http://nopr.niscair.res.in/handle/123456789/2795 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/4714 Title: Trace gases over the Indian region <br/> <br/>Authors: Lal, Shyam <br/> <br/>Abstract: <smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="country-region" downloadurl="http://www.5iantlavalamp.com/"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place" downloadurl="http://www.5iantlavalamp.com/"> Some of the main results related to atmospheric ozone, related trace gases and aerosols in India are reviewed in this paper. Variability in tropospheric ozone has been observed, while there are no observed changes in the stratospheric ozone. Surface measurements of these species are being carried out by various research groups. Even though pollution levels are higher, surface ozone rarely exceed 100 ppbv in India. Aerosols show large spatial and temporal variability. There is a need for detailed measurements of these trace gases covering different regions in India and vertical distributions in the troposphere. Satellite measurements of these constituents are needed to understand their long range transport. </smarttagtype></smarttagtype> <br/> <br/>Page(s): 556-570 http://nopr.niscair.res.in/handle/123456789/4713 Title: A short review on wind profiler observations of lower and middle atmospheric processes over Gadanki <br/> <br/>Authors: Rao, T Narayana; Rao, D Narayana <br/> <br/>Abstract: National Atmospheric Research Laboratory (NARL), a unique site having Mesosphere Stratosphere Troposphere (MST) Radar, Lower Atmospheric Wind Profiler (LAWP), Lidars, disdrometer, Optical Rain Gauge, Automatic Weather Station, vertical profiling with GPS soundings, and a dual frequency GPS receiver, has been operating all these instruments to support the scientific research dealing with dynamics of the lower, middle and upper atmosphere, coupling between these regions and precipitating systems. Several interesting results have been obtained making use of the experimental facilities at NARL. It is, indeed, a difficult task to review all of them in a short paper. In this communication, an attempt has been made; however, to review the exciting scientific outcome resulted from Indian MST radar LAWP measurements, confining ourselves to dynamical and microphysical aspects of atmospheric processes in the troposphere and lower stratosphere. A variety of atmospheric phenomena occurring over a wide range of temporal and spatial scales are discussed, starting from microscale turbulence within the radar resolution volume to mesoscale processes, like convection and associated processes, and to synoptic and planetary scale waves with proper referencing, wherever required. <br/> <br/>Page(s): 526-542 http://nopr.niscair.res.in/handle/123456789/4712 Title: Daytime optical investigation of the equatorial mesopause energetics in the context of equatorial MLTI coupling: Recent results <br/> <br/>Authors: Pant, Tarun Kumar; Vineeth, C; Sridharan, R <br/> <br/>Abstract: <smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="City" downloadurl="http://www.5iamas-microsoft-com:office:smarttags"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place" downloadurl="http://www.5iantlavalamp.com/"> First experimental evidences for the mesopause energetic changes in context of (a) counter electrojet (CEJ); (b) solar flare; and (c) solar eclipse in the equatorial mesopause region using a daytime optical photometer are presented. The photometer has been operated in a scanning mode to probe the thermosphere and mesopause regions simultaneously in north-south direction over Trivandrum (8.5^oN; 77^oE; dip lat. 0.5^oN). The striking features observed are (i) enhancement in the wave activity as seen in the mesopause temperature, during the eclipse, (ii) cooling of the mesopause during the equatorial electrojet (EEJ) reversal and (iii) decrease in mesopause temperature during a flare. These observations are discussed to highlight the vertical coupling of the mesopause with thermosphere-ionosphere region, mainly through neutral dynamics. </smarttagtype></smarttagtype> <br/> <br/>Page(s): 514-525 http://nopr.niscair.res.in/handle/123456789/4711 Title: <smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="country-region" downloadurl="http://www.5iantlavalamp.com/"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place" downloadurl="http://www.5iantlavalamp.com/"> Recent studies on cloud and precipitation phenomena for propagation characteristics over India </smarttagtype></smarttagtype> <br/> <br/>Authors: Sarkar, S K; Kumar, Anil <br/> <br/>Abstract: <smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="country-region" downloadurl="http://www.5iantlavalamp.com/"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place" downloadurl="http://www.5iantlavalamp.com/"> Radio propagation above a frequency of 10 GHz is affected by precipitation in terms of attenuation due to its high dielectric constant. As far as Indian subcontinent is concerned, rain and cloud are the most important ones. Thus, there is still tremendous need to develop a strong database on these parameters. The work carried out on cloud and rain characteristics in relation to radio wave propagation over India in recent years only, from 2000 till today is reviewed in this paper. These results are useful to design as well as for estimation performance of microwave communication and for radar propagation over different locations situated in different geographical regions of India. </smarttagtype></smarttagtype> <br/> <br/>Page(s): 502-513