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Microphysical and radiative effects of aerosols on warm clouds during the Amazon biomass burning season as observed by MODIS: impacts of water vapor and land cover
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 7. Ten Hoeve J.E.; Remer L.A.; Jacobson M.Z. - Copernicus GmbH, 2011Aerosol, cloud, water vapor, and temperature profile data from the Moderate Resolution Imaging Spectroradiometer (MODIS) are utilized to examine the impact of aerosols on clouds during the Amazonian biomass burning season in Rondônia, Brazil. It is found that increasing background column water vapor (CWV) throughout this transition season between the Amazon dry and wet seasons likely exerts a strong effect on cloud properties. As a result, proper analysis of aerosol-cloud relationships requires that data be stratified by CWV to account better for the influence of background meteorological vari ...
[article]Microphysical and radiative effects of aerosols on warm clouds during the Amazon biomass burning season as observed by MODIS: impacts of water vapor and land cover
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Available online: http://dx.doi.org/10.5194/acp-11-3021-2011
in Atmospheric Chemistry and Physics (ACP) > Vol. 11. N° 7 [04/01/2011] . - p.3021-3036Aerosol, cloud, water vapor, and temperature profile data from the Moderate Resolution Imaging Spectroradiometer (MODIS) are utilized to examine the impact of aerosols on clouds during the Amazonian biomass burning season in Rondônia, Brazil. It is found that increasing background column water vapor (CWV) throughout this transition season between the Amazon dry and wet seasons likely exerts a strong effect on cloud properties. As a result, proper analysis of aerosol-cloud relationships requires that data be stratified by CWV to account better for the influence of background meteorological variation. Many previous studies of aerosol-cloud interactions over Amazonia have ignored the systematic changes to meteorological factors during the transition season, leading to possible misinterpretation of their results. Cloud fraction (CF) is shown to increase or remain constant with aerosol optical depth (AOD), depending on the value of CWV, whereas the relationship between cloud optical depth (COD) and AOD is quite different. COD increases with AOD until AOD ~ 0.3, which is assumed to be due to the first indirect (microphysical) effect. At higher values of AOD, COD is found to decrease with increasing AOD, which may be due to: (1) the inhibition of cloud development by absorbing aerosols (radiative effect/semi-direct effect) and/or (2) a possible retrieval artifact in which the measured reflectance in the visible is less than expected from a cloud top either from the darkening of clouds through the addition of carbonaceous biomass burning aerosols within or above clouds or subpixel dark surface contamination in the measured cloud reflectance. If (1) is a contributing mechanism, as we suspect, then an empirically-derived increasing function between cloud drop number and aerosol concentration, assumed in a majority of global climate models, is inaccurate since these models do not include treatment of aerosol absorption in and around clouds. The relationship between aerosols and both CWV and clouds over varying land surface types is also analyzed. The study finds that the difference in CWV between forested and deforested land is not correlated with aerosol loading, supporting the assumption that temporal variation of CWV is primarily a function of the larger-scale meteorology. However, a difference in the response of CF to increasing AOD is observed between forested and deforested land. This suggests that dissimilarities between other meteorological factors, such as atmospheric stability, may have an impact on aerosol-cloud correlations between different land cover types.
Language(s): English
Format: Digital (Free)Tags: Aerosols ; Amazon ; Biomass ; Warm cloud ; Observations ; Water vapour ; Region III - South America
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The 2009–2010 Arctic polar stratospheric cloud season: a CALIPSO perspective
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 5. Pitts M.C.; Poole L.R.; Dörnbrack A.; et al. - Copernicus GmbH, 2011Spaceborne lidar measurements from CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) are used to provide a vortex-wide perspective of the 2009–2010 Arctic PSC (polar stratospheric cloud) season to complement more focused measurements from the European Union RECONCILE (reconciliation of essential process parameters for an enhanced predictability of Arctic stratospheric ozone loss and its climate interactions) field campaign. The 2009–2010 Arctic winter was unusually cold at stratospheric levels from mid-December 2009 until the end of January 2010, and was one of only ...
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Available online: http://dx.doi.org/10.5194/acp-11-2161-2011
in Atmospheric Chemistry and Physics (ACP) > Vol. 11. N° 5 [03/11/2011] . - p.2161-2177Spaceborne lidar measurements from CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) are used to provide a vortex-wide perspective of the 2009–2010 Arctic PSC (polar stratospheric cloud) season to complement more focused measurements from the European Union RECONCILE (reconciliation of essential process parameters for an enhanced predictability of Arctic stratospheric ozone loss and its climate interactions) field campaign. The 2009–2010 Arctic winter was unusually cold at stratospheric levels from mid-December 2009 until the end of January 2010, and was one of only a few winters from the past fifty-two years with synoptic-scale regions of temperatures below the frost point. More PSCs were observed by CALIPSO during the 2009–2010 Arctic winter than in the previous three Arctic seasons combined. In particular, there were significantly more observations of high number density NAT (nitric acid trihydrate) mixtures (referred to as Mix 2-enh) and ice PSCs. We found that the 2009–2010 season could roughly be divided into four periods with distinctly different PSC optical characteristics. The early season (15–30 December 2009) was characterized by patchy, tenuous PSCs, primarily low number density liquid/NAT mixtures. No ice clouds were observed by CALIPSO during this early phase, suggesting that these early season NAT clouds were formed through a non-ice nucleation mechanism. The second phase of the season (31 December 2009–14 January 2010) was characterized by frequent mountain wave ice clouds that nucleated widespread NAT particles throughout the vortex, including Mix 2-enh. The third phase of the season (15–21 January 2010) was characterized by synoptic-scale temperatures below the frost point which led to a rare outbreak of widespread ice clouds. The fourth phase of the season (22–28 January) was characterized by a major stratospheric warming that distorted the vortex, displacing the cold pool from the vortex center. This final phase was dominated by STS (supercooled ternary solution) PSCs, although NAT particles may have been present in low number densities, but were masked by the more abundant STS droplets at colder temperatures. We also found distinct variations in the relative proportion of PSCs in each composition class with altitude over the course of the 2009–2010 Arctic season. Lower number density liquid/NAT mixtures were most frequently observed in the lower altitude regions of the clouds (below ~18–20 km), which is consistent with CALIPSO observations in the Antarctic. Higher number density liquid/NAT mixtures, especially Mix 2-enh, were most frequently observed at altitudes above 18–20 km, primarily downstream of wave ice clouds. This pattern is consistent with the conceptual model whereby low number density, large NAT particles are precipitated from higher number density NAT clouds (i.e. mother clouds) that are nucleated downstream of mountain wave ice clouds.
Language(s): English
Format: Digital (Free)Tags: Aerosols ; Environment and landscape ; Cloud ; Observations ; Air pollution ; Stratosphere ; Arctic
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Dependence of aerosol-precipitation interactions on humidity in a multiple-cloud system
This study examines the dependence of aerosol-precipitation interactions on environmental humidity in a mesoscale cloud ensemble (MCE) which is composed of convective and stratiform clouds. The author found that increases in aerosol concentration enhance evaporative cooling, which raises not only the intensity of vorticity and entrainment but also that of downdrafts and low-level convergence. The increase in vorticity tends to suppress precipitation. The increase in low-level convergence tends to enhance precipitation by generating more secondary clouds in a muptiple-cloud system simulated her ...
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Available online: http://dx.doi.org/10.5194/acp-11-2179-2011
in Atmospheric Chemistry and Physics (ACP) > Vol. 11. N° 5 [03/11/2011] . - p.2179-2196This study examines the dependence of aerosol-precipitation interactions on environmental humidity in a mesoscale cloud ensemble (MCE) which is composed of convective and stratiform clouds. The author found that increases in aerosol concentration enhance evaporative cooling, which raises not only the intensity of vorticity and entrainment but also that of downdrafts and low-level convergence. The increase in vorticity tends to suppress precipitation. The increase in low-level convergence tends to enhance precipitation by generating more secondary clouds in a muptiple-cloud system simulated here.
Language(s): English
Format: Digital (Free)Tags: Aerosols ; Water ; Environment and landscape ; Hydrology ; Cloud ; Stratiform cloud ; Precipitation
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Characteristics, sources, and transport of aerosols measured in spring 2008 during the aerosol, radiation, and cloud processes affecting Arctic Climate (ARCPAC) Project
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 3. Brock C.A.; Cozic J.; Bahreini R.; et al. - Copernicus GmbH, 2011We present an overview of the background, scientific goals, and execution of the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC) project of April 2008. We then summarize airborne measurements, made in the troposphere of the Alaskan Arctic, of aerosol particle size distributions, composition, and optical properties and discuss the sources and transport of the aerosols. The aerosol data were grouped into four categories based on gas-phase composition. First, the background troposphere contained a relatively diffuse, sulfate-rich aerosol extending from the top of the sea ...
[article]Characteristics, sources, and transport of aerosols measured in spring 2008 during the aerosol, radiation, and cloud processes affecting Arctic Climate (ARCPAC) Project
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Available online: http://dx.doi.org/10.5194/acp-11-2423-2011
C.A. Brock ; J. Cozic ; R. Bahreini ; K.D. Froyd ; A.M. Middlebrook ; A. McComiskey ; J. Brioude ; O.R. Cooper ; A. Stohl ; K.C. Aikin ; J.A. de Gouw ; D.W. Fahey ; R.A. Ferrare ; R.-S. Gao ; W. Gore ; J.S. Holloway ; G. Hübler ; A. Jefferson ; D.A. Lack ; S. Lance ; R.H. Moore ; D.M. Murphy ; A. Nenes ; P.C. Novelli ; J.B. Nowak ; J.A. Ogren ; J. Peischl ; R.B. Pierce ; P. Pilewskie ; P.K. Quinn ; T.B. Ryerson ; K.S. Schmidt ; J.P. Schwarz ; H. Sodemann ; J.R. Spackman ; H. Stark ; D.S. Thomson ; T. Thornberry ; P. Veres ; L.A. Watts ; C. Warneke ; A.G. Wollny
in Atmospheric Chemistry and Physics (ACP) > Vol. 11. N° 3 [03/01/2011] . - p.2423-2453We present an overview of the background, scientific goals, and execution of the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC) project of April 2008. We then summarize airborne measurements, made in the troposphere of the Alaskan Arctic, of aerosol particle size distributions, composition, and optical properties and discuss the sources and transport of the aerosols. The aerosol data were grouped into four categories based on gas-phase composition. First, the background troposphere contained a relatively diffuse, sulfate-rich aerosol extending from the top of the sea-ice inversion layer to 7.4 km altitude. Second, a region of depleted (relative to the background) aerosol was present within the surface inversion layer over sea-ice. Third, layers of dense, organic-rich smoke from open biomass fires in southern Russia and southeastern Siberia were frequently encountered at all altitudes from the top of the inversion layer to 7.1 km. Finally, some aerosol layers were dominated by components originating from fossil fuel combustion.
Of these four categories measured during ARCPAC, the diffuse background aerosol was most similar to the average springtime aerosol properties observed at a long-term monitoring site at Barrow, Alaska. The biomass burning (BB) and fossil fuel layers were present above the sea-ice inversion layer and did not reach the sea-ice surface during the course of the ARCPAC measurements. The BB aerosol layers were highly scattering and were moderately hygroscopic. On average, the layers produced a noontime net heating of ~0.1 K day−1 between 3 and 7 km and a slight cooling at the surface. The ratios of particle mass to carbon monoxide (CO) in the BB plumes, which had been transported over distances >5000 km, were comparable to the high end of literature values derived from previous measurements in wildfire smoke. These ratios suggest minimal precipitation scavenging and removal of the BB particles between the time they were emitted and the time they were observed in dense layers above the sea-ice inversion layer.Language(s): English
Format: Digital (Free)Tags: Aerosols ; Atmospheric circulation ; Climate ; Impact studies ; Cloud formation ; Research ; Arctic
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Optical properties of pristine ice crystals in mid-latitude cirrus clouds: a case study during CIRCLE-2 experiment
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 3. Gayet J.-F.; Mioche G.; Shcherbakov V.; et al. - Copernicus GmbH, 2011In this paper, we describe in situ observations of mid-latitude cirrus cloud band carried out on 16 May 2007 during the CIRCLE-2 experiment. The Polar Nephelometer and the Cloud Particle Imager (CPI) instruments with PMS FSSP-300 and 2D-C probes were used for the description of the optical and microphysical cloud properties. Two selected cloud regions are compared and discussed in detail. Significant differences in optical properties are evidenced in terms of 22° halo occurrences even though prevalent planar-plate ice crystals are observed in both cloud regions. Featureless scattering phase fu ...
[article]Optical properties of pristine ice crystals in mid-latitude cirrus clouds: a case study during CIRCLE-2 experiment
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Available online: http://dx.doi.org/10.5194/acp-11-2537-2011
J.-F. Gayet ; G. Mioche ; V. Shcherbakov ; C. Gourbeyre ; R. Busen ; A. Minikin
in Atmospheric Chemistry and Physics (ACP) > Vol. 11. N° 3 [03/01/2011] . - p.2537-2544In this paper, we describe in situ observations of mid-latitude cirrus cloud band carried out on 16 May 2007 during the CIRCLE-2 experiment. The Polar Nephelometer and the Cloud Particle Imager (CPI) instruments with PMS FSSP-300 and 2D-C probes were used for the description of the optical and microphysical cloud properties. Two selected cloud regions are compared and discussed in detail. Significant differences in optical properties are evidenced in terms of 22° halo occurrences even though prevalent planar-plate ice crystals are observed in both cloud regions. Featureless scattering phase functions are measured in the first cloud region located near the trailing edge of the cirrus-band at about 11 800 m/−57 °C. In contrast, well pronounced 22° halo peaks are observed with predominant similar-shaped ice crystals near the cirrus-band leading edge at 7100 m/−27 °C. CPI ice crystal images with Polar Nephelometer observations are carefully analysed and interpreted from a theoretical light scattering model in order to explain occurrence and non-occurrence of the 22° halo feature. The results highlight that the halo peaks are inherent only in perfect plate ice crystals (or pristine crystals). On the basis of previous datasets in mid-latitude cirrus, it is found that simple pristine crystals are uncommon whereas particles with imperfect or complex shapes are prevalent. As a result, phase functions that are smooth and featureless best represent cirrus scattering properties.
Language(s): English
Format: Digital (Free)Tags: Cirrus (Ci) ; Cloud ; Observations
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Evaluating the effects of microphysical complexity in idealised simulations of trade wind cumulus using the Factorial Method
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 3. Dearden C.; Connolly P.J.; Choularton T.W.; et al. - Copernicus GmbH, 2011The effect of microphysical and environmental factors on the development of precipitation in warm idealised cloud is explored using a kinematic modelling framework. A simple one-dimensional column model is used to drive a suite of microphysics schemes including a flexible multi-moment bulk scheme (including both single and dual moment cloud liquid water) and a state-of-the-art bin-resolved scheme with explicit treatments of liquid and aerosol. The Factorial Method is employed to quantify and compare the sensitivities of each scheme under a set of controlled conditions, in order to isolate the ...
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Scale-by-scale analysis of probability distributions for global MODIS-AQUA cloud properties: how the large scale signature of turbulence may impact statistical analyses of clouds
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 3. de la Torre Juárez M.; Davis A.B.; Fetzer E.J. - Copernicus GmbH, 2011Means, standard deviations, homogeneity parameters used in models based on their ratio, and the probability distribution functions (PDFs) of cloud properties from the MODerate resolution Infrared Spectrometer (MODIS) are estimated globally as function of averaging scale varying from 5 to 500 km. The properties – cloud fraction, droplet effective radius, and liquid water path – all matter for cloud-climate uncertainty quantification and reduction efforts. Global means and standard deviations are confirmed to change with scale. For the range of scales considered, global means vary only within 3% ...
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Chemical composition and mixing-state of ice residuals sampled within mixed phase clouds
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 3. Ebert M.; Worringen A.; Benker N.; et al. - Copernicus GmbH, 2011During an intensive campaign at the high alpine research station Jungfraujoch, Switzerland, in February/March 2006 ice particle residuals within mixed-phase clouds were sampled using the Ice-counterflow virtual impactor (Ice-CVI). Size, morphology, chemical composition, mineralogy and mixing state of the ice residual and the interstitial (i.e., non-activated) aerosol particles were analyzed by scanning and transmission electron microscopy. Ice nuclei (IN) were identified from the significant enrichment of particle groups in the ice residual (IR) samples relative to the interstitial aerosol. In ...
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On the impacts of phytoplankton-derived organic matter on the properties of the primary marine aerosol – Part 2: Composition, hygroscopicity and cloud condensation activity
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 3. Fuentes E.; Coe H.; Green D.; et al. - Copernicus GmbH, 2011The effect of nanogel colloidal and dissolved organic matter <0.2 μm, secreted by marine biota, on the hygroscopic growth and droplet activation behaviour of the primary marine aerosol was studied. Seawater proxies were prepared by the combination of artificial seawater devoid of marine organics and natural seawater enriched in organic exudate released by laboratory-grown phytoplankton cultures, as described in a companion paper. The primary aerosol was produced by bubble bursting, using a plunging multijet system as an aerosol generator.
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Cloud condensation nuclei in polluted air and biomass burning smoke near the mega-city Guangzhou, China – Part 2: Size-resolved aerosol chemical composition, diurnal cycles, and externally mixed weakly CCN-active soot particles
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 3. Rose D.; Gunthe S.S.; Su H.; et al. - Copernicus GmbH, 2011Size-resolved chemical composition, mixing state, and cloud condensation nucleus (CCN) activity of aerosol particles in polluted mega-city air and biomass burning smoke were measured during the PRIDE-PRD2006 campaign near Guangzhou, China, using an aerosol mass spectrometer (AMS), a volatility tandem differential mobility analyzer (VTDMA), and a continuous-flow CCN counter (DMT-CCNC).
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A new method for retrieval of the extinction coefficient of water clouds by using the tail of the CALIOP signal
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 3. Li J.; Hu Y.; Huang J.; et al. - Copernicus GmbH, 2011A method is developed based on Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) level 1 attenuated backscatter profile data for deriving the mean extinction coefficient of water droplets close to cloud top. The method is applicable to low level (cloud top <2 km), opaque water clouds in which the lidar signal is completely attenuated beyond about 100 m of penetration into the cloud. The photo multiplier tubes (PMTs) of the 532 nm detectors (parallel and perpendicular polarizations) of the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) both exhibit a non-id ...
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Satellite Meteorology: GOES Channel Selection V2
This module is an update to the previous Satellite Meteorology: GOES Channel Selection module. It reviews the five GOES imager channels and their use, incorporating conceptual visualizations and numerous imagery examples. The module also includes updated information on improvements for the GOES-13, -14 and -15 satellites. Highlights include a higher resolution 13.3 micrometer CO2 channel (GOES-14 & -15), modified spectral response of the visible channel, improved radiometric performance and pixel geolocation, and shortened data outages during the fall and spring satellite eclipse periods.
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Kinematic and Thermodynamical Structures of Longitudinal-Mode Snow Bands over the Sea of Japan during Cold-Air Outbreaks Part I: Snow Bands in Large Vertical Shear Environment in the Band-Transverse Direction
Journal of the Meteorological Society of Japan, Vol. 88. No 4. Yamada Yoshinori; Murakami Masataka; Mizuno Hakaru - Meteorological Society of Japan, 2010The kinematic and thermodynamical structures of two longitudinal-mode (termed “L-mode”) snow bands over the Sea of Japan occurring on February 8, 1991 and January 21, 1993 are analyzed mainly based on dual-Doppler radar data. The L-mode snow bands with multicellular structure in 1991 and 1993 formed, respectively, at the early onset of and toward the end of cold-air outbreaks, where the magnitude of the band-transverse vertical shear was roughly 2 × 10-3 s-1 approximately in the lower-half of the mixed layer. This magnitude was larger than that associated with L-mode snow bands characterized b ...
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The Structure and Formation Mechanism of Transversal Cloud Bands Associated with the Japan-Sea Polar-Airmass Convergence Zone
Journal of the Meteorological Society of Japan, Vol. 88. No 4. Eito Hisaki; Murakami Masataka; Muroi Chiashi - Meteorological Society of Japan, 2010During a cold-air outbreak, a broad cloud band is occasionally observed over the Japan-Sea Polar-Airmass Convergence Zone (JPCZ) that forms over the Sea of Japan from the base of the Korean Peninsula to the Japanese Islands. On 14 January 2001, a broad cloud band associated with the JPCZ (JPCZ cloud band) extended in a southeastward direction from the base of the Korean Peninsula to Wakasa Bay, and it stagnated for half a day. The JPCZ cloud band consisted of two cloud regions: one was a long cloud band extending along its southwestern edge (a developed convective cloud band), and the other wa ...
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Regime Behavior in the Sea Surface Temperature-Cloud Radiative Forcing Relationships over the Pacific Cold Tongue Region
Atmospheric and Oceanic Science Letters, Volume 3 Number 5. Wu Chun-Qiang; Zhou Tian-Jun; De-Zheng Xiao-Li - Science Press, 2010Previous analyses on the estimates of water vapor and cloud-related feedbacks in the tropics usually use observations over the Earth Radiation Budget Experiment (ERBE) period (1985–89). To examine the sample dependence of previous estimates, the authors extend the analysis to two additional periods: 1990–94 and 1995–99. The results confirm our hypothesis, i.e., the values of the feedbacks depend on the period of data coverage. The differences in the feedbacks from cloud radiative forcings (CRFs) estimated from the three periods are particularly significant. Two possible causes for these differ ...
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Special issue - Atmospheric brown cloud in the Himalayas
is an issue of Atmospheric Chemistry and Physics (ACP). Copernicus GmbH, 2010
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Aerosol Indirect Effects on Warm Clouds in the Grid-Point Atmospheric Model of IAP LASG (GAMIL)
Atmospheric and Oceanic Science Letters, Volume 3 Number 4. Shi Xiang-Jun; Wang Bin; Liu Xiao-Hong; et al. - Science Press, 2010Aerosol indirect effects on warm clouds are estimated in the Grid-point Atmospheric Model of IAP LASG (GAMIL) with a new two-moment cloud microphysics scheme using two different physically-based aerosol activation parameterizations: Abdul-Razzak and Ghan, and Nenes and Seinfeld. The annual global mean changes in shortwave cloud forcing from preindustrial times to present day (a measure of the aerosol indirect effects) estimated from these two parameterizations are remarkably similar: 0.76 W m-2 with the Abdul-Razzak and Ghan parameterization, and 0.78 W m-2 with the Nenes and Seinfeld paramete ...
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Volume 3 Number 4 - 16 July 2010
is an issue of Atmospheric and Oceanic Science Letters. Science Press, 2010
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Cloud effects on erythemal UV radiation in a complex topography
Walker Daniel - Confédération Suisse, 2010UV radiation is part of the solar spectrum with wavelengths between 100 and 400 nm. In this study, erythemal UV is investigated; a measure directly related to the harmfulness of
solar radiation to our skin. UV radiation has important impacts on di?fferent ecosystems, life and also on public health. Therefore, detailed information about the spatial distribution of UV radiation and its temporal evolution is required. Since observations are spatially and temporally sparse, these issues are often approached by radiative transfer modeling. These models perform well for simulating UV radiatio ...
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S-290 Unit 4: Basic Weather Processes
The “S-290 Unit 4: Basic Weather Processes” distance learning module summarizes atmospheric structure and composition, the Sun-Earth radiation budget, weather elements used to describe the atmosphere, the greenhouse effect, and temperature lags observed both daily and seasonally. The content introduces the concepts of pressure, atmospheric heating, and temperature and provides a basis for understanding weather topics that are explored in more detail in other modules of the Intermediate Wildland Fire Behavior Course.
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Feature Identification Exercises: Clouds, Snow, and Ice Using MODIS
This module consists of four exercises where users identify surface features, distinguish clouds from snow on the ground, and determine cloud phase using multispectral analysis. The module also includes an overview of multispectral techniques available on many operational and research polar-orbiting satellites. A page with links to real-time polar-orbiting data and information is also included.
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WCRP Informal/Series Report, 19/2001. Report of the ninth session of the GEWEX Cloud system study (GCSS)
World Meteorological Organization (WMO) ; Intergovernmental Oceanographic Commission (IOC); International Council for Science (ICSU) - WMO, 2001
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