cr0.izmiran.ru/gmdnet

1. GEO 625 Seasonal variations of the m fluxseen by the muon super telescope MuSTAnG Ganeva1 M., Peglow 1 S., Hippler1 R., Berkova2 M., Yanke2 V. 1 Institute of Physics, Ernst-Moritz-Arndt University of Greifswald, Felix-Hausdorff-Str. 6, D-17487 Greifswald, Germany 2 Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation RAN of N.V. Pushkov (IZMIRAN), Moscow, RU-142190, Russia qvark8@yandex.ru http://cr0.izmiran.ru/gmdnet

2. Goals • Further development of the methods of temperature effect exclusion from the cosmic ray muon component using the model’s temperature data • To research the temperature effect of the muon cosmic ray component on the MuSTAnG super telescope data (Greifswald, Germany) for the whole period of its work (from 2007). • To determine temperature coefficients for the MuSTAnG. • To estimate the model’s accuracy and applicability

3. Temperature effect of the muon CR component From D.Rocco P. M. B l a c k e t in 1938 was the first foretold the temperature effect [P. M. B l a c k e t , Phys. Rev. 54, 973 (1938)] From E.W.Grashorn

4. Temperature effect exclusion from the muon CR component The integral method где Densities of the temperature coefficients for different detectors Dorman L.I. “Meteorological effects of Cosmic Rays”, 1972

5. Temperature effect exclusion from the muon CR component The method of the effective temperature = = where temperature coefficient

6. Temperature data. GFS model and sounding In the work the data of the Global Forecast System (GFS) temperature model representing by the National Centers for Environmental Prediction — NCEP (USA) has been used. http://www.nco.ncep.noaa.gov/pmb/products/gfs/ A query about temperature distribution is carried out at the beginning of every day, realizing the forecast for current day. To obtain hourly data the interpolation by the cubic spline function is carried out. The GFS model’s output data are temperature at the 17 isobaric levels: observation level, 1000, 925, 850, 700, 500, 400, 300, 250, 200, 150, 100, 70, 50, 30, 20, 10 hPa for four times: 00, 06, 12 and 18 hours. The data are interpolated on the grid of 1°x1° resolution. Weather serverhttp://esse.wdcb.ru; Atmosphere temperature profile in real timehttp://phoenix.wdcb.ru, (mirror http://dimm.wdcb.ru) Sounding data: http://weather.uwyo.edu/upperair/sounding.html Soundings are carried out twice a day – 00UT and 12UT. To get hourly data interpolation was carried out.

7. Temperature data GFS model and sounding Comparison of experimental and model temperature data for Greifswald.

8. MuSTAnG Muon Spaceweather Telescope for Anisotropies Greifswald http://www.mustang.uni-greifswald.de , где The MuSTAnG telescope – a part of a global network of similar muon telescopes, located in Australia, Japan and Brazil. MuSTAnG • 100 m above sea level (1013 mb) • two rows of 16 (4x4x2) plastic scintillation counters • 4 m2 of total areaseparated by 5 cm of lead • runs stably from the end of 2007

9. MuSTAnG Calculation of the temperature effect of the muon component First, the effective temperature Teff was calculated for 2009 Then the experimental temperature coefficient αE %/C was determined as the regression coefficient. The values ​​of Teff. and αE are calculated separately for the vertical (0 º) and for each of the three angles of the particles arrival (30 º, 39 º and 49 º). Densities of the temperature coefficients used for MuSTAnG are from: L.I.Dorman and V.G.Yanke “To the theory of cosmic ray meteorological effects” Bulletin of the Russian Academy of Sciences: Physics, 1971. Vol. 35, pp 2556-2570

10. MuSTAnG Calculation of the temperature effect of the muon component For the control theoretical temperature coefficients αТ were calculated. And then the corresponding experimental and theoretical temperature coefficients were compared. From the ​​obtained relations αT / αE (see table) we can conclude that the densities of the temperature coefficients WT, calculated before and well-suited for other ground-based telescopes (e.g., Nagoya), are somewhat different for the MuSTAnG detector. Rather this is due to the peculiarities of the MuSTAnG (high latitude, special ceilings, geometry). After the corresponding adjustment of the temperature coefficients densities WT, the theoretical temperature coefficients αT were recalculated again. The corrected values ​​are given in Table. After adjusting theoretical and experimental temperature coefficients are minimally different.

11. MuSTAnG. Results Mass average temperature: daily (black curve) monthly (red histogram) annual (black histogram) Muon rate variations, corrected for the barometric and temperature effect (average monthly) for all directions. The base period is 2009.

12. MuSTAnG. Results a), b) uncorrected (gray) and corrected for temperature effect(black)MuSTAnG data and neutron monitor data (blue) of Rome and Thailand; с) corrected for the temperature effectNagoya data(black) and Thailandneutron monitor data (blue).

13. MuSTAnG. Results

14. MuSTAnG. Conclusions • The analysis have shown the stability of the MuSTAnG telescope since it started, maybe with the exception of the initial debugging period. • Corrected for temperature variations of MuSTAnG (vertical) are in good agreement with the neutron monitor variations of Rome. Even better agreement is observed for the vertical direction of the Nagoya telescope and the neutron monitor of Thailand. • For MuSTAnG the densities of the temperature coefficients were experimentally adjusted and the temperature coefficient was determined.