Visibility(A proposal to add another important weather paramether - Visibility. The visibility parameter tells you how far can you see other objects, due to the atmosphere conditions, mainly dust. It's in meter units. It can be as big as 70 km [record on Earth] or 0 m. Visibility can be a random parameter which would make sometimes harder for players to navigate, cousing dust-fog (not a dust storm). If there is a dust-storm the visibility would drop significantly. Due to the visibilit parameter, players wouldn't be usualy be able to see as far as the horizon goes. If visibility is bad at the moment, players would simply stay in shelter, and wait untill it passes. If good - it would encurage them for longer trips).
(http://img28.imageshack.us/img28/381/visibility2.jpg) (http://tomsastroblog.com/images/mars072107B.jpg)
Visibility is a random parameter, that one day could be perfect, and on the other it would be near zero.
Visibility on Mars is mainly minimalized becouse of the dust.
Certain events can lover the visibility - mainly Dust Storm, which raises the dust from the ground. At that point, the visibility can be near zero meters.
But regardles if ther's a dust storm or not - mars atmosphere contains aiborn dust particles, constantly floating in the air. At some point there are more of them, and on the other there are less. Those changes in the visibility are totaly random from our point of view, and it may happen that at one point that there are lot's of dust particles in the air...so much that regardles if ther's a dust storm or not, there is a fog.
This fog can be very dangerous when outside, becouse if you lost radio-contact, you won't be able to get back to the base.
Becouse of the random visibility parameter changes, players will decide not to go outide just yet...wait an hour or so for the air to clear.
On the other hand - if the visibility is perfect! it may encourage players to make long-distance escapades.
In meteorology, visibility is a measure of the distance at which an object or light can be clearly discerned. It is reported within surface weather observations and METAR code either in meters or statute miles, depending upon the country. Visibility affects all forms of traffic: roads, sailing and aviation. Meteorological visibility refers to transparency of air: in dark, meteorological visibility is still the same as in daylight for the same air.
http://en.wikipedia.org/wiki/Visibility (http://en.wikipedia.org/wiki/Visibility)
Example: visibility graph
http://www.tceq.state.tx.us/assets/public/compliance/monops/air/sigevents/02/020618-saa-k.gif (http://www.tceq.state.tx.us/assets/public/compliance/monops/air/sigevents/02/020618-saa-k.gif)
The international definition of fog is a visibility of less than 1 kilometre (3,300 ft); mist is a visibility of between 1 kilometre (0.62 mi) and 2 kilometres (1.2 mi) and haze from 2 kilometres (1.2 mi) to 5 kilometres (3.1 mi). Fog and mist are generally assumed to be composed principally of water droplets, haze and smoke can be of smaller particle size; this has implications for sensors such as Thermal Imagers (TI/FLIR) operating in the far-IR at wavelengths of about 10 μm which are better able to penetrate haze and some smokes because their particle size is smaller than the wavelength; the IR radiation is therefore not significantly deflected or absorbed by the particles.
- wikipedia (Note that an IR camera that an astronaut has on his EVA-suit would be perfect to use at that time ;) )
Earth during extremely poor visiblity, cousing fog:
http://images.smh.com.au/2009/09/23/747806/rae-dust3-600x400.jpg (http://images.smh.com.au/2009/09/23/747806/rae-dust3-600x400.jpg)
Mars base during meduim-poor visibility (not encuraging for long distance walk):
http://library.thinkquest.org/C007571/images/base.jpg (http://library.thinkquest.org/C007571/images/base.jpg)
Mars terrain during quite good visibility:
http://www.thelivingmoon.com/43ancients/04images/Mars4/Seminole_L257atc-A677R1/Fog_001.png (http://www.thelivingmoon.com/43ancients/04images/Mars4/Seminole_L257atc-A677R1/Fog_001.png)
Mars terrain during superb visibility (ecuraging for long distance escapades):
http://spacegizmo.livingdazed.com/wp-content/uploads/2009/09/Mars-Fog-Small.jpg (http://spacegizmo.livingdazed.com/wp-content/uploads/2009/09/Mars-Fog-Small.jpg)