A link between Arctic daily warming, the equator region, and Atlantic storms was recently discovered by Prof. Baohua Ren and his group from the School of Earth and Space Sciences at the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS). The research was published in the journals npj Climate and Atmospheric Science, Environmental Research Letters, and Advances in Atmospheric Sciences.
Atmospheric conditions associated with the CP ENSO. Image Credit: Image from Prof. Ren’s team
The Arctic has experienced melting points multiple times, including in late December 2015 and 2022. The Arctic is one of the coldest places on earth, with an average winter temperature of –30 °C. To understand the effects of these melting events, researchers have been investigating daily warming events in the Arctic.
At the moment, the majority of scientists concentrate on the long-term increase in Arctic temperatures but pay little attention to Arctic daily warming events. The research team looked into the effects of the El Niño-Southern Oscillation (ENSO), the Central Pacific El Niño-Southern Oscillation (CP ENSO), and the North Atlantic Oscillation (NAO) on the frequency of daily warming in the Arctic.
The researchers looked into the effect of the NAO on Arctic winter daily warming events caused by Atlantic storms, dubbed the Atlantic pattern-Arctic Rapid Tropospheric Daily Warming (Atlantic-RTDW).
Researchers found that the relationship between the NAO and the frequency of Atlantic RTDW events has weakened since the mid-1980s, which they attributed to increased AST activity intensity. The strong AST induced an enhanced NAO-related cyclone during this time period, resulting in the disappearance of southerly and northerly wind anomalies over the NA.
Moreover, the researchers discovered that since the late 1970s, ENSO has pushed for a stronger Rossby wave, allowing El Niño to deepen the Aleutian Low and thus lowering (increasing) Arctic daily warming events. This model provided a possible link between the equator and the Arctic, which can help predict extreme Arctic daily warming events. This potential relationship may be strengthened as a result of global warming.
Nonetheless, the planetary wave linked with CP ENSO could not propagate upwards into the stratosphere after the mid-1980s, cutting the teleconnection between CP ENSO and Iceland Low. As a result, CP ENSO’s influence on the frequency of A-RTDW events was diminished.
The observations shed new light on the weather and climate changes in the Arctic. These studies can help improve the forecasting of Arctic daily warming events.
Journal References:
Wang, C., et al. (2023). Change of the CP ENSO’s role in the occurrence frequency of Arctic daily warming events triggered by Atlantic storms. Npj Climate and Atmospheric Science. doi.org/10.1038/s41612-023-00399-y.
Wang, C., et al. (2023). An Interdecadal Change in the Influence of the NAO on Atlantic-Induced Arctic Daily Warming around the Mid-1980s. Advances in Atmospheric Sciences. doi.org/10.1007/s00376-022-2218-8.