How could strange energies cause massive droughts within a localized region?

Question

The scenario:

Background

Let me begin by explaining the surreal parts of this scenario: essentially there is an archipelago of islands just south of Australia that have existed under the world's noses. These islands formed from the continental fragments of Gondwana, a supercontinent which once linked Antarctica and Australia together. This continent had access to distinct and supernatural minerals, uplifted from the Earth's core, which were condensed with significant magnetic energy. When the continent slowly split over the eons, these minerals were pushed and shoved tightly into this archipelago. (bear with me)

Meanwhile, there was an ancient race, a hybridized race of humans, predating man. These were Lemurians, who lived on the ancient continent of Lemuria in the Pacifc Ocean, between South America and Asia. Circa 4,000 BC, their extensive research into destructive technologies caused their civilization to collapse and their continent to be destroyed. (bear with me)

Via naval ships, the Lemurians travelled in two directions: one migratory group travelled to South America and another towards Asia. These groups went on to found the meso-American and Asian civilizations, who kept records of this origin within their myths. The Lemurians developed advanced societies but over the years, due to the mixing of their seed, their societies became increasingly primitive and they forgot their past.

Realizing the end was quickly coming for their society, a group of revolutionary Lemurians gathered a small following to venture out into the oceans once more. They set off with no exact destination in mind, with only the goal to find a better home for themselves. They traveled as a fleet of three distinct ships. This was circa 3,000 BC, and at this time, though the Lemurians were devolving, they still kept some of the more advanced navigation methods of their ancestors.

Somehow, someway, they eventually found themselves south of Australia after a year of wandering, stopping, wandering, stopping, and then wandering again. They discovered the Archipelago, which at this point was only inhabited by hunter gather pre-Lemurians who traveled to the islands over a land bridge during Australia's last glacial period. (almost there)

The Lemurians would live on this archipelago for nearly 3000 years. Near the tail end of their colonization, their mining efforts discovered the aforementioned magnetic gems. They were able to harness the gems' energies in order to develop fascinating technology, but it all culminated in a civil war which destroyed their civilization. Before this happened, they developed a "superconductor" of magnetic energy which created a giant sphere of magnetic protection around the breadth of the archipelago. The light particles of the sphere constantly quaked due to the intensity of the gems’ looping effect, and prevented the light particles from interacting with each other normally. The archipelago was effectively invisible.

The magnetic energies would manipulate compasses, and additionally the tidal energies influenced the perimeter of this magnetic sphere to be channeled with strong tidal waves which would subtly "push" ships away. Because of this, the islands remained hidden perpetually after the Lemurian collapse.

Fast Forward

A malicious organization rediscovers the archipelago in secret, and begin conducting experiments there. In their experiments, they incorporate the energies of these gems into their new technology. The results of these experiments causes the climate of the area to be somehow adversely affected. All the Southern Ocean's wind currents, temperature regulation, rainclouds, and more, are all drawn towards the archipelago and kept away from other regions. This messes up Tasmania and Australia's climates to the point that they experience massive droughts, lasting for years on end.

This is noticed by the world, and eventually they use these anomalies to pinpoint the location of the archipelago.

Question

But I need better ideas for how this works. How could the energies exhibited by the gems, experiments, or a mixture of both, cause these massive droughts? (You can even decide what you want the experiments to be).

The gem's harness magnetic energies, but they also have other special qualities, the limit of which has no end to your imagination.

Remember, the extent of these things only impact Tasmania and Australia. Other regions are only impacted by how much they in turn rely on the climates around Australia. The domino effect can theoretically go as far as you wish, but the focus is on Australia and Tasmania.

And by the way, how bad are the droughts?

• Harshly diminished crop growth
• Australia and Tasmania are quickly becoming deserts
• Extinctions
• Economic instability
• Social unrest
• Wildfires

It literally doesn't rain in ALL of Tasmania or MOST of Australia anymore.

How did the gems and experiments cause the droughts?

Answer 1

Have a look at what causes current drought in Australia

Australia experiences drought for a few reasons, but evidence exists that the large, long term droughts are caused by the El Nino phenomenon in the Pacific.

This essentially is that ocean currents cause air movement from the Pacific to pass over the Eastern coast of Australia, bringing with it moisture and accompanying rainfall. This by the way in turn means no rainfall falls on the deserts of South America during this time.

However, the current does not operate like normal and sometimes the air flow is therefore reversed. As a result, South America receives flooding rainfall, and Australia receives no rain at all.

There are other localised causes of drought such as sustained high pressure systems over central Australia - these last shorter but are nonetheless particularly debilitating as these also cause very high temperatures.

Your gems could have the power to control ocean currents, and affect therefore wind currents and surrounding rainfall. Alternatively, by producing high pressure systems, wind can be controlled such that it mostly flows away (wind generally goes from high pressure to low pressure) from water sources such as oceans and instead flows from land, reducing the amount of moisture in the air and therefore bringing less rain. Perhaps your gems produce copious amounts of air or heat to create such high pressure systems, or cause water to flow in certain directions to affect currents.

Answer 2

Gem force field deflected external influences away from the remains of Lemuria. The same gem force field is now doing the same thing now over a larger area.

Your hidden archipelago was protected by gem force fields that deflected everything: light, ships, wind. It would be a creepy place, that archipelago - bone dry, dark and dead.

When people started messing with the gem force, they changed it so the archipelago was no longer so well hidden. They wanted it to be easier to come and go. They did this by expanding the size of the gem force field, weakening it. They may not have understood this was what they were doing - they just cared about being able to come and go.

They did not turn it off. This repulsion gem force field, centered in the archipelago, now extends over a large swath including Tasmania and easter Australia. It is slightly darker there but the main effect is deflection. Small massive things people and ships are not detectably deflected but large nondense things like air masses are redirected, and tend to skirt the force shield. These air masses are what brought rain. Areas along the edge of the field get substantially more rain.

This lets you keep how you determined your gem field to work, and just expand it to a larger area.