Euler Pole Parameters of the North American Terrestrial Reference Frame of 2022

Euler pole parameters (EPPs) were estimated for the North American Terrestrial Reference Frame of 2022 (NATRF2022), which is a modernized plate-fixed reference frame based on the International Terrestrial Reference Frame of 2020 (ITRF2020), replacing the North American Datum of 1983 (NAD83). NATRF2022 is aligned with ITRF2020 at epoch 2020.0 with the same geocentric origin that is compatible with GNSS products and applications. The EPP estimation was based on a spherical model of Earth, using station velocities derived from the latest velocity estimates: version 8 from the Canadian Geodetic Survey and the Multi-Year CORS Solution version 3.0 from the United States National Geodetic Survey, both referenced to ITRF2020. This paper details the collaborative development of the definitional EPPs for NATRF2022, presents its values, and discusses the results. EPP estimates are close to other Euler pole estimates for North America plate motion; however, it further reduces the frame velocities sampled at more than 4,000 stations within the rigid part of North American plate, thus providing more stable coordinates over time. Since the EPP estimation was simplified by assuming that unit vectors of vertical velocities are perpendicular to the surface of Earth, we examine the effect of this simplification on the north and up velocities as well as the geodetic ellipsoidal heights. We show that ellipsoidal heights will change with a maximum subsidence rate of − 0.07 mm / year over western and southern parts of Alaska transitioning to an uplift rate of + 0.04 mm / year over St. John’s and southeast of Greenland. These values are well below the Global Geodetic Observing System recommendation for the stability of reference frames ( 0.1 mm / year ) and therefore are negligible. The presented estimates are the official values of EPPs that will be implemented in Canada and the United States for NATRF2022 by their respective geodetic agencies.