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)

The effect of modafinil on the rat dopamine transporter and dopamine receptors D1–D3 paralleling cognitive enhancement in the radial arm maze

A series of drugs have been reported to increase memory performance modulating the dopaminergic system and herein modafinil was tested for its working memory (WM) enhancing properties. Reuptake inhibition of dopamine, serotonin (SERT) and norepinephrine (NET) by modafinil was tested. Sixty male Sprague–Dawley rats were divided into six groups (modafinil-treated 1–5–10 mg/kg body weight, trained and untrained and vehicle treated trained and untrained rats; daily injected intraperitoneally for a period of 10 days) and tested in a radial arm maze (RAM), a paradigm for testing spatial WM. Hippocampi were taken 6 h following the last day of training and complexes containing the unphosphorylated or phosphorylated dopamine transporter (DAT-CC and pDAT-CC) and complexes containing the D1–3 dopamine receptor subunits (D1–D3-CC) were determined. Modafinil was binding to the DAT but insignificantly to SERT or NET and dopamine reuptake was blocked specifically (IC50 = 11.11 μM; SERT 1547 μM; NET 182 μM). From day 8 (day 9 for 1 mg/kg body weight) modafinil was decreasing WM errors (WMEs) in the RAM significantly and remarkably at all doses tested as compared to the vehicle controls. WMEs were linked to the D2R-CC and the pDAT-CC. pDAT and D1–D3-CC levels were modulated significantly and modafinil was shown to enhance spatial WM in the rat in a well-documented paradigm at all the three doses and dopamine reuptake inhibition with subsequent modulation of D1–3-CC is proposed as a possible mechanism of action. © 2015 Karabacak, Sase, Aher, Sase, Saroja, Cicvaric, Höger, Berger, Bakulev, Sitte, Leban, Monje and Lubec

Track D Social Science, Human Rights and Political Science

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138414/1/jia218442.pd

Multiple wavelength solar radiometer studies at Pune

197-203A multiple wavelength radiometer was developed and used to study the behaviour of aerosol optical depth at Pune during the Indian Middle Atmosphere Programme (IMAP). The radiometer was calibrated using the Langley technique at four selected wavelengths, viz. 558, 630, 690 and 735 nm. The data collected during December 1986-April 1987 was discussed. Application of Langley technique reveals that besides the linear type, two-segment Langley plot is a special feature of the aerosol behaviour at Pune during winter months. Optical depth due to particulates (i.e. the aerosol optical depth, ap) exhibits diurnal variation which is large in February and small in April. Day-to-day variation in ap is small with occasional high values on hazy days. In the monthly data, ap values are high in February and April. While the April high is the expected summer high, February high is related to the large difference in the morning and afternoon values of relative humidity (RH) observed at Pune. This effect gets further strengthened during the temperature inversion episodes occurring in the atmospheric boundary layer at Pune. Aerosol optical depth increases in the annual plot from 1983 to 1987. The spectral variation of ap exhibits a peak around 630 nm. The corresponding particle size distribution has logarithmic Gausian form. The size spectrum is unimodal with a mode radius of 0.378 m. This points to a single source of particles

Determination of atmospheric turbidity at Pune

53-59Factors affecting atmospheric turbidity are discussed. The solar radiometer measurements carried out from Pune using narrow band interference filters are analyzed to determine aerosol extinction coefficient, atmospheric turbidity coefficients and their monthly variations. Values of Angstrom turbidity coefficients α and β are computed and the results are discussed. Coefficient α which is correlated with aerosol size spectrum shows seasonal variation. For the visible region the mean value of α is about -0.49, showing the dominance of large-size aerosols. Angstrom turbidity coefficient β and Schuepp’s turbidity coefficient B have a similar trend of variation with high values in summer and low values in winter. Angstrom turbidity coefficient β and Linke’s turbidity factor T follow a liner relation. Their mean values for Pune lie in the ranges 0.16-0.42 and 3.4-4.6 respectively. Compared to the earlier reported study by Mani et al [Tellus (Sweden), 21 (1969) 829], summer turbidity at Pune has increased by 2.5-3 times. There is a rise in turbidity level at Pune even from 1986 to 1996, which is the period covered by the present study. The results show that the atmospheric haze is a major contributor to the high turbidity value in February, while wind-blown dust and influx of aerosols through pre-monsoon circulation is a major source of high turbidity value during April-May