Slicing the earth to study Cloud Fraction and VPD.
1 day ago Guest Blogger
By: Charles Blaisdell PhD ChE
Abstract
According to many sources, the earth’s Cloud Fraction, CF, is the major source of climate change uncertainty. Cloud Fraction varies a lot from northern hemisphere to southern hemisphere and in-between. Global measurement of CF has a narrow range (64% to 60%). With accuracy challenging climate change models. This essay will slice the earth by latitude and analyze the larger cloud fraction range (82% to 52%) and vapor pressure deficit, VPD. The results show the logical correlation of sun angle to cloud fraction, VPD, and Enthalpy, En, and an unexpected correlation to land fraction. The land fraction correlation is most likely related to the lower water evaporation (per unit of global surface) from land vs ocean. On a global basis land fraction is constant implying that any change in cloud fraction or VPD is related to a change in land’s ET.
Resent research by H. Wu et al (2023), (2), and H Liu et al (2022), (1) have uncovered the effects of El Nino and La Nina on cloud fraction. This essay will show these perturbations in the cloud fraction do not affect the albedo, VPD, or En.
The H. Liu et al paper (1) also shows land moisture is related to climate change. Water evaporation change from land is the basis of the Cloud Reduction Global Warming, CRGW, theory (and model), (3). Global VPD and En are the main variables in the CRGW, theory of climate change.
Introduction
https://wattsupwiththat.com/2025/10/11/slicing-the-earth-to-study-cloud-fraction-and-vpd/