Impact of stratospheric ozone on the subseasonal prediction in the southern hemisphere spring

• Published in: Progress in Earth and Planetary Science
• Main Authors: Oh, Jiyoung, Son, Seok-Woo, Choi, Jung, Lim, Eun-Pa, Garfinkel, Chaim, Hendon, Harry, Kim, Yoonjae, Kang, Hyun-Suk
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer 2022
• Subjects: Antarctic ozone; Downward coupling; Subseasonal-to-seasonal prediction; Antarctic; Antarc*
• Online Access: https://hdl.handle.net/10371/179863; https://doi.org/10.1186/s40645-022-00485-4

Antarctic ozone has been regarded as a major driver of the Southern Hemisphere (SH) circulation change in the recent past. Here, we show that Antarctic ozone can also affect the subseasonal-to-seasonal (S2S) prediction during the SH spring. Its impact is quantified by conducting two reforecast experiments with the Global Seasonal Forecasting System 5 (GloSea5). Both reforecasts are initialized on September 1st of each year from 2004 to 2020 but with different stratospheric ozone: one with climatological ozone and the other with year-to-year varying ozone. The reforecast with climatological ozone, which is common in the operational S2S prediction, shows the skill re-emergence in October after a couple of weeks of no prediction skill in the troposphere. This skill re-emergence, mostly due to the stratosphere–troposphere dynamical coupling, becomes stronger in the reforecast with year-to-year varying ozone. The surface prediction skill also increases over Australia. This result suggests that a more realistic stratospheric ozone could lead to improved S2S prediction in the SH spring. This work was supported by the National Research Foundation of Korea (NRF) grant (2017R1E1A1A01074889) and NRF R&D Program for Oceans and Polar Regions (NRF-2020M1A5A1110579) funded by the Ministry of Science and ICT.