How to generate powerful cyclonic storms in an ocean basin

Question

I have a region on a planet with identical parameters to Earth but different landmasses that is rather similar to the southern ocean on Earth.

There is a single piece of land around the size of the Pacific Northwest that sticks down into the 50 S latitudes. To the west of it but beneath the 60 S parallel, there is a continent twice the size of Greenland generally extending south and fully glaciated. There is no other land south of the 45th parallel.

I'd like this ocean to generate cyclonic storms stronger than the ones in our own Southern Ocean. Will it already do that or are there any other changes to the distribution of land and water and other things that aren't like orbital distance and mass that I can do to increase the strength of low pressure systems forming in this ocean that will impact the land?

This is a map of southern winter average temperatures for reference.

Answer 1

If you want a strong Southern ocean:

1. Place a single small landmass in the middle. This will help anchor the swirling water so that it doesn't swirl off balance, and get in its own way.
2. Place a few pointy land masses that angle down any current that drifts northwards. (eg South America, Africa, Australia)
3. Two or more relatively large heat basins (eg, the Indian and Pacific oceans) that use the sun to cycle large amounts of current that help push the circulation in the southern ocean.

If you don't you'll get the equivalent of the northern ocean.

1. No central landmass, causing the current to flow into its own path, reducing its own strength.
2. Many relatively flat landmasses that make a ring, but more importantly are angled to deflect the current away from the pole.
3. connection to oceans in such a way that the cycle pushes against, or simply pulls current strength from the ocean.

Going off on a tangent it looks like your wanting some extreme climate and variability.

If your after storms, the most violent storm periods in earth (geologically speaking) form when a clean band of ocean forms through the tropics. This causes the warm water to heat year round increasing the frequency/strength of strong weather. It also has the nice effect of caging in the northern/southern oceans own currents concentrating their own strength.

Also be aware that this kind of event tends to throw the oceanic ecosystems into disarray, as cooler water species cannot cross the equator easily, hot water is much less oxygenated and tends to create massive dead zones, and depending on the oceans recent history, it can release copious amounts of green house gases strengthening global warming trends. Needless to say there will be no reliable fishing in such a world.

Take a look at the Gondwana/Lurasia super-continent split for a recent example in earth history.

Conversely if you get a continent or near perfect large continent linking north to south it diverts most ocean currents warming the poles and cooling the tropics, producing an overall more stable climate. You can still get massive storms particularly if you have a giant pacific ocean/indian ocean style where the ocean currents are mostly forced to cycle. Couple that with a giant mountain range relatively close to the coastline, this will trap massive weather events along the coast causing massive amounts of rain, and flooding. While turning the rest of the continent into a relatively barren and unforgiving desert. Take a look at Australia or India for an example.

Also do not forget other events such as volcanism, or world forests for playing hell with the weather.

• The Siberian Lava Traps are firmly believed to have shifted the climate during the great Permian Extinction. They released so much CO2, Sulfur, and other chemicals, particular small particles that it both cooled and heated the atmosphere on different timescales. This disrupts weather patterns, usually allowing larger storm weather systems to strengthen as relatively strong stable weather patterns are weakened.
• The Carboniferous Period was so heavily populated by trees, and lacked a good decomposition cycle. This caused an atmosphere relatively devoid of CO2 and very rich in Oxygen, producing a large net difference in static charge. This resulted in powerful lightning storms, and fireballs in the sky, as relatively rich pockets of oxygen were combusted with other atmospheric elements during those lightning strikes.

Answer 2

Given the parameters that you've given, it is very likely that the storms generated in the southern hemisphere would be quite stronger than what exists in our world, and also likely that the South Pole, in the absence of any landmass, might end up being covered by a permanent storm system.

I draw a parallel with the recent discovery on Jupiter's pole, showing a massive storm orbited by smaller storms. While Jupiter isn't Earth-like, the physical laws governing the movement of a fluid, like an atmosphere, are the same no matter what your atmosphere is made of.

Thus, I believe that in your setting, the South Pole would be covered by a giant permanent storm system, fueled and maintained by sea currents, jet streams and the rotation of the planet, that would generate side storm that would wreak havoc on your Greenland and the south shores of the other landmass.

Given how 'thin', so to speak, the two landmasses you described are, this leaves a lot of open seas for storm systems to develop and acquire energy before they make landfall.