The solar forcing dataset prepared for the 6th round of the Coupled Model Intercomparison Project (CMIP6) has been used extensively in climate model experiments. Recently, an International Space Science Institute (ISSI) Working Group was established to revisit the solar forcing recommendations in order to define a roadmap for building a revised solar forcing dataset for the upcoming 7th round...
This presentation will provide an overview of the next generation ozone forcing database in support of the Coupled Model Intercomparison Project phase 7 (CMIP7). Tropospheric and stratospheric ozone changes are key drivers of climate change and need to be accounted for in climate model simulations that aim at understanding past and future climate responses to anthropogenic emissions of...
The energetic electrons in the Earth’s radiation belts and ring current can precipitate to the atmosphere. Such precipitation of energetic particles from space can generate nitric oxide in the atmosphere, and nitric oxide can destroy ozone very efficiently. Geomagnetic activity that controls the precipitation of magnetospheric particles is now recommended as part of the solar forcing of the...
The Total Radiation Belt Electron Content (TRBEC) is a measure of the global number of electrons that occupy the radiation belts. It can be calculated based on electron flux measurements and provides a simple, global assessment of the radiation belts. When expressed in adiabatic coordinates, the TRBEC increases abruptly during storms and then decreases with a repeatable and consistent...
Energetic particle precipitation (EPP) increases ionization in the D-region ionosphere, elevating cosmic radio signal absorption. This impact is monitored by a Canadian network of wide-beam passive radio receivers, or riometers. Ionospheric absorption expected during a specific EPP event, as recorded by a Polar Orbiting Environmental Satellite (POES), is modelled and compared with measurements...
AISstorm (Atmospheric Ionization during Substorms Model) derives the global atmospheric ionization due to particle precipitation based on in-situ particle measurements. The model covers auroral precipitation as well as solar particle events on an altitude range of about 250km down to 16km for protons and down to 70km for electrons.
The ionization of alpha particles is also included, but in a...
The long-predicted climate change signal is emerging outside the noise in many regions. These changes in climate are accompanied by changes in extreme events that impact society. While early warnings of such changes are now potentially possible through, e.g., operational decadal predictions, there are several challenges: there is a lack of understanding of the dynamical mechanisms that enable...
In this paper we investigated the Oceanic Niño Index (ONI), for simplicity called in this paper an El Nino Southern Oscillation (ENSO) index in 1950-2023 by applying the wavelet spectral transform and the IBM SPSS correlations analysis. ONI follows the three months current measurements of an average temperature of the sea surface in the East-Central tropical part of the Pacific ocean...
To better understand possible reasons for the diverse modeling results and large discrepancies of the detected solar fingerprints, we took one step back and assessed the "initial" solar signals in the middle atmosphere based on large ensemble simulations with multiple climate models — FOCI, EMAC, and MPI-ESM-HR. Consistent with previous work, we find that the 11-year solar cycle signals in the...
The ground temperature variability in the Northern Hemisphere winter is greatly influenced by the state of the polar vortex. When the vortex collapses during sudden stratospheric warmings (SSWs), rapid changes in stratospheric circulations propagate downward to the troposphere in the subsequent weeks. The ground effect following SSWs is typically manifested as the negative phase of the North...
The EISCAT incoherent scatter radars in Tromsø, northern Norway, and in Longyearbyen, Svalbard measure key parameters of the ionospheric plasma (electron density, electron and ion temperatures, and plasma bulk velocity) at multiple altitudes along the radar beam. The radars are thus ideal instruments for observing electron density enhancements produced by particle impact ionization....
Solar, auroral, and radiation belt electrons enter the atmosphere at polar regions leading to ionization and affecting its chemistry. Whole-atmosphere chemistry--climate models such as WACCM(-X) or EDITh usually parametrize this ionization based on in-situ satellite particle measurements. Widely used particle data are derived from the POES and GOES satellite measurements which provide in-situ...
Modelling the distribution of odd nitrogen (NOx) in the polar middle and upper atmosphere has proven to be a complex task.
Firstly, its production by energetic electron precipitation is highly variable on hourly time scales. Secondly, there are uncertainties in the measurement-based but simplified electron flux data sets that are currently used in atmosphere and climate models. The altitude...
Incoming solar irradiance establishes Earth’s surface and atmospheric temperature, driving coupled radiative, dynamical, and chemical processes that produce myriad land, ocean, and atmospheric interactions. The Sun’s irradiance is spectrally dependent, as is its variability, on time scales from days to centuries and longer. A fundamental quantity for Earth’s energy and climate studies, solar...
Solar variability varies on many timescales from minutes to decades and beyond. To determine the effect of solar irradiance on the Earth's system the knowledge of the incoming solar radiation needs to be known with high precision. We report on latest advances in measuring TSI with the CLARA radiometer onboard NorSat-1 and compare it to the latest TSI measurements. Besides TSI, CLARA also...
There is growing evidence that variability associated with the 11-year solar cycle has an impact at the Earth’s surface and influences its weather and climate. Although the direct global response to the Sun’s variability is extremely small, a number of different mechanisms have been suggested that could amplify the signal, resulting in regional signals that are much larger than expected. The...
We discuss long range forecasting from months to a few years ahead with a focus on current predictions systems, levels of prediction skill and the physical mechanisms that provide predictability, including the role of solar variability and its representation in prediction systems. On these timescales, initial conditions play a significant role in predictability and initialised climate...
Keystone is a proposed upper atmospheric limb sounding mission with the aim of providing a comprehensive measurement of the Mesosphere and Lower Thermosphere (MLT) composition, temperature and winds, and its variability (from a diurnal to a seasonal scale). It’s currently in Phase-0 study as ESA’s 12th Earth Explorer.
The MLT is the upper atmosphere region which goes from 70km to 120km,...
The Changing-Atmosphere Infra-Red Tomography Explorer (CAIRT) is currently in Phase A as one of two candidates for ESA’s Earth Explorer 11. As a Fourier transform infrared limb imager, CAIRT will observe simultaneously from the middle troposphere to the lower thermosphere at high spectral resolution and with unprecedented horizontal and vertical resolution. With this, CAIRT will provide...
The evolution of changes in the zonal mean vertical distribution of ozone from the set of models participating in the CCMI-2022 project, using data from the REF-D1 and REF-D2 series of simulations is examined. This work presents the effects of natural variability forcings, focusing on solar cycle effects, as well as ENSO and volcanic eruptions on ozone and temperature profiles using the...
Polar winter descent of reactive nitrogen (NOy) produced by energetic particle precipitation (EPP) in the mesosphere and lower thermosphere affects polar stratospheric ozone by catalytic reactions. This, in turn, may have implications for regional climate via radiative and dynamical feedbacks. NOy observations taken by the MIPAS/Envisat instrument during 2002--2012 have provided observational...
B. Funke (1), Thierry Dudok de Wit (2,3), Margit Haberreiter (4), Dan Marsh (5,6), Ilaria Ermolli (7), Doug Kinnison (5), Hilde Nesse (8), Annika Seppälä (9), Miriam Sinnhuber (10), Ilya Usoskin (11), Timo Asikainen (11), Stefan Bender (1), Theodosios Chatzistergos (12), Odele Coddington (13), Sergey Koldoboskiy (11), Judith Lean (14), Max van der Kamp (15), and Pekka Verronen (11,15)
(1)...
The Icosahedral Non-hydrostatic model framework is the open-source numerical weather prediction model and climate model developed by the German Weather Service DWD and the Max-Planck Institute of Meteorology. A consolidated climate setup with interactive ocean, land surface and atmosphere is currently being developed and tested. However, while ICON in its base setup includes varying solar TSI...
The eigen vectors of magnetic oscillations obtained with Principal Component Analysis from full disk synoptic maps of solar background magnetic field (SBMF) from the Wilcox Solar Observatory are shown to come in pairs assigned to magnetic waves produced by dipole, quadruple, sextuple and octuple magnetic sources. The first pair is linked to dipole magnetic waves with their summary curve...
This study compares the electron ionization peak altitudes observed by the Special Sensor Ultraviolet Spectrographic Imager (SSUSI) and the Atmospheric Ionization during Substorm Model (AISstorm) over 70.2°N during 2010. SSUSI data predominantly shows ionization peaks at 100 km altitude, while AISstorm data indicates peaks primarily at 110 km. The discrepancy may partly be impacted by the...
Precipitating plasma sheet, ring current, and radiation belt electrons will affect the ionization level and composition of the neutral atmosphere. Knowledge gaps remain regarding the frequency, intensity, and energy spectrum of the Medium Energy Electron (MEE) precipitation ($\gtrsim$30 keV). In particular, the understanding and predictive capabilities of the high-energy tail ($\gtrsim$300...
The tropical Madden-Julian oscillation (MJO), also known as the 40-50 day oscillation, is an eastward-propagating,convectively-coupled wave which functions as a key driver of sub-seasonal to seasonal convection and precipitation variability in the tropics (e.g., Madden and Julian 1994). The MJO generates a Rossby wave train that strongly influences weather in the extratropics on subseasonal...
Recent studies have shown that geomagnetic activity, used as a proxy for energetic electron precipitation (EEP), influences weather conditions, e.g. temperature and wind speed, during winter in certain regions of the Northern hemisphere. EEP forms ozone-depleting hydrogen and nitrogen oxides (HOx & NOx), which alter the radiative balance in wintertime atmosphere and enhance the northern polar...
Cosmic dust particles are produced from the sublimation of comets and by collisions between asteroids. The input rate to the atmosphere is estimated to be 27 +/- 14 tonnes per day globally. Because the particles enter the atmosphere at hypersonic velocities, collisional heating with air molecules causes about 30% of them to melt, leading to vaporization of their metallic constituents. The...
On May 10-11, two CMEs arriving within few hours initiated a geomagnetic storm with a DST of around -400 nT in the main phase. With a Kp of 9 for several hours, the threshold for an “extreme” geomagnetic storm was reached for the first time since the Halloween storm in October/November 2003, and polar lights were clearly visible well into magnetic midlatitudes. Proton fluxes were enhanced for...
In the polar middle and upper atmosphere, Nitric Oxide (NO) is produced in large amounts by both solar EUV and X-ray radiation and energetic particle precipitation (EPP), and its chemical loss is driven by photodissociation. As a results, polar atmospheric NO has a clear seasonal variability and a solar cycle dependency which have been measured by satellite-based instruments. On shorter...
Cross-disciplinary research efforts have led to the emergence of numerical tools capable of taking advantage of the present-day heterogeneous supercomputers, enabling computing at Exa-scale. The first results of running these tools in full production are emerging. In contrast to the CPU paradigm, these runs can be completed within days - a week in contrast to several months. Hence, when...
Solar irradiance is one of the forcing agents of the Earth's climate system. Space-based monitoring
of solar irradiance since the late 1970s has revealed variations across all observed time scales,
providing crucial insights into the physical mechanisms behind solar irradiance changes. However,
the relatively short duration of these records limits our ability to fully assess the Sun’s...
Geomagnetic forcing is considered part of the natural forcing of the climate system, and recommended to be included in chemistry-climate model experiments since CMIP6. The starting point is the formation of NO mainly in the lower thermosphere by energetic electron precipitation from the aurora and radiation belts and EUV radiation. We compare results of NO from five high-top chemistry-climate...
Earth system models with tops in the thermosphere have historically struggled to recreate the large nitric oxide (NO) mixing ratios in the high-latitude winter and spring mesosphere and stratosphere. Possible causes include missing sources of energetic particle precipitation, missing chemistry, and errors in the general circulation of the upper atmosphere. Additionally, transport by...
Direct measurements of solar irradiance variations began in the late 1970s.
Recovery of irradiance over earlier periods is only possible with appropriate models.
Such reconstructions require solid understanding of the physical processes driving the irradiance fluctuations as well as information on the past changes of the magnetic activity of the Sun.
The magnetic field emerging at the...
Reconstructions of energetic electron precipitation (EEP) and the atmospheric ionization it produces are important for state-of-the-art chemistry-climate models, which aim to model the climate impacts of EEP. The current version of the Coupled Model Inter-comparison Project, CMIP6, includes a reconstruction of EEP-induced ionization based on a parameterization dependent on geomagnetic Ap...
A new dataset has been provided for CMIP7, to model the ion pair production due to mid-energy electron precipitation.
The data set has been calculated using an updated version of the CMIP6 electron flux model and an atmospheric ionization parameterization (Fang et al., Geophys. Res. Lett., 37, L22106, doi:10.1029/2010GL045406, 2010). The electron flux model is fit to equivalent isotropic...
The RADiation Impacts on Climate and Atmospheric Loss Satellite (RADICALS) is a low-Earth orbiting Canadian small satellite mission investigating the transport of space radiation into the atmosphere, and its impact on Earth’s climate. Scheduled for launch in late 2026, the mission will launch into a polar orbit with an integrated payload comprising two back-to-back look direction High Energy...
A flexible new scheme has been implemented in the Socrates radiative transfer code in order to parametrise a unified treatment of radiative heating, photolysis and photoionisation covering the whole spectrum of solar emission.
Socrates is currently used only for radiative heating within the UK Earth System Model. For CMIP7 this will represent solar spectral variability in 12 bands including...
Solicited talk
Solar variability contributes to climate variability at global and regional scales. It is therefore important to include this forcing alongside other natural and anthropogenic factors to simulate past climate and to account for the potential solar influence on future climate projections. However, many challenges exist particularly around how to capture the full effect of...
We have extended the Linearized ozone scheme LINOZ in the ICON (ICOsahedral Nonhydrostatic)-ART (the extension for Aerosols and Reactive Trace gases) model system to include ozone loss caused by energetic particle precipitation (EPP) and changes in the rate of ozone formation due to the variability of the solar radiation in the ultraviolet wavelength range. This extension allows us to...
In recent years, increasing evidence has pointed that winter-time middle atmospheric ozone changes initiated by energetic particle precipitation (EPP) are linked to regional climate variability at ground-level. The mechanism for this link is, however, still unclear. Proposed explanations focusing on EPP-indirect effect does not explain the timing of the observed ground-level changes, which...
Energetic electron precipitation (EEP) directly impacts the high-latitude thermosphere and mesosphere by forming ozone-depleting NOx and HOx. During winter the EEP-NOy (NOx and its reservoir species such as HNO3 formed by EEP) molecules descend to the stratosphere and establish the indirect effect of EEP. Earlier studies based on models and reanalysis datasets have shown that increased EEP is...
In order to determine the effect of energetic particle forcing on the Earth’s atmosphere over decadal timespans it has been necessary to develop models of energetic electron precipitation (EEP) based on long time-series geomagnetic indices. This has been done using the geomagnetic index, Ap, and recommended for use as one of the solar forcing factors in the Coupled Model Intercomparison...
This study examined the effect of solar flux (F10.7) and sunspots number (R) on the daily variation of equatorial electrojet (EEJ) and morning/afternoon counter electrojet (MCEJ/ACEJ) in the ionospheric E region across the eight longitudinal sectors during quiet days from January 2008 to December 2013. In particular, we focus on both minimum and maximum solar cycle of 24. For this purpose, we...
The wavenumber-4 (wave-4) structure in the longitude variation of zonal and meridional winds observed by the Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) instrument onboard the Ionospheric Connection Explorer (ICON) satellite is investigated. The amplitude of the wave-4 pattern in meridional wind displays semi-annual variation with equinoctial maxima. In...
