On the Climatological Characteristics of Anomalously Lower Air Temperature in Guangdong in May 2022 and Its Causation
Based on the reanalysis datasets of NCEP/NCAR,the SST and outgoing longwave radiation data of NOAA and the average temperature data from national meteorological observation stations across Guangdong,this work analyzes the climatological characteristics of the province's anomalously lower temper-ature in May 2022 and its causation using the methods of linear tendency and composite analysis.The results are shown as follows.In May 2022,the monthly average temperature of Guangdong was 1.9 ℃ lower than u-sual,becoming the lowest provincial record since 1961.The anomalously lower temperature took place under the background of an La Nina episode,which exerted significant impact on the climate of the Eurasian conti-nent via the general circulation.Compared with the average year,the circulation was more meridional in the mid-and higher-latitudes of Eurasia and a major trough in East Asia and a prominent high in Mongolia were stronger,steering excessive cold air from eastern Siberia and the regions to its north to advance southward.In the meantime,a southerly warm and humid airflow active over the low latitudes met with the cold air from the north over the province to cause clouds and rains,inhibiting adiabatic heating at the surface and heating effects arising from descending atmospheric motion,and thus leading to the anomalously lower temperature in May 2022.
climatologyanomalously lower temperaturecirculation anomaliesLa Nina episodeMayGuangdong province