NHC director Proenza calls for new satellite

At a news conference last week, incoming National Hurricane Center director Bill Proenza issued a plea for new funding to replace the aging QuikSCAT satellite. Ocean surface winds measured by the QuikSCAT satellite are one of the most important sources of data used by hurricane forecasters, and losing the satellite would be a major blow. The QuikSCAT satellite's "SeaWinds" instrument emits a pulse of microwave energy that bounces off the ocean surface and returns to the satellite. The amount of microwave energy bounced back to the instrument is inversely proportional to how rough the sea surface is, and one can compute the wind speed and direction at the ocean surface based on this information. These measurements, performed twice per day over most of the Earth's surface, are the only reliable source of wind information for much of the remote ocean areas. As a result, this data is critical for the computer models that forecast hurricanes, since hurricanes typically move over data-poor ocean areas. Proenza estimated that without winds from the QuikSCAT satellite, two day hurricane track forecasts would be 10% worse, and three day forecasts 16% worse. I imagine that these increased errors would primarily affect weaker systems far from land, where we don't have data from the Hurricane Hunters. Still, the average cost of putting a single mile of the U.S. coast under a hurricane warning is about $1 million. These are the costs due to evacuation, preparation, and lost business before the hurricane's winds start to blow. Given that the average error in a two-day forecast was about 100 miles last year, even a 5% increase in hurricane track errors could add up to more than $100 million in false alarm costs in just a few years. Consider the case of 1999's Hurricane Floyd--2000 miles of coast were warned, resulting in over $1 billion in false alarm costs.


Figure 1. The NASA QuikSCAT satellite. Image credit: NASA Earth Observatory.

The QuikSCAT satellite was launched in 1999, and was originally scheduled for a two-year mission. The satellite is now entering its 8th year of operation, and is down to its backup sensors. QuikSCAT could fail at any time. A replacement would cost about $400 million dollars and take at least four years to construct and launch, according to Proenza. No replacement is currently planned. Funding a replacement QuikSCAT satellite is one of the most urgent hurricane-related funding issues Congress needs to address, and I'm pleased the new NHC director is drawing attention to this need early in his tenure.

I'll have a new blog on Wednesday.
Jeff Masters