WEATHER, CLIMATE AND TOPOGRAPHY:
THE POSSIBILITY OF SEEING THE ECLIPSE

by Knut Jørgen Røed Ødegaard and Unni Fuskeland

If it is cloudy during the eclipse, we will only notice a slight darkening. We will miss most of the great experience of an eclipse.

That is why it is interesting to see how the weather tends to be in the areas where the eclipse is largest.

Thunder clouds in the east of Norway on August 16, 2002. Photo: Oddleiv Skilbrei

ABROAD

In the Faroe Islands, Iceland, Greenland and Scotland the eclipse is annular. But the weather in these areas is heavily affected by the wandering low pressure zones from the west and humid sea air that make a lot of clouds, fog and in general bad visibility. In addition, the Sun is very low while the eclipse is at its maximum.

In Reykjavik for instance, the forecasts are very poor. The possibility of sunshine is only 5% and for a clear sky so small that it can not be measured.....

Reykjavik is apparently still somewhat better than the rest of Iceland when the weather is concerned. Experience shows, however, that the weather conditions may vary a lot from place to place on Iceland, and that forecasts may suggest where on Iceland one should be to observe the annular phase.

On Iceland, the problem is especially low clouds and fog.

The Faroe Islands lies more in the middle of the low pressure zones and have extremely poor weather expectations. With luck one can naturally get good weather, even though the chance is small.

In Scotland the statistics is not promising, but the best chances of good weather is in the east. The Sun is very low during maximal phase, and the weather conditions is therefore enhanced.

Greenland is a very inaccessible area of the world, especially the east which is the most interesting. Also here the weather conditions varies a lot from place to place. If one has access to a plane/helicopter and reliable weather forecasts, or even better, updated satellite photos, one can travel to places with good conditions. This is, however, difficult and expensive and not an option for "most people".

Photo: Norwegian Meteorological Institute

NORWAY

Norway is just outside of the zone where the eclipse is annular, but is more favorable with respect to the weather conditions. The areas in the west are most exposed to clouds and fog. The statistics are best in the eastern part of the country and the inner parts of the west.

In the areas with the fjords in the west the topography is a problem. In many places the Sun is not visible during the eclipse. From hills, mountains etc. the conditions should be just fine.

In the east of Norway the topography is more flat and makes it possible to see the eclipse over large areas. Tests show that in Oslo the hills and buildings shade many places. The most favorable areas are probably Frognerparken (a perfect horizon towards the direction in question), the Fornebu peninsula and the fjord. Read more about the weather conditions in the east of Norway.

Other places: Use the table to find the elevation of the Sun over a perfect horizon. During the eclipse, the Sun is to the NE-ENE (north-east, east-north-east). Use a compass and try to estimate how good horizon you have.

The heights can be estimated by holding a straight arm in front of you:
-A forefinger on a straight arm's distance corresponds to about one degree.
-The backside of a closed hand corresponds to about ten degrees.
-A hand with fingers spread out corresponds to about 16 degrees.
The problem may be to estimate where the horizon would have been without all the hills and mountains. This requires some thinking - look for instance for the lowest place along your horizon. How high can it be?

One possibility is to get up early a few mornings before the eclipse to see if the Sun rises above the horizon at the time in question. The changes are small in a few days, and they will in any case be in your favor!

OTHER EUROPEAN COUNTRIES

In the countries east of Norway, for instance Sweden, Finland and Russia, the eclipse is somewhat less than in Norway (look at the table). The further east one travels, the smaller the maximum covered area becomes. The maximum coverd area is rather large in Stockholm and Copenhagen, but not as large as in the south of Norway. In Denmark and Germany the Sun is lower in the sky during the maximum phase than it is in Norway.

Photo: Norwegian Meteorological Institute

CONTACT PERSON:

Knut Jørgen Røed Ødegaard
Project leader

Institute of Theoretical Astrophysics
P.O.Box 1029 Blindern
N-0315 Oslo
Norway

Phone: +47 22 85 75 22 (Institute of Theoretical Astrophysics)
+47 992 77 172 (mobile phone)
+47 613 11 359 (private, weekend)

Email: knutjo@astro.uio.no