scholarly journals The Role of Cloud Radiative Forcing in the Asian-Pacific Summer Monsoon

2007 ◽  
Vol 18 (3) ◽  
pp. 623
Author(s):  
Chi-Hua Wu ◽  
Wen- Shung Kau
Keyword(s):  
Summer Monsoon ◽  
Radiative Forcing ◽  
Cloud Radiative Forcing ◽  
Asian Pacific

Role of vertical structure of cloud microphysical properties on cloud radiative forcing over the Asian monsoon region

2015 ◽  
Vol 45 (11-12) ◽  
pp. 3331-3345 ◽  
Author(s):  
V. Ravi Kiran ◽  
M. Rajeevan ◽  
H. Gadhavi ◽  
S. Vijaya Bhaskara Rao ◽  
A. Jayaraman
Keyword(s):  
Radiative Forcing ◽  
Vertical Structure ◽  
Asian Monsoon ◽  
Monsoon Region ◽  
Asian Monsoon Region ◽  
Cloud Radiative Forcing ◽  
Microphysical Properties

scholarly journals Investigation of negative cloud radiative forcing over the Indian subcontinent and adjacent oceans during the summer monsoon season

2014 ◽  
Vol 14 (13) ◽  
pp. 6739-6758 ◽  
Author(s):  
B. V. Thampi ◽  
R. Roca
Keyword(s):  
Summer Monsoon ◽  
Radiative Forcing ◽  
Indian Monsoon ◽  
Indian Subcontinent ◽  
Monsoon Season ◽  
Radiative Properties ◽  
Monsoon Region ◽  
Summer Monsoon Season ◽  
Cloud Radiative Forcing ◽  
Indian Monsoon Region

Abstract. Radiative properties of clouds over the Indian subcontinent and nearby oceanic regions (0–25° N, 60–100° E) during the Asian summer monsoon season (June–September) are investigated using the Clouds and Earth's Radiant Energy System (CERES) top-of-the-atmosphere (TOA) flux data. Using multiyear satellite data, the net cloud radiative forcing (NETCRF) at the TOA over the Indian region during the Asian monsoon season is examined. The seasonal mean NETCRF is found to be negative (with its magnitude exceeding ~30 Wm−2) over (1) the northern Bay of Bengal (close to the Myanmar–Thailand coast), (2) the Western Ghats and (3) the coastal regions of Myanmar. Such strong negative NETCRF values observed over the Indian monsoon region contradict the assumption that near cancellation between LWCRF and SWCRF is a generic property of all tropical convective regions. The seasonal mean cloud amount (high and upper middle) and corresponding cloud optical depth observed over the three regions show relatively large values compared to the rest of the Indian monsoon region. Using satellite-derived cloud data, a statistical cloud vertical model delineating the cloud cover and single-scattering albedo was developed for the three negative NETCRF regions. The shortwave (SW), longwave (LW) and net cloud radiative forcing over the three negative NETCRF regions are calculated using the rapid radiative transfer model (RRTM) with the cloud vertical model as input. The NETCRF estimated from CERES observations show good comparison with that computed using RRTM (within the uncertainty limit of CERES observations). Sensitivity tests are conducted using RRTM to identify the parameters that control the negative NETCRF observed over these regions during the summer monsoon season. Increase in atmospheric water vapor content during the summer monsoon season is found to influence the negative NETCRF values observed over the region.

scholarly journals Snow-darkening versus direct radiative effects of mineral dust aerosol on the Indian summer monsoon onset: role of temperature change over dust sources

2019 ◽  
Vol 19 (3) ◽  
pp. 1605-1622 ◽  
Author(s):  
Zhengguo Shi ◽  
Xiaoning Xie ◽  
Xinzhou Li ◽  
Liu Yang ◽  
Xiaoxun Xie ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Central Asia ◽  
Black Carbon ◽  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Radiative Forcing ◽  
Indian Monsoon ◽  
Indian Subcontinent ◽  
Direct Radiative Forcing

Abstract. Atmospheric absorptive aerosols exert complicated effects on the climate system, two of which are through their direct radiative forcing and snow-darkening forcing. Compared to black carbon, the snow-darkening effect of dust on climate has been scarcely explored till now. When depositing in snow, dust can reduce the albedo of snow by darkening it and increasing the snowmelt. In this study, the snow-darkening effect of dust, as well as the direct radiative effect, on the Indian summer monsoon are evaluated by atmospheric general circulation model experiments. The results show that the snow-darkening and direct radiative forcing of dust both have significant impacts on the onset of the Indian monsoon, but they are distinctly opposite. The snow-darkening effect of dust weakens the Indian monsoon precipitation during May and June, opposite to black carbon. The surface temperature over central Asia and the western Tibetan Plateau becomes warmer due to the dust-induced decrease in snow cover, which leads to a local low-level cyclonic anomaly as well as an anticyclonic anomaly over the Indian subcontinent and Arabian Sea. This circulation pattern allows air currents penetrating into the Indian subcontinent more from central Asia but less from the Indian Ocean. In contrast, the direct radiative forcing of dust warms the low troposphere over the Arabian Peninsula, which intensifies moisture convergence and precipitation over the Indian monsoon region. The upper tropospheric atmospheric circulation over Asia is also sensitive to both effects. Compared to previous studies which emphasized the temperature over the Tibetan Plateau, our results further highlight an important role of surface/low tropospheric temperature changes over dust source areas, which can also significantly modify the response of summer monsoon. Thus, links between the climatic impact of dust and complicated thermal conditions over Asia are of importance and need to be clarified accurately.

scholarly journals Investigation of negative cloud radiative forcing over the Indian subcontinent and adjacent oceans during the summer monsoon season

2013 ◽  
Vol 13 (11) ◽  
pp. 28895-28951
Author(s):  
B. V. Thampi ◽  
R. Roca
Keyword(s):  
Summer Monsoon ◽  
Radiative Forcing ◽  
Indian Monsoon ◽  
Indian Subcontinent ◽  
Monsoon Season ◽  
Radiative Properties ◽  
Monsoon Region ◽  
Summer Monsoon Season ◽  
Cloud Radiative Forcing ◽  
Indian Monsoon Region

Abstract. Radiative properties of clouds over the Indian subcontinent and nearby oceanic regions (0–25° N, 60–100° E) during the Asian summer monsoon season (June–September) are investigated using the Clouds and Earth's Radiant Energy System (CERES) Top of the Atmosphere (TOA) flux data. Using multi-year satellite data, the net cloud radiative forcing (NETCRF) at the TOA over the Indian region during the Asian monsoon season is examined. The seasonal mean NETCRF is found to be negative (with its magnitude exceeding ~ 30 W m−2) over (1) the northern Bay of Bengal (close to the Myanmar–Thailand coast), (2) the Western Ghats and (3) the coastal regions of Myanmar. Such strong negative NETCRF values observed over the Indian monsoon region contradicts the assumption that near cancellation between LWCRF and SWCRF is a generic property of all tropical convective regions. The seasonal mean cloud amount (high and upper middle) and corresponding cloud optical depth observed over the three regions show relatively large values compared to rest of the Indian monsoon region. Using satellite derived cloud data, a statistical cloud vertical model delineating the cloud cover and single scattering albedo was developed for the three negative NETCRF regions. The shortwave (SW), longwave (LW) and net cloud radiative forcing over the three negative NETCRF regions are calculated using the Rapid Radiative Transfer Model (RRTM) with cloud vertical model as input. The NETCRF estimated from CERES observations show good comparison with that computed using RRTM (within the uncertainty limit of CERES observations). Sensitivity tests are conducted using RRTM to identify the parameters that control the negative NETCRF observed over these regions during the summer monsoon season. Increase in atmospheric water vapor content during the summer monsoon season is found to influence the negative NETCRF values observed over the region.

scholarly journals Comment on "Clouds and the Faint Young Sun Paradox" by Goldblatt and Zahnle (2011)

2012 ◽  
Vol 8 (2) ◽  
pp. 701-703 ◽  
Author(s):  
R. Rondanelli ◽  
R. S. Lindzen
Keyword(s):  
Radiative Forcing ◽  
Cirrus Clouds ◽  
Climate Feedback ◽  
Cloud Radiative Forcing ◽  
Convective Clouds ◽  
Cloud Properties ◽  
Deep Convective Clouds ◽  
The Tropics ◽  
High Clouds

Abstract. Goldblatt and Zahnle (2011) raise a number of issues related to the possibility that cirrus clouds can provide a solution to the faint young sun paradox. Here, we argue that: (1) climates having a lower than present mean surface temperature cannot be discarded as solutions to the faint young sun paradox, (2) the detrainment from deep convective clouds in the tropics is a well-established physical mechanism for the formation of high clouds that have a positive radiative forcing (even if the possible role of these clouds as a negative climate feedback remains controversial) and (3) even if some cloud properties are not mutually consistent with observations in radiative transfer parameterizations, the most relevant consistency (for the purpose of hypothesis testing) is with observations of the cloud radiative forcing. Therefore, we maintain that cirrus clouds, as observed in the current climate and covering a large region of the tropics, can provide a solution to the faint young sun paradox, or at least ease the amount of CO2 or other greenhouse substances needed to provide temperatures above freezing during the Archean.

Sign in / Sign up

Export Citation Format

Share Document