TITLE:
Relationship between the Standardized Precipitation Index and Global Temperature on the North American Continent
AUTHORS:
Masaharu Nishioka
KEYWORDS:
Global Warming, Standardized Precipitation Index, Global Temperature, Correlation Coefficient, El Niño, Wildfires, Climate Change
JOURNAL NAME:
Atmospheric and Climate Sciences,
Vol.15 No.2,
March
19,
2025
ABSTRACT: Dryness and droughts may be related to changes in precipitation due to climate change. If climate change continues, wildfires may worsen due to increased dryness. In this work, we investigated the relationship between the standardized precipitation index (SPI) and global temperature in North America. The following results were obtained: 1) The global temperature is closely related to the global ocean temperature; 2) When the global temperature increases, the SPI becomes slightly larger inland; and 3) there is no correlation between the global temperature and the SPI in coastal and highland areas. In conclusion, on the basis of this study and recent studies, we propose a climate process between the global temperature and the standardized index. The temperature changes approximately one year after the change in the ENSO index, and the CO2 change rate follows the temperature change with a lag of several months. The emission and absorption of CO2 at the Earth’s surface respond to temperature changes. It is like the Earth’s breathing. CO2 emissions due to temperature increases are related to plant respiration and decomposition processes. During El Niño events, as indicated by changes in the ENSO index, temperatures increase, but the SPI is only slightly greater inland and is not related to changes in CO2. Caution should be taken when interpreting the relationship between wildfires and climate change.