Atmospheric Newtonian noise modeling for third-generation gravitational wave detectors

TL;DR

This paper develops advanced atmospheric Newtonian noise models for third-generation gravitational wave detectors, assessing how environmental factors like wind and depth influence noise levels relative to detector sensitivity.

Contribution

It introduces refined models accounting for finite correlation times and vertical inhomogeneity, providing a reliable reference for atmospheric noise evaluation in GW detectors.

Findings

Atmospheric NN exceeds ET sensitivity at the surface during strong winds.

Underground construction reduces NN below ET sensitivity, but marginally for strong winds.

NN decay with depth is slow, limiting passive noise mitigation effectiveness.

Abstract

The sensitivity and the frequency bandwidth of third-generation gravitational-wave (GW) detectors are such that the Newtonian noise (NN) signals produced by atmospheric turbulence could become relevant. We build models for atmospheric NN that take into account finite correlation times and inhomogeneity along the vertical direction, and are therefore accurate enough to represent a reliable reference tool for evaluating this kind of noise. We compute the NN spectral density from our models and compare it with the expected sensitivity curve of the Einstein Telescope (ET) with the xylophone design. The noise signal decays exponentially for small values of the frequency and the detector's depth, followed by a power-law for large values of the parameters. We find that, when the detector is built at the earth's surface, the NN contribution in the low-frequency band is above the ET sensitivity curve for strong wind. Building the detector underground is sufficient to push the noise signal under the ET sensitivity curve, but the decrement is close to marginal for strong wind. In light of the slow decay with depth of the NN, building the detector underground could be only partially effective as passive noise mitigation.