In meteorological terms the far northern section and much of eastern Australia along with its islands are situated in the South-West Pacific.
Along with the Maritime Continent (the region between the Indian and Pacific Oceans including the archipelagos of Indonesia, Borneo, New Guinea, the Philippine Islands, the Malay Peninsula, and the surrounding seas), Solomon Islands, New Caledonia, Fiji, Tuvalu, Nauru, Samoa, Micronesia, Kiribati and New Zealand.
On 27 August 2024 the World Meteorological Organisation released its "State of the Climate in the South-West Pacific 2023".
By way a brief look at some of the key issues in the report it is worth noting that:
> Atmospheric concentrations of the three major greenhouse gases reached new record observed highs in 2022, the latest year for which consolidated global figures are available. Real-time data from specific locations, including Mauna Loa (Hawaii, United States of America) and Kennaook/Cape Grim (Tasmania, Australia) indicate that levels of CO2 (carbon dioxide), CH4 (methane) and N2O (nitrous oxide) continued to increase in 2023;
> Over the past two decades, the ocean warming rate has increased; the ocean heat content in 2023 was the highest on record;
> Temperatures in 2023 were higher than normal in many areas of the region. The most significant warmth was over an area extending from south-east Australia to east of New Zealand. The most prominent and persistent marine heatwave in 2023 occurred in a large area around New Zealand. This heatwave was categorized as extreme and lasted approximately six months;
> Ocean warming and accelerated loss of ice mass from the ice sheets contributed to the rise of the global mean sea level by 4.77 mm per year between 2014 and 2023, reaching a new record high in 2023.
> In 2023, the sea level continued to rise globally and regionally as shown by high precision satellite altimetry measurements. The average global mean sea level rise (GMSL) was 3.4 mm +/- 0.3 mm/year over the January 1993 to May 2023 period. Sea levels continued to rise at rates higher than the global mean in several parts of the South West Pacific;
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Figure 7 shows the sea-level trend over the January 1993–May 2023 period as measured by satellite altimeters. In the South-West Pacific region, the sea-level rise of the last three decades exceeds the global mean sea-level rise. Altimetry-based sea-level time series from January 1993 to May 2023 have been averaged over two areas within the region (Figure 7, bottom left and bottom right). The mean rate of sea-level rise in both areas is significantly higher than the global mean (4.52 mm +/-0.25 mm/year in area 1 and 4.13 mm +/-0.08 mm/year in area 2). The sea-level time series in area 1 (Figure 7,bottom left) displays strong inter-annual variability, mostly driven by ENSO (see the strong sea-level drops in 1997/1998 and 2015/2016). Sea-level rise is more regular in area 2 except for a steep increase around 1998.
NOTE: Regional sea-level trends are based on gridded C3S altimetry data, averaged from 50 km
offshore to the coast, by the Laboratory of Space Geophysical and Oceanographic Studies (LEGOS);
> The South-West Pacific region is extremely prone to disasters associated with hydrometeorological hazards, especially storms and floods. In 2023, a total of 34 hydrometeorological hazard events were reported in the region according to the International Disaster Database (EM-DAT), of which over 90% were flood and storm events. These reported hydrometeorological hazard events resulted in over 200 fatalities, most of which were associated with floods, storms, and landslides.
Over 25 million people were directly affected by these hazards, and they caused total economic damage of close to US$ 4.4 billion. Floods were the leading cause of death, whereas drought was the natural hazard type that affected the greatest number of people.
Storms were the hazard type that caused the greatest economic damage, followed by floods.
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In March, a landslide triggered by flooding in north-western Indonesia resulted in 54 fatalities, more than 2,800 displaced people and 27 buried houses. This disaster event caused the greatest number of fatalities in the South-West Pacific in 2023, highlighting the importance of understanding the multiple and cascading impacts of natural hazard events;
> Precipitation is a key climate parameter, closely related to indispensable resources for human activities such as water for drinking and domestic purposes, agriculture, and hydropower. It also drives major climatic events such as droughts and floods.
In 2023, the largest precipitation deficits (measured as a percentage of the average) were observed in the Hawaiian Islands and south-western Australia. Other areas with below-average rainfall amounts were New Caledonia, Tuvalu, parts of Fiji, Tonga and the Cook Islands, parts of northern Australia, Tasmania, the southern South Island of New Zealand, some areas in the Greater Sunda Islands (Indonesia) and parts of Luzon (Philippines). Based on time series analyses (not shown), it was unusually dry (below the 10th percentile) in southern Borneo, south-west and East Australia (around Brisbane) and some central Pacific islands.
Above-normal precipitation amounts were recorded around the Solomon Sea, the Solomon Islands, Vanuatu, Samoa, Niue, the Line Islands, the southern Philippines, northern Borneo, the Malay Peninsula, Sumatra, large parts of New Zealand, and northern Central Australia.
Download full report at:
https://library.wmo.int/records/item/68995-state-of-the-climate-in-south-west-pacific-2023
