Browsing by Author "Goncharenko, Larisa P."
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Item Restricted Equatorial and low latitude ionospheric effects during sudden stratospheric warming events(Instituto Geofísico del Perú, 2011-08-13) Chau Chong Shing, Jorge Luis; Goncharenko, Larisa P.; Fejer, Bela G.; Liu, Han L.The sources of ionospheric forcing are from above (solar and magnetospheric forces), internal (chemistry, local neutral dynamics), and from below (lower atmosphere). In this work we review the observed ion-neutral coupling effects at equatorial and low latitudes during large meteorological events called sudden stratospheric warming (SSW). Research in this direction has been accelerated in recent years mainly due to: (1) extensive observing campaigns, and (2) solar minimum conditions. The former has been instrumental to catch the events before, during, and after the peak SSW temperatures. The latter has permitted a reduced forcing contribution from above and internal. The main ionospheric effects are clearly observed in the zonal electric fields (or vertical E×B drifts), total electron content, and peak electron densities. We include results from different ground- and satellite-based observations, covering different longitudes and years. We also present and discuss the modeling efforts that support most of the observations. Given that SSW can be forecast with a few days in advanced, there is potential for using the connection with the ionosphere for forecasting the occurrence and evolution of electrodynamic perturbations at low latitudes, and sometimes mid latitudes, during arctic winter warmings.Item Restricted Equatorial and low latitude ionospheric effects during sudden stratospheric warming events: Ionospheric effects during SSW events(Springer, 2012) Chau Chong Shing, Jorge Luis; Goncharenko, Larisa P.; Fejer, Bela G.; Liu, Han LiThere are several external sources of ionospheric forcing, including these are solar wind-magnetospheric processes and lower atmospheric winds and waves. In this work we review the observed ion-neutral coupling effects at equatorial and low latitudes during large meteorological events called sudden stratospheric warming (SSW). Research in this direction has been accelerated in recent years mainly due to: (1) extensive observing campaigns, and (2) solar minimum conditions. The former has been instrumental to capture the events before, during, and after the peak SSW temperatures and wind perturbations. The latter has permitted a reduced forcing contribution from solar wind-magnetospheric processes. The main ionospheric effects are clearly observed in the zonal electric fields (or vertical E×B drifts), total electron content, and electron and neutral densities. We include results from different ground- and satellite-based observations, covering different longitudes and years. We also present and discuss the modeling efforts that support most of the observations. Given that SSW can be forecasted with a few days in advance, there is potential for using the connection with the ionosphere for forecasting the occurrence and evolution of electrodynamic perturbations at low latitudes, and sometimes also mid latitudes, during arctic winter warmings.Item Open Access Perplexing atmosheric connections(Instituto Geofísico del Perú, 2009) Goncharenko, Larisa P.; Chau Chong Shing, Jorge Luis; Liu, Han-LiDiapositivas presentadas en 2009 Joint Assembly. The Meeting of the Americas. 24-27 May 2009. Toronto, Ontario, Canada.Item Restricted The August 2011 URSI World Day campaign: Initial results(Elsevier, 2015-11) Immel, Thomas J.; Liu, Guiping; England, Scott L.; Goncharenko, Larisa P.; Erickson, Phillip J.; Lyashenko, Mykhaylo V.; Milla, Marco; Chau Chong Shing, Jorge Luis; Frey, Harald U.; Mende, Stephen B.; Zhou, Qihou; Stromme, Anja; Paxton, Larry J.During a 10-day URSI World Day observational campaign beginning on August 1, 2011, an isolated, major geomagnetic storm occurred. On August 5, Kp reached values of 8− and Dst dropped to −113 nT. The occurrence of this isolated storm in the middle of a 10-day URSI World Day campaign provides and unprecedented opportunity to observe the coupling of solar wind energy into the magnetosphere and to evaluate the varied effects that occur in the coupled magnetosphere–ionosphere–thermosphere system. Dramatic changes in the ionosphere are seen at every one of the active radar stations, extending from Greenland down to equatorial Peru in the American sector and at middle latitudes in Ukraine. Data from TIMED and THEMIS are shown to support initial interpretations of the observations, where we focus on processes in the middle latitude afternoon sector during main phase, and the formation of a dense equatorial ionosphere during storm recovery. The combined measurements strongly suggest that the changes in ionospheric conditions observed after the main storm phase can be attributed in large part to changes in the stormtime thermosphere. This is through the generation of disturbance dynamo winds and also global neutral composition changes that either reduce or enhance plasma densities in a manner that depends mainly upon latitude. Unlike larger storms with possibly more sustained forcing, this storm exhibits minimal effects of persistent meridional stormtime wind drag, and little penetration of solar wind electric potentials to low latitudes. It is, therefore, an outstanding example of an impulsive event that exhibits longer-term effects through modification of the background atmosphere.