Quasi-periodic oscillations of aerosol backscatter profiles and surface meteorological parameters during winter nights over a tropical station

Atmospheric gravity waves, which are a manifestation of the fluctuations in buoyancy of the air parcels, are well known for their direct influence on concentration of atmospheric trace gases and aerosols, and also on oscillations of meteorological variables such as temperature, wind speed, visibility and so on. The present paper reports quasi-periodic oscillations in the lidar backscatter signal strength due to aerosol fluctuations in the nocturnal boundary layer, studied with a high space-time resolution polarimetric micro pulse lidar and concurrent meteorological parameters over a tropical station in India. The results of the spectral analysis of the data, archived on some typical clear-sky conditions during winter months of 2008 and 2009, exhibit a prominent periodicity of 20–40 min in lidar-observed aerosol variability and show close association with those observed in the near-surface temperature and wind at 5% statistical significance. Moreover, the lidar aerosol backscatter signal strength variations at different altitudes, which have been generated from the height-time series of the one-minute interval profiles at 2.4 m vertical resolution, indicate vertical propagation of these waves, exchanging energy between lower and higher height levels. Such oscillations are favoured by the stable atmospheric background condition and peculiar topography of the experimental site. Accurate representation of these buoyancy waves is essential in predicting the sporadic fluctuations of weather in the tropics

Atmospheric stability effects on aerosol structure and stratification

This paper essentially addresses the structure and stratification of the nocturnal boundary layer (NBL) derived from the vertical profile measurements of aerosol concentration made with a computer-controlled Argon ion lidar system at the Indian Institue of Tropical Meteorology (IITM), Pune, India. Companions are made between the lidar observations during clear night-sky conditions and concurrent aerometric observations carried out on some selected experimental days. The results show multiple stratified aerosol layer structures in the nocturnal lower atmosphere, which drift either upward or downward depending on atmospheric stability conditions prevailing at different altitudes. The normalized aerosol concentration gradient (NCG) profiles indicate the variations in the nocturnal mixing depth from 200 to 426 m and that in the stable layer height from 325 to 725 m during the period of observations. The importance of such observations in the context of monitoring and/or assesment of airborne particulate pollutants over the urban environments associated with non-uniform terrain is discussed

Comparison of aerosol products retrieved from AERONET, MICROTOPS and MODIS over a tropical urban city, Pune, India

Aerosol Optical Depth (AOD) measurements from Aerosol Robotic NETwork (AERONET; level 2.0), Microtops - II sun-photometer and MODerate Resolution Imaging Spectroradiometer (MODIS) (Terra and Aqua; level 2, collection 5, dark target) were compared and used to characterize aerosols over Pune, India. AODs from Microtops and MODIS were compared with those measured by AERONET to evaluate the measurement quality. To the best of our knowledge, this is the first systematic comparison of MODIS aerosol products over Pune, India. The results of the analysis show that during 2008-10, 68 to 84 of the MODIS AODs fell within an expected error, as defined by the MODIS science team, and thus the retrievals from this system are validated and accepted. In addition, during pre-monsoon periods MODIS retrievals are better-matched with ground-based measurements. On the seasonal scale, MODIS retrievals corroborate well with ground-based measurements, with correlation coefficients ranging from 0.62 to 0.93. Despite an overall satellite-ground agreement, MODIS tends to under-estimate AOD during winter, and this may be due to improper assumptions of surface reflectance and the incorrect selection of aerosol types. AERONET retrieved single scattering albedo (SSA) values in winter (0.82-0.86), suggesting the dominance of absorbing aerosols, slightly increased (0.87-0.89) in pre-monsoon season, indicating more scattering type of aerosols. These values are about 8.9-1.1 lower than those of the assumed SSA values in the MODIS algorithm

Total column ozone variations over oceanic region around Indian sub-continent during pre-monsoon of 2006

International audienceSpecial campaign mode ship-based sun photometric observations of total column ozone over the oceanic regions around the Indian sub-continent (56° E?6° E, 4° N?° N) during the pre-monsoon period (18 March?11 May) of 2006 have been used to investigate the spatial and temporal distributions. The overall mean ozone content over the sea region during this period is 298 DU with a variability of ±10 DU. There is a well defined diurnal (daytime) variation in total column ozone with maximum content around the noon-time hours. The amplitude of diurnal variation is higher over the Arabian Sea compared to that over Bay of Bengal. Spatial distribution of total ozone shows higher values over the Head Bay (North Bay of Bengal) and all along the west coast of India strongly pointing to continental origin of possible anthropogenic source. This is further corroborated from the spatial distribution of simultaneously measured aerosol optical thickness (AOT, at 1020 nm) and precipitable water. The overall mean AOT over the oceanic region is 0.09 and mean precipitable water (water vapor) over Indian Ocean region was 3.25 cm which is almost 1 cm higher than that observed over Bay of Bengal and Arabian Sea during the above pre-monsoon period

Synthesis and Characterization of Magnetic Methyl Methacrylate Microspheres Loaded with Indomethacin by Emulsion Solvent Evaporation Technique

Magnetic nanoparticles encapsulated in Methyl methacrylate (Eudragit L-100) microspheres containing Indomethacin drug were prepared and their detailed structural and magnetic characteristics were studied. Iron oxide nanoparticles were obtained by chemical coprecipitation of Fe(II) and Fe(III) salts and stabilized with tetra-methyl ammonium hydroxide. Microspheres were prepared by solvent evaporation technique. We characterized the magnetic microspheres in terms of morphology, composite microstructure, size and size distribution, magnetic properties and in-vitro release patterns. The microspheres were uniform both in shape and usually also in size; their size distribution was narrow. All the magnetic parameters confirm superparamagnetic nature of the microspheres with magnetizations up to 20–30 emu/g of microspheres. The in-vitro release profile was studied in pH 7.4 phosphate buffer medium up to 8 hours using USP XXII dissolution apparatus. Drug release in the first hour was found to increase and reached a maximum, releasing approximately 60-85% of the total drug content from the microspheres within 8 hours. From this study, it could be suggested that magnetic Methyl methacrylate microspheres could be retained at their target site in-vivo and such microspheres can be used in biomedical applications and research areas such as target drug delivery, selective blood detoxification, tissue engineering and replacement, and magnetic resonance imaging (MRI) contrast agents.Keywords: Methyl methacrylate, Magnetite, Indomethacin, single emulsion solvent evaporation Technique, Chemical co-precipitation technique

Validation of MODIS Aerosol Optical Depth Retrievals over a Tropical Urban Site, Pune, India

In the present paper, MODIS (Terra and Aqua; level 2, collection 5) derived aerosoloptical depths (AODs) are compared with the ground-based measurements obtained from AERONET (level 2.0) and Microtops - II sun-photometer over a tropical urban station, Pune (18 deg 32'N; 73 deg 49'E, 559 m amsl). This is the first ever systematic validation of the MODIS aerosol products over Pune. Analysis of the data indicates that the Terra and Aqua MODIS AOD retrievals at 550 nm have good correlations with the AERONET and Microtops - II sun-photometer AOD measurements. During winter the linear regression correlation coefficients for MODIS products against AERONET measurements are 0.79 for Terra and 0.62 for Aqua; however for premonsoon, the corresponding coefficients are 0.78 and 0.74. Similarly, the linear regression correlation coefficients for Microtops measurements against MODIS products are 0.72 and 0.93 for Terra and Aqua data respectively during winter and are 0.78 and 0.75 during pre-monsoon. On yearly basis in 2008-2009, correlation coefficients for MODIS products against AERONET measurements are 0.80 and 0.78 for Terra and Aqua respectively while the corresponding coefficients are 0.70 and 0.73 during 2009-2010. The regressed intercepts with MODIS vs. AERONET are 0.09 for Terra and 0.05 for Aqua during winter whereas their values are 0.04 and 0.07 during pre-monsoon. However, MODIS AODs are found to underestimate during winter and overestimate during pre-monsoon with respect to AERONET and Microtops measurements having slopes 0.63 (Terra) and 0.74 (Aqua) during winter and 0.97 (Terra) and 0.94 (Aqua) during pre-monsoon. Wavelength dependency of Single Scattering Albedo (SSA) shows presence of absorbing and scattering aerosol particles. For winter, SSA decreases with wavelength with the values 0.86 +/- 0.03 at 440 nm and 0.82 +/- 0.04 at 1020nm. In pre-monsoon, it increases with wavelength (SSA is 0.87 +/- 0.02 at 440nm; and 0.88 +/-0.04 at 1020 nm)

Celebration-induced air quality over a tropical urban station, Pune, India

AbstractIn this paper, we studied the regional aerosol and air quality over an urban location, Pune, India during the period from 8 to 18 November 2012, encompassing a major Indian celebration, namely, Diwali Festival (12–14 November 2012) and also a clean (control) day (9 November 2012). A suit of ground–based measurements, employing solar radiometers (Microtops II and Cimel Sun–sky radiometer), Nephelometer, and satellite observations carried out over the study region have been applied for these investigations. The study revealed many interesting results which include (i) almost four–fold enhancement in AOD and fine mode dominated aerosol size distribution (ASD) during Diwali compared to clean day conditions; (ii) higher columnar water vapor (H2O), nitrogen dioxide (NO2), and lower ozone (O3) during Diwali period; (iii) higher cooling at bottom (–117W m−2) and top of the atmosphere (–33W m−2) and warming (+82W m−2) in the atmosphere during the festival period, (iv) abundance of fine mode anthropogenic scattering particles associated with greater real part and smaller imaginary part of refractive index, and higher single scattering albedo, (v) higher backscattering coefficient revealing intrusion of more aerosol particles, higher depolarization ratio indicating particles of non–spherical nature, presence of water–phase particles, more polluted smoke and dust particles, (vi) greater attenuation and poor horizontal/vertical visibility, and (vii) dominance of urban industrial/biomass burning aerosols among other aerosol types. These results have been compared with concurrent satellite products and found to be consistent. The results have been further explained with local meteorology, back–trajectory analysis and satellite rapid response images

Heterogeneity in pre-monsoon aerosol types over the Arabian Sea deduced from ship-borne measurements of spectral AODs

Ship-borne sunphotometer measurements obtained in the Arabian Sea (AS) in the pre-monsoon season (18 April–10 May 2006) during a cruise campaign (ICARB) have been used to retrieve the Aerosol Optical Depth (AOD; τ) and the Ångström wavelength exponent (α). The continents surrounding the AS produce natural and anthropogenic aerosols that have distinctive influences on α and its spectral distribution. The α values were estimated by means of the least-squares method over the spectral bands 340–1020 nm and 340–870 nm. The spectral distribution of AOD in logarithmic co-ordinates could be fit using a 2nd order polynomial with higher accuracy in the wavelength band 340–1020 nm than in the 340–870 nm band. A polynomial fit analytically parameterizes the observed wavelength dependencies of AOD with least errors in spectral variation of α and yields accurate estimates of the coefficients (<i>a</i><sub>1</sub> and <i>a</i><sub>2</sub>). The coarse-mode (positive curvature in the lnτ<sub>λ</sub> vs. lnλ) aerosols are mainly depicted in the Northern part of the AS closely associated with the nearby arid areas while fine-mode aerosols are mainly observed over the far and coastal AS regions. In the study period the mean AOD at 500 nm is 0.25±0.11 and the α<sub>340-1020</sub> is 0.90±0.19. The α<sub>340-870</sub> exhibits similar values (0.92±0.18), while significant differences revealed for the constant terms of the polynomial fit (<i>a</i><sub>1</sub> and <i>a</i><sub>2</sub>) proportionally to the wavelength band used for their determination. Observed day-to-day variability in the aerosol load and optical properties are direct consequence of the local winds and air-mass trajectories along with the position of the ship

Comparison of Sleep Attitudes and Beliefs among Older Adult Vietnamese Migrants and Australians with and without Insomnia

Sleep is an essential part of human life and is associated with both physical and mental health. When, where and how people sleep is known to vary across different cultures (Glaskin and Chenhall, 2013) but very little is documented about whether there are significant differences in attitudes and beliefs about sleep across different cultures or different ethnic groups. Previous research has found that both dysfunctional beliefs and attitudes about sleep and poor sleep hygiene knowledge can contribute to sleeping problems, especially for those with insomnia. As non-pharmacological treatments for insomnia often include addressing cognitive aspects related to sleep it is important that there is a good understanding of how sleep beliefs and attitudes may vary across groups and individuals, including possible ethnic differences. However, there has been no research, to the author’s knowledge, investigating the possible differences in sleep attitudes and beliefs between older adult Vietnamese migrants and Australians. This study aimed to examine the dysfunctional beliefs and attitudes about sleep, sleep hygiene knowledge and sleep perceptions between these two ethnic groups. Sex differences on the dependent variables were also of interest. Insomnia status was addressed as it is a possible confound. The participants consisted of 207 subjects (100 Vietnamese and 107 Australians). There were 36 males and 54 females for the Vietnamese sample with a mean age of 65.50 years (SD = 5.62). The Australian sample consisted of 50 males and 57 females with a mean age of 68.82 years (SD = 7.32)

PENYULUHAN TEKNOLOGI BRIKET BIOARANG DARI SAMPAH ORGANIK BAGI KADER LINGKUNGAN

Abstrak: Diseminasi teknologi pembuatan briket bioarang dari sampah organik telah diberikan untuk warga dan kader lingkungan RW 03 Kelurahan Tambak Rejo, Kecamatan Simokerto, Kota Surabaya. Hal ini sangat penting mengingat wilayah RW 03 Kelurahan Tambak Rejo Surabaya, yang menjadi mitra kegiatan ini, merupakan daerah pemukiman padat penduduk dengan banyak tanaman perindang sehingga banyak dihasilkan sampah daun-daun tanaman. Selama ini, daun-daun tersebut hanya dibuang atau dibakar saja. Sementara itu, sebagian warga (mitra) belum memiliki pekerjaan tetap sehingga lebih daripada 50% warganya masuk dalam kategori masyarakat berpenghasilan rendah. Oleh karena itu, kegiatan ini ditujukan untuk membantu RW 03 Kelurahan Tambak Rejo, dalam hal ini sebagai mitra kegiatan, untuk menangani permasalahan sampah organik dan sekaligus memberikan peluang usaha/kerja dengan mengolah sampah organik tersebut menjadi produk energi alternatif yaitu briket bioarang. Untuk mencapai tujuan tersebut, tahapan kegiatan meliputi tahap persiapan, tahap pelaksanan pembuatan briket, dan tahap evaluasi kegiatan. Sistem evaluasi yang digunakan untuk mengukur kinerja kegiatan adalah dengan membagikan kuisioner kepada mitra. Indikator keberhasilan kegiatan ditunjukkan dengan minimal 70% mitra yang mengikuti kegiatan penyuluhan ini merasa puas dan merasakan manfaat kegiatan sehingga dapat membantu menyelesaikan masalah yang dihadapi mitra. Adapun yang menjadi mitra adalah 46 orang warga dan perangkat RW 03 Kelurahan Tambak Rejo Surabaya. Dari hasil kegiatan dapat disimpulkan bahwa mitra dapat memahami dan membuat briket dari sampah organik dengan baik. Parameter briket yang telah sesuai SNI adalah kadar air, kadar abu, kadar karbon, dan nilai kalor, sedangkan parameter volatile matter sedikit melebihi ketentuan SNI (7%). Hasil pengisian kuisioner yang dilakukan oleh mitra menunjukkan bahwa 100% peserta kegiatan puas dengan pelaksanaan kegiatan. Tidak hanya itu saja, kegiatan ini juga menjawab kebutuhan mereka sehinga tercipta peluang untuk menjadi sumber ekonomi baru.Abstract: Technology dissemination to prepare biocharcoal briquettes from organic waste has been carried out to residents and environmental cadres from RW 03 Tambak Rejo Village, Simokerto District, Surabaya City. The activity is urgent to be performed since the region is considered as the area with dense population with many plants and therefore, the kampong possesses a lot of leaves. So far, leaves waste is only thrown away or just burned. Meanwhile, some residents do not yet have permanent jobs and therefore, more than 50% of the residents are lied into society with low-income category. Accordingly, this activity was aimed to help society of RW 03 Tambak Rejo Village, in this context as our partners, to deal with leaves problem and in the same time provide business or work opportunity by processing those leaves into alternative energy product, namely briquette. To achieve these aims, several steps involve the preparation, the implementation and finally, the evaluation step have been carried out to assess the activity. The evaluation was performed by filling out questionnaires by partners who join in this activity, i.e. 46 people. In order to measure the success of this activity, we set that at least 70% of our partners feel satisfied that this activity will solve their problems. From the results it can be concluded that participants can understand theory behind organic wastes and briquettes, as well as able to make briquettes by theirselves. Several briquette parameters that comply with SNI are water content, ash content, carbon content and heating value, while the volatile matter parameters slightly exceed the SNI provisions (7%). Questionnaires filled out by mitra show that 100% of participants were satisfied with the implementation of this activity. In addition, the activity also answers their needs which in turn can create an opportunity to become a new economic source