edu.ucar.opensky::articles:18685 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T02:46:27.708478 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d78c9xwn The whole atmosphere response to changes in the Earth's magnetic field from 1900 to 2000: An example of "top-down" vertical coupling 2016-07-16T00:00:00Z publication https://n2t.org/ark:/85065/d78c9xwn https://doi.org/10.1002/2016JD024890 Cnossen, I. author Liu, Hanli author Lu, H. author UCAR/NCAR - Library publisher We study the effects of changes in the Earth's magnetic field between 1900 and 2000 on the whole atmosphere (0–500 km altitude), based on simulations with the Whole Atmosphere Community Climate Model eXtension. Magnetic field changes directly affect the temperature and wind in the upper atmosphere (> ~110 km) via Joule heating and the ion drag force. However, we also find significant responses in zonal mean temperature and zonal wind in the Southern Hemisphere (SH) middle- to high-latitude troposphere, stratosphere, and mesosphere of up to ±2 K and ±2 m/s, as well as regionally significant changes in Northern Hemisphere (NH) polar surface temperatures of up to ±1.3 K, in December-January-February. In the SH, changes in gravity wave filtering in the thermosphere induce a change in the residual circulation that extends down into the upper mesosphere, where further changes in the mean wind climatology are generated, together with changes in local planetary wave generation and/or amplification and gravity wave filtering. This induces further changes to a residual circulation cell extending down into the troposphere. However, inaccuracies in the simulated SH upper mesospheric wind climatology probably mean that the simulated temperature and wind responses in the SH lower and middle atmosphere are also inaccurate. The NH middle atmosphere response is zonally asymmetric, consisting of a significant change in the positioning and shape of the upper stratospheric polar vortex, which is dynamically consistent with the surface temperature response. However, the downward coupling mechanism in the NH is generally less clear.We study the effects of changes in the Earth's magnetic field between 1900 and 2000 on the whole atmosphere (0–500 km altitude), based on simulations with the Whole Atmosphere Community Climate Model eXtension. Magnetic field changes directly affect the temperature and wind in the upper atmosphere (> ~110 km) via Joule heating and the ion drag force. However, we also find significant responses in zonal mean temperature and zonal wind in the Southern Hemisphere (SH) middle- to high-latitude troposphere, stratosphere, and mesosphere of up to ±2 K and ±2 m/s, as well as regionally significant changes in Northern Hemisphere (NH) polar surface temperatures of up to ±1.3 K, in December-January-February. In the SH, changes in gravity wave filtering in the thermosphere induce a change in the residual circulation that extends down into the upper mesosphere, where further changes in the mean wind climatology are generated, together with changes in local planetary wave generation and/or amplification and gravity wave filtering. This induces further changes to a residual circulation cell extending down into the troposphere. However, inaccuracies in the simulated SH upper mesospheric wind climatology probably mean that the simulated temperature and wind responses in the SH lower and middle atmosphere are also inaccurate. The NH middle atmosphere response is zonally asymmetric, consisting of a significant change in the positioning and shape of the upper stratospheric polar vortex, which is dynamically consistent with the surface temperature response. However, the downward coupling mechanism in the NH is generally less clear. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2016 American Geophysical Union. None eng geoscientificInformation