Abstract Northeast China (NEC) is one of the major crop producing regions in China, which is severely affected by persistently extreme temperatures during summer. Previous works focused on understanding the intensity of extreme temperatures, yet neglecting its duration and timing. Considering the critical role of 25–60‐day intraseasonal variability (ISV) in inducing persistent temperature anomalies, our investigation found that 25–60‐day ISVs over both subtropical jet (SJ) and polar front jet (PJ) regions regulate the NEC temperature via the modulation of humidity and related longwave radiation (LR). During positive (negative) phase of PJ ISV, advection of climatological potential vorticity by strong meridional winds within the cyclonic‐anticyclonic (anticyclonic‐cyclonic) circulation favors the wave train corresponding to negative (positive) phase of SJ ISV. This interaction further amplifies and prolongs the impacts of SJ and PJ ISVs nonlinearly, with temperature decreases during the configuration of positive SJ and negative PJ ISV becoming 83% larger, and 6 days longer.
Observations from the Little Bunker
Last updated: August 18, 2025 04:13 PM
Atmospheric CO₂
425.4 ppm
+18.4
ppm/year
Atmospheric CH₄
1934.91 ppb
+9.11
ppb/year
Global Temperature
+1.48 °C
Peak: +1.73°C
World Population
8.1 billion
+67
million/year