SANTA ROSA -- February commercial passenger volume at the Charles M. Schulz--Sonoma County Airport declined by 0.3 percent compared to the same month in 2012, but has increased 15.5 percent since commercial flights returned to the airport in 2008, according to the airport's monthly passenger report.

[caption id="attachment_43320" align="alignleft" width="300"] Horizon Air Bombardier Q400 airplane parked at the Charles M. Schulz–Sonoma County Airport terminal[/caption]

A total of 14,944 passengers flew Horizon Air in February. Volume of flights originating outside of Santa Rosa totaled 49.2 percent of total flights.

Horizon Air, a subsidiary of Alaska Air Group (NYSE: ALK) and the airport's only commercial carrier, began offering commercial flights at Sonoma County Airport in March 2007. The regional carrier offered 140 flights last month, versus 134 in 2012.

The carrier offers five flights a day from Santa Rosa to Portland, Seattle, Los Angeles and San Diego, and will offer an additional Los Angeles flight this summer.

The airport recently issued notice that commercial flights will continue uninterrupted even if mandated federal budget cuts force the closure of the airport's air traffic control tower. Horizon operates at other regional airports without such facilities.