  In this paper, we analyze the influence of characteristic solar activity
parameters as well as the competition effects in solar activity and atmospheric
pressure on the records of cosmic radiation based on HiSPARC (The High School
Project on Astro physics Research with Cosmic rays), a ground-based muon
detector system monitoring secondary cosmic ray intensity. We gather the data
from No.501 HiSPARC station situated at Nikhef in Science Park, Amsterdam,
Netherlands (52.3558963{\deg}N, 4.9509827{\deg}E, 56.18 m of altitude). The
accepted anticorrelation between solar activity and the intensity of near
ground cosmic ray is confirmed by comparing the number of solar flares,
relative number of sunspots and counting rates of the detector. The barometric
effect has been considered to correct the number of events. Furthermore, a new
empirical equation is given to show the correlation between the cosmic ray
intensity and the characteristic solar activity parameters, including the
number, the area and the latitude of sunspot groups. As for the competition
effects of solar activity and atmospheric pressure, we find there exists a
threshold in detector's sensitivity to the sunspot numbers. Above the
threshold, the detector is more sensitive to the atmospheric pressure rather
than the solar activity. Our discovery delineating the solar activities and
atmospheric pressure competition effects on the event rate can provide a
different way to monitor real-time space weather and cast light on the
investigation of short-term solar activity forecast.
