Wednesday, December 7, 2011

sunlight, frost, rime ice, climate change

We've had a full week of thermal inversion here in Seattle, with sprinkles of sunshine, fog and frost.  The freezing level has retreated to 11,000 feet, below the summit of 14,410 Mt. Rainier, except it is "on the deck" in the passes at 3,000 to 4,000 feet.  We get great, thick pea soup fogs at night, that begin to freeze just before dawn.  Morning driving is hazardous and our usual commute snarl has gotten much worse.

 Yesterday, on a walk at Tiger Mountain, I was delighted with the frozen fog on foliage, quickly thawing in the morning sun.

This phenomenon is called "rime."  It doesn't happen only on this small scale -- summits of the Great Northwest westernmost Peaks, like volcanic Mt. Shasta, often are covered with rime ice from the moisture laden winds that come in from the Pacific and condense as they rise to go inland.  When I climbed Shasta in 1996, the entire summit looked like a big, frozen cauliflower -- today, sadly, climate change has left Shasta mostly snow and ice free.  This is true of all the great summits and glaciers I have known; they have become noticeably bare in just the last 10 years.  Glaciers have retreated as ablation zones grow wider.  Climbing routes now entail slogging through loose dirt, mud and stone before getting onto any proper mountaineering ground.

Still, on  a pretty, frosty morning, lower down, you can see the rime ice making beautiful lace of the winter leaves and grasses, ephemeral as it is, appreciate the beauty, and hope we can turn ourselves around in time to save ourselves and the great glaciers and summits that are the top of our watershed, where the winter snows and ice save the waters for us until summer.

The day before, on a walk in woodland Meadowdale Park, the sunlight slanted through the canopy and shone through maple leaves, sword fern, and Oregon grape.  The woodland floors in the Northwest are incredibly dense, and evolved shaped by moisture that rolls in from the sea through the high canopies of fir, hemlock, and  lowlands maple and alder -- all have lived and worked together to provide pure, clean water and bless us and our rivers with pure and abundant water, trout and salmon.  What will become of this wealth if we steal it away?  You cannot hold it in your hands, yet it shapes your life, each day.

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