Measurements of atmospheric electricity aloft

Measurements of the electrical characteristics of the atmosphere above the surface have been made for over 200 years, from a variety of different platforms, including kites, balloons, rockets and aircraft. From these measurements, a great deal of information about the electrical characteristics of the atmosphere has been gained, assisting our understanding of the global atmospheric electric circuit, thunderstorm electrification and lightning generation mechanisms, discovery of transient luminous events above thunderstorms, and many other electrical phenomena. This paper surveys the history of atmospheric electrical measurements aloft, from the earliest manned balloon ascents to current day observations with free balloons and aircraft. Measurements of atmospheric electrical parameters in a range of meteorological conditions are described, including clear air conditions, polluted conditions, non-thunderstorm clouds, and thunderstorm clouds, spanning a range of atmospheric conditions, from fair weather, to the most electrically active

Observations in India of turbulence in the upper air from sounding balloon ascents

The paper describes the special features of the F-type radiosonde in distinguishing from the rotation of the fan whether the downward movement of the radiosonde balloon is due to a strong vertical downward current or due to the accumulation of snow. It shows how the rate of rotation of the fan can be used to identify regions of turbulence in the atmosphere. The observations of the turbulence with the F-type radiosonde are compared with the inferences drawn by turbasondes in the U.S.A. and the Dines meteorograph records in India, The regions where turbulence may be observed in India have been indicated. The existence of severe turbulence in the upper troposphere and in the stratosphere has been emphasised

Operation of allgaier type (6-8)KW wind electric generator at Porbandar

The Allgaier wind Electric Generator presented to the Wind Power Division of the National Aeronautical Laboratory by the West German Government is described briefly in this paper. It is capable of giving 6 Kd on 220 Volts D.C. at a wind speed of about 32 kilometres per hour. This equipment is installed at an Agricultural Farm at Porbandar (Lat. 21'38' N Long. 69' 37' El, where a Diesel operated pump is at present working for supplying water for irrigation13; purposes, The meteorological conditions including13; detailed information about the wind speed are given13; for Porbandar. The mean power output from the Wind13; Electric Generator for different periods of the13; day during the year are also given. The cost per DIH13; electricity with the wind Electric Generator without13; employing a battery works out to 28 nPs, if energy13; is based only during the daylight hours of morning 0830 to 1730 IST

Utilisation of wind power for irrigation of crops in India with special reference to the distribution of wind and rainfall

The need for increasing food production in India, through an13; increase in area under irrigation cannot be overemphasised. Utilization of wind power for minor irrigation using windmills would be very helpful, particularly in areas under irrigation from wells. Two types of direct water-pumping windmills, viz., the WP-1 and the WP-2. have been developed in the National Aeronautical Laboratory, Bangalore. The monthly quantities of water that can be pumped by a WP-2 windmill at 16 places in India have been computed, based on the mean hourly wind speeds at these places. fall at these places shows that at most of the places under study, the water pumped is B maximum when the rainfall is minimum.13; Comparison of the water pumped against the monthly rainfall at these places shows that at most of the places under study,the water pumped is a maximum when the rainfall is minimum. The trials with a 6 kW, 220 volts D.C. Allgaier wind electric generator, at an agricultural farm at Porbandar for pumping water for irrigation show that the cost of pumping water is less than half that by a 10 H.P. Diesel Engine

An estimate of Thermal Comfort at some stations in India

The paper describes briefly how the thermal aspect influences comfort. Since comfort depends not only on the temperature of the air, but also on the relative humidity and air movement, no simple formula to obtain an index involving all the factors is available. In this paper Thorn's simple empirical formula for a Discomfort Index =0.4(td +tw )+15, where td is air temperature and tw is the wet bulb temperature, is used and the mean hourly  values of discomfort index are calculated for different months for the 5 stations, New Delhi, Calcutta, Poona, Madras and Trivandrum. According to Thom, people in the U.S.A., feel discomfort as the index rises above 70 and everyone is uncomfortable by the time the index reaches 79. When the index becomes 86 or higher, in Washington metropolitan area, mass dismissal of employees are permitted. The analysis of Indian data shows that in general, the prevailing DI for India is in the range 76-80 or less, except in the summer months, April-May to September, when it exceeds this value. Poona has the largest number of hour days with DI = or &lt;75. In the range Dl= 76-80, Poona and Trivandrum have the largest and almost similar values, viz., 8224 and 8343 hour days respectively but a possible total  of 8760 during the year. Dl = 86-90 is experienced in the pre-monsoon months only in New Delhi (368 hour-days), Calcutta (183) and Madras (239). It is generally observed that the indices can be adopted for the tropical Indian conditions also. They will, therefore, be of value to visitors from abroad and to the Indians. They will also be useful to plan, air conditioning units for Indian use.</jats:p

Performance of the 6-8 KW Allgaier wind electric generator at porbandar

The performance of the Allgaier 6-8 kW wind electric generator at a site in the Khapat Agricultural Farm in Porbandar has been examined. The actual electric energy produced a t various wind speeds has been13; compared with the energy calculated on the basis of the power-speed characteristics of the generator, supplied by the manufacturers. Ihe cost of power has also been estimated. The cost per kWh works out to 19 nP. without battery and 45 nP.with battery. The cost of pumping 1,000 gallons of water works out to 12 nP. a s against 35 nP. in the case of a 10 h.p. diesel engine working alongside the wind electric generator

Utilisation of wind power in ARID and SEMI-ARID areas in India

Utilisation of wind power through windmills and wind electronic generators has a vast scope in the development of the arid and semi-arid areas in India. Direct water pumping windmills can make a substantial contribution in supplying water for domestic purposes, live stock and minor irrigation in many villages of Rajasthan. The WP-2 type of water pumping windmill designed and developed in the National Aeronautical Laboratory, Bangalore, is useful in regions of low and moderate wind speeds. The average wind speed at most cf the places in Rajasthan during the summer months, which are the windiest, varies from 12 to 18 km.p.h. and the windmill gives its optimum output in this range of wind speeds. The wind speed data available for five stations in Rajasthan have been analysed and the monthly quantities of water that can be pumped by a WP-2 windmill through a height of 10 metres have been worked out for these stations. It is seen that the WP-2 windmill can pump about 15,000 gal. of water per day through a height of 10 metres under favourable wind speeds during summer months. The economics of operation of WP-2 windmills at these places has also been studied.13; An examination of the monthly quantities of water pumped against the monthly rainfall shows that a t all places studied the water pumped is a maximum during the summer months, i.e., from April to July when water is needed most.13; A study of the characteristics of wind electric generators of different capacities ranging from 1 kW to 25 kW. in relation to the wind regime in Rajasthan shows that wind electric generators in the range of 2-5 kW are comparatively economical

Observations of Turbulence over Minicoy with the F-type Radiosonde

The paper discusses the F-type radiosonde ascents at Minicoy during the period May 1963 to Apri11964. It is observed that the rate of rotation of the fan remains unchanged upto about 150 mb and that it decreases above. The rotation is related to the rate of ascent of the balloon and its decrease beyond 150 mb shown to be the same or decreases due to leakage of hydrogen through balloon fabric. The regions of turbulence in the upper tropopause and stratosphere are studied from the rate of rotation of the fan. From January to March, turbulence occurs in the tropopause and stratosphere causing often the balloon to burst. This observation confirme the infcrences drawn from the blur at the end of the traces in the Dines’ meteorograph ascents. The vertical component of gusts is estimated to be between 10-20 kmph. The thickness of the region of turbulence is found to be about 4 km and the region of turbulence duping the monsoon months is in the upper troposphere below the tropopause.</jats:p

A notice on the feasibility of wind generation of electric power for communication links in India13;

The power requirements of solid-state microwave radio links are very low, and could be adequately met by storage batteries charged by small wind electric generators. This would be possible at sites that a r e sufficiently windy to operate the generator to give a stable output. Wind electric generators in this range are not commercially available in this country at present. The paper describes a wind electric generator designed in the Laboratory for this purpose. The estimates of output in watt-hours using such a generator at five stations in India have also been computed in the paper

Observations of Turbulence at Delhi during the winter months - November 1966 to February 1967 with the F-type Radiosondes

Study of turbulence at Delhi during the winter months when the westerly jets prevail was made by special F-type radiosonde ascents from November 1966 to February 1967 and in April 1967" The vertical components of gusts and their thicknesses were determined by measuring the rate of rotation of the fan from the length of complete Olland cycles which consists of 1000 impulses" Since the duration of the gust may not last as much as a full cycle, lengths of tapes for 100 impulses and 500 impulses were measured. It was then found that the duration of the gnats is only of the order of 200-300 impulses. The vertical components of the gusts were therefore larger and thicknesses smaller when the length of 100 impulses were used. One of the interesting features at Delhi was the presence of turbulence fu thin layers of air (about 1500 m thick), fu which the lapse rate was different from those in the layers above and below. These regions were above the jet stream and were between 150 and 100-mb levels.</jats:p