{"id":273862,"date":"2023-08-16T14:09:24","date_gmt":"2023-08-16T12:09:24","guid":{"rendered":"https:\/\/climatescience.press\/?p=273862"},"modified":"2023-08-16T14:09:40","modified_gmt":"2023-08-16T12:09:40","slug":"climate-modelling-in-australia","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=273862","title":{"rendered":"Climate Modelling in Australia"},"content":{"rendered":"\n
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From Watts Up With That?<\/a><\/p>\n\n\n\n

Rick Willoughby<\/p>\n\n\n\n

Australia\u2019s mostly government funded scientific research organisation, CSIRO, has participated in the United Nations IPCC program to identify human impacts on climate.\u00a0 CSIRO has contributed to the various assessment reports through evolving climate models over the past 20 years.<\/p>\n\n\n\n

This article examines how well the CSIRO climate models serve the Australian community that fund their work.<\/p>\n\n\n\n

El Nino Southern Oscillation (ENSO)<\/strong><\/p>\n\n\n\n

The phases of the Tropical Pacific have a significant impact on the weather that most Australians experience.\u00a0 The Eastern States of Australia, where most of the population live, experience dry and hot conditions during the El Nino phase that often result in droughts while the La Nina phase is associated with higher rainfall and often regional flooding.<\/p>\n\n\n\n

This\u00a0statement<\/a>\u00a0from the Australia Bureau of Meteorology:<\/p>\n\n\n\n

Australia\u2019s weather is influenced by many climate drivers. El Ni\u00f1o and La Ni\u00f1a have perhaps the strongest influence on year-to-year climate variability in Australia. They are a part of a natural cycle known as the El Ni\u00f1o\u2013Southern Oscillation (ENSO) and are associated with a sustained period (many months) of warming (El Ni\u00f1o) or cooling (La Ni\u00f1a) in the central and eastern tropical Pacific. The ENSO cycle loosely operates over timescales from one to eight years.<\/em><\/strong><\/p>\n\n\n\n

Identification of the Pacific phases dates back to the 17th<\/sup>\u00a0century when South American fishermen observed warmer waters off their coast during the El Nino phase resulting in the origin of the phase names.\u00a0 Henry Blanford, the Imperial Meteorological Reporter to the government of India, identified a connection between dry conditions in India and other regions of the globe associated with ENSO phases in the late 1800s.\u00a0 A statistical connection was formalised in the 1920s.<\/p>\n\n\n\n

The best indication of the shifting phases is the ocean surface temperature in the central Pacific identified as the Nino 3.4 region that extends across the equator from 5S to 5N and along the equator from 120W to 170W.\u00a0 There are reliable Nino 3.4 surface temperature records dating back to the late 1800s because of the regions importance to global weather.<\/p>\n\n\n\n

Nino3.4 Satellite Sea Surface Temperature<\/strong><\/p>\n\n\n\n

Satellite based monitors have been providing high spatial resolution spectral data as the basis for determining the sea surface temperature globally since the early 1980s.\u00a0 The US based centre for environmental prediction (NCEP) produces a sea surface temperature data set that uses the satellite data to interpolate between surface based measurements at moored buoys; combining the accuracy of in-situ measurements with high spatial resolution.\u00a0 Chart 1 plots the NCEP interpolated data for the Nino 3.4 region throughout the satellite era.<\/p>\n\n\n\n

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The measured temperature has averaged 27C for the 42 years of the data collection and currently has a slight downward trend of 0.63C\/century.\u00a0 El Nino phase is associated with regional temperature above 28C while La Nina phase is present when the temperature is below 26C.\u00a0 The significant El Nino occurrences around 1982, 1998 and 2016 stand out in the plot.<\/p>\n\n\n\n

Coupled Model Intercomparison Project (CMIP)<\/strong><\/p>\n\n\n\n

The CMIP framework dates back to 1995 and set an agreed basis for the inputs to climate models produced by numerous research groups around the world for comparing their model output.<\/p>\n\n\n\n

CMIP3<\/strong><\/p>\n\n\n\n

CMIP3 was established for the third assessment report that projects climate state from the year 2000.  The Special Report for Emissions Scenarios (SRES) provided a number of scenarios with a range of inputs but only two are noted here:<\/p>\n\n\n\n