The Los Angeles Morning Glory



The Gulf of Carpenteria region of Australia is well known for spectacular sets of roll clouds that sometimes form, especially in the morning. This beautiful atmospheric condition has come to be known as the "Morning Glory" (see picture, courtesy of dropbears.com ). A change in pressure accompanies these clouds, thus making it possible to detect them with barometers.

It turns out that long-period seismometers are sensitive to the ground tilt that results from pressure changes. From examining seismograms in the Los Angeles Basin, we have found atmospheric waves similar to those in Australia and we therefore call them Los Angeles morning glory waves (Tsai et al., 2004). See publications section for details.