The cause of this scattering, if not due to off-fault seismicity, may be partly attributable to lateral heterogeneity in the vicinity of the fault plane and to the areal extent in the MJHD analysis.
The causes of the scatter may include the action of multiple nonisotropic sources, measurement errors associated with departure from the plane-wave assumption, severe ray bending associated with medium heterogeneities, and focusing effects resulting from free-surface interactions related to the volcano topography (e.g., Ripperger et al., 2003).
The contours of the GRET's action, and its ability to fill these gaps within trophic ecology at the French national scale, will depend on the causes of this relative scattering.
Correlation coefficients at noontime for low geomagnetic activity condition are more than 0.86 for all months except summer months, when the data are scattered severely for Kp < 2. We will discuss causes of the scattered NmF2 values during summer in later sections.
Below we support this view by discussing the causes of the residual scattering.
The results show that, while some experimental uncertainty is evident, the likely cause of scatter (between facilities) is systematic in nature.
The third set of relationships tie directly to the optical Principal Component 1 found by Boroson and Green [Boroson, T., Green, R.F., Astrophys. J. Suppl. 80, 109, 1992 (BG92)], and are the primary cause of scatter in the Baldwin relationships.
It has been suggested that path effects (e.g., Atkinson 2006; Anderson and Uchiyama 2011) are one of the key factors causing this data scatter; source effects (e.g., Brillinger and Preisler 1984; Ripperger et al. 2008) and site effects (e.g., Chen and Tsai 2002; Lin et al. 2011; Yoshimoto and Takemura 2014) also play a part.
(Note that grain boundary scattering is reported to be more dominant than scattering from rough surfaces and thus can be assumed to be the cause of scattering).
This means that the lower sub-window for I-123, which was narrow and near to the photopeak, caused overestimation of scatter; however, the FiveEW method reduced this scatter overestimation and thereby improved the linearity and reproducibility of activity measurement.
