Subseasonal relationship between Arctic and Eurasian surface air temperature

Area of Science:

• Atmospheric Science
• Climatology
• Meteorology

Background:

• Subseasonal variability in Arctic-Eurasian surface air temperature (SAT) is a key area of climate research.
• Previous studies established a negative correlation between Arctic and Eurasian SAT during the cold season.

Purpose of the Study:

• To re-examine the subseasonal relationship between Arctic and Eurasian SAT.
• To investigate the dominant patterns (WACE and CAWE) and their drivers.
• To assess the role of Ural blocking in the WACE pattern.

Main Methods:

• Analysis of reanalysis data for Arctic and Eurasian SAT.
• Identification and characterization of Warm Arctic-Cold Eurasia (WACE) and Cold Arctic-Warm Eurasia (CAWE) patterns.
• Budget analyses to determine the drivers of WACE and CAWE patterns.

Main Results:

• A significant negative SAT correlation was observed from November to February, with a minimum in late December.
• Both WACE and CAWE patterns were identified as dominant modes of variability.
• Temperature advection linked to Ural region sea level pressure anomalies primarily drives WACE and CAWE, with diabatic heating playing a partial role.
• Ural blocking is not essential for WACE, as non-blocking high-pressure systems also contribute.

Conclusions:

• The subseasonal Arctic-Eurasian SAT relationship is significantly influenced by WACE and CAWE patterns.
• Temperature advection over the Ural region is the primary driver, modulated by diabatic heating.
• Transient weather systems, not solely Ural blocking, are crucial for Arctic-Eurasian SAT co-variability.