scholarly journals Phobos 2/ASPERA data revisited: Planetary ion escape rate from Mars near the 1989 solar maximum

2013 ◽  
Vol 40 (3) ◽  
pp. 477-481 ◽  
Author(s):  
Robin Ramstad ◽  
Yoshifumi Futaana ◽  
Stas Barabash ◽  
Hans Nilsson ◽  
Sergio Martin del Campo B ◽  
...  
Keyword(s):  
Solar Maximum ◽  
Escape Rate ◽  
Ion Escape

scholarly journals Planetary magnetic field control of ion escape from weakly magnetized planets

2019 ◽  
Vol 488 (2) ◽  
pp. 2108-2120 ◽  
Author(s):  
Hilary Egan ◽  
Riku Jarvinen ◽  
Yingjuan Ma ◽  
David Brain
Keyword(s):  
Magnetic Field ◽  
Effective Interaction ◽  
Three Dimensional ◽  
Power Laws ◽  
Wind Pressure ◽  
Escape Rate ◽  
Opening Angle ◽  
Plasma Environment ◽  
Ion Escape ◽  
Planetary Magnetic Field

ABSTRACT Intrinsic magnetic fields have long been thought to shield planets from atmospheric erosion via stellar winds; however, the influence of the plasma environment on atmospheric escape is complex. Here we study the influence of a weak intrinsic dipolar planetary magnetic field on the plasma environment and subsequent ion escape from a Mars-sized planet in a global three-dimensional hybrid simulation. We find that increasing the strength of a planet’s magnetic field enhances ion escape until the magnetic dipole’s standoff distance reaches the induced magnetosphere boundary. After this point increasing the planetary magnetic field begins to inhibit ion escape. This reflects a balance between shielding of the Southern hemisphere from ‘misaligned’ ion pickup forces and trapping of escaping ions by an equatorial plasmasphere. Thus, the planetary magnetic field associated with the peak ion escape rate is critically dependent on the stellar wind pressure. Where possible we have fit power laws for the variation of fundamental parameters (escape rate, escape power, polar cap opening angle, and effective interaction area) with magnetic field, and assessed upper and lower limits for the relationships.

scholarly journals Effects of the crustal magnetic fields on the Martian atmospheric ion escape rate

2016 ◽  
Vol 43 (20) ◽  
pp. 10,574-10,579 ◽  
Author(s):  
Robin Ramstad ◽  
Stas Barabash ◽  
Yoshifumi Futaana ◽  
Hans Nilsson ◽  
Mats Holmström
Keyword(s):  
Magnetic Fields ◽  
Escape Rate ◽  
Ion Escape

scholarly journals Heavy ion escape from Martian wake enhanced by magnetic reconnection

2021 ◽  
Author(s):  
Lei Wang ◽  
Can Huang ◽  
Yasong Ge ◽  
A. M. Du ◽  
Rongsheng Wang ◽  
...  
Keyword(s):  
Magnetic Reconnection ◽  
Flux Rope ◽  
Heavy Ion ◽  
Escape Rate ◽  
Wake Region ◽  
Atmospheric Evolution ◽  
Oxygen Ions ◽  
Plasma Environment ◽  
Ion Escape ◽  
Reconnection Region

Abstract How ion escape from the near-Mars space is one of the biggest puzzles for understanding the atmospheric evolution of Mars. Ions in the plasma wake region continuously escape from the unmagnetized planet. Although the average ion escape rate in the wake region is relatively low, observations also have revealed the presence of events that contribute bursty and enhanced ion escape fluxes. Boundary instabilities and magnetic reconnection are suggested to be the candidate mechanisms. However, there is a lack of evaluation of ion escape caused by reconnection and comparison of the two mechanisms under a similar plasma environment. Here, we show an exciting reconnection event in the Martian wake. Two types of flux ropes are observed during the event. One was generated by reconnection, while others were produced by dayside boundary instability and convected to tail. The escape rate of oxygen ions in the reconnection region was estimated to be about 53–72% of the total tailward escape. Furthermore, the escape flux in the flux rope produced by reconnection was over twice that caused by dayside instabilities.

scholarly journals The Martian atmospheric ion escape rate dependence on solar wind and solar EUV conditions: 1. Seven years of Mars Express observations

2015 ◽  
Vol 120 (7) ◽  
pp. 1298-1309 ◽  
Author(s):  
Robin Ramstad ◽  
Stas Barabash ◽  
Yoshifumi Futaana ◽  
Hans Nilsson ◽  
Xiao-Dong Wang ◽  
...  
Keyword(s):  
Solar Wind ◽  
Rate Dependence ◽  
Escape Rate ◽  
Mars Express ◽  
Ion Escape

The escape of CO2+ and other heavy minor ions from Mars

2020 ◽  
Author(s):  
Lukas Maes ◽  
Markus Fraenz ◽  
James McFadden ◽  
Mehdi Benna
Keyword(s):  
Mass Spectra ◽  
Heavy Ion ◽  
Escape Rate ◽  
Neutral Gas ◽  
Peak Fitting ◽  
Ion Escape ◽  
Fitting Method ◽  
Static Data ◽  
Martian Ionosphere ◽  
Ion Species

<p>Next to its main constituent O<sub>2</sub><sup>+</sup>, the Martian ionosphere consists of several other ion species, like CO<sub>2</sub><sup>+</sup>, O<sup>+</sup>, CO<sup>+</sup>, HCO<sup>+</sup>, N2<sup>+</sup>, etc. The ionospheric escape is dominated by O<sub>2</sub><sup>+</sup> and O<sup>+</sup> ions, and as a result the escape of these species is well studied. The other, minor ion species are more difficult to measure in the escaping plasma, because their contribution is typically obscured in the mass spectra of ion instruments by the more abundant O<sub>2</sub><sup>+</sup> peak.</p> <p>In this study we use data from the SupraThermal And Thermal Ion Composition instrument (STATIC) on board MAVEN to investigate the escape of these ions. We use a peak-fitting method to separate the contribution of several ion species, including O<sub>2</sub><sup>+</sup>, CO<sub>2</sub><sup>+</sup>, O<sup>+</sup> and ions with a mass between 28-30 AMU. Our method is validated against Neutral Gas and Ion Mass Spectrometer (NGIMS), also onboard MAVEN, and results in the ionosphere agree qualitatively very well.</p> <p>We apply this method to STATIC data from January 2016 until May 2019 to perform a statistical study examining the escape of low energy (<100 eV) heavy (>=16 AMU) ions throughout the Martian magnetosphere and its surrounding. We find that CO<sub>2</sub><sup>+</sup> ions do escape through the tail but at a very limited rate, namely at less than 1% of the O<sub>2</sub><sup>+</sup> escape rate. Ions with a mass between 28-30 AMU, however, are found to constitute a significant part of the ionospheric outflow, with an escape rate 30% of the O<sub>2</sub><sup>+</sup> rate and 15% of the total heavy ion escape.</p>

Coronal Mass Ejections and Solar Filament Disappearances at Solar Maximum

1994 ◽  
Vol 144 ◽  
pp. 127-129
Author(s):  
S. Dinulescu ◽  
G. Maris
Keyword(s):  
Coronal Mass Ejections ◽  
Solar Maximum ◽  
Solar Filament

AbstractOccurrence of CMEs as a result of solar filament disappearance is discussed over the cycle 22.

Increased transcapillary escape rate of albumin in nondiabetic men in response to hyperinsulinemia

Diabetes ◽  
1990 ◽  
Vol 39 (10) ◽  
pp. 1212-1217 ◽  
Author(s):  
J. E. Nestler ◽  
C. O. Barlascini ◽  
G. A. Tetrault ◽  
M. J. Fratkin ◽  
J. N. Clore ◽  
...  
Keyword(s):  
Escape Rate ◽  
Transcapillary Escape Rate

scholarly journals Myocardial extraction and retention of 2-iododesmethylimipramine: a novel flow marker

1986 ◽  
Vol 250 (6) ◽  
pp. H1060-H1070 ◽  
Author(s):  
S. E. Little ◽  
J. M. Link ◽  
K. A. Krohn ◽  
J. B. Bassingthwaighte
Keyword(s):  
Escape Rate ◽  
Flow Imaging ◽  
Rapid Loss ◽  
Ideal Flow ◽  
Regional Flow ◽  
Myocardial Flow

An ideal deposition marker for measuring regional flow is completely extracted during transcapillary passage and permanently retained. beta-Labeled desmethylimipramine ([3H]DMI) is a nearly ideal flow marker. To obtain gamma- and positron-emitting markers, DMI was iodinated to form 2-iododesmethylimipramine (IDMI). IDMI was more lipophilic than DMI. In isolated saline-perfused rabbit hearts its transorgan extraction was greater than 99%; and retention was greater than 98% at 5 min at mean flows of up to 3.5 ml X g-1 X min-1. During washout, the fractional escape rate was less than 0.1% X min-1 and was independent of flow. In isolated blood-perfused rabbit hearts, extraction was still 98%, but retention was as low as 86% after 5 min at a flow of 1.6 ml X g-1 X min-1. The fractional escape rate was up to 2% X min-1 but independent of flow. Despite this relatively rapid loss, regional IDMI deposition remains proportional to regional flow for many minutes. Therefore IDMI is useful as an externally detectable "molecular microsphere" for myocardial flow imaging in vivo.

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