Influence of aerosols on the shortwave cloud radiative forcing from North Pacific oceanic clouds: Results from the Cloud Indirect Forcing Experiment (CIFEX)

Wilcox, E. M.; Roberts, Greg; Ramanathan, V.

doi:10.1029/2006gl027150

Cited by 27 publications

(27 citation statements)

References 17 publications

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“…Unfortunately, the preindustrial observations needed to constrain the sensitivities are not available. One could estimate relationships from regressions on spatial and temporal variability during the recent decades when data from satellite, aircraft, and surface-based remote sensing are available (30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41). However, Penner et al (7) have shown that, at least for the relationship between N d and aerosol optical depth from one model, estimates from recent variability underestimate the relationship from anthropogenic emissions.…”

Section: Relationships From Pd Variations Vs Pi−pd Changesmentioning

confidence: 99%

Challenges in constraining anthropogenic aerosol effects on cloud radiative forcing using present-day spatiotemporal variability

Ghan

Wang

Zhang

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

162

211

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A large number of processes are involved in the chain from emissions of aerosol precursor gases and primary particles to impacts on cloud radiative forcing. Those processes are manifest in a number of relationships that can be expressed as factors dlnX/dlnY driving aerosol effects on cloud radiative forcing. These factors include the relationships between cloud condensation nuclei (CCN) concentration and emissions, droplet number and CCN concentration, cloud fraction and droplet number, cloud optical depth and droplet number, and cloud radiative forcing and cloud optical depth. The relationship between cloud optical depth and droplet number can be further decomposed into the sum of two terms involving the relationship of droplet effective radius and cloud liquid water path with droplet number. These relationships can be constrained using observations of recent spatial and temporal variability of these quantities. However, we are most interested in the radiative forcing since the preindustrial era. Because few relevant measurements are available from that era, relationships from recent variability have been assumed to be applicable to the preindustrial to present-day change. Our analysis of Aerosol Comparisons between Observations and Models (AeroCom) model simulations suggests that estimates of relationships from recent variability are poor constraints on relationships from anthropogenic change for some terms, with even the sign of some relationships differing in many regions. Proxies connecting recent spatial/temporal variability to anthropogenic change, or sustained measurements in regions where emissions have changed, are needed to constrain estimates of anthropogenic aerosol impacts on cloud radiative forcing.

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Section: Relationships From Pd Variations Vs Pi−pd Changesmentioning

confidence: 99%

Challenges in constraining anthropogenic aerosol effects on cloud radiative forcing using present-day spatiotemporal variability

Ghan

Wang

Zhang

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

162

211

View full text Add to dashboard Cite

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“…A number of models have been developed and used to simulate the PM other than mineral dust aerosol in East Asia in several projects, e.g. TRACER-P, ACE-Asia and MICS-ASIA projects (Chin et al, 2003;Gong et al, 2003b;Zhang et al, 2003;Tang et al, 2004;Tsai et al, 2004;Carmichael et al, 2008) and the Cloud Indirect Forcing Experiment (CIFEX) (Wilcox et al, 2006) and the East Asian regional Experiment (EAREX) (Nakajima et al, 2007). However, due to different purposes, those works were mostly focused on aerosols in the outflow of Asian continent or in Asian mega cities.…”

Section: Introductionmentioning

confidence: 99%

Towards the improvements of simulating the chemical and optical properties of Chinese aerosols using an online coupled model – CUACE/Aero

Zhou

Gong

Zhang

et al. 2012

Tellus B: Chemical and Physical Meteorology

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A B S T R A C T CUACE/Aero, the China Meteorological Administration (CMA) Unified Atmospheric Chemistry Environment for aerosols, is a comprehensive numerical aerosol module incorporating emissions, gaseous chemistry and size-segregated multi-component aerosol algorithm. On-line coupled into a meso-scale weather forecast model (MM5), its performance and improvements for aerosol chemical and optical simulations have been evaluated using the observations data of aerosols/gases from the intensive observations and from the CMA Atmosphere Watch network, plus aerosol optical depth (AOD) data from CMA Aerosol Remote Sensing network (CARSNET) and from Moderate Resolution Imaging Spectroradiometer (MODIS). Targeting Beijing and North China region from July 13 to 31, 2008, when a heavy hazy weather system occurred, the model captured the general variations of PM10 with most of the data within a factor of 2 from the observations and a combined correlation coefficient (r) of 0.38 (significance level00.05). The correlation coefficients are better at rural than at urban sites, and better at daytime than at nighttime. Chemically, the correlation coefficients between the daily-averaged modelled and observed concentrations range from 0.34 for black carbon (BC) to 0.09 for nitrates with sulphate, ammonium and organic carbon (OC) in between. Like the PM10, the values of chemical species are higher for the daytime than those for the nighttime. On average, the sulphate, ammonium, nitrate and OC are underestimated by about 60, 70, 96.0 and 10.8%, respectively. Black carbon is overestimated by about 120%. A new size distribution for the primary particle emissions was constructed for most of the anthropogenic aerosols such as BC, OC, sulphate, nitrate and ammonium from the observed size distribution of atmospheric aerosols in Beijing. This not only improves the correlation between the modelled and observed AOD, but also reduces the overestimation of AOD simulated by the original model size distributions of primary aerosols. The normalised mean error has been reduced to 62% with the CARSNET observations and 76% with MODIS, from the original 111% and 143%, respectively. The factors resulting in the underestimation of aerosol concentrations and other discrepancies in the model are explored, and improvements in enhancing the model performance are proposed from the analysis. It is found that the accuracy in meteorological predictions plays a critical role on the simulation of the occurrence and accumulation of heavy pollution episode, especially the circulation winds and the treatment of Planetary Boundary Layer (PBL).

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“…Sea salt aerosols are mostly distributed over oceans. Some field studies, such as the Cloud Indirect Forcing Experiment (CIFEX; Wilcox et al 2006), the Aerosols over China and their Climate Effect (Zhang 2007), the East Asian Regional Experiment (EAREX; Nakajima et al 2007), have investigated aerosol properties and radiative effects. Satellite data have also been used to estimate the global direct radiative forcing (DRF) of aerosols.…”

Section: Introductionmentioning

confidence: 99%

Simulation of direct radiative forcing of aerosols and their effects on East Asian climate using an interactive AGCM-aerosol coupled system

et al. 2011

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International audienceAn interactive system coupling the Beijing Climate Center atmospheric general circulation model (BCC_AGCM2. 0. 1) and the Canadian Aerosol Module (CAM) with updated aerosol emission sources was developed to investigate the global distributions of optical properties and direct radiative forcing (DRF) of typical aerosols and their impacts on East Asian climate. The simulated total aerosol optical depth (AOD), single scattering albedo, and asymmetry parameter were generally consistent with the ground-based measurements. Under all-sky conditions, the simulated global annual mean DRF at the top of the atmosphere was -2. 03 W m-2 for all aerosols including sulfate, organic carbon (OC), black carbon (BC), dust, and sea salt; the global annual mean DRF was -0. 23 W m-2 for sulfate, BC, and OC aerosols. The sulfate, BC, and OC aerosols led to decreases of 0. 58° and 0. 14 mm day-1 in the JJA means of surface temperature and precipitation rate in East Asia. The differences of land-sea surface temperature and surface pressure were reduced in East Asian monsoon region due to these aerosols, thus leading to the weakening of East Asian summer monsoon. Atmospheric dynamic and thermodynamic were affected due to the three types of aerosol, and the southward motion between 15°N and 30°N in lower troposphere was increased, which slowed down the northward transport of moist air carried by the East Asian summer monsoon, and moreover decreased the summer monsoon precipitation in south and east China. © 2011 Springer-Verlag

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Influence of aerosols on the shortwave cloud radiative forcing from North Pacific oceanic clouds: Results from the Cloud Indirect Forcing Experiment (CIFEX)

Cited by 27 publications

References 17 publications

Challenges in constraining anthropogenic aerosol effects on cloud radiative forcing using present-day spatiotemporal variability

Challenges in constraining anthropogenic aerosol effects on cloud radiative forcing using present-day spatiotemporal variability

Towards the improvements of simulating the chemical and optical properties of Chinese aerosols using an online coupled model – CUACE/Aero

Simulation of direct radiative forcing of aerosols and their effects on East Asian climate using an interactive AGCM-aerosol coupled system

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