Phys.org April 1, 2024 Changes in anvil clouds with warming remain a leading source of uncertainty in estimating Earth’s climate sensitivity. An international team of researchers (France, UK) developed a feedback analysis that decomposes changes in anvil clouds and creates testable hypotheses for refining their proposed uncertainty ranges with observations and theory. They derived a simple but quantitative expression for the anvil area feedback, which depended on the present-day measurable cloud radiative effects and the fractional change in anvil area with warming. Satellite observations suggested an anvil cloud radiative effect of about ±1 W m−2, which requires the fractional change in anvil […]
Tag Archives: Cloud formation
Biological particles play crucial role in Arctic cloud ice formation
Science Daily September 28, 2023 Primary biological aerosol particles (PBAP) play an important role in the climate system, facilitating the formation of ice within clouds, consequently PBAP may be important in understanding the rapidly changing Arctic climate. An international team of researchers (Sweden, Switzerland, Japan, Norway) used single-particle fluorescence spectroscopy to identify and quantify PBAP at an Arctic mountain site, with transmission electronic microscopy analysis supporting the presence of PBAP. They found that PBAP concentrations ranged between 10−3–10−1 L−1 and peak in summer. Evidence suggested that the terrestrial Arctic biosphere was an important regional source of PBAP, given the high […]
Dust lifted into the air by cyclones provides anchor points for cloud-forming ice
Phys.org March 14, 2023 Researchers in China examined dust-infused baroclinic storm (DIBS) over East Asia in May 2017 to study the dust effects on cirrus clouds. The data indicated that the 2017 storm produced extremely high ice particle concentrations of 1 to 10 particles per cubic centimeter, with particle sizes in the range of 10 to 30 micrometers. They found that the more sophisticated parameterization matched cloud observations more closely than the simple model: The new, more complex model yielded ice particle concentrations that were 10 to 100 times higher and particle sizes that were 2 to 3 times smaller. […]
Turbulence affects aerosols and cloud formation
Science Daily September 16, 2020 Traditionally the mechanics of cloud formation have not accounted for turbulence. Researchers at the Michigan Technological University investigated the aspects of cloud formation under controlled conditions including the effects of fluctuations, produced by turbulence. The measurements show a clear transition from a regime in which the mean saturation ratio dominates to one in which the fluctuations determine cloud properties. Measurements in the chamber show that turbulence can mimic the behaviors that have been attributed to particle variation, primarily size and composition. According to the researchers their model will help forecasters predict the fluctuations Planet Ocean-Cloud […]
Nanoparticles of Fungal Spores Have Been Detected Floating in Our Atmosphere
Science Alert January 26, 2020 Aerosol nanoparticles play an important role in the climate system by affecting cloud formation and properties, as well as in human health because of their deep reach into lungs and the circulatory system. The sudden appearance of large numbers of atmospheric nanoparticles is commonly attributed to secondary formation from gas-phase precursors. Researchers at UC Irvine have detected a mode of fungal fragments with a mobility diameter of roughly 30 nm released in episodic bursts in ambient air over an agricultural area in northern Oklahoma. These events reached concentrations orders of magnitude higher than other reports […]