Water vapor is the dominant greenhouse gas in the atmosphere, and the dominant mode of variability in the ocean-atmosphere system is El Nino. The connection between El Nino and water vapor above ~17km is unclear, with single model studies reaching a range of conclusions. This study examines this connection in 12 different models. While there are substantial differences among the models, all models appear to capture the fundamental physical processes correctly.
Water vapor is the dominant greenhouse gas in the atmosphere, and the dominant mode of...
Review status: this preprint is currently under review for the journal ACP.
Influence of ENSO on entry stratospheric water vapor in coupled chemistry-ocean CCMI and CMIP6 models
Chaim Israel Garfinkel1,Ohad Harari1,Shlomi Ziskin1,2,3,Jian Rao1,4,Olaf Morgenstern5,Guang Zeng5,Simone Tilmes6,Doug Kinnison6,Fiona M. O'Connor7,Neal Butchart7,Makoto Deushi8,Patrick Jöckel9,and Andrea Pozzer10,11Chaim Israel Garfinkel et al.Chaim Israel Garfinkel1,Ohad Harari1,Shlomi Ziskin1,2,3,Jian Rao1,4,Olaf Morgenstern5,Guang Zeng5,Simone Tilmes6,Doug Kinnison6,Fiona M. O'Connor7,Neal Butchart7,Makoto Deushi8,Patrick Jöckel9,and Andrea Pozzer10,11
1The Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
2Department of Physics, Ariel University, Ariel, Israel
3Eastern R&D center, Ariel, Israel
4Key Laboratory of Meteorological Disaster, Ministry of Education (KLME)/Joint International Research Laboratory of Climate and Environment Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science & Technology, Nanjing 210044, China
5National Institute of Water and Atmospheric Research, Wellington, New Zealand
6National Center for Atmospheric Research, Boulder, Colorado, USA
7Met Office Hadley Centre, Exeter, UK
8Meteorological Research Institute, Tsukuba, Japan
9Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany
10Max Planck Institute for Chemistry, Mainz, Germany
11International Centre for Theoretical Physics, Trieste, Italy
1The Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
2Department of Physics, Ariel University, Ariel, Israel
3Eastern R&D center, Ariel, Israel
4Key Laboratory of Meteorological Disaster, Ministry of Education (KLME)/Joint International Research Laboratory of Climate and Environment Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science & Technology, Nanjing 210044, China
5National Institute of Water and Atmospheric Research, Wellington, New Zealand
6National Center for Atmospheric Research, Boulder, Colorado, USA
7Met Office Hadley Centre, Exeter, UK
8Meteorological Research Institute, Tsukuba, Japan
9Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany
10Max Planck Institute for Chemistry, Mainz, Germany
11International Centre for Theoretical Physics, Trieste, Italy
Received: 30 Jul 2020 – Accepted for review: 24 Aug 2020 – Discussion started: 10 Sep 2020
Abstract. The connection between the dominant mode of interannual variability in the tropical troposphere, El Nino Southern Oscillation (ENSO), and entry of stratospheric water vapor, is analyzed in a set of the model simulations archived for the Chemistry-Climate Model Initiative (CCMI) project and for phase 6 of the Coupled Model Intercomparison Project. While the models agree on the temperature response to ENSO in the tropical troposphere and lower stratosphere, and all models also agree on the zonal structure of the response in the tropical tropopause layer, the only aspect of the entry water vapor with consensus is that La Nina leads to moistening in winter relative to neutral ENSO. For El Nino and for other seasons there are significant differences among the models. For example, some models find that the enhanced water vapor for La Nina in the winter of the event reverses in spring and summer, other models find that this moistening persists, while some show a nonlinear response with both El Nino and La Nina leading to enhanced water vapor in both winter, spring, and summer. Focusing on Central Pacific ENSO versus East Pacific ENSO, or temperatures in the mid-troposphere as compared to temperatures near the surface, does not narrow the inter-model discrepancies. Despite this diversity in response, the temperature response near the cold point can explain the response of water vapor when each model is considered separately. While the observational record is too short to fully constrain the response to ENSO, it is clear that most models suffer from biases in the magnitude of interannual variability of entry water vapor. This bias could be due to missing forcing processes that contribute to observed variability in cold point temperatures.
Water vapor is the dominant greenhouse gas in the atmosphere, and the dominant mode of variability in the ocean-atmosphere system is El Nino. The connection between El Nino and water vapor above ~17km is unclear, with single model studies reaching a range of conclusions. This study examines this connection in 12 different models. While there are substantial differences among the models, all models appear to capture the fundamental physical processes correctly.
Water vapor is the dominant greenhouse gas in the atmosphere, and the dominant mode of...