Solar cycle variations in daytime ionospheric Es parameters in the South Pacific area

Daytime occurrence frequencies of foFs and fbEs are presented for stations Rarotonga and Christchurch for a period of two solar cycles and for Scott Base for a period of one cycle. Although foEs shows little association with sunspot activity, fbEs shows a strong positive correlation with both sunspot number and with noon foE. The data also indicate the presence of a 4-month time lag of fbEs peaks after sunspot maximums.