Maybe it’s the fog, or the rolling green landscape, or the distant echoes of a Celtic sensibility in which exuberant celebration in the face of inevitable affliction is a virtue. Whatever the reason, the musicians in Ireland’s leading traditional band Lúnasa find themselves drawn to Northern California. The group returns to Freight and Salvage on Nov. 14, Wednesday as part of a double bill with the rollicking Quebecois combo Le Vent Du Nord.

Lúnasa established a bond with the Bay Area as a young band just making an international name for itself in the late 1990s with an incendiary performance at the San Francisco Celtic Music Festival, but it really laid down roots here a decade ago in the weeks following the September 11 attacks. Rather than postpone their tour the band decided to play the dates that weren’t canceled, and during one of the resulting gaps in the schedule they ended up hanging out at their agent’s ranch near Sebastopol, a sylvan environment that seemed to stoke their creative energy.

“It was such a good experience we decided to record our next album in California,” says All-Ireland fiddle champion Sean Smyth, a founding member of the band. “So during our spring tour we came back and took 10 days in Prairie Sun Studio in Cotati. We were all staying in cabins, sitting among the trees putting music together.”

While the band acknowledged its source of inspiration by naming the album “Redwood” (Green Linnet), the Northern California landscape didn’t alter Lúnasa’s sound (the name comes from an ancient Celtic harvest festival in honor of the Irish god Lugh, patron of the arts).

Featuring Smith, flutist Kevin Crawford, uilleann piper Cillian Vallely, acoustic bassist Trevor Hutchinson, and the recent addition of Flook guitarist Ed Boyd, the instrumental quintet has won a passionate international following with its turbo-charged arrangements. While often compared to the Bothy Band, the sextet that revitalized traditional Irish music during its brief but brilliant run in the late 70s, Lúnasa has developed an innovative, streamlined sound powered by the dynamic rhythm section combo of Boyd’s percussive guitar chords and Hutchinson’s agile acoustic bass lines.

Lúnasa’s supple, streamlined sound hasn’t diminished the music’s terpsichorean imperative. With its full arsenal of jigs and reels, the band believes that traditional Irish music shouldn’t travel to far from its origins as fuel for communal celebrations. Without a vocalist, the group strikes a fine balance between delivering the exquisite, sweet melodies and the churning rhythms. For Smyth, “the energy between the musician and the dancer, that’s the heart of Irish traditional music. The melodies are very simple but very pure.”

While the band has incorporated tunes from far-flung Celtic lands into its repertoire, including pieces from Galicia and Cape Breton, they draw most of their material from childhood memories or impromptu jam sessions.

“There are situations when people just sit around in the pub playing tunes,” Smyth says. “If you’re going out for a pint, you bring the fiddle and sit in with whoever’s playing and you get exposed to different tunes in different parts of the country. That’s the biggest well we go to for music.”

The band wasn’t launched with any great ambitions. A doctor undergoing further medical training in London, Smyth decided to take a musical detour in 1996 when he was invited to tour in Scandinavia. Already an All-Ireland champion on both fiddle and tin whistle, he didn’t have much trouble recruiting Hutchinson and guitarist Donogh Hennessy, who were bandmates in the traditional Sharon Shannon Band. The trio was so well received and the chemistry was so promising they decided to stay together.While the band’s reputation grew quickly, it was only in 1999 that Lúnasa became a full-time project. At the end of the year the band released its Green Linnet debut “Otherworld,” which was hailed as both an artistic breakthrough and commercial triumph, becoming the fastest selling record in the label’s 25 year history.

The band spent much of last decade winning new converts to Irish music by touring internationally, for instance opening for the great South African ensemble Ladysmith Black Mambazo, and collaborating with Natalie Merchant. Bay Area residents might also remember the band for the central role it played in the San Jose Rep’s popular production of Marina Carr’s “By the Bog of Cats” starring Holly Hunter.

While the group is thrilled about introducing traditional Irish music around the globe, they don’t feel a need to bring the rest of the world into their music.

“This whole thing about fusion, take Caribbean and fuse it with Irish music and Irish music with jazz,” Smyth says, “somehow it doesn’t fit as well. We do explore Celtic music, tunes from Galicia and Brittany, but that’s still very close to what we do. That would be our experimentation.”

Founded in 2002, Le Vent du Nord (The North Wind) has played a central role in the recent resurgence of traditional music from Quebec. With all four musicians contributing vocals, Le Vent features a dynamic cast of multi-instrumentalists, including Nicolas Boulerice on hurdy-gurdy, acoustic guitarist Simon Beaudry, fiddler Olivier Demers, and Réjean Brunet on accordion. The Francophone ensemble earned a coveted Juno award for traditional an album of the year with its 2003 debut recording “Maudite moisson!” Playful and virtuosic, the band has compiled a treasure trove of dance tunes, rustic laments, work songs and cheerfully lascivious airs.