Over the past two weeks, torrential rains have brought both drought
relief and severe flooding to parts of Queensland and Northern
Territory in northern Australia. The wet weather was due primarily to
the start of the wet phase of the monsoon, but may have been
intensified by a La Niña episode that has been going on since
February 2007.
This pair of images of the event is made from the results of the
near-real-time, Multi-satellite Precipitation Analysis (TMPA) at NASA
Goddard Space Flight Center. The analysis is based on data collected
by the Tropical Rainfall Measuring Mission satellite (TRMM) between December 24, 2008, and January 7, 2009. The top
image shows total rainfall accumulation in shades from yellow (light
rain) to blue (heavy rain). The bottom image shows the rainfall
anomaly—how unusual this event was compared to average rainfall
for this time of year. Places where rainfall was unusually high are
blue, while unusually low rainfall is shown in brown.
The most prominent feature in the top image is a northwest-southeast band of very heavy rain that lies just inland from the coast
across central northern Australia. The band extends from the western
edge of Northern Territory in the west to the base of the Cape York
Peninsula in the east. Rainfall totals in many places exceed 300
millimeters (about 12 inches). Pockets of even higher amounts
(400 millimeters, or about 16 inches) are embedded in the band.
The bottom image shows rainfall anomalies for this two-week period
compared to the five-year average (2002-2007). Above-average rainfall extended over northern and eastern Australia northward
towards the islands in the Western Pacific. This pattern is consistent
with the broad-scale rainfall “signature” of La
Niña. The anomaly was significant across north-central
Australia and the Gulf of Carpentaria, with rainfall at least 15
millimeters per day higher than normal. For more information on this
event, see the related story
on the TRMM Webpage.
TRMM includes the first precipitation radar in space, and the
mission is a partnership between NASA and the Japanese Space Agency,
JAXA.
NASA image by Hal Pierce. Caption by Steve Lang and Rebecca Lindsey.