A MAVEN investigation of O++ in the dayside Martian ionosphere
O++ is an interesting species in the ionospheres of both the Earth and Venus. Recent measurements made by the Neutral Gas and Ion Mass Spectrometer (NGIMS) on board the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft provide the first firm detection of O++ in the Martian ionosphere. This s...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Science Press
2020-01-01
|
| Series: | Earth and Planetary Physics |
| Subjects: | |
| Online Access: | http://www.eppcgs.org/article/doi/10.26464/epp2020009?pageType=en |
| _version_ | 1811218730590404608 |
|---|---|
| author | Hao Gu Jun Cui ZhaoGuo He JiaHao Zhong |
| author_facet | Hao Gu Jun Cui ZhaoGuo He JiaHao Zhong |
| author_sort | Hao Gu |
| collection | DOAJ |
| description | O++ is an interesting species in the ionospheres of both the Earth and Venus. Recent measurements made by the Neutral Gas and Ion Mass Spectrometer (NGIMS) on board the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft provide the first firm detection of O++ in the Martian ionosphere. This study is devoted to an evaluation of the dominant O++ production and destruction channels in the dayside Martian ionosphere, by virtue of NGIMS data accumulated over a large number of MAVEN orbits. Our analysis reveals the dominant production channels to be double photoionization of O at low altitudes and photoionization of O+ at high altitudes, respectively, in response to the varying degree of O ionization. O++ destruction is shown to occur mainly via charge exchange with CO2 at low altitudes and with O at high altitudes. In the dayside median sense, an exact balance between O++ production and destruction is suggested by the data below 200 km. The apparent discrepancy from local photochemical equilibrium at higher altitudes is interpreted as a signature of strong O++ escape on Mars, characterized by an escape rate of 6×1022 s–1. |
| first_indexed | 2024-04-12T07:14:20Z |
| format | Article |
| id | doaj.art-dcc13b1e489b41f59f56d8098e2ce355 |
| institution | Directory Open Access Journal |
| issn | 2096-3955 |
| language | English |
| last_indexed | 2024-04-12T07:14:20Z |
| publishDate | 2020-01-01 |
| publisher | Science Press |
| record_format | Article |
| series | Earth and Planetary Physics |
| spelling | doaj.art-dcc13b1e489b41f59f56d8098e2ce3552022-12-22T03:42:33ZengScience PressEarth and Planetary Physics2096-39552020-01-0141111610.26464/epp2020009guhaoA MAVEN investigation of O++ in the dayside Martian ionosphereHao Gu0Jun Cui1ZhaoGuo He2JiaHao Zhong3State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau 999078, ChinaSchool of Atmospheric Sciences, Sun Yat-sen University, Zhuhai Guangdong 519082, ChinaSchool of Atmospheric Sciences, Sun Yat-sen University, Zhuhai Guangdong 519082, ChinaSchool of Atmospheric Sciences, Sun Yat-sen University, Zhuhai Guangdong 519082, ChinaO++ is an interesting species in the ionospheres of both the Earth and Venus. Recent measurements made by the Neutral Gas and Ion Mass Spectrometer (NGIMS) on board the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft provide the first firm detection of O++ in the Martian ionosphere. This study is devoted to an evaluation of the dominant O++ production and destruction channels in the dayside Martian ionosphere, by virtue of NGIMS data accumulated over a large number of MAVEN orbits. Our analysis reveals the dominant production channels to be double photoionization of O at low altitudes and photoionization of O+ at high altitudes, respectively, in response to the varying degree of O ionization. O++ destruction is shown to occur mainly via charge exchange with CO2 at low altitudes and with O at high altitudes. In the dayside median sense, an exact balance between O++ production and destruction is suggested by the data below 200 km. The apparent discrepancy from local photochemical equilibrium at higher altitudes is interpreted as a signature of strong O++ escape on Mars, characterized by an escape rate of 6×1022 s–1.http://www.eppcgs.org/article/doi/10.26464/epp2020009?pageType=enmarsionospheredoubly ionized oxygenmaven |
| spellingShingle | Hao Gu Jun Cui ZhaoGuo He JiaHao Zhong A MAVEN investigation of O++ in the dayside Martian ionosphere Earth and Planetary Physics mars ionosphere doubly ionized oxygen maven |
| title | A MAVEN investigation of O++ in the dayside Martian ionosphere |
| title_full | A MAVEN investigation of O++ in the dayside Martian ionosphere |
| title_fullStr | A MAVEN investigation of O++ in the dayside Martian ionosphere |
| title_full_unstemmed | A MAVEN investigation of O++ in the dayside Martian ionosphere |
| title_short | A MAVEN investigation of O++ in the dayside Martian ionosphere |
| title_sort | maven investigation of o in the dayside martian ionosphere |
| topic | mars ionosphere doubly ionized oxygen maven |
| url | http://www.eppcgs.org/article/doi/10.26464/epp2020009?pageType=en |
| work_keys_str_mv | AT haogu amaveninvestigationofointhedaysidemartianionosphere AT juncui amaveninvestigationofointhedaysidemartianionosphere AT zhaoguohe amaveninvestigationofointhedaysidemartianionosphere AT jiahaozhong amaveninvestigationofointhedaysidemartianionosphere AT haogu maveninvestigationofointhedaysidemartianionosphere AT juncui maveninvestigationofointhedaysidemartianionosphere AT zhaoguohe maveninvestigationofointhedaysidemartianionosphere AT jiahaozhong maveninvestigationofointhedaysidemartianionosphere |