North Australian monsoons
The North Australian monsoon system is a regional expression of the monsoon on the Australian continent . In relation to its small size, Australia has a relatively strong monsoon effect, here the interaction with the Asian continent plays a major role.
In the southern summer , the influence of a northwest monsoon can be felt in northern Australia. The main heat area on earth is in the interior of Australia in the southern summer, so that the core of a heat depression forms over northern Australia. From this low, the air pressure increases steadily to the cold high in the interior of the Asian continent. As a result, the northeast trade wind blowing across South Asia is sucked over the equator in the direction of the Innertropical Convergence Zone (ITCZ) over northern Australia. In the southern hemisphere, this wind changes into the northwest monsoon, which is deflected to the left in accordance with the Coriolis force .
On its long journey across the world's warmest sea area on average, the air can soak up plenty of water vapor. If it then hits the Australian coast, it brings lush summer rain, depending on the location and height of the mountain ridges. January is the wettest month with an average of 400 mm. In Kimberley , the land rises from the coast to Mount Hann in less than 100 km to 776 m, so there is so much precipitation due to wind effects that the soil on the slopes is extensively denuded and washed into the lowland savannas (see climate diagrams). On the other hand, the low heat in the Australian outback ensures warm and dry conditions, especially in the lee of the mountains. The prevailing daytime temperatures of sometimes over 40 ° C make the hinterland of the Kimberley the hottest place in the southern hemisphere.
In March, the low heat shifts back to the northern hemisphere and a subtropical high pressure cell forms over northern Australia . A very consistently blowing, dry southeast trade wind sets in.