monsoon-bike_1449924cBy Claire

My PhD topic involves recreating the Indo-Australian monsoon rainfall over the last 40,000 years using stalagmites from caves. Now, I know that’s a bit of a mouthful and when I tell people that’s what i’m doing I often get met with blank stares and the inevitable question, “what does that mean?”

At the moment I’m putting together a draft paper and yesterday I needed to write my, “conclusions and implications” paragraph. This meant that I actually had to think about what the implications of looking at the past monsoon actually has.

In my musings, I thought that I might try and connect the dots between my paleo-monsoon (i.e. “past” monsoon) record, and the present day monsoon system. In order to do that, I needed to better acquaint myself with the modern monsoon system, and I actually realised that what I’m studying could (if you squint) have real world implications. 

Average monthly rainfall for Darwin. As you can see, most rain falls during summer, and is associated with the Australian monsoon.
Average monthly rainfall for Darwin. As you can see, most rain falls during summer, and is associated with the Australian monsoon.

The term monsoon refers to the seasonal change in winds that bring large amounts of rain to tropical areas. In my head at least, monsoon means rain. When you watch the weather report on t.v. in summer, you quite often hear the term monsoon used to describe the rainfall predicted for Darwin almost every day. It’s also synonymous with the term “wet-season” or “rainy-season” and basically is the source of annual rainfall in affected areas.

Inflow of moist air from the Western Pacific brings monsoon rainfall to Eastern Asia during northern hemisphere summer.
Inflow of moist air from the Western Pacific brings monsoon rainfall to Eastern Asia during northern hemisphere summer.

But it also means a lot more than that. The East Asian Monsoon (the monsoon rainfall received across China, Japan, The Philippines, Taiwan and Hong Kong) affects approximately 1/3 of the world’s population. Now, this is quite difficult to comprehend, but we are talking billions of people who rely on the annual monsoon rainfall in this region to survive and when you add in the people who rely on the Indian Monsoon, this number increases again.

A small change in the strength or timing of the monsoon has huge impacts on the livelihood of farmers, who rely on this rainfall to water their crops. This year, the Indian Monsoon has arrived early, bringing with it well above average rainfall. While this has been a relief for farmers and economists, who predict a record harvest this year, some areas of India have seen severe floods and deaths as a result of the excess rainfall. Some people are blaming climate change and excess development for the disastrous flooding seen in Uttarakhand, India.

Understanding the past behaviour of the monsoon in response to different climate forcings may be able to help us understand how the monsoon may behave in response to human forcings. At least, that’s what I hope to be able to apply my PhD work to in the future…