|The large Galaxy S3 has a decent atmospheric pressure sensor.|
First, which smartphones have pressure sensors in them? Right now they are mainly Android 3 phones, including: the Galaxy Nexus, Galaxy S3, Galaxy Note, Galaxy Note II, Nexus 4, Nexus 10 and Xoom. Tens of millions of these phones have been sold worldwide, so there are undoubtedly millions in the U.S. alone. Millions of weather observatories, if only if they were collected in real time.
One company has stepped up to the plate: a small Canadian firm called, appropriately enough, Cumulonimbus Software. They have developed a nice app for the Android 3 phones called PressureNet2.1 that can be downloaded for free. This app accesses your
I have been talking to the developers of PressureNet2 and they said that thousands of folks signed up for their app before and during Hurricane Sandy hit the East Coast. Here is a plot of the smartphone pressure observations for an area of New York City during landfall. Amazing....you can see the pressure minimum and the calibrations were really quite good.
Pressure is a uniquely valuable observation...in many ways better than temperature or wind. Surface pressure expresses the state of the deep atmosphere, since it depends on the weight of the air above. Pressure doesn't have the same exposure "issues" as temperature (is the thermometer in the sun?) or wind (is the anemometer behind a tree or house?). Pressure sensor can be inside a house or outside...doesn't really matter since the pressure is essential the same. Pressure errors are generally easy to remove (e.g., elevation differences or errors in a particular barometer). And you can also use the pressure change information.
Even better a number of research groups include those at the UW are studying the use of new data assimilation methods to take advantage of pressure observations. (data assimilation is the combination of models and observations to produce the best possible three dimensional descriptions of the atmosphere. Data assimilation provides the starting point of weather forecasts done by computers). With Professor Greg Hakim and Graduate Student Luke Madaus we are testing the use of advanced ensemble-based data assimilation using surface pressure, with sophisticated quality control of the pressure observations. Here is an example of a Puget Sound convergence zone. You can see the radar an area of heavy precipitation over Seattle.
So imagine the possibilities.
Millions of surface pressure observations across the country EVERY HOUR, allowing us to define local scale features, such as the cold pools and dry lines associated with the initiation of severe convection. Using these observations we could radically improve our definition and description of fine-scale atmospheric features and short-term forecasts.
This could be a major advance in weather prediction technology. And then we can use the smartphones to provide folks with highly detailed and accurate forecasts at their location. so the benefits flow both ways.
Exciting times ahead!