Posted on February 1, 2010.
How does a current account deficit to weaken the Australian dollar? The translation of a deficit of "money of account" is "The Aussie Govt to issue bonds to pay the bills. As the amount of money the Aussie Govt owe it grows, the Australian dollar will decline. Its a normal market response to the possibility that the Aussie govt will be unable to repay debt and to devalue the currency (ie, printing new dollars) to repay the debt.
So in summary, the Australian dollar will decline as the debt is carried on the balance of the Govt.
Unlike the previous answer, we will try to resolve what is a "current account deficit" is ... LOL
This means that Oz has become a net importer of goods (a current account surplus "means net exporter).
As a smallish economy if Oz has a current acount deficit it indicates that the global economy is to buy fewer goods Oz. The same thing happened here in Canada as demand for commodities has slowed, because the majority of Canada's export dollars from oil and metals extracted. (With the cars.)
Oz also exports a lot of metal extracted, particularly nickel, which has experienced a significant slowdown in demand in China that hunger for steel alloys took a dive.
With less currency within the Oz economy the purchasing power of a dollar drops Oz abroad as a result. Oz can meet to buy more dollars taking Oz traffic so that the proportion of foreign currency into dollars inside remains the same, which would enhance the strength of the dollar Oz, but have unpleasant side effect boosted the inflation, hardly a desirable thing when times are tight.
So Oz can share the slide over the national currency, which leads to a weaker dollar Oz. Not necessarily a bad thing because it makes products more affordable for Oz economies with strong currencies. However, it increases the cost of imported goods, which must hurt when you live on a big, big island ...
Hope that helped.