The paper focuses on the south eastern edge of Sputnik Planum (SP) where I have encircled what appears to be an impact site (red arrows labeled 1) circular edges seem to rise from below SP nitrogen methane fluid mix.
Originally, I thought these circular features were left behind by impacts but with this new view it appears as though the circles are bits of eroded mountain peaks accumulating in patterns that match the fluid's flow pattern.
This is part of the Eastern Uplands. There are many lakes created by the run off fluid.
Here's a quote from The Paper.
The ancient uplands surrounding SP to the west, north, and northeast feature a variety of erosional morphologies, primarily expressed as linear depressions, broadly described here as valleys, but genetic implication.
They are careful to explain how depressions are loosely described as valleys, rather than making broad references to tectonics or rifts and such, they express caution when describing a depression as a valley.
I decided to draw arrows to show how I perceive the fluid on SP is moving.
It displays a couple interesting things. The south eastern area of SP is where we see smaller icebergs which previously, I thought were traveling toward the eastern land called the uplands. Now it appears these icebergs have been eroded off the eastern uplands/wetlands and are floating off into SP leaving behind circular patterns in the fluid.
Icebergs still clump and cluster in low pressure zones called troughs on the surface of SP but they apparently are moving in the opposite directions from what I thought previously. That suggest these icebergs are being swallowed or dissolved into the viscous nitrogen material as they migrate toward its center.
Along the western edge where large chunks of land ice are eroded (circled in yellow), the flow pattern suggest these icebergs are carried south and north until they collided with land.
SP is bounded by elevated ridges or walls.
In the South East the nitrogen fluid sublimates creating an atmosphere then travels eastward accumulating on upland peaks and runs back to the lowlands of SP.
To the north the fluid is trying to flow out of SP onto a beach like land.
To the west the fluid is eroding massive chunks of ice off the land wall. where the fluid is deepest.
One interesting feature to me is how the sublimated nitrogen methane mix has spread out eastwards into the uplands/wetlands but there is no sign of this sublimated then condensed material on the western land ice which instead is covered in red tholin.
If you're not familiar with the adiabatic lapse rate, its the rate at which air cools as it rises. When warm moist ocean air travels onto land and up mountain ranges it cools 3 degrees Fahrenheit for every thousand feet it rises in elevation.
This causes the moisture to condensate out of the air turning it into rain. This process is similar to what you see with moisture condensing onto a cold glass of ice water on a hot humid summer day.
The mountains cause the air to rise and cool, in turn, wringing out the water from the air, this leaves one side of a mountain range dry, arid and desert like while the other side is wet, green and lush.
Here is an image of the Andes mountain range showing how clouds develop on one side of the mountain range wringing out the moisture such that the land to the left is dry and barren.
This is very similar to the processes observed at the eastern side of Sputnik Planum in an area we are now calling the uplands/wetlands.
This line of thought makes me think the nitrogen fluid at SP while evaporating is not really rising much, its more like a fog but not foggy in other words it hangs near the surface but somewhat elevated above it.
As Pluto turns this nitrogen rich gas collides with raised land. As the land forces the gas to rise higher it cools and condenses turning back into a fluid which runs down the elevated surfaces and back into SP.
Just south of Sputnik Planitia at the Sun lit vs dark side is the terminator line within this area you can see foggy long shadows indicating how there is a mist in the atmosphere and the sun light cast shadows as we also see on earth.
This is Pluto's version of fog or mist or clouds which can be wrung out and dried of its moisture by condensation via adiabatic processes.
This whole thought process forces me to conclude, the jagged edged landscape east of the Uplands/Wetlands (outlined in pink) aka Tartarus Dorsa is likely Pluto's version of a high altitude desert with dunes.
The smooth rolling dunes or hill like formations with sharp jagged edges mimic what we see from dunes here on Earth.
Pluto's version of wind infused nitrogen gas travels from off the surface of SP collecting gasses.
The land rotates underneath the gasses pushing them upwards along elevated peaks condensing and stripping the atmosphere of the low lying nitrogen gasses (Pluto's version of moisture).
The Desert Dunes become a byproduct of that dry stripped arid atmosphere as methane snow accumulates slowly in this zone.
Well that's my guess and I'm sticking with it until a better description comes along.
I'm calling it the Desert Dunes. there have been several attempts to explain the snake skin look of these rolling dunes but I believe this is the best I've heard yet.
It fits what we see on Earth, it matches the terrain, it makes sense.
This area called Tartarus Dorsa is my "Desert Dunes".
In January 2017 (9 months after writing this page) NASA described this spiky bladed terrain aka Tartarus Dorsa as Penitentes.
Penitentes develop on Earth at high elevations where it is arid and cold. These conditions allow for slow accumulation of snow deposits with dry air and sun light which can then sublimate the snow from a solid to a gas without any trace of fluid. These seem to be ripe conditions for Penitente development. Arid, high and sun lit.
A key difference between Penitentes on Earth and those observed on Pluto are the multitude of lakes dotting Pluto's landscape at the base of the Penitentes. The land ice on Pluto is soft yet rigid as there are no obvious impacts in this area.
The lake looking area's suggest their is a warmish fluid which fills the cracks or more likely this fluid is where impacts have occurred and this gray material has oozed up to fill and flatten the terrain at the points of impact. The lakes seem to only exist in the southern section of Tartarus Dorsa whereas to the north the lakes completely disappear but signs of impacts then do appear.
The tall spikes of ice demonstrate a rigid strength however the gravity on Pluto is much less than on Earth so these Penitentes don't have to be as strong to maintain long straight forms.
No impacts indicate the land is capable of absorbing impacts then filling over on short time scales yet the land is firm enough to support tall ice crystals.
This seems to suggest the southern portion of Tartarus Dorsa is softer than the northern portion.
On page 63, I explain why I think the underbelly of the Wetlands is softened whereas the northern portion is not as much so, it has to do with fluids of N2 flowing from Venera Terra in the NW into SP and SE into the Wetlands.
Penitentes on Earth tend to form in dry arid cold high elevated areas this allows for sublimation but occasionally they also exist around bodies of water or liquids like we see on Pluto.
Here's some desert dunes on Earth. Looks similar, dry, arid wind swept small particles of sand or silica, I wonder what the sand equivalent on Pluto is? Perhaps small particles of water ice that look like silica rock or sand on Earth.
The only difference between these desert dunes and the ones we see on Pluto is temperature, these dunes are hot Pluto's are cold.
On Earth the Antarctic is considered a desert since it's annual snowfall aka precipitation is less than 10cm (4in) per year.
These images of concentrations of various materials at various sites indicates the material on the Desert Dunes is primarily Methane with some Nitrogen which has been stripped mostly dry of Carbon Monoxide and water.
There are seasons on Pluto which would allow for times of more dense atmospheric conditions while at other times the atmosphere will have less volatiles in it.
The atmosphere will have more or less gasses in it depending on the season. Each season last 62 years. These climatic changes could create the wind swept and sharp angular cuts in the peaks of Pluto at the Desert Dunes area.
The bladed landscape on Pluto east of the Uplands/Wetlands looks and feels like a desert to me especially in light of the mountain peaks creating the wetlands facing SP.
In this image we can see a little bit beyond the eastern horizon. We can see that the Desert Dunes extend further beyond what can be seen in the above images.
The troughs that make up the valleys of the Desert Dunes align with a feature that is being referred to as a Spider.
We can also see that some of the spider's legs are in fact valleys within the Desert Dunes.
This suggest that the dry arid environment at this location is causing the land ice to pucker and fracture.
These thoughts below about the seasons are not strictly my own, they are my thoughts mingled with some thoughts expressed by Richard P Benzil and Alan Stern at the 47th Lunar and Planetary Science Conference (2016)
I may not have given enough consideration to the seasons of Pluto. Here on Earth each season last three months, whereas, on Pluto each season last 62 years.
Pluto's axial tilt ranges from 102 to 126 degrees this 24 degree axial wobble is known as axial precession or Milankovitch cycles. At some point in time the south pole is aimed directly at the Sun when Pluto is closest to the Sun. This causes wide variations in the atmospheric pressures. Along the equator and below is where Pluto feels its summer Sun shine. The Southern hemisphere receives the vast majority of the summer Sun UV radiation energy.
Atmospheric pressures change drastically on Pluto from season to season and from the wobble of its axis. When New Horizons flew by Pluto the atmospheric pressure was around 10 micro-bars but it can be a thousand to ten thousand times higher. On Earth we experience one bar of atmospheric pressure at sea level.
When Pluto is in its summer closest to the Sun at perihelion, the UV radiation cause the environment to be such that nitrogen reaches its triple point, meaning it can actually become a liquid not a soft solid or a gas but actually a liquid which is likely what we see in these images.
When Pluto returns to its winter season or farthest from the Sun at aphelion, lakes like the ones seen in these images likely freeze solid. This is likely occurring at the uplands/wetlands as well as at the south pole area where the UV radiation from the Sun has the greatest impact.
While Pluto is in its summer time, nitrogen can reach triple point on Sputnik Planum and at the south pole, the nitrogen then acts like water vapor and/or rain seen as runoff which creates the tributaries, rivers and lakes.
Pluto cycles out of summer into fall slowing the process then finally into winter freezing the scene and lowering the atmospheric pressure. Throughout each season the atmospheric pressure changes significantly.