Scaling of extreme precipitation records in Antarctica from 1 day to 2 years

Extreme weather records are important in determining the boundaries of the atmospheric system and in determining whether the Earth’s climate is changing or becoming more extreme (Cerveny, 2007). For this reason, the WMO Commission for Climatology decided to create a database to archive and verify the world weather extreme records. Due to the lack of an extensive database of reliable precipitation measurements in Antarctica, the only continental value in this table that has yet to be determined is the greatest precipitation in the Antarctic Region (average annual), which is estimated at more 800 mm. In order to evaluate the extreme precipitation records in Antarctica, in this communication the most extreme records are determined on different timescales, from 1 day to 2 years, using the RACMO2.3p2 model reanalysis (van Wessem et al. 2014), whose evaluation indicates that it performs well concerning the precipitation estimates. Records of extreme precipitation in Antarctica are found on the west side of the Antarctic Peninsula and are likely produced by utmost atmospheric river events (Gorodetskaya 2014). Extreme precipitation records closely follow a potential scaling such as the global precipitation records (Galmarini, 2004). Extreme precipitation in Antarctica has a higher exponent, indicating that small timescales (days) have less impact with respect to the large timescales (years) in relation to the global extreme precipitation. In addition, we show the regional variability of the extreme values and scaling in Antarctica. Although the values shown in this research emanate from model simulations and are not effectively measured, they help to constrain the upper limit of the maximum annual precipitation on the continent to well above one thousand millimeters.

 

References

Cerveny, R. S., Lawrimore, J., Edwards, R., & Landsea, C. (2007). Extreme weather records: Compilation, adjudication, and publication. Bulletin of the American Meteorological Society, 88(6), 853-860.

Galmarini, S., Steyn, D. G., & Ainslie, B. (2004). The scaling law relating world point‐precipitation records to duration. International Journal of Climatology: A Journal of the Royal Meteorological Society, 24(5), 533-546.

Gorodetskaya, I. V., Tsukernik, M., Claes, K., Ralph, M. F., Neff, W. D., & Van Lipzig, N. P. (2014). The role of atmospheric rivers in anomalous snow accumulation in East Antarctica. Geophysical Research Letters, 41(17), 6199-6206.

Van Wessem et al., 2014. Improved representation of East Antarctica surface mass balance in a regional climate model. J. Glac., 60(222), 761-770