Photochemistry - Revision history

RichardWSmith: /* Nitrogen Photo-Dissociation */

2024-12-07T12:07:12Z

Nitrogen Photo-Dissociation

2024-12-07T12:06:20Z

Biography

2024-12-07T12:04:08Z

Edge of Space

2024-12-07T12:02:11Z

Sulphur & Chlorine Chemistries

2024-12-07T12:00:59Z

2024-12-07T11:59:01Z

Middle atmosphere

2024-12-07T11:53:33Z

Edge of Space

2024-11-29T05:04:44Z

Sulphur & Chlorine Chemistries: formatting

2024-11-29T05:04:10Z

Sulphur & Chlorine Chemistries

2024-11-29T05:03:35Z

Sulphur & Chlorine Chemistries

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 Note that NO<sub>2</sub> weakly dissolves in water, forming nitrous acid, and will be permanently lost to the atmosphere if it is absorbed in the soil.
 The presence of these nitrogen species act as a catalyst, helping to react CO and O<sub>2</sub> to form CO<sub>2</sub> and atomic Oxygen.
 ===Carbon Dioxide Photo-Disassociation===

← Older revision		Revision as of 12:06, 7 December 2024
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	==Biography==		==Biography==
		+	The Atmosphere and Climate of Mars, Cambridge Planetary Science, Edited by Robert M. Habgerle, et all, ISBN 978-1-107-01618-7.

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 ==Edge of Space==
-In the middle atmosphere, Extreme UltraViolet (EUV) is mostly absorbed by CO<sub>2</sub>.  In the upper atmosphere, surprisingly, it is most often absorbed by atomic oxygen.
+In the middle atmosphere, Extreme UltraViolet (EUV) is mostly absorbed by CO<sub>2</sub>.  Extreme UV is the highest energy UV light, blending into soft X-rays.  EUV can easily break molecular bonds.  In the upper atmosphere, surprisingly, it is most often absorbed by atomic oxygen.
 One difference is this region of Mars' atmosphere is directly heated by collisions by the solar wind.  Protons, atomic hydrogen, and helium nuclei collide with the atmosphere, heating it, and for a time becoming part of the atmosphere.  (Mars' gravity is so weak, that these are short lived additions to Mars' air.)

← Older revision		Revision as of 12:02, 7 December 2024
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	SO<sub>3</sub> + H<sub>2</sub>O + H<sub>2</sub>O --> H<sub>2</sub>SO<sub>4</sub> + H<sub>2</sub>O		SO<sub>3</sub> + H<sub>2</sub>O + H<sub>2</sub>O --> H<sub>2</sub>SO<sub>4</sub> + H<sub>2</sub>O

−	Sulphuric acid (H<sub>2</sub>SO<sub>4</sub>) can either condense at the surface, or be dissolved in water and enter the water table, being lost to the atmosphere. It has been estimated that the half life of sulphur compounds in the Martian atmosphere is ~2 years. This suggests that Martian vulcanism must be ~1,500 times less on Mars than on Earth.	+	Sulphuric acid (H<sub>2</sub>SO<sub>4</sub>) can either condense at the surface, or be dissolved in water and enter the water table, being lost to the atmosphere. It has been estimated that the half life of sulphur compounds in the Martian atmosphere is ~2 years. This suggests that Martian vulcanism must be at least ~1,500 times less on Mars than on Earth.

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 There are three major gases in the Martian atmosphere [[Carbon dioxide]] (CO<sub>2</sub>), [[Nitrogen]] (N<sub>2</sub>), and [[Water]] (H<sub>2</sub>O).  The major photochemistry in the Martian atmosphere are based on these.
-There are two areas where this occurs: the lower atmosphere (from UV light), and the edge of space (which has UV light, and also particles of the solar wind).  These are both discussed below.
+There are two areas where this occurs: the lower atmosphere (from UV light), the middle regions where the molecules are largely unionized, and the edge of space (which has UV light, and also particles of the solar wind).  These are all discussed below.
 Our current models of the Martian atmosphere overestimate the amount of CO, and underestimate the amount of O<sub>3</sub> by significant amounts.  This is an area of active research.

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 This region gets more Extreme UltraViolet light (EUV), so molecules are more easily broken apart.  At this height, few molecules are ionized.
-The highly energized molecules can lose this energy with collisions with other air particles, or they can radiate the energy away as light.  (This later is called, 'sky glow', and gives useful information about the amounts of various molecules and their energies at different heights in the atmosphere.)
+The highly energized molecules can lose this energy with collisions with other air particles, or they can radiate the energy away as light.  (This later is called, 'sky glow' or 'air glow', and gives useful information about the amounts of various molecules and their energies at different heights in the atmosphere.) (It is also called 'day glow' and 'night glow' based on time of day.)
-This superheated air causes winds, which helps move the warm day time air to the night side of the planet.
+Air glow is about 40% brighter when mars is at [[Perihelion]] simply because Mars gets more light when it is closest to the sun.
 ==Edge of Space==

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 ===The Methane Controversy===
 [[Methane]] (CH<sub>4</sub>) may have been detected on Mars.  (Most detections are at the error limits of the instruments finding it.)  If it does exist, it will be broken up by reacting with OH or O(<sup>1</sup>D).  Its expected lifetime in the atmosphere is ~300 years, so any methane formed will have plenty of time to be well mixed in the Martian atmosphere.  This makes the methane spikes found by Curiosity hard to explain, unless they took place very near the lander.
 ==Edge of Space==
 ==Biography==

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 These rapidly react:
 S + O<sub>2</sub> --> SO + O
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 Sulphuric acid (H<sub>2</sub>SO<sub>4</sub>) can either condense at the surface, or be dissolved in water and enter the water table, being lost to the atmosphere.  It has been estimated that the half life of sulphur compounds in the Martian atmosphere is ~2 years.  This suggests that Martian vulcanism must be ~1,500 times less on Mars than on Earth.
 Chlorine is likewise released by volcanoes, but perchlorates from the surface dust may also be a source in the Martian air.  Chlorine is removed from the air by this reaction:

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 SO<sub>2</sub> + hV --> SO + O
 SO + hV --> S + O
 These rapidly react:
 S + O<sub>2</sub> --> SO + O
 SO + O<sub>2</sub> --> SO<sub>2</sub> + O
 SO + OH --> SO2 + H
 SO + H<sub>2</sub>O --> OH
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 SO<sub>2</sub> + OH --> HSO<sub>3</sub>  (Using some other particle as a catalyst.)
 HSO<sub>3</sub> + O2 --> SO<sub>3</sub> + HO<sub>2</sub>
 SO<sub>3</sub> + H<sub>2</sub>O + H<sub>2</sub>O --> H<sub>2</sub>SO<sub>4</sub> + H<sub>2</sub>O