The storm, tracked for the last week, created atmospheric phenomena recorded by instruments on the Curiosity rover, whose weather station instruments measured decreased air pressure and a slight rise in overnight low temperature, NASA Jet Propulsion Laboratory in Pasadena, Calif., reported Wednesday.
"This is now a regional dust storm. It has covered a fairly extensive region with its dust haze, and it is in a part of the planet where some regional storms in the past have grown into global dust hazes," said JPL chief Mars scientist Rich Zurek.
"For the first time since the Viking missions of the 1970s, we are studying a regional dust storm both from orbit and with a weather station on the surface."
Regional dust storms affected vast areas of Mars in 2001 and 2007, but not between those years nor since 2007, Zurek said.
"One thing we want to learn is why do some Martian dust storms get to this size and stop growing, while others this size keep growing and go global," Zurek said.