Snow effect for total NM intensity and different multiplicities on Mt. Hermon during 1998 - 2014
Abstract
All CR stations on mountains and at about sea level at middle and high latitudes in winter periods are covered by snow with the depth (in g/cm2) varied in time. For using these data for space weather forecasting, it is necessary to determine the snow effect for each moment in time and correct observation data not only from barometric and temperature effects (as usual), but also from the snow effect. According to observations on Mt. Hermon, the snow effect in the NM total intensity and different multiplicities is comparable with 11-year variation. The other problem is, that with increasing of snow depth, the sensitivity of the CR detector changed - it moved to higher energies. To determine the snow effect in NM on Mt. Hermon, we made the following investigations step by step: 1) we determined the connection of CR intensity observed on Mt. Hermon during periods without snow with CR intensity on stations which are never covered by snow; 2) by finding the regression coefficients we determine the expected CR variations on Mt. Hermon in winter time on the basis of data of stations which in winter time are not covered by snow; 3) the difference between observed CR intensity and that calculated in point 2 will give the snow effect. This method can be used for any CR station that is covered at some periods by snow. By this method data of CR station can be corrected on snow effect. As an example we determined the snow effect on Mt. Hermon for total neutron intensity and different multiplicities for 1998 - 2014 (the amplitude of this effect in some years reached a big values - more than 40%).
- Publication:
-
40th COSPAR Scientific Assembly
- Pub Date:
- 2014
- Bibcode:
- 2014cosp...40E1800L