Especially on a cold winter day, Mark Ostapchuk's sunny abstractions lift the spirits with their jazzy, quilt-like patches of coral, lemon and aqua overlaid with painted chains and stripes in summery citrus hues. Filling a spacious gallery at the Minneapolis Institute of Arts, his paintings are a diverting antidote to the midwinter blues.

In a companion show next door, Chris Willcox evokes the minimalist landscape of Antarctica when European explorers first trekked across its frozen wastes a century ago. Her blue-gray landscapes, streaked with pale, lemony light, dwarf puny humans who confront nature's indifference with plucky determination.

Organized by the Minnesota Artists Exhibition Program, an artist-run curatorial department at the museum, the shows are a study in contrasts: colorful abstractions vs. monochrome vistas, busy patterns vs. empty expanses, dense layers of pigment vs. transparent veils of color. And so on.

Both artists are college instructors, and their shows also illustrate different sources of inspiration and ways of working. Ostapchuk, who teaches at the University of Minnesota, likens his abstractions to jazz, which suggests moods and emotions through an improvisational mix of sounds, textures, rhythms and thematic variations. Willcox, by contrast, was inspired by photos documenting polar expeditions from the so-called "Heroic Age of Antarctic Exploration." The shows run through April 1.

Standards: Mark Ostapchuk

Like a tropical holiday, Ostapchuk's paintings assault the senses with luscious colors and layered patterns. There aren't any recognizable forms -- no palm leaves or hibiscus blossoms -- yet the paintings evoke the balmy atmosphere of Southern California or the Côte d'Azur. Though abstract, his paintings glow with the kind of light that shimmers from David Hockney's early swimming pool paintings or Bonnard's luxurious hymns to the domestic pleasures of alfresco dining.

There's a repetitious quality to Ostapchuk's motifs that's limiting but not unpleasant. His 15 pictures have a lilting, almost hypnotic prettiness -- the sort of mind-buzzing effect caused by staring too long at Moroccan floor tiles, aerial maps or urban grids. He builds images by layering simple designs -- patches of coral interspersed with orchid ribbons, overlaid with mats of woven aqua, a nest of blue circles, a web of pale pink. Then he switches colors. Adds loops. Blocks out sections. Lets undertones bleed through. Repeats. And repeats.

By endlessly recycling basic motifs in variant colors, Ostapchuk is able to build paintings that range from notebook scale up to 6 feet wide and 4 feet tall. He claims they're inspired by everything from Henri Matisse's lush idylls to the playful ornamentation of Fragonard and Watteau. Such claims seem aspirational and a little far-fetched in the face of designs that could just as well be triggered by the intricate mazes printed on computer chips. These are pretty, seductive paintings worth enjoying for their own sake.

90° South: Chris Willcox

In previous series, Willcox established herself as a deft realist with an interest in edgy subjects (tornadoes, conjoined twins) and surrealistic contexts (infants in birds' nests, grimacing faces in swim helmets).

Her new subjects are fragments of history suspended in an existential miasma -- tiny tents pitched on bleak ice floes, spectral figures dissolving in snowy landscapes, a dangerously listing boat trapped in ice. The scenes are loosely derived from century-old photos taken by Antarctic explorers who endured ghastly privations, and in some cases died, in pursuit of the dubious glory of being first -- first to reach the South Pole, first to cross Antarctica.

With thin washes of ink and acrylic paint, she has created watery images that suggest the barren hopelessness of their quests and their enduring relevance. There's just enough realism to underscore the traumatic facts. With their ghostly figures and artful drips that echo glacial fissures, the paintings rip the fading images from the pages of adventure tales and update them into psychodramas of modern life. Think "Waiting for Godot" on ice.