Figure 4.
Ratio of acoustic power (i.e. SNR) for the 86–88 Hz band versus the arithmetic mean of the 80–82 and 92–94 Hz bands. Two-hourly data were subjected to a 14-day arithmetic running mean.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.