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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Click on image to enlarge
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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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Click on image to enlarge
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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
