scholarly journals Radiative Effects of Increased Water Vapor Associated with Enhanced Dustiness in the Saharan Air Layer

2021 ◽  
Author(s):  
Claire L Ryder
2018 ◽  
Author(s):  
Javier Vaquero-Martínez

2008 ◽  
Vol 4 (1) ◽  
pp. 69-78 ◽  
Author(s):  
D. B. Kirk-Davidoff ◽  
J.-F. Lamarque

Abstract. Previous work has shown that polar stratospheric clouds (PSCs) could have acted to substantially warm high latitude regions during past warm climates such as the Eocene (55 Ma). Using a simple model of stratospheric water vapor transport and polar stratospheric cloud (PSC) formation, we investigate the dependence of PSC optical depth on tropopause temperature, cloud microphysical parameters, stratospheric overturning, and tropospheric methane. We show that PSC radiative effects can help slow removal of water from the stratosphere via self-heating. However, we also show that the ability of PSCs to have a substantial impact on climate depends strongly on the PSC particle number density and the strength of the overturning circulation. Thus even a large source of stratospheric water vapor (e.g. from methane oxidation) will not result in substantial PSC radiative effects unless PSC ice crystal number density is high compared to most current observations, and stratospheric overturning (which modulates polar stratospheric temperatures) is low. These results are supported by analysis of a series of runs of the NCAR WACCM model with methane concentrations varying up to one thousand times present levels.


2019 ◽  
Vol 46 (24) ◽  
pp. 14854-14862 ◽  
Author(s):  
Manuel Gutleben ◽  
Silke Groß ◽  
Martin Wirth ◽  
Claudia Emde ◽  
Bernhard Mayer

2021 ◽  
Vol 251 ◽  
pp. 105418
Author(s):  
Vasileios Salamalikis ◽  
Ioannis Vamvakas ◽  
Christian A. Gueymard ◽  
Andreas Kazantzidis

2000 ◽  
Vol 105 (D10) ◽  
pp. 12221-12234 ◽  
Author(s):  
Merlinde J. Kay ◽  
Michael Box

2005 ◽  
Vol 44 (1) ◽  
pp. 72-85 ◽  
Author(s):  
M. N. Deeter ◽  
J. Vivekanandan

Abstract Measurements from passive microwave satellite instruments such as the Advanced Microwave Sounding Unit B (AMSU-B) are sensitive to both liquid and ice cloud particles. Radiative transfer modeling is exploited to simulate the response of the AMSU-B instrument to mixed-phase clouds over land. The plane-parallel radiative transfer model employed for the study accounts for scattering and absorption from cloud ice as well as absorption and emission from trace gases and cloud liquid. The radiative effects of mixed-phase clouds on AMSU-B window channels (i.e., 89 and 150 GHz) and water vapor line channels (i.e., 183 ± 1, 3, and 7 GHz) are studied. Sensitivities to noncloud parameters, including surface temperature, surface emissivity, and atmospheric temperature and water vapor profiles, are also quantified. Modeling results indicate that both cloud phases generally have significant radiative effects and that the 150- and 183 ± 7-GHz channels are typically the most sensitive channels to integrated cloud properties (i.e., liquid water path and ice water path). However, results also indicate that AMSU-B measurements alone are probably insufficient for retrieving all mixed-phase cloud properties of interest. These results are supported by comparisons of AMSU-B observations of a mixed-phase cloud over the Atmospheric Radiation Measurement (ARM) Program’s Southern Great Plains (SGP) site with corresponding calculated clear-sky values.


2018 ◽  
Vol 205 ◽  
pp. 18-25 ◽  
Author(s):  
Javier Vaquero-Martínez ◽  
Manuel Antón ◽  
José Pablo Ortiz de Galisteo ◽  
Roberto Román ◽  
Victoria E. Cachorro

2020 ◽  
Vol 33 (20) ◽  
pp. 8789-8811 ◽  
Author(s):  
Michael P. Byrne ◽  
Laure Zanna

AbstractMonsoons are summertime circulations shaping climates and societies across the tropics and subtropics. Here the radiative effects controlling an axisymmetric monsoon and its response to climate change are investigated using aquaplanet simulations. The influences of clouds, water vapor, and CO2 on the axisymmetric monsoon are decomposed using the radiation-locking technique. Seasonal variations in clouds and water vapor strongly modulate the axisymmetric monsoon, reducing net precipitation by approximately half. Warming and moistening of the axisymmetric monsoon by seasonal longwave cloud and water vapor effects are counteracted by a strong shortwave cloud effect. The shortwave cloud effect also expedites onset of the axisymmetric monsoon by approximately two weeks, whereas longwave cloud and water vapor effects delay onset. A conceptual model relates the timing of monsoon onset to the efficiency of surface cooling. In climate change simulations CO2 forcing and the water vapor feedback have similar influences on the axisymmetric monsoon, warming the surface and moistening the region. In contrast, clouds have a negligible effect on surface temperature yet dominate the monsoon circulation response. A new perspective for understanding how cloud radiative effects shape the monsoon circulation response to climate change is introduced. The radiation-locking simulations and analyses advance understanding of how radiative processes influence an axisymmetric monsoon, and establish a framework for interpreting monsoon–radiation coupling in observations, in state-of-the-art models, and in different climate states.


Sign in / Sign up

Export Citation Format

Share Document