Aerosol absorption constitutes a significant component of the total radiative effect of aerosols, and hence its representation in general circulation models is crucial to radiative forcing estimates. ...We use here multiple observations to evaluate the performance of CAM5.3-Oslo with respect to its aerosol representation. CAM5.3-Oslo is the atmospheric component of the earth system model NorESM1.2 and shows on average an underestimation of aerosol absorption in the focus region over East and South Asia and a strong aerosol absorption overestimation in desert and arid regions compared to observations and other AeroCom phase III models. We explore the reasons of the model spread and find that it is related to the column burden and residence time of absorbing aerosols, in particular black carbon and dust. We conduct further sensitivity simulations with CAM5.3-Oslo to identify processes which are most important for modelled aerosol absorption. The sensitivity experiments target aerosol optical properties, and contrast their impact with effects from changes in emissions and deposition processes, and the driving meteorology. An improved agreement with observations was found with the use of a refined emission data set, transient emissions and assimilation of meteorological observations. Changes in optical properties of absorbing aerosols can also reduce the under- and overestimation of aerosol absorption in the model. However, changes in aerosol absorption strength between the sensitivity experiments are small compared to the inter-model spread among the AeroCom phase III models.
A detailed analysis of optical and microphysical properties of aerosol particles during the dry winter monsoon season above the northern Indian Ocean is presented. The Cloud Aerosol Radiative Forcing ...Experiment (CARDEX), conducted from 16 February to 30 March 2012 at the Maldives Climate Observatory on Hanimaadhoo island (MCOH) in the Republic of the Maldives, used autonomous unmanned aerial vehicles (AUAV) to perform vertical in situ measurements of particle number concentration, particle number size distribution as well as particle absorption coefficients. These measurements were used together with surface- based Mini Micro Pulse Lidar (MiniMPL) observations and aerosol in situ and off-line measurements to investigate the vertical distribution of aerosol particles.Air masses were mainly advected over the Indian subcontinent and the Arabian Peninsula. The mean surface aerosol number concentration was 1717 ± 604 cm−3 and the highest values were found in air masses from the Bay of Bengal and Indo-Gangetic Plain (2247 ± 370 cm−3). Investigations of the free tropospheric air showed that elevated aerosol layers with up to 3 times higher aerosol number concentrations than at the surface occurred mainly during periods with air masses originating from the Bay of Bengal and the Indo-Gangetic Plain. This feature is different compared to what was observed during the Indian Ocean Experiment (INDOEX) conducted in winter 1999, where aerosol number concentrations generally decreased with height. In contrast, lower particle absorption at the surface (σabs(520 nm) = 8.5 ± 4.2 Wm−1) was found during CARDEX compared to INDOEX 1999.Layers with source region specific single-scattering albedo (SSA) values were derived by combining vertical in situ particle absorption coefficients and scattering coefficients calculated with Mie theory. These SSA layers were utilized to calculate vertical particle absorption profiles from MiniMPL profiles. SSA surface values for 550 nm for dry conditions were found to be 0.94 ± 0.02 and 0.91 ± 0.02 for air masses from the Arabian Sea (and Middle East countries) and India (and Bay of Bengal), respectively. Lidar-derived particle absorption coefficient profiles showed both a similar magnitude and structure as the in situ profiles measured with the AUAV. However, primarily due to insufficient accuracy in the SSA estimates, the lidar-derived absorption coefficient profiles have large uncertainties and are generally weakly correlated to vertically in situ measured particle absorption coefficients.Furthermore, the mass absorption efficiency (MAE) for the northern Indian Ocean during the dry monsoon season was calculated to determine equivalent black carbon (EBC) concentrations from particle absorption coefficient measurements. A mean MAE of 11.6 and 6.9 m2 g−1 for 520 and 880 nm, respectively, was found, likely representing internally mixed BC containing particles. Lower MAE values for 880 and 520 nm were found for air masses originating from dust regions such as the Arabian Peninsula and western Asia (MAE(880 nm) = 5.6 m2 g−1, MAE(520 nm) = 9.5 m2 g−1) or from closer source regions as southern India (MAE(880 nm) = 4.3 m2 g−1, MAE(520 nm) = 7.3 m2 g−1).
Methods for determining aerosol types in cases where chemical composition measurements are not available are useful for improved aerosol radiative forcing estimates. In this study, two aerosol ...characterization methods by Cazorla et al. (2013, https://doi.org/10.5194/acp-13-9337-2013; CA13) and Costabile et al. (2013, https://doi.org/10.5194/acp-13-2455-2013; CO13) using wavelength‐dependent particle absorption and scattering are used, to assess their applicability and examine their limitations. Long‐term ambient particle optical property and chemical composition (major inorganic ions and bulk carbon) measurements from the Maldives Climate Observatory Hanimaadhoo as well as concurrent air mass trajectories are utilized to test the classifications based on the determined absorption Ångström exponent, scattering Ångström exponent, and single scattering albedo. The resulting aerosol types from the CA13 method show a good qualitative agreement with the particle chemical composition and air mass origin. In general, the size differentiation using the scattering Ångström exponent works very well for both methods, while the composition identification depending mainly on the absorption Ångström exponent can result in aerosol misclassifications at Maldives Climate Observatory Hanimaadhoo. To broaden the applicability of the CA13 method, we suggest to include an underlying marine aerosol group in the classification scheme. The classification of the CO13 method is less clear, and its applicability is limited when it is extended to aerosols in this environment at ambient humidity.
Key Points
Optical aerosol classifications conform reasonable well with chemical measurements and air mass origin analysis
The extension of optical characterization methods to a remote marine site is limited due to strong aerosol mixing and humidification
An underlying sea spray category should be considered for optical aerosol characterization at sites with marine influence
A detailed analysis of optical and microphysical properties of aerosol particles during the dry winter monsoon season above the northern Indian Ocean is presented. The Cloud Aerosol Radiative Forcing ...Experiment (CARDEX), conducted from 16 February to 30 March 2012 at the Maldives Climate Observatory on Hanimaadhoo island (MCOH) in the Republic of the Maldives, used autonomous unmanned aerial vehicles (AUAV) to perform vertical in situ measurements of particle number concentration, particle number size distribution as well as particle absorption coefficients. These measurements were used together with surface- based Mini Micro Pulse Lidar (MiniMPL) observations and aerosol in situ and off-line measurements to investigate the vertical distribution of aerosol particles.Air masses were mainly advected over the Indian subcontinent and the Arabian Peninsula. The mean surface aerosol number concentration was 1717â±â604 cm.sup.-3 and the highest values were found in air masses from the Bay of Bengal and Indo-Gangetic Plain (2247â±â370 cm.sup.-3). Investigations of the free tropospheric air showed that elevated aerosol layers with up to 3 times higher aerosol number concentrations than at the surface occurred mainly during periods with air masses originating from the Bay of Bengal and the Indo-Gangetic Plain. This feature is different compared to what was observed during the Indian Ocean Experiment (INDOEX) conducted in winter 1999, where aerosol number concentrations generally decreased with height. In contrast, lower particle absorption at the surface (Ï.sub.abs (520 nm)â=â8.5â±â4.2 Wm.sup.-1) was found during CARDEX compared to INDOEX 1999.Layers with source region specific single-scattering albedo (SSA) values were derived by combining vertical in situ particle absorption coefficients and scattering coefficients calculated with Mie theory. These SSA layers were utilized to calculate vertical particle absorption profiles from MiniMPL profiles. SSA surface values for 550â¯nm for dry conditions were found to be 0.94â±â0.02 and 0.91â±â0.02 for air masses from the Arabian Sea (and Middle East countries) and India (and Bay of Bengal), respectively. Lidar-derived particle absorption coefficient profiles showed both a similar magnitude and structure as the in situ profiles measured with the AUAV. However, primarily due to insufficient accuracy in the SSA estimates, the lidar-derived absorption coefficient profiles have large uncertainties and are generally weakly correlated to vertically in situ measured particle absorption coefficients.Furthermore, the mass absorption efficiency (MAE) for the northern Indian Ocean during the dry monsoon season was calculated to determine equivalent black carbon (EBC) concentrations from particle absorption coefficient measurements. A mean MAE of 11.6 and 6.9 m.sup.2 g.sup.-1 for 520 and 880â¯nm, respectively, was found, likely representing internally mixed BC containing particles. Lower MAE values for 880 and 520â¯nm were found for air masses originating from dust regions such as the Arabian Peninsula and western Asia (MAE(880â¯nm)â¯â=â5.6 m.sup.2 g.sup.-1, MAE(520â¯nm)â¯â=â9.5 m.sup.2 g.sup.-1) or from closer source regions as southern India (MAE(880â¯nm)â¯â=â4.3 m.sup.2 g.sup.-1, MAE(520â¯nm)â¯â=â7.3 m.sup.2 g.sup.-1).
In contrast to other countries, no collective study of Rehbein's procedure in German-speaking nations has been performed. Therefore, our intention was, analogously to Goto and Ikeda's (10) Japanese ...study in 1984, Kleinhaus's (13) study on Swenson's procedure in 1979, Bourdelat's (2) French-Canadian investigation into Duhamel's technique in 1997 and Martuciello's (11) and Teitelbaum's (16) follow-up in the year 2000, to perform a follow-up study of Rehbein's technique of deep anterior resection.
The data of 200 patients from 22 German-speaking centers in Switzerland, Austria and Germany were collected. These data were gathered by questionnaire and the children were followed up in the individual participating hospitals for at least 3.5 years after the procedure. The procedure was performed between 1993 and 1997, over a 5-year period. The questionnaire contained 74 items including anamnestic data, diagnostic postoperative treatment and reoperations.
Concerning the incidence of anastomotic leaks and resolving anastomotic strictures there was no significant difference between the results in our series and those of the collective analyses made by Hofmann von Kap-herr (7), Holschneider (9) and Sherman (18). In 6.6 % of the 191 patients an anastomotic leak and in 9.9 % a rectal stricture, which had to be dilated, was observed. Concerning late complications, 22.8 % of the children suffered from constipation, 4.3 % from encopresis, 10.6 % from enterocolitis and only 0.5 % from enuresis. The frequency of constipation diminishes over the years. A comparison of the different large series in the literature clearly shows that the incidence of constipation is higher after Rehbein's procedure and the frequency of urinary incontinence and encopresis higher following Swenson's, Soave's and Duhamel's techniques. The incidence of enterocolitis is less after Rehbein's procedure than after Swenson's, Soave's and Duhamel's techniques.
The different results in the literature are due to the individual experience of the author, the very different follow-up methods and the date of follow-up. Therefore, the different results are hard to compare with our study. Nevertheless, Rehbein's anterior resection still could be presented as an adequate and important method to treat Hirschsprung's disease.
Premature fusion of all major cranial and facial sutures, termed pancraniofacial synostosis by us, was first described as "Kleeblattschädel deformity," but can also be found in anomalies such as ...Crouzon's disease, Apert's syndrome, Pfeiffer's syndrome, and severe forms of plagiocephaly. This rare craniofacial anomaly often presents an immediate threat to life right after birth. Early subtotal craniectomy frequently combined with frontoorbitofacial advancement must be performed to decrease intracranial pressure, preserve vision, and open up the blocked upper airway. Concomitant hydrocephaly is shunted preoperatively for internal decompression. Eleven patients with pancraniofacial synostosis underwent craniofacial surgery in infancy or early childhood. Only shunting of the hydrocephalus was done in 1 child. Two children died in the course of an emergency procedure and 2 children died after secondary operations for miniplate removal and revision of a valve shunting the hydrocephalus several months after the initial successful craniofacial surgery. The remaining 8 children have developed satisfactorily so far. Further corrective surgeries had to be performed in 2 patients. Good functional and aesthetic improvement could be obtained. In view of the high mortality especially after emergency procedures, we believe that early total craniofacial mobilization should be reserved for severe cases where the natural course is dismal without immediate intervention and temporary procedures such as shunting and tracheostomy are not sufficient. Elective surgeries after the age of 3 months can be performed safely in milder cases.
Cranio-orbital facial scoliosis is the result of unilateral premature stenosis of the craniofacial skeleton. Plagiocephaly is only a subform of the syndrome. The deformity progresses unless operative ...treatment is given. Operative treatment is indicated for functional, aesthetic, and psychosocial reasons. We advocate early operation in infancy (3 to 6 months) consisting of wide resection of the stenosed sutures of the cranium and orbit, repositioning, and remodeling relying on the spontaneous autodynamic reshaping of the nasoethmoidal complex and the midface structures during the course of further growth. In adolescents and adults, multisegmental osteotomies and remodeling into a definitive position are necessary.
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