Seaside signs of spring ~ color on dunes, birds on nests ~ wind-ruffled ocean

Spring along the edge of Monterey Bay is colorful, lusty and cold. Drab sand dunes gain dabs of color from flowering paintbrushes, lupines and seaside daisies. Songbirds and shorebirds brighten for courting and mating, build nests and busily nourish young. And the wind blows strong and cold. Our iconic sign of spring is the northwesterly wind.

This spring has been one of the windiest I recall. For weeks, we’ve had fairly steady 15 to 20 mph (13 – 17 knot) winds. From my window the bright blue sky entices me outside, but on a coast walk I get buffeted by cold winds until my bones chill. On the water, swells are fairly small (usually less than 4 feet or 1.2 m), but when combined with choppy wind waves that start building around 10 a.m., kayaking can get rough (I’m not a windy-water kayaker).

The northwesterly winds form along the boundary of low pressure that sits in the Gulf of Alaska and high pressure over the Pacific off California (called the Pacific High). Each morning we think we’ll get a reprieve when mild morning breezes flow offshore, but as the sun warms the land, the flow reverses, pulling onshore a cold wind that strengthens as the day progresses.

Although the strong winds are tough on beach walkers, kayakers and surfers, they’re great for sailors, kiters and whales. Because of the wind direction and the Coriolis effect, surface waters move to the right of the wind direction, that is, move offshore (not intuitive). This opens space along the coast for deep, cold ocean water to surface. The upwelling of deep nutrient-rich water feeds plankton blooms. Like blooming sand dunes plants, plankton blooms not only add color to the ocean but also food for a variety of plankton feasters — from krill and fishes to seabirds and whales. This is when humpback whales and blue whales arrive to scoop up giant mouthfuls of krill and fish (although the humpbacks arrived early this year).

This is also a great time of year for raising young along the shore. With so much food in the bay, nesting cormorants can find fish for hungry chicks and just-weaned harbor seal pups can practice their hunting skills. So although the winds restrict some of my fun, it’s a high-flying time for wildlife in and around the bay.

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Sources

NOAA Ocean Explorer: Upwelling

Seasons in the Sea: April and May

SIMoN Archives: Upwelling Along the Central California Coast

Resources

Pitcher,  G.C. et al. (2010). The physical oceanography of upwelling systems and the development of harmful algal blooms. Progress in Oceanography 85(1-2): 5-32.