Werner K Schmutz

Werner K Schmutz
Physikalisch-Meteorologisches Observatorium Davos · World Radiation Center

Prof. Dr. sc. nat.

About

414
Publications
38,057
Reads
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7,201
Citations
Citations since 2017
34 Research Items
2731 Citations
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20172018201920202021202220230100200300400
20172018201920202021202220230100200300400
20172018201920202021202220230100200300400
Additional affiliations
September 2010 - December 2016
SNF SINERGIA
Position
  • FUPSOL+FUPSOL-2 - Future and Past Solar Influence on the Terrestrial Climate
Description
  • Aims: 1. How did past solar variations affect climate, and how can we use this information to constrain solar-climate modeling? 2. How will a decrease in solar forcing in the next decades affect climate at global and regional scales?
Education
March 1979 - March 1984
ETH Zürich, Switzerland
Field of study
  • Sci. Nat.
March 1974 - March 1979
ETH Zürich, Switzerland
Field of study
  • Physics

Publications

Publications (414)
Article
Full-text available
Since the late 1970s, successive satellite missions have been monitoring the sun's activity and recording the total solar irradiance (TSI). Some of these measurements have lasted for more than a decade. In order to obtain a seamless record whose duration exceeds that of the individual instruments, the time series have to be merged. Climate models c...
Poster
Full-text available
Since the late 70's, successive satellite missions have been monitoring the sun's activity, recording total solar irradiance observations. These measurements provide estimates of the Earth's energy imbalance, i.e. the difference of energy absorbed and emitted by our planet. With this amount of TSI data, solar irradiance reconstruction models can be...
Preprint
Full-text available
We present first science observations taken during the commissioning activities of the Spectral Imaging of the Coronal Environment (SPICE) instrument on the ESA/NASA Solar Orbiter mission. SPICE is a high-resolution imaging spectrometer operating at extreme ultraviolet (EUV) wavelengths. In this paper we illustrate the possible types of observation...
Article
Full-text available
A mission to view the solar poles from high helio-latitudes (above 60°) will build on the experience of Solar Orbiter as well as a long heritage of successful solar missions and instrumentation (e.g. SOHO Domingo et al. (Solar Phys. 162 (1-2), 1–37 1995), STEREO Howard et al. (Space Sci. Rev. 136 (1-4), 67–115 2008), Hinode Kosugi et al. (Solar Phy...
Presentation
Total Solar Irradiance (TSI) is one of the Essential Climate Variables (ECV) identified by the World Meteorological Organization's Global Climate System (GCOS). The Compact Lightweight Absolute RAdiometer (CLARA) experiment onboard the Norwegian micro satellite NorSat-1 is a SI traceable radiometer and was launched July 14, 2017 with the primary sc...
Preprint
Full-text available
The Spectral Imaging of the Coronal Environment (SPICE) instrument is a high-resolution imaging spectrometer operating at extreme ultraviolet (EUV) wavelengths. In this paper, we present the concept, design, and pre-launch performance of this facility instrument on the ESA/NASA Solar Orbiter mission. The goal of this paper is to give prospective us...
Article
Context . Comparison studies of Sun-like stars with the Sun suggest an anomalously low photometric variability of the Sun compared to Sun-like stars with similar magnetic activity. Comprehensive understanding of stellar variability is needed to find a physical reason for this observation. Aims . We investigate the effect of metallicity and effectiv...
Preprint
Context. Comparison studies of Sun-like stars with the Sun suggest an anomalously low photometric variability of the Sun compared to Sun-like stars with similar magnetic activity. Comprehensive understanding of stellar variability is needed, to find a physical reasoning for this observation. Aims. We investigate the effect of metallicity and effect...
Article
Solar disk radius measured by Solar occultation by the Moon using bolometric and photometric instruments on board the PICARD satellite - Volume 14 Symposium - G. Thuillier, P. Zhu, A. I. Shapiro, S. Sofia, R. Tagirov, M. van Ruymbeke, J.-M. Perrin, T. Sukhodolov, W. Schmutz
Article
Context. There is no consensus on the amplitude of historical solar forcing. The estimated magnitude of the total solar irradiance (TSI) difference between the Maunder minimum and the present time ranges from 0.1 to 6 W m ⁻² making the simulation of the past and future climate uncertain. One reason for this disagreement is the applied evolution of...
Article
Full-text available
Continued anthropogenic greenhouse gas (GHG) emissions are expected to cause further global warming throughout the 21st century. Understanding the role of natural forcings and their influence on global warming is thus of great interest. Here we investigate the impact of a recently proposed 21st century grand solar minimum on atmospheric chemistry a...
Article
Full-text available
Self-organization is a property of dissipative nonlinear processes that are governed by a global driving force and a local positive feedback mechanism, which creates regular geometric and/or temporal patterns, and decreases the entropy locally, in contrast to random processes. Here we investigate for the first time a comprehensive number of (17) se...
Article
Full-text available
A new sprayable carbon nanotube coating for bolometric detectors aims to increase the absorptance compared to regular space qualified black paints. In collaboration with the National Institute of Standards and Technology (NIST), we have characterized the optical properties and mechanical and thermal stability of the carbon nanotube coating inside c...
Article
Full-text available
The solar brightness varies on timescales from minutes to decades. Determining the sources of such variations, often referred to as solar noise, is of importance for multiple reasons: a) it is the background that limits the detection of solar oscillations, b) variability in solar brightness is one of the drivers of the Earth's climate system, c) it...
Article
Full-text available
The pre-industrial millennium is among the periods selected by the Paleoclimate Model Intercomparison Project (PMIP) for experiments contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6) and the fourth phase of the PMIP (PMIP4). The past1000 transient simulations serve to investigate the response to (mainly) natural f...
Article
Full-text available
The present study is an effort to deepen the understanding of Indian summer monsoon rainfall (ISMR) on decadal to multi-decadal timescales. We use ensemble simulations for the period AD 1600–2000 carried out by the coupled Atmosphere-Ocean-Chemistry-Climate Model (AOCCM) SOCOL-MPIOM. Firstly, the SOCOL-MPIOM is evaluated using observational and rea...
Article
The compact lightweight absolute radiometer (CLARA) experiment aims at measuring the total solar irradiance (TSI) in space and is scheduled to fly on the Norwegian NORSAT-1 micro satellite. The CLARA experiment will contribute to the long term monitoring of the TSI variability to support the analysis of potential long term trends in the Sun's varia...
Article
Determining the sources of solar brightness variations 1,2, often referred to as solar noise ³, is important because solar noise limits the detection of solar oscillations ³, is one of the drivers of the Earth's climate system 4,5 and is a prototype of stellar variability 6,7-an important limiting factor for the detection of extrasolar planets. Her...
Article
Context. Small-scale heating events (SSHEs) are believed to play a fundamental role in understanding the process responsible for heating of the solar corona, the pervading redshifts in the transition region, and the acceleration of spicules. Aims. We determine the properties of the SSHEs and the atmospheric response to them in 3D magnetohydrodynami...
Article
Context. Physics-based models of solar and stellar magnetically-driven variability are based on the calculation of synthetic spectra for various surface magnetic features as well as quiet regions, which are a function of their position on the solar or stellar disc. Such calculations are performed with radiative transfer codes tailored for modeling...
Article
Variations in the solar spectral irradiance (SSI) are an important driver of the chemistry, temperature, and dynamics of the Earth's atmosphere, and ultimately the Earth's climate. To investigate the detailed response of the Earth's atmosphere to SSI variations, a reliable SSI dataset is needed. We present an observational SSI composite dataset tha...
Article
Full-text available
Sporadic solar energetic particle (SEP) events affect the Earth’s atmosphere and environment, in particular leading to depletion of the protective ozone layer in the Earth’s atmosphere, and pose potential technological and even life hazards. The greatest SEP storm known for the last 11 millennia (the Holocene) occurred in 774–775 AD, serving as a l...
Article
Context. Stellar wind mass-loss in binary systems carries away angular momentum causing a monotonic increase in the orbital period, P > 0. Despite possessing a significant stellar wind, the eclipsing Wolf-Rayet (WR) binary system CQ Cep does not show the expected monotonic period increase, in fact, it is sometimes reported to display the opposite b...
Article
Full-text available
The World Radiometric Reference (WRR) is an artefact based reference for Direct Solar Irradiance (DSI) measurements. The WRR is realized by a group of electrical substitution radiometers, the World Standard Group (WSG). In recent years, a relative difference of about -0.3% between the International System of Units (SI) scale and the WRR scale was o...
Thesis
Full-text available
The Indian summer monsoon is a complex phenomenon that, other than its own internal variability, is governed by a number of factors. Due to its complex nature, it is hard to predict precisely. The variability of the Indian summer monsoon is important to understand because a large population in the Indian subcontinent depends on it. Several factors,...
Article
Context. Despite the importance of having an accurate measurement of the solar disc radius, there are large uncertainties of its value due to the use of different measurement techniques and instrument calibration. An item of particular importance is to establish whether the value of the solar disc radius correlates with the solar activity level. Ai...
Article
Colliding stellar winds in massive binary systems have been studied through their radio, optical lines and strong X-ray emission for decades. More recently, spectro-interferometric observations in the near-infrared have become available in a few systems, but isolating the contribution from the individual stars and the wind collision region still re...
Article
Full-text available
Effects of the Quasi-Biennial Oscillation (QBO) on tropospheric climate are not always strong or they appear only intermittently. Studying them requires long time series of both the QBO and climate variables, which has restricted previous studies to the past 30–50 years. Here we use the benefits of an existing QBO reconstruction back to 1908. We fi...
Article
Full-text available
We find that wintertime temperature anomalies near 4g hPa and 50°g N/S are related, through dynamics, to anomalies in ozone and temperature, particularly in the tropical stratosphere but also throughout the upper stratosphere and mesosphere. These mid-latitude anomalies occur on timescales of up to a month, and are related to changes in wave forcin...
Article
The solar rotational variability (27-day) signal in the Earth's middle atmosphere has been studied for several decades, as it was believed to help in the understanding of the Sun's influence on climate at longer timescales. However, all previous studies have found that this signal is very uncertain, likely due to the influence of the internal varia...
Article
Full-text available
The pre-industrial millennium is among the periods selected by the Paleoclimate Model Intercomparison Project (PMIP) for experiments contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6) and the fourth phase of PMIP (PMIP4). The past1000 transient simulations serve to investigate the response to (mainly) natural forci...
Article
Full-text available
The switching of the total solar irradiance (TSI) backup radiometer (PREMOS-B) to a primary role for 2 weeks at the end of the PICARD mission provides a unique opportunity to test the fundamental hypothesis of radiometer experiments in space, which is that the sensitivity change of instruments due to the space environment is identical for the same...
Conference Paper
PICARD is a mission devoted to solar variability observation, through imagery and radiometric measurements, with the goal to provide data for scientific investigation first in the area of solar physics, and second in the assessment of the influence of the solar variability on the Earth climate variability. PICARD contains a double program with in-s...
Conference Paper
The Extreme Ultraviolet Imager (EUI) instrument is one of the ten scientific instruments on board the Solar Orbiter mission to be launched in October 2018. It will provide full-sun and high-resolution images of the solar corona in the extreme ultraviolet (17.1 nm and 30.4 nm) and in the vacuum ultraviolet (121.6 nm). The validation of the EUI instr...
Article
Full-text available
We find that wintertime temperature anomalies near 4 hPa and 50° N/S are related, through dynamics, to anomalies in ozone and temperature, particularly in the tropical stratosphere, but also throughout the upper stratosphere and mesosphere. These mid-latitude anomalies occur on timescales of up to a month, and are related to changes in wave-forcing...
Article
Full-text available
Effects of the Quasi-Biennial Oscillation (QBO) on tropospheric climate are relatively small or appear only intermittently. Studying them requires long time series of both the QBO and climate variables, which has restricted previous studies to the past 30–50 years. Here we use the benefits of an existing QBO reconstruction back to 1908. We first in...
Article
In this brief communication we provide the rationale for, and the outcome of the International Astronomical Union (IAU) resolution vote at the XXIX-th General Assembly in Honolulu, Hawaii, in 2015, on recommended nominal conversion constants for selected solar and planetary properties. The problem addressed by the resolution is a lack of establishe...
Article
Full-text available
The state of the stratospheric ozone layer and the temperature structure of the atmosphere are largely controlled by the solar spectral irradiance (SSI) through its influence on heating and photolysis rates. This study focuses on the uncertainties in the photolysis rate response to solar irradiance variability related to the choice of SSI data set...
Article
Full-text available
The state of the stratospheric ozone layer and the temperature structure of the atmosphere are largely controlled by the solar spectral irradiance (SSI) through its influence on heating and photolysis rates. This study focuses on the uncertainties in the photolysis rate response to solar irradiance variability related to the choice of SSI data set...
Article
Full-text available
The PREcision Monitoring Sensor (PREMOS) is a solar radiometer on board the French PICARD mission that was launched in June 2010 and decommissioned in April 2014.Aims. The PREMOS radiometer obtains solar irradiance measurements in specific spectral windows in the UV, visible, and near- infrared. In this paper, the PREMOS data and calibration method...
Article
Some of the natural variability in climate is understood to come from changes in the Sun. A key route whereby the Sun may influence surface climate is initiated in the tropical stratosphere by the absorption of solar ultraviolet (UV) radiation by ozone, leading to a modification of the temperature and wind structures and consequently to the surface...
Article
Full-text available
Regular spaceborne measurements have revealed that solar brightness varies on multiple timescales, variations on timescales greater than a day being attributed to surface magnetic field. Independently, ground-based and spaceborne measurements suggest that Sun-like stars show a similar, but significantly broader pattern of photometric variability. T...
Article
Solar variability can influence surface climate, for example by affecting the mid-to-high-latitude surface pressure gradient associated with the North Atlantic Oscillation. One key mechanism behind such an influence is the absorption of solar ultraviolet (UV) radiation by ozone in the tropical stratosphere, a process that modifies temperature and w...
Article
Full-text available
We present a comprehensive method to analyze small-scale heating events in detail in a 3D magnetohydrodynamics simulation for quiet-Sun conditions. The method determines the number, volume, and some general geometric properties of the small-scale heating events at different instants in a simulation with a volume of 16 × 8 × 16 Mm3, spanning from th...
Conference Paper
Full-text available
The Solar Orbiter mission is composed of ten scientific instruments dedicated to the observation of the Sun’s atmosphere and its heliosphere, taking advantage of an out-of ecliptic orbit and at perihelion reaching a proximity close to 0.28 A.U. On board Solar Orbiter, the Extreme Ultraviolet Imager (EUI) will provide full-Sun image sequences of the...
Article
Full-text available
The solar brightness varies on timescales from minutes to decades. A clear identification of the physical processes behind such variations is needed for developing and improving physics-based models of solar brightness variability and reconstructing solar brightness in the past. This is, in turn, important for better understanding the solar-terrest...
Article
Full-text available
A solar spectrum extending from the extreme ultraviolet to the near-infrared is an important input for solar physics, climate research, and atmospheric physics. Ultraviolet measurements have been conducted since the beginning of the space age, but measurements throughout the contiguous visible and infrared (IR) regions are much more sparse. Ageing...
Article
Full-text available
The short-period (1.64 d) near-contact eclipsing WN6+O9 binary system CQ Cep provides an ideal laboratory for testing the predictions of X-ray colliding wind shock theory at close separation where the winds may not have reached terminal speeds before colliding. We present results of a Chandra X-ray observation of CQ Cep spanning ~1 day during which...
Article
Full-text available
Onboard the International Space Station (ISS), two instruments are observing the solar spectral irradiance (SSI) at wavelengths from 16 to 2900 nm. Although the ISS platform orientation generally precludes pointing at the Sun more than 10 – 14 days per month, in November/December 2012 a continuous period of measurements was obtained by implementing...
Article
Full-text available
Solar radiation is the main source of energy for the Earth's atmosphere and in many respects defines its composition, photochemistry, temperature profile and dynamics. The magnitude of the solar irradiance variability strongly depends on the wavelength, making difficult its representation in climate models. Due to some deficiencies in the applied r...
Article
Full-text available
A recently built cryogenic solar absolute radiometer aims to reduce the uncertainty of terrestrially measured direct solar irradiance from 0.3% to 0.01%. Because solar irradiance entering a cryogenic radiometer is partly reflected and absorbed by the entrance window, the spectrally integrated transmittance of the broadband solar irradiance needs to...
Article
Full-text available
PMOD/WRC is building the Compact and Light-weight Absolute RAdiometer (CLARA) to fly on the Norwegian Space Centre's (NSC) NORSAT-1 mission. The CLARA is based on a new design by PMOD/WRC which minimizes size and weight while improving the radiometric performance. The NORSAT-1 mission is planned to be launched to a polar LEO in Q4 2015. The nominal...
Article
Full-text available
The newly developed atmosphere–ocean–chemistry–climate model SOCOL-MPIOM is presented by demonstrating the influence of chemistry–climate interactions on the climate state and the variability. Therefore, we compare pre-industrial control simulations with (CHEM) and without (NOCHEM) interactive chemistry. In general, the influence of the chemistry o...
Conference Paper
Since the launch of PICARD in 2010 the PMO6 absolute radiometers of the PREMOS experiment had been measuring Total Solar Irradiance. We will present the TSI data record, corrected for sensor degradation, and review the stability of the radiometers during the entire mission. Implications for the uncertainty of Composite Total Solar Irradiance time S...
Conference Paper
Full-text available
The Extreme Ultraviolet Imager (EUI) on-board the Solar Orbiter mission will provide full-sun and high-resolution image sequences of the solar atmosphere at selected spectral emission lines in the extreme and vacuum ultraviolet. After the breadboarding and prototyping activities that focused on key technologies, the EUI project has completed the de...
Article
Full-text available
The Sun and stars with low magnetic activity levels, become photometrically brighter when their activity increases. Magnetically more active stars display the opposite behaviour and get fainter when their activity increases. We reproduce the observed photometric trends in stellar variations with a model that treats stars as hypothetical Suns with c...
Article
Full-text available
On 7 February 2008, the SOLAR payload was placed onboard the International Space Station. It is composed of three instruments, two spectrometers and a radiometer. The two spectrometers allow us to cover the 16 – 2900 nm spectral range. In this article, we first briefly present the instrumentation, its calibration and its performance in orbit. Secon...