The importance of neutral hydrogen for the maintenance of the midlatitude winter nighttime ionosphere: Evidence from IS observations at Kharkiv, Ukraine, and field line interhemispheric plasma model simulations

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378289%3A_____%2F16%3A00461584" target="_blank" >RIV/68378289:_____/16:00461584 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1002/2016JA022442" target="_blank" >http://dx.doi.org/10.1002/2016JA022442</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/2016JA022442" target="_blank" >10.1002/2016JA022442</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The importance of neutral hydrogen for the maintenance of the midlatitude winter nighttime ionosphere: Evidence from IS observations at Kharkiv, Ukraine, and field line interhemispheric plasma model simulations

Popis výsledku v původním jazyce

This study investigates the causes of nighttime enhancements in ionospheric density that are observed in winter by the incoherent scatter radar at Kharkiv, Ukraine. Calculations with a comprehensive physical model reveal that large downward ion fluxes from the plasmasphere are the main cause of the enhancements. These large fluxes are enabled by large upward H+ fluxes into the plasmasphere from the conjugate summer hemisphere during the daytime. The nighttime downward H+ flux at Kharkiv is sensitive to the thermosphere model H density, which had to be increased by factors of 2 to 3 to obtain model-data agreement for the topside H+ density. Other studies support the need for increasing the thermosphere model H density for all seasons at solar minimum. It was found that neutral winds are less effective than plasmaspheric fluxes for maintaining the nighttime ionosphere. This is partly because increased equatorward winds simultaneously oppose the downward H+ flux. The model calculations also reveal the need for a modest additional heat flow from the plasmasphere in the afternoon. This source could be the quiet time ring current.

Název v anglickém jazyce

The importance of neutral hydrogen for the maintenance of the midlatitude winter nighttime ionosphere: Evidence from IS observations at Kharkiv, Ukraine, and field line interhemispheric plasma model simulations

Popis výsledku anglicky

This study investigates the causes of nighttime enhancements in ionospheric density that are observed in winter by the incoherent scatter radar at Kharkiv, Ukraine. Calculations with a comprehensive physical model reveal that large downward ion fluxes from the plasmasphere are the main cause of the enhancements. These large fluxes are enabled by large upward H+ fluxes into the plasmasphere from the conjugate summer hemisphere during the daytime. The nighttime downward H+ flux at Kharkiv is sensitive to the thermosphere model H density, which had to be increased by factors of 2 to 3 to obtain model-data agreement for the topside H+ density. Other studies support the need for increasing the thermosphere model H density for all seasons at solar minimum. It was found that neutral winds are less effective than plasmaspheric fluxes for maintaining the nighttime ionosphere. This is partly because increased equatorward winds simultaneously oppose the downward H+ flux. The model calculations also reveal the need for a modest additional heat flow from the plasmasphere in the afternoon. This source could be the quiet time ring current.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

DG - Vědy o atmosféře, meteorologie

OECD FORD obor

—

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Geophysical Research: Space Physics

ISSN

2169-9380

e-ISSN

—

Svazek periodika

121

Číslo periodika v rámci svazku

7

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

13

Strana od-do

7013-7025

Kód UT WoS článku

000383422100071

EID výsledku v databázi Scopus

2-s2.0-84990234373