Variability of Australian climate and future changes
I. G. Watterson
A *
A
Abstract
The variability of climate is assessed using the observational fifth generation of the European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis (ERA5) for 1980–2019 and data from 35 Coupled Model Intercomparison Project Phase 6 (CMIP6) models for a suite of variables, including the vertically integrated horizontal moisture flux vector from 10 models. The standard deviation of the seasonal anomalies within the 40-year period is calculated for grid points and for rainfall averaged over Australian regions. The four-season average of standard deviation, denoted VAR, is a measure of overall variability. From ERA5, the average for grid points over Australia (AUS) is 4–11% higher than that from all land in 60°S–60°N (LAN) for each variable, except for flux and 850-hPa eastward wind, which are 31–41% higher. The variability linked to two mode indices, NINO34 and PID (Pacific–Indian Dipole), is quantified by the four-season average of the magnitude of the regression anomaly. For each index, the 35-model average (av35) of the linked variability averaged over AUS and LAN for rainfall, temperature and pressure is typically less than 30% of the net VAR. The statistics for 2040–2079 under the shared socioeconomic pathway with expected radiative forcing 5–8.5 W m−2 (SSP5-8.5) are scaled to provide a change representative of the 2°C global warming level. There is little change overall in VAR, except for moisture variables, with flux increasing typically 10%. From av35, for rainfall AUS increased 6% and LAN 9%, in part owing to an increase in the VAR of the NINO34 index of 14%. The PID index provides a stronger link to the range of model change of the variability of all-Australia rainfall, and hence the uncertainty in projected change.
Keywords: Australian climate, Australian rainfall, climate modes, climate variability, ENSO, ERA5, future climate, moisture flux, NINO34.
References
Alexander LV, Uotila P, Nicholls N (2009) Influence of sea surface temperature variability on global temperature and precipitation extremes. Journal of Geophysical Research 114, D18116.
| Crossref | Google Scholar |
Bureau of Meteorology and CSIRO (2022) State of the Climate Report. (Commonwealth of Australia) Available at http://www.bom.gov.au/state-of-the-climate/2022/documents/2022-state-of-the-climate-web.pdf
Cai W, Ng B, Geng T, Jian F, Wu L, et al. (2023) Anthropogenic impacts on twentieth-century ENSO variability changes. Nature Reviews Earth and Environment 4, 407-418.
| Crossref | Google Scholar |
Chung C, Boschat G, Taschetto A, Narsey S, McGregor S, Santoso A, Delage F (2023) Evaluation of seasonal teleconnections to remote drivers of Australian rainfall in CMIP5 and CMIP6 models. Journal of Southern Hemisphere Earth System Science 73, 219-261.
| Crossref | Google Scholar |
Douville H, Raghavan K, Renwick J, Allan RP, Arias PA, Barlow M, Cerezo-Mota R, Cherchi A, Gan TY, Gergis J, Jiang D, Khan A, Pokam Mba W, Rosenfeld D, Tierney J, Zolina O (2021) Water Cycle Changes. In ‘Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change’. pp. 1055–1210. (Cambridge University Press) 10.1017/9781009157896.010
Gu G, Adler RF (2019) Precipitation, temperature, and moisture transport variations associated with two distinct ENSO flavors during 1979–2014. Climate Dynamics 52, 7249-7265.
| Crossref | Google Scholar |
Gutiérrez JM, Jones RG, Narisma GT, Alves LM, Amjad M, Gorodetskaya IV, Grose M, Klutse NAB, Krakovska S, Li J, Martínez-Castro D, Mearns LO, Mernild SH, Ngo-Duc T, van den Hurk B, Yoon J-H (2021) Atlas. In ‘Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change’. pp. 1927–2058. (Cambridge University Press) 10.1017/9781009157896.021
Hersbach H, Bell B, Berrisford P, et al. (2020) The ERA5 global reanalysis. Quarterly Journal of the Royal Meteorological Society 146, 1999-2049.
| Crossref | Google Scholar |
Holgate CM, Evans JP, van Dijk AIJM, Pitman AJ, Di Virgilio G (2020a) Australian precipitation recycling and evaporative source regions. Journal of Climate 33, 8721-8735.
| Crossref | Google Scholar |
Holgate CM, Van Dijk AIJM, Evans JP, Pitman AJ (2020b) Local and remote drivers of southeast Australian drought. Geophysical Research Letters 47(18), e2020GL90238.
| Crossref | Google Scholar |
Klingaman NP, Woolnough SJ, Syktus J (2013) On the drivers of inter-annual and decadal rainfall variability in Queensland, Australia. International Journal of Climatology 33, 2413-2430.
| Crossref | Google Scholar |
Lee J-Y, Marotzke J, Bala G, Cao L, Corti S, et al. (2021) Future Global Climate: Scenario-Based Projections and Near-Term Information. In ‘Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change’. pp. 553–672. (Cambridge University Press) 10.1017/9781009157896.006
Maher N, Jnglin Wills RC, Di Nezio P, Klavans J, Milinski S, Sanchez SC, Stevenson S, Stuecker MF, Wu X (2023) The future of the El Niño–Southern Oscillation: using large ensembles to illuminate time-varying responses. Earth System Dynamics 14, 413-431.
| Crossref | Google Scholar |
McGregor S, Cassou C, Kosaka Y, Phillips AS (2022) Projected ENSO teleconnection changes in CMIP6. Geophysical Research Letters 49, e2021GL097511.
| Crossref | Google Scholar |
McMahon TA, Peel MC, Vogel RM, Pegram GGS (2007) Global streamflows – part 3: country and climate zone characteristics. Journal of Hydrology 347, 272-291.
| Crossref | Google Scholar |
Nicholls N, Wong KK (1990) Dependence of rainfall variability on mean rainfall, latitude, and the Southern Oscillation. Journal of Climate 3, 163-170.
| Crossref | Google Scholar |
Pendergrass AG, Knutti R, Lehner F, Deser C, Sanderson BM (2017) Precipitation variability increases in a warmer climate. Scientific Reports 7, 17966.
| Crossref | Google Scholar | PubMed |
Power S, Delage F, Chung C, Kociuba G, Keay K (2013) Robust twenty-first-century projections of El Niño and related precipitation variability. Nature 502, 541-545.
| Crossref | Google Scholar | PubMed |
Scherrer SC (2011) Present-day interannual variability of surface climate in CMIP3 models and its relation to future warming. International Journal of Climatology 31, 1518-1529.
| Crossref | Google Scholar |
Schroeter S, Bi D, Law RM, Loughran TF, Rashid HA, Wang Z (2024) Global-scale future climate projections from ACCESS model contributions to CMIP6. Journal of Southern Hemisphere Earth System Science 74, ES23029.
| Crossref | Google Scholar |
Schubert SD, Stewart RE, Wang H, Barlow M, Berbery EH, et al. (2016) Global meteorological drought: a synthesis of current understanding with a focus on SST drivers of precipitation deficits. Journal of Climate 29, 3989-4019.
| Crossref | Google Scholar |
Seager R, Henderson N, Cane M (2022) Persistent discrepancies between observed and modeled trends in the tropical Pacific Ocean. Journal of Climate 35, 4571-4584.
| Crossref | Google Scholar |
Van Oldenborgh GJ, Hendon H, Stockdale T, L’Heureux M, Coughlan de Perez E, Singh R, van Aalst M (2021) Defining El Niño indices in a warming climate. Environmental Research Letters 16, 044003.
| Crossref | Google Scholar |
Watterson IG (2019) Indices of climate change based on patterns from CMIP5 models, and the range of projections. Climate Dynamics 52, 2451-2466.
| Crossref | Google Scholar |
Watterson IG (2020) Australian rainfall anomalies in 2018–2019 linked to Indo-Pacific driver indices using ERA5 reanalyses. Journal of Geophysical Research 125, e2020JD033041.
| Crossref | Google Scholar |
Watterson IG (2022) Atmospheric moisture anomalies associated with modes of variability and future changes. In ‘AMOS 2022 Conference’, 28 November–1 December 2022, Adelaide, SA, Australia. p. 72. (Australian Meteorological and Oceanographic Society) Available at http://hdl.handle.net/102.100.100/481740?index=1 [Abstract]
Watterson IG (2023) Atmospheric moisture transport associated with precipitation in present and simulated future climates. Journal of Climate 36, 6409-6425.
| Crossref | Google Scholar |
Watterson IG, Chua Z-W, Hope PK (2016) Extreme monthly rainfall over Australia in a changing climate. Journal of Southern Hemisphere Earth System Science 66, 402-423.
| Crossref | Google Scholar |
Watterson IG, O’Kane TJ, Kitsios V, Chamberlain MA (2021) Australian rainfall anomalies and Indo-Pacific driver indices: links and skill in 2-year-long forecasts. Journal of Southern Hemisphere Earth System Science 71, 303-319.
| Crossref | Google Scholar |
