I study the aquatic world off shore. How ocean water moves and mixes is often reduced to equations full of Greek symbols – I find it fascinating, but typically not relevant to the food producing ecosystem I’ve planted in the yard*. This year is different. I’m gambling on a hot summer like last year and here is why: (a detailed description can be found here and is where I got most of my information)
For those of us who live mid-latitude along the west coast of North America our weather is modulated by the ocean. Prevailing winds blow from the Pacific onto land. Since water holds heat better than land, our proximity to the ocean keeps us warmer than similar latitudes on the east coast (on the east coast the same winds blow from the land out to sea, so they don’t get the warming effect of the water).
In a ‘normal’ year the sun to warms surface waters over the summer. Then in the fall, strong winds create upwelling that brings up cold, deep water to cool the surface waters. The pattern then repeats.
In 2013, oceanographers (not me personally since my work is based in the Arctic) noticed that the surface of the north east Pacific was getting warmer than usual. That winter the winds were weaker, as a result not as much upwelling occurred and the water stayed warm into 2014. This is why last summer was so long and hot. This year, before the summer warming has even begun, water is still warmer than usual. This means there is a good chance that this summer will be another hot one.
Although a hot summer is potentially good news for my home pepper and eggplant production, there is a down side. Upwelling brings food (nutrients) up to where our coastal aquatic inhabitants can take advantage of it. Without upwelling our waters will not be as productive. Also, the warmer waters mean new fish are swimming north.
There are several large scale patterns that occur in the Pacific, such as el Nino, but this warming is something we haven’t observed before. We don’t know why this warming is occurring, or how long it will last, but oceanographers are working on figuring this out.
*there is a surprising number of oceanographers with kitchen gardens. At scientific meetings I’ve swapped seed potatoes, stories of squash harvests and even full-sized wintercress plants.
**photo is from here