIA crest has local minimum, at fixed UT, with in longitude region being weaker than that east west sides. In GOLD field‐of‐view,...

The long‐duration positive ionospheric storm effect that occurred on 15 December 2006 is investigated using a combination of ground‐based Global Positioning System (GPS) total electron content (TEC), TOPEX and Jason‐1 TEC, topside ionosphere/plasmasphere GPS radio occultation, tiny photometer (TIP) observations from the Constellation Observing for Meteorology, Ionosphere, Climate (COSMIC) satellites. This multi‐instrument approach provides unique view by revealing time response in different...

In‐situ plasma density measurements from the CHAMP satellite between about 350–420 km altitude are used to delineate intra‐annual variations in longitudinal structure of F‐region ionosphere. It is shown that longitude structures during mid‐day local times dominated by space‐based wavenumbers k s = 2, 4 and 3 January, July December, respectively. These conform same dominating ‐values characterizing solar thermal tide zonal winds dynamo region, namely westward‐propagating semidiurnal with...