The average properties of the network cells geometry and their temporal var
iations are investigated for quiet solar regions at the center of the solar
disk, These regions were extracted from the daily Ca II K full-disk observ
ations carried out at the Rome Observatory with the PSPT telescope during o
ne year (from July 1996 to June 1997) at the beginning of Solar Cycle 23.
We applied an automated procedure to derive the skeleton of bright Ca II K
regions. By using this skeleton as representative of the chromospheric netw
ork, we identified and characterized the network cells on the images.
The results we found seemed to point out that network cells are regular in
shape and slightly flat. We found an upper limit of 2% for the anisotropy o
f the cell orientation. By analyzing the latitudinal dependence of the cell
size, we found that the cell area decreases by about 30% towards the poles
.
We also characterized the network pattern by using wavelet analysis. We com
pared the results obtained by the different analyzes.
Finally we analyzed the temporal behaviours of the network cell geometrical
properties. In particular, we found a decrease of the characteristic scale
value of about 8% for the period analyzed.