Weather Watch

Some pressure to download a weather app

Marbled godwits make pressure waves in Morro Bay.
Marbled godwits make pressure waves in Morro Bay.

In last week’s column, I wrote about weather forecast models that run on computers. These numerical models collect as much atmospheric information (pressure, humidity, temperature and wind) as possible throughout the world and perform calculations to mimic the motion of weather patterns in the chaotic atmosphere. The greater amount of accurate data that the model initializes or starts with, the better able it is to predict the weather in the future.

This atmospheric data comes from weather stations, weather balloons, marine buoys, ship and surface observations, aircraft, satellites and other oceanographic resources. In the near future, this information may come from your own personal cellphone.

Many people don’t realize it, but certain smartphones, such as the popular Galaxy III, collect air pressure observations, while most others have GPS installed.

Just think about that — millions of tiny barometers stretched across Earth, each one recording and reporting a treasure trove of atmospheric pressure and location data that could be used to vastly improve weather models.

Cliff Mass, an atmospheric scientist at the University of Washington, is working on assimilating this vast amount of pressure information into the models.

The strong invisible force of gravity accelerates trillions of air molecules toward Earth’s surface and produces weight. The weight of the air is what we feel as pressure.

According to Mass, “Surface pressure is a uniquely valuable surface observation since it reflects the atmosphere above. Recent research has revealed that with sufficient surface pressure sensors and a sophisticated model-based data assimilation system, one can accurately reconstruct the three-dimensional structure of the atmosphere.”

In other words, just by using pressure information, you can calculate the current wind at any given location and even pinpoint when and where a storm may strike.

A new company from Canada, Cumulonimbus Inc., has created a new Android app that collects pressure observations from these smartphones. They are currently sending thousands of pressure observations to the University of Washington per hour.

Recently, Cumulonimbus Inc. released a newer version of its app called PressureNet3, which includes graphics for seeing your own and others’ pressure observations. Their website is at www.cumulo

Mass encourages everyone with these cellphones to consider downloading the app. Personal information is not included in the database. One day, these smartphones may vastly improve weather forecasting and save lives.

•  •  •

PG&E delivers some of the nation’s cleanest power. Nearly 60 percent of the electricity the company provides to customers comes from sources that are renewable and/or emit no greenhouse gases.