{'fraction_non_alphanumeric': 0.02373887240356083, 'fraction_numerical': 0.019782393669634024, 'mean_word_length': 4.883720930232558, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Comparison of Equatorial Winds as Measured by Cup and Propeller Anemometers

Abstract This study compares the performance of cup vs. propeller anemometers from surface-following taut-line moorings in the equatorial Pacific. Vector wind components at 4 m above the sea surface were measured from a mooring instrumented with a cup anemometer and concurrently from a nearby mooring instrumented with a propeller anemometer. Mean wind conditions over the 115-day comparison period were typical of the southeast trade winds with a mean speed of 6.7 m s−1 and a steadiness factor of 0.96. Differences between the time series measured by the two wind sensors were small. Mean speed differed by 0.02 m s−1 and mean direction by 1.4°. Correlation coefficients for 2-hour vector-averaged zonal component, meridional component, speed and direction were 0.97 or above. The small differences in measurements imply that the two systems are equally suited for near-surface wind observations under typical tradewind conditions.