The winds of Mars, and the dust storms that aren't anymore

Something has been puzzling me for a long time, and once again the puzzle got reawakened a bit, when reading the article
http://www.sciencenews.org/view/generic/id/56221/title/Bouncing_sands_explain_Mars_rippled_surface "Bouncing sands explain Mars' rippled surface - Study finds dunes and ridges can form without much wind"

I was working as a contract electronic technician at the Jet Propulsion Laboratory back in 1972-73, working in the Space Sciences building next to the Von Karman Auditorium. The first pictures were coming in from the earlier Mariner Mars '69 spacecraft freshly arriving in orbit around Mars, and sending back the first pictures it was taking. Typical photos were occasionally printed on plain orange colored paper along with some scientific info, and placed as handouts for employees to pick up if interested. The first photo on such a sheet of paper showed a planet blurred out, all except for the very peak of Olympus Mons, the highest volcanic mountain on the planet. All else was just a blur, a spherical blurry ball in space.

It was announced that Carl Sagan was going to give a talk in the Von Karman Auditorium, so I took a break and wandered next door and took a seat.

Carl Sagan got on stage and began to talk, telling about the spacecraft that had just gone into orbit around Mars, MM '69, taking photos and radioing them back to here. And what they saw was a dust storm seven miles high driven by 200 mph winds, incredibly cold down there.

Carl, in his entertaining way, went on to relate that when he was a boy, he was fascinated by reading Edgar Rice Burroughs' "John Carter of Mars" science fiction novels, where the hero would just meditate and suddenly be transported to Mars where his earth gravity conditioned muscles were far superior to the people living there and he was ever winning spectacular battles with those folks of Mars. So, as that boy, Carl would sometimes go out into the night and look up at the speck that was the red planet, and meditate as hard as he could, but no matter how hard he tried, he never could get transported to Mars.

And now, he continued, finding a Mars with 200 mph winds driving a seven mile high dust storm covering the planet, extremely cold and only thin carbon dioxide for an atmosphere, he was sure glad that the meditation did not work!

As the weeks went by, there at JPL, the photos that MM'69 was sending back continued to show a planet totally covered by a raging dust storm blotting out just about everything. It took a long time before more of Olympus Mons became visible, then slowly other high altitude features started showing up. Seems like it took months for the surface details to become visible.

In the 37 years since then, I have maintained a casual interest in the photos that have come back from Mars, from orbit and from on the ground. Nice, sharp photos, only limited by the capability of the cameras and optics. No dust storms.

No mention of even a teeny dust storm since then.

A few small brief twisters were photographed at one time. Some dust reported collecting on solar panels, with not enough breeze to blow the dust off sometimes.

Prior to MM'69's arrival at Mars, there had been lots of observations of Mars via earth-based telescopes, with detail enough to provide imagination for the astronomer Lowell to draw networks of canals thought to be used for irrigation on Mars. So a blurred out planet was not evident way back, either.

Where have the huge dust storms been, since the one that coincided with our first arrival to get a good look at Mars, hiding it for a long time? It is nice that they are gone, of course. But something ... just seems a bit odd about it all, to me.