An Ocean for All Seasons

Pumpkin Spice. Yummmmm. I wait every year for it. It signals the cooling of summer and the promise of jackets and boots. School is well underway and the remnants of summer dangle in the trees: gold, amber, and ruby. Well, it’s the idea of fall, and that it happens somewhere, that makes me happy. The blast of heat that hits my face at the coffee drive-thru window is a cruel reminder that fall doesn’t quite happen here the way I wish it would. I live in the desert of California where summer is eternal. (sigh)…Fall happens here for a second and then it’s gone, almost as fast as my pumpkin spiced latte!

While I lament the “barely-there” seasons as I sip my coffee, it’s nice to know seasons DO happen elsewhere - even in our oceans! In my quest to create the world of Enchantails, I always look for real world facts about the mysterious seas. I originally had no idea the oceans were as seasonal as the land above. The seasons above bring changes to the oceans below. Marine life, especially zooplankton, and phytoplankton which feed the animals of the ocean, are completely dependent upon these changes. Seasons regulate the sunlight, the day length, water temperatures and wind. All of these in turn affect our ocean currents, which
change with the calendar year.

We are used to four seasons on land, but there are actually only three seasons in the ocean: upwelling, oceanic, and winter storms. Spring and summer combine into one season known as “upwelling.” Upwelling occurs between March and August, when brisk spring winds move the churned up waters of winter from the deeper parts of the ocean. These tides spark photosynthesis in microscopic sea plants, known as phytoplankton. As the water temperatures warm, these phytoplankton bloom and feed the zooplankton (microscopic animals), which are the staple food for larger marine animals. Toward the end of August with the onset of fall, the phytoplankton supply depletes and the ocean currents begin to cease, signaling the
arrival of winter.

The “oceanic” season is the calm before the storm. From September to November, winds around the globe slow or reverse direction, causing the ocean to shift warmer waters towards the coastlines. The warm waters expand on the surface, and the deeper waters become denser. As the upwelling ceases, ocean nutrients become depleted from the surface and sink back into the depths. With the continuation of fall, the tides slowly begin to move faster, and larval fish and invertebrates are swept towards the coast lines. This draws out the deep sea creatures towards the shores. The deep waters begin to become colder as sunlight fades. The tides and
winds start to pick up at the end of fall, signaling winter.

“Winter storms” is the final oceanic season. From December to February, immense swells and winter squalls churn up the ocean, changing its chemistry. Ocean currents become stronger in the winter. Just like a snow globe when it is shaken, the ocean mixes vertically over depths of several hundred meters. Vertical mixing brings nutrients up from the bottom to the surface, feeding organisms like phytoplankton, which are depleted from summer. Limited sunlight around the globe preserves these surface nutrients until spring, when the phytoplankton can bloom.

As winter fades, the waters warm up, the tides begin to calm, and winter is swallowed up into upwelling once again… sort of like my pumpkin-spiced latte. The fine layers of my drink that were poured into the perfect assembling of coffee, milk, and whipped cream, jostle around my cup and blend into one last delicious sip, that I eagerly ingest. Mmmm…It’s not boots and jackets, but there’s nothing quite like the thrill of my once-a-year flavor. It’s the promise of my coming winter, which for me means 80 degrees instead of 100. Not quite the winter wonderland I wish for, but I’ll take it!

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