SPARC/IO3C/GAW LOTUS Report iii

Authors & Reviewers

SPARC LOTUS Activity leaders (1) NOAA Earth System Research Laboratory Irina Petropavlovskikh USA (2) CIRES, University of Colorado Sophie Godin-Beekmann LATMOS-IPSL, CNRS/UVSQ/Sorbonne University France Daan Hubert Royal Belgian Institute for Space Aeronomy (BIRA-IASB) Belgium

Working group leaders of the SPARC LOTUS Activity Robert Damadeo NASA Langley Research Center USA Birgit Hassler Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre Viktoria F. Sofieva Finnish Meteorological Institute Finland

Review editors Neil R.P. Harris Cranfield University United Kingdom Fiona Tummon Federal Office of and Climatology, MeteoSwiss Switzerland Donald J. Wuebbles University of Illinois USA

Authors and Contributors

Executive Summary Chapter lead authors

(1) NOAA Earth System Research Laboratory Irina Petropavlovskikh USA (2) CIRES, University of Colorado Sophie Godin-Beekmann LATMOS-IPSL, CNRS/UVSQ/Sorbonne University France Daan Hubert Royal Belgian Institute for Space Aeronomy (BIRA-IASB) Belgium Robert Damadeo NASA Langley Research Center USA Birgit Hassler Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre Germany Viktoria F. Sofieva Finnish Meteorological Institute Finland (1) Science Systems and Applications Inc. Stacey M. Frith USA (2) NASA Goddard Space Flight Center Kleareti Tourpali Aristotle University of Thessaloniki Greece

Chapter 1: Introduction Chapter lead authors

Sophie Godin-Beekmann LATMOS-IPSL, CNRS/UVSQ/Sorbonne University France (1) NOAA Earth System Research Laboratory Irina Petropavlovskikh USA (2) CIRES, University of Colorado Daan Hubert Royal Belgian Institute for Space Aeronomy (BIRA-IASB) Belgium

Chapter 2: Observations and model data

Chapter lead authors (1) NOAA Earth System Research Laboratory Irina Petropavlovskikh USA (2) CIRES, University of Colorado Viktoria F. Sofieva Finnish Meteorological Institute Finland iv SPARC/IO3C/GAW LOTUS Report

Co-authors (1) Science Systems and Applications Inc. Stacey M. Frith USA (2) NASA Goddard Space Flight Center Kleareti Tourpali Aristotle University of Thessaloniki Greece Corinne Vigouroux Royal Belgian Institute for Space Aeronomy (BIRA-IASB) Belgium (1) Innovim, LLC, Greenbelt, MD Jeannette D. Wild USA (2) NOAA/NCEP/ Prediction Center (1) Institute for Atmospheric and Climate Science, ETH William T. Ball Switzerland (2) Physikalisch-Meteorologisches Observatorium Davos - World Radiation Center Kai-Lan Chang National Research Council Fellow at NOAA Earth System Research Laboratory USA (1) NOAA Earth System Research Laboratory Sean M. Davis USA (2) CIRES, University of Colorado Doug A. Degenstein University of Saskatchewan Canada Lucien Froidevaux Jet Propulsion Laboratory, California Institute of Technology USA Sophie Godin-Beekmann LATMOS-IPSL, CNRS/UVSQ/Sorbonne University France Daan Hubert Royal Belgian Institute for Space Aeronomy (BIRA-IASB) Belgium Alexandra Laeng KIT, Institute of Meteorology and Climate Research (IMK-ASF) Germany Thierry Leblanc Jet Propulsion Laboratory, California Institute of Technology USA Eliane Maillard Barras Federal Office of Meteorology and Climatology, MeteoSwiss Switzerland Herman G.J. Smit Institute of Energy and Climate Research at Forschungszentrum Jülich Germany Wolfgang Steinbrecht , Meteorological Observatory Hohenpeissenberg Germany

Data providers John Anderson School of Science, Hampton University USA Omaira E. García IARC, Agencia Estatal de Meteorología (AEMET) Spain James W. Hannigan National Center for Atmospheric Research (NCAR) USA Bryan J. Johnson NOAA Earth System Research Laboratory, Global Monitoring Division USA Nicholas B. Jones University of Australia Emmanuel Mahieu University of Liège Belgium Ankie J. M. Piters Royal Netherlands Meteorological Institute (KNMI) The Netherlands Françoise Posny Laboratoire de l’Atmosphère et des Cyclones (LACy), UMR8105, Saint-Denis, Réunion France Richard Querel National Institute of Water and Atmospheric Research (NIWA) New Zealand Dan Smale National Institute of Water and Atmospheric Research (NIWA) New Zealand René Stübi Federal Office of Meteorology and Climatology, MeteoSwiss Switzerland Daan P.J. Swart National Institute for Public Health and the Environment (RIVM) The Netherlands David W. Tarasick Environment and Climate Change Canada, Toronto Canada Anne M. Thompson NASA Goddard Space Flight Center USA Matthew B. Tully Australia Joanna A.E. van Gijsel Faculty of Geo-Information Science and Earth Observation, University of Twente The Netherlands Roeland Van Malderen Royal Meteorological Institute of Belgium (RMIB) Belgium Ray Wang School of Earth and Atmospheric Sciences, Georgia Institute of Technology USA (1) Science Systems and Applications Inc. Jacquelyn C. Witte USA (2) NASA Goddard Space Flight Center

CCMI modelers Slimane Bekki LATMOS-IPSL, CNRS, Paris France Neal Butchart Hadley Centre United Kingdom Martyn P. Chipperfield University of Leeds United Kingdom Makoto Deushi Meteorological Research Institute (MRI) Japan Sandip S. Dhomse University of Leeds United Kingdom Steven C. Hardiman Met Office Hadley Centre United Kingdom SPARC/IO3C/GAW LOTUS Report v

Michaela I. Hegglin University of Reading United Kingdom Patrick Jöckel Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre Germany Douglas Kinnison National Center for Atmospheric Research (NCAR) USA Jean-François Lamarque National Center for Atmospheric Research (NCAR) USA Martine Michou Météo-France CNRM France Olaf Morgenstern National Institute of Water and Atmospheric Research (NIWA) New Zealand Fiona M. O'Connor Met Office Hadley Centre United Kingdom Luke D. Oman NASA Goddard Space Flight Center USA Giovanni Pitari Department of Physical and Chemical Sciences, Università dell’Aquila Italy David A. Plummer Environment and Climate Change Canada, Montreal Canada Laura E. Revell Bodeker Scientific New Zealand (1) Physikalisch-Meteorologisches Observatorium Davos - World Radiation Center Eugene Rozanov Switzerland (2) Institute for Atmospheric and Climate Science, ETH Zurich David Saint-Martin CNRM/GMGEC/AMACS France (1) School of Earth Sciences, University of Robyn Schofield Australia (2) ARC Centre of Excellence for Climate System Science Andrea Stenke Institute for Atmospheric and Climate Science, ETH Zurich Switzerland (1) School of Earth Sciences, Kane A. Stone (2) ARC Centre of Excellence for Climate System Science Australia *Now at: Department of Earth, Atmospheric, and Planetary Science, MIT Simone Tilmes National Center for Atmospheric Research (NCAR) USA Daniele Visioni Department of Physical and Chemical Sciences, Università dell’Aquila Italy Guang Zeng National Institute of Water and Atmospheric Research (NIWA) New Zealand

Chapter 3: Challenges for trend studies Chapter lead authors Daan Hubert Royal Belgian Institute for Space Aeronomy (BIRA-IASB) Belgium Viktoria F. Sofieva Finnish Meteorological Institute Finland Co-authors (1) Institute for Atmospheric and Climate Science, ETH Zurich William T. Ball Switzerland (2) Physikalisch-Meteorologisches Observatorium Davos - World Radiation Center Robert Damadeo NASA Langley Research Center USA (1) Science Systems and Applications Inc. Stacey M. Frith USA (2) NASA Goddard Space Flight Center Kleareti Tourpali Aristotle University of Thessaloniki Greece (1) Innovim, LLC, Greenbelt, MD Jeannette D. Wild USA (2) NOAA/NCEP/Climate Prediction Center Christos S. Zerefos Research Centre for Atmospheric Physics and Climatology, Academy of Greece Contributing authors Center for Computational Astrophysics, Flatiron Institute, NY Justin Alsing USA *Now at : Oskar Klein Centre for Cosmoparticle Physics, Stockholm University Kostas Eleftheratos Dep. of Geology and Geoenvironment, National and Kapodistrian University of Athens Greece Sophie Godin-Beekmann LATMOS-IPSL, CNRS/UVSQ/Sorbonne University France John Kapsomenakis Research Centre for Atmospheric Physics and Climatology, Academy of Athens Greece Jean-Christopher Lambert Royal Belgian Institute for Space Aeronomy (BIRA-IASB) Belgium Thierry Leblanc Jet Propulsion Laboratory, California Institute of Technology USA Gerald E. Nedoluha Remote Sensing Division, Naval Research Laboratory USA Wolfgang Steinbrecht Deutscher Wetterdienst, Meteorological Observatory Hohenpeissenberg Germany René Stübi Federal Office of Meteorology and Climatology, MeteoSwiss Switzerland vi SPARC/IO3C/GAW LOTUS Report

Chapter 4: The LOTUS regression model Chapter lead authors Robert Damadeo NASA Langley Research Center USA Birgit Hassler Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre Germany Co-authors

Daniel J. Zawada University of Saskatchewan Canada (1) Science Systems and Applications Inc. Stacey M. Frith USA (2) NASA Goddard Space Flight Center (1) Institute for Atmospheric and Climate Science, ETH Zurich William T. Ball Switzerland (2) Physikalisch-Meteorologisches Observatorium Davos - World Radiation Center Kai-Lan Chang National Research Council Fellow at NOAA Earth System Research Laboratory USA Doug A. Degenstein University of Saskatchewan Canada Daan Hubert Royal Belgian Institute for Space Aeronomy (BIRA-IASB) Belgium Stergios Misios University of Oxford United Kingdom (1) NOAA Earth System Research Laboratory Irina Petropavlovskikh USA (2) CIRES, University of Colorado Chris Z. Roth University of Saskatchewan Canada Viktoria F. Sofieva Finnish Meteorological Institute Finland Wolfgang Steinbrecht Deutscher Wetterdienst, Meteorological Observatory Hohenpeissenberg Germany Kleareti Tourpali Aristotle University of Thessaloniki Greece Christos S. Zerefos Research Centre for Atmospheric Physics and Climatology, Academy of Athens Greece Contributing authors Center for Computational Astrophysics, Flatiron Institute, NY Justin Alsing USA *Now at : Oskar Klein Centre for Cosmoparticle Physics, Stockholm University Dimitris Balis Aristotle University of Thessaloniki Greece Melanie Coldewey-Egbers Deutsches Zentrum für Luft- und Raumfahrt (DLR), Inst. für Methodik der Fernerkundung Germany Kostas Eleftheratos Dep. of Geology and Geoenvironment, National and Kapodistrian University of Athens Greece Sophie Godin-Beekmann LATMOS-IPSL, CNRS/UVSQ/Sorbonne University France Aleksandr Gruzdev A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Science Russia John Kapsomenakis Research Centre for Atmospheric Physics and Climatology, Academy of Athens Greece Alexandra Laeng KIT, Institute of Meteorology and Climate Research (IMK-ASF) Germany Marko Laine Finnish Meteorological Institute Finland Eliane Maillard Barras Federal Office of Meteorology and Climatology, MeteoSwiss Switzerland Michael Taylor Department of Meteorology, University of Reading United Kingdom Thomas von Clarmann KIT, Institute of Meteorology and Climate Research (IMK-ASF) Germany Mark Weber Institute of Environmental Physics, University of Bremen Germany (1) Innovim, LLC, Greenbelt, MD Jeannette D. Wild USA (2) NOAA/NCEP/Climate Prediction Center

Chapter 5: Time series and trend results Chapter lead authors Birgit Hassler Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre Germany Robert Damadeo NASA Langley Research Center USA Co-authors Kai-Lan Chang National Research Council Fellow at NOAA Earth System Research Laboratory USA Viktoria F. Sofieva Finnish Meteorological Institute Finland Kleareti Tourpali Aristotle University of Thessaloniki Greece SPARC/IO3C/GAW LOTUS Report vii

(1) Science Systems and Applications Inc. Stacey M. Frith USA (2) NASA Goddard Space Flight Center (1) Institute for Atmospheric and Climate Science, ETH Zurich William T. Ball Switzerland (2) Physikalisch-Meteorologisches Observatorium Davos - World Radiation Center Doug A. Degenstein University of Saskatchewan Canada Sophie Godin-Beekmann LATMOS-IPSL, CNRS/UVSQ/Sorbonne University France Daan Hubert Royal Belgian Institute for Space Aeronomy (BIRA-IASB) Belgium Eliane Maillard Barras Federal Office of Meteorology and Climatology, MeteoSwiss Switzerland Stergios Misios University of Oxford United Kingdom (1) NOAA Earth System Research Laboratory Irina Petropavlovskikh USA (2) CIRES, University of Colorado Chris Z. Roth University of Saskatchewan Canada Wolfgang Steinbrecht Deutscher Wetterdienst, Meteorological Observatory Hohenpeissenberg Germany Corinne Vigouroux Royal Belgian Institute for Space Aeronomy (BIRA-IASB) Belgium Thomas von Clarmann KIT, Institute of Meteorology and Climate Research (IMK-ASF) Germany Daniel J. Zawada University of Saskatchewan Canada Christos S. Zerefos Research Centre for Atmospheric Physics and Climatology, Academy of Athens Greece Contributing authors Center for Computational Astrophysics, Flatiron Institute, NY Justin Alsing USA *Now at : Oskar Klein Centre for Cosmoparticle Physics, Stockholm University Dimitris Balis Aristotle University of Thessaloniki Greece Melanie Coldewey-Egbers Deutsches Zentrum für Luft- und Raumfahrt (DLR), Inst. für Methodik der Fernerkundung Germany Kostas Eleftheratos Dep. of Geology and Geoenvironment, National and Kapodistrian University of Athens Greece Aleksandr Gruzdev A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Science Russia John Kapsomenakis Research Centre for Atmospheric Physics and Climatology, Academy of Athens Greece Alexandra Laeng KIT, Institute of Meteorology and Climate Research (IMK-ASF) Germany Marko Laine Finnish Meteorological Institute Finland Michael Taylor Department of Meteorology, University of Reading United Kingdom Mark Weber Institute of Environmental Physics, University of Bremen Germany (1) Innovim, LLC, Greenbelt, MD Jeannette D. Wild USA (2) NOAA/NCEP/Climate Prediction Center

Reviewers

Gufran Beig Indian Institute of Tropical Meteorology (Ministry of Earth Sciences, Govt. of India) India Greg E. Bodeker Bodeker Scientific New Zealand Pablo O. Canziani University of Argentina Martin Dameris Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre Germany Richard D. Eckman NASA USA James Keeble Centre for Atmospheric Science, University of Cambridge United Kingdom Paul A. Newman NASA Goddard Space Flight Center USA Scott Osprey NCAS, University of Oxford United Kingdom Richard S. Stolarski Department of Earth and Planetary Sciences, Johns Hopkins University USA Susann Tegtmeier GEOMAR Helmholtz Centre for Ocean Research Kiel Germany Matthew B. Tully Bureau of Meteorology Australia Claus Zehner European Space Agency (ESA/ESRIN) Italy