Every Friday, Decoded Science features places with some of the best and worst weather. This week, some of that weather is literally out of this world.
A Vacationer’s Oasis On The Arabian Peninsula
Our search this week for the perfect fair weather spot takes us to Muscat, Oman.
Muscat is almost exactly at the edge of the tropics — 23 degrees north latitude — and while the interior of Oman is mostly searing-hot desert, winds from the Arabian Sea cool off the coast in the winter and spring.
Temperatures routinely top 100 degrees in the summer, when a local offshore wind called a shamal prevails, even at water’s edge, but right now conditions are perfect for lying on the beach, exploring the city, or visiting the forts that the Persians and the Portuguese once used in their struggle for dominance of the region in the Middle Ages.
Here are the particulars on Muscat’s March temperatures:
- Daytime highs are in the mid 80s.
- Nighttime lows are around 70.
- Water temperature is about 80.
The shoreline consists of rocky cliffs alternating with sandy beaches, and it’s easy to get a tan: the sun shines more than 90% of the possible time. Situated in the zone of subsidence that circles the globe at around 30 degrees latitude, Oman receives sparse rainfall. Rain typically occurs on only about three days in March, and the total for the month is less than two-thirds of an inch.
While you’re in Muscat, you can take a side trip to a religious mecca — in fact THE religious mecca: Mecca, Saudi Arabia — about a thousand miles to the west as an ambitious crow would fly. Be advised that the temperature in Mecca, even now, will be over a hundred degrees. But that’s not as hot as some other locations this week.
India’s Hot Season
Mumbai, India (Why did they change the name? Bombay is so much more expressive) gets this week’s nod as most unpleasant city to visit. There, adding unpleasantness to the choking smog and stifling humidity, the temperature will rise to over 110 degrees for the next week. Though the sun rises higher in the sky, things actually improve in April, as sea breezes bring a little cooling and push the smog inland. And by June, the monsoon sets in and cools temperatures to the 90s.
The Real Hot Spot
The Earth has a sister planet – and it’s a really ugly sister. It’s not ugly to look at. In fact as the brightest object in the sky that’s not a star or a satellite (the sun and the moon), it often enhances the beauty of the evening sky, even without arms. I’m talking about Venus.
Because Venus is inferior to the Earth (this is not a value judgment; it means Venus is closer to the sun), it cannot rise higher than about 40 degrees from the horizon.
Living Conditions On Venus
If you go to Mumbai, you can survive the smog, the heat, and the humidity, but on Venus things are orders of magnitude worse:
- The air is unbreatheable, consisting of 96% carbon dioxide.
- The temperature is over 800 degrees (and that’s in the shade).
- The pressure at the surface of Venus is 90 times that of Earth. This is the equivalent of the pressure 3,000 feet down in the ocean.
Why Is Venus So Hot?
Venus is an example of what happens when the greenhouse effect gets out of control. There is so much carbon dioxide in the atmosphere of Venus that the planet can radiate very little heat. Meanwhile, the atmosphere traps much of the incoming solar radiation and the temperature rises until an equilibrium is obtained between the incoming radiation and that given off by the top of the atmosphere. That equilibrium produces an average temperature of 860 degrees at the surface.
Could It Happen On Earth?
There is much ado these days about greenhouse gases. The Earth goes through cycles in which the greenhouse gases wax and wane. There is a self-regulation mechanism called the carbon-silicon cycle that puts boundaries on the alternate glacial and interglacial temperatures.
Global warming is not a threat to make the Earth like Venus. Rather, it is likely to accelerate a move towards a much hotter interglacial period. The rapidity of the change is the main cause for concern. Plants, diseases, animals, and people will have to adapt quickly and the new dynamics of species relationships is not certain. Diseases could get out of control and famines could develop due to changing agricultural conditions. The rising sea level, though it will not inundate the entire planet, will cause whole cities to move.
Weather Closer To Home
It is now Spring in the northern hemisphere by any measure. Decoded Science takes you to places fair and foul around the world — this week even around the solar system. But there’s plenty of good weather nearby. Tell us about a perfect day where you live.
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