Daily Archives: January 18, 2010

Fog

There’s a blog of exceptional literary quality that I check on daily, and while bookmarked on my home page there is also a link here on the right side of the page in my “Blog Roll”…it’s called “The Task At Hand…A Writer’s On-Going Search for Just the Right Word” and is found here: http://shoreacres.wordpress.com/. Not only are the posts themselves a great read, but so are the comments and the author’s responses to them.

In her most recent posting one of the comments mentioned fog and it brought back memories I have had with fog.  Having a problem falling asleep tonight thoughts of  fog kept tickling my brain to the point that here I am at the keyboard at 3:25 a.m. writing about the stuff.

The poet Carl Sandburg wrote:

The fog comes

on little cat feet

It sits looking

over harbor and city

on silent haunches

and then moves on.

Sandburg was a fool. The only thing he got right was relating fog to a cat…both equally sinister, evil, sneaky and despicable entities.

Basically fog is little more than a cloud with a fear of flying. Fog forms when water vapor in the air at the surface begins to condense into liquid water and normally occurs at a relative humidity of 100%. This can be achieved by either adding moisture to the air or dropping the ambient air temperature.

There are several kinds of fog. Radiation Fog is formed by the cooling of the land after sunset by thermal radiation  in calm conditions with clear sky. The cool ground produces condensation  in the nearby air by heat conduction.  It occurs at night and generally doesn’t last long after sunrise when things begin to warm up. Radiation fog is most often referred to as Ground Fog.

Then there’s Advection fog which occurs when moist air passes over a cool surface by advection  (wind) and is cooled. It is common as a  warm front  passes over an area with significant snowpack and is most common at sea when tropical air encounters cooler waters. In Louisiana, where I worked for several years running crew boats, we would encounter advection fog in the Spring and Fall. In the Fall it was caused by cold air from northern winds sweeping over the warm waters of the marshes and the Gulf waters and in the Spring time when the shallow waters had been cooled by winter temperatures the fog would form when the warm air returned from the south. Advection fog is also known by sailors as Sea Smoke.

Precipitation fog (or frontal fog) forms as rain  falls into drier air below the cloud and the liquid droplets evaporate into water vapor. The water vapor cools and at the dewpoint it condenses and fog forms.

Upslope fog or hill fog forms when winds blow air up a slope  (called orographic lift), adiabatically (occurring without loss or gain of heat) as it rises, and causing the moisture in it to condense. This often causes freezing fog on mountaintops, where the cloud ceinling would not otherwise be low enough.

Valley fog forms in mountain valleys, often during winter. It is the result of a temperature inversion caused by heavier cold air settling into a valley, with warmer air passing over the mountains above. It is essentially radiation fog confined by local topography, and cal last for several days in calm conditions.

Frozen fog is any kind of fog where the droplets have frozen into extremely tiny crystals of ice in midair. Generally this requires temperatures at or below −35 °C (−30 °F), making it common only in and near the Arctic and Antarctic  regions. It is most often seen in urban areas where it is created by the freezing of water vapor present in automobile exhaust and combustion -products from heating and power generation. Urban ice fog can become extremely dense and will persist day and night until the temperature rises.

Garua fog is a type of fog which happens to occur by the coast of Chile and Peru. The normal fog produced by the sea travels inland, but suddenly meets an area of hot air. This causes the water particles of fog to shrink by evaporation, producing a transparent mist. Garua fog is nearly invisible, yet it still forces drivers to use windshield wipers.

Hail fog sometimes occurs in the vicinity of significant hail accumulations due to decreased temperature and increased moisture leading to saturation in a very shallow layer near the surface. It most often occurs when there is a warm, humid layer atop the hail and when wind is light. This ground fog tends to be localized but can be extremely dense and abrupt. It may form shortly after the hail falls; when the hail has had time to cool the air and as it absorbs heat when melting and evaporating.

None of the stuff is any good.

Fog was quite common where I grew up on Cape Cod since, essentially, the Cape is surrounded by water. To the east of my town of Orleans was the Atlantic Ocean and the cold Labrador current passes quite close to shore. The waters of Cape Cod and Buzzard’s Bay and Nantucket Sound to the north west and south are relatively warmer than the ocean so the mixing of warm and cold air passing over these bodies of water is very conducive to the formation of fog.

I vividly remember one night when my mother was driving my brothers and I back home from an excursion to Boston. Around Hyannis, about 30 miles west of where we lived, we ran into a real “pea souper.” Fog so thick we could barely see past the hood of the old “Woody” Ford station wagon we had at the time. (Boy, do I wish I had that car now; my financial worries would be over.)

Headlights are worthless in fog. The droplets of water diffuse and scatter the rays of light making visibility even worse. Knowing that the fog wouldn’t lift until after sunrise, there was no way my mother was going to have us camping out in the car over night. We were driving on what is now known as Route 6A, a narrow, two-lane, twisting road through Barnstable, Yarmouth, Harwich, Brewster and Orleans and then on up all the way to Provincetown where the Cape ends. Her solution was simple. She opened her door a crack and crept along in first gear keeping her eyes on the white line running down the center of the road. We spent several hours in that fashion moving slowly along the deserted road until we reached the road where we had to turn to get to our house. That wasn’t hard to recognize since there was only one stop light on 6A between Hyannis and Orleans.

For boaters there is absolutely NOTHING worse than fog. High winds and heavy seas can be dealt with rather easily. It’s hand to hand combat against the elements. A battle of survival. Fog is creepy. It distorts the perceptions. It blinds you. The horizon disappears. Fog even bends sound waves so that what you hear over there is actually over here. If you’re lucky and have radar you can at least determine what is hidden out of sight. Under normal operating conditions, out of sight of land, you steer the course indicated on your compass, but that’s not easy in the fog. In the brief time you take looking in the radar to check your surroundings by the time you look back at your compass you’ll be way off your course.

My first winter in Louisiana I worked in the oil and gas production field for Kerr-McGee in Breton Sound running a small, 48 foot crew boat similar to this:

We actually lived on Breton Island which is about 30 miles south east of the mainland and the southernmost of a chain of islands that extend north eastwards to Mississippi Sound. The field was immense, extending about 20 miles north of the island and 12 miles south and 10 miles or so east and west. There were hundreds of oil and high-pressure gas wells that fed into five “facilities” like this:

Each morning at 6 a.m. we would take the men who maintained the wells to their facilities and then spend the days running them to each well leading into their facilities for the next 12 hours. And we did it, literally, in all kinds of weather short of a hurricane. “Small craft warnings?” We laughed at small craft warnings. Actually we didn’t laugh at them, we simply ignored them and went about our work. The operating principle for crew boat skippers is you “go or go home.” And if you go home they don’t let you come back.

We would get horrible fog conditions each Fall and Spring but we went to work anyway. I remember one horrid day of fog. We’d taken the men to their facilities and then just tied off to the nearby barges that the crude oil was stored in to wait for the end of the day when we could take the men back to the island. I picked up three men and was heading back at idle speed peering into an ancient Kelvin-Hughes radar to pick up the day marker at the seaward side of the channel leading into the island’s lagoon.

I loved that old Kelvin-Hughes. All the other boats were equipped with newer Furunos but mine was the only radar that could pick up the marker, simply a piece of drill pipe driven into the bottom, and I could spot it from about three miles away. The Furunos couldn’t pick it up from anything over a half mile.

While I was creeping along the idiot captain of another boat was blasting along full-bore, and those boats topped out at around 35 mph, when he ran head-on into one of the big day markers that guided ocean-going freighters up the Mississippi Gulf Outlet Channel  to the Port of New Orleans. The accommodations in the crew boat cabins were aluminum bench-type, three-man seats through bolted to the aluminum deck. When he hit the day marker, and believe me he couldn’t have hit it any more perfectly had he been aiming for it, everyone was thrown forward by the sudden stop. One poor soul hit the back of the seat in front of him ripping the seat out of the deck and destroying everything south of his nose. The injured man had to suffer for another four hours as another crew boat searched for the damaged vessel, transferred him aboard and crept the 30 miles to the closest dock where an ambulance waited to take him to a hospital. Of the five boats out there that day, mine was the only one to make it back to the island for the night. Everyone else had to spend the night in the field.

No, fog is the only thing that scares me out on the water.

The great science fiction author, Ray Bradbury, had this to say:

“One day many years ago a man walked along and stood in the sound of the ocean on a cold, sunless shore and said, ‘We need a voice to call across the water, to warn ships; I’ll make one. I’ll make a voice like all of time and all the fog that ever was; I’ll make a voice that is like an empty bed beside you all night long, and like an empty house when you open the door, and like trees in autumn with no leaves. A sound like the birds flying south, crying, and a sound like November wind and the sea on the hard cold shore. I’ll make a sound that’s so alone that no one can miss it, that whoever hears it will weep in their soul, and hearths will seem warmer, and being inside will seem better to all who hear it in distant towns. I’ll make me a sound and an apparatus and they’ll call it a foghorn and whoever hears it will know the sadness of eternity and the briefness of life.’

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