A run of consecutive spells. …
4th January 2009, the lunar phase is at 11:56. I'm never sure which phase it is. First Quarter. That means the moon rises 90 degrees after the sun, in a couple of days time.
On the 27th of December, the New Moon rose at the same time as the sun; some 23 minutes (of time) past Greenwich. There isn't that much difference between 11:56 and 12:23. So by rights, the weather should remain substantially the same for this coming spell.
For us that should mean more cold weather. Your mileage will vary.
Minutes of arc:
The sun moves across the sky one hour every 15 degrees on average. Or, as some would have it: Every hour the sun moves across the face of the earth some 15 degrees.
There are 60 minutes in a degree, the same for geometry as for chronology.
The Atlantic basin contains a large elliptical mascon that stretches from Norway to Florida (IIRC) along its major axis. That is, there is a minute change in the attraction of gravity from the continent of Europe to that of North America.
It really is tiny. The earth's atmosphere has more effect on satellites than the change in the pull of the earth. Even (I imagine ) on the ones that are quite far out. This "pull of the earth" cause a minute change in the trajectory of satellites. Enough to cause them to burn fuels every once in a while for course correction.
That and the occasional hydrogen atom hitting them means that what is essentially a radio/computer operated camera needs to be the size of a bus instead of a suitcase. And thus more attractive to the earth, which means it requires yet more fuel to stay in orbit.
Or if you are running a satellite that weighs trillions of tons… (So handy that the economy allows us to think in such large numbers, is it not?) If you are running a satellite that weighs trillions of tons, your course corrections might be viewed on earth as stirring the weather.
Not a lot of people know that.
(The major axis is a posh way of saying: an oval circle's largest diameter.)
Having looked at the latest GRACE images, I'm struck that what I remember is a wide blue area that I though of as an ellipse is now a distinct red region on one side of the Mid Atlantic Ridge and on the other side a broad swathe of blue running in a clumn all the way up the eastern side of N America.
I wonder what it will look like in a few year's time as images have sharper and sharper focii.