Аскаплоты советских станций за 1978 год : (оперативно-информационный материал) / Акад. наук СССР, Кол. фил. им. С. М. Кирова, Поляр. геофиз. ин-т. – Апатиты : Кольский филиал АН СССР, 1981.

10 Methods of ascaplotting. Information about aurorae for each station according to /1,2/, are encoded in 5 lines divided by vertical lines. One vertical dividing corresponds to half-an-hour interval centered to the beginning and the middle of each universal time hour. The local geomagnetic midnight is marked by a circle under asca- plots. Three upper lines are denoting aurorae location in the sky. The blacked second line corresponds to aurorae in the zenith (from 60°N to 60°S) and the third one - to aurorae in the south (from 60°S to BO°S). Aurorae occurence of the corresponding part of the sky was marked when an aurora was observed during one minute in the given time interval. Aurorae location was estimated by the bottom edge. Supposing that low edge height equale to 100 km, we'll obtain that all three zenith angle intervals have ap- proxin ntely sufficient extent along the meridian corresponding to 3 degrees of a la titude. Thus, ascaplots give information about spatial aurorae distribution in 9-de- gree-latitude range with its center in the zenith of a station. Stars presence in the films make it possible to estimate meteorological condi tions in each latitudinal interval. According to /1,2/ a dot in the middle of the square shows a weak cloudiness occurence or cloudiness with rents in the given part of the sky and in the given time interval. Vertical line denotes complete cloudiness. A tick inside the square of the third line points out bad quality of an askafilm due to technical reasons. Horizontal line denotes that there were no observations. For marking moon lighting, sufficiently reducing askafilm quality, we used additional designation - horizontal line over ascaplots. Information of aurorae activity carry the bottom two lines of squares. The very bottom line blacking means that 2 ball aurorae were observed. Blacking of two bottom lines refers to 3 ball aurorae activity. One still must note that activity in asca plots does not coinside intirely with brightness of the forms. But ascaplots also in clude such parameters as type of the form and its existence duration within the given half-an-hour interval. So that angle range pressing for the north and for the south doesn't permit similar determinations of aurorae forms pecularities, aurbrae activity in ascaplots was estimated only for the zenith region. Activity of the aurorae series offered in /11/, characterized by substorm phases connection with its Intensity and type of form, were taken as an example. The table of activity estimating is given in Fig. 1. Here in the bottom the balls of activity are marked and in horizontal lines - types of forma, corresponding to the internatio nal classification, and their brightness ( W-weak ,M-mean ,B-bright ). Two circles de note observations duration, the left circle means that the given aurora form was ob served lesb than the right one (more than 15 min). The indices s by which balls of ac tivity are calculated, axe given in the top of the Table. Indices 1-3 correepond to 1 ball, indices 4—6 correspond to the second ball, indices from 7 to 9 - third ball. At oeveral forms simultaneously осcuring the index is calculated by the most impor tant form plus 1. For example, if during more than 15 minutes a weak homogeneous arc (HA) and a weak radiant band (HB) were observed in the slfy. the index equals to 6 (radiant band) + 1 (another form occurence) = 7, that corresponds to the third ball of auroral activity. One is added at quick motions of aurora form being the main ons, For example, bright quickly moving radiant band existing less than 15 minutes with other forms occurence give 7(bright radiant band) + 1(its quick motion) + 1 (other auroral forms occurence) = 9. Table 2 shows that homogeneous very bright arc observed during the whole half- an-hour interval gives only 2 balls whereas the feet of corona appearance itself cor responds to the similar activity. Bvren short time appearance of bright ccrona corres ponds to the third bail. Such estimation of aurorae activity in balls is connected with pecularities of auroral, substorm development. According to /12/ at disturbances