Low Pressure
Low Pressure Systems From International Space Station (ISS) cupola window, astronauts have a field of view stretching as much as 1,000 miles (1,600 kilometers).

Low Pressure Systems

The cupola is a panoramic control center for the ISS—a dome-shaped module with windows for observing and guiding robotic operations outside of the station. The 360-degree view also allows for observing the Earth and celestial bodies.

In these astronaut photographs from the cupola—taken one minute and thirteen seconds apart on March 20, 2011—two distinct cyclonic vortices whirl within an area of low pressure that spanned the Pacific coast from southern California to Vancouver Island. Part of one of the ISS solar arrays also is visible at image upper left in both images.

The vortices indicate the positions of two storm systems located within a broad area of low pressure over the northeastern Pacific Ocean. Through a process known as cyclogenesis, rotating cyclonic weather systems develop, mature, and dissipate along the frontal zones between different air masses. The smaller of the two systems (upper image) displays a dense cloud pattern and arcing band of convection, indicating a young, developing cyclone. The diffuse cloud pattern of the larger system (middle image) indicates an older, dissipating system. The accompanying Geostationary Operational Environment Satellite (GOES-11) image illustrates the relative positions of both storm systems.