Publications


Ice-shelf damming in the glacial Arctic Ocean: dynamical regimes of a basin-covering kilometre-thick ice shelf

CRYOSPHERE 11 (2017) 1745-1765

J Nilsson, M Jakobsson, C Borstad, N Kirchner, G Bjork, RT Pierrehumbert, C Stranne


A rotating annulus driven by localized convective forcing: a new atmosphere-like experiment

EXPERIMENTS IN FLUIDS 58 (2017) ARTN 75

H Scolan, PL Read


Phase synchronization of baroclinic waves in a differentially heated rotating annulus experiment subject to periodic forcing with a variable duty cycle

Chaos 27 (2017)

PL Read, X Morice-Atkinson, EJ Allen, AA Castrejón-Pita

© 2017 Author(s). A series of laboratory experiments in a thermally driven, rotating fluid annulus are presented that investigate the onset and characteristics of phase synchronization and frequency entrainment between the intrinsic, chaotic, oscillatory amplitude modulation of travelling baroclinic waves and a periodic modulation of the (axisymmetric) thermal boundary conditions, subject to timedependent coupling. The time-dependence is in the form of a prescribed duty cycle in which the periodic forcing of the boundary conditions is applied for only a fraction δ of each oscillation. For the rest of the oscillation, the boundary conditions are held fixed. Two profiles of forcing were investigated that capture different parts of the sinusoidal variation and δ was varied over the range 0:1 ≤ δ ≤ 1. Reducing δ was found to act in a similar way to a reduction in a constant coupling coefficient in reducing the width of the interval in forcing frequency or period over which complete synchronization was observed (the "Arnol'd tongue") with respect to the detuning, although for the strongest pulse-like forcing profile some degree of synchronization was discernible even at δ = 0:1. Complete phase synchronization was obtained within the Arnol'd tongue itself, although the strength of the amplitude modulation of the baroclinic wave was not significantly affected. These experiments demonstrate a possible mechanism for intraseasonal and/or interannual "teleconnections" within the climate system of the Earth and other planets that does not rely on Rossby wave propagation across the planet along great circles.


Regimes of Axisymmetric Flow and Scaling Laws in a Rotating Annulus with Local Convective Forcing

Fluids 2 (2017) 41-41

S Wright, S Su, H Scolan, R Young, P Read


Forward and inverse kinetic energy cascades in Jupiter's turbulent weather layer

NATURE PHYSICS 13 (2017) 1135-+

RMB Young, PL Read


Ertel potential vorticity versus Bernoulli streamfunction on Mars

QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY 143 (2017) 37-52

TE Dowling, ME Bradley, J Du, SR Lewis, PL Read


Observational evidence against strongly stabilizing tropical cloud feedbacks

GEOPHYSICAL RESEARCH LETTERS 44 (2017) 1503-1510

IN Williams, RT Pierrehumbert


Linking the Climate and Thermal Phase Curve of 55 Cancri e

Astrophysical Journal 849 (2017)

M Hammond, RT Pierrehumbert

© 2017. The American Astronomical Society. All rights reserved. The thermal phase curve of 55 Cancri e is the first measurement of the temperature distribution of a tidally locked super-Earth, but raises a number of puzzling questions about the planet's climate. The phase curve has a high amplitude and peak offset, suggesting that it has a significant eastward hot-spot shift as well as a large day-night temperature contrast. We use a general circulation model to model potential climates, and investigate the relation between bulk atmospheric composition and the magnitude of these seemingly contradictory features. We confirm theoretical models of tidally locked circulation are consistent with our numerical model of 55 Cnc e, and rule out certain atmospheric compositions based on their thermodynamic properties. Our best-fitting atmosphere has a significant hot-spot shift and day-night contrast, although these are not as large as the observed phase curve. We discuss possible physical processes that could explain the observations, and show that night-side cloud formation from species such as SiO from a day-side magma ocean could potentially increase the phase curve amplitude and explain the observations. We conclude that the observations could be explained by an optically thick atmosphere with a low mean molecular weight, a surface pressure of several bars, and a strong eastward circulation, with night-side cloud formation a possible explanation for the difference between our model and the observations.


Reconstructing Climate from Glaciers

Annual Review of Earth and Planetary Sciences 45 (2017) 649-680

AN Mackintosh, BM Anderson, RT Pierrehumbert

Copyright © 2017 by Annual Reviews. All rights reserved. Glaciers offer the potential to reconstruct past climate over timescales from decades to millennia. They are found on nearly every continent, and at the Last Glacial Maximum, glaciers were larger in all regions on Earth. The physics of glacier-climate interaction are relatively well understood, and glacier models can be used to reconstruct past climate from geological evidence of past glacier extent. This can lead to significant insights regarding past, present, and future climate. For example, glacier modeling has demonstrated that the near-ubiquitous global pattern of glacier retreat during the last few centuries resulted from a global-scale climate warming of ∼1°C, consistent with instrumental data and climate proxy records. Climate reconstructions from glaciers have also demonstrated that the tropics were colder at the Last Glacial Maximum than was originally inferred from sea surface temperature reconstructions. Future efforts to reconstruct climate from glaciers may provide new constraints on climate sensitivity to CO2 forcing, polar amplification of climate change, and more.


Global energy budgets and "Trenberth diagrams' for the climates of terrestrial and gas giant planets

QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY 142 (2016) 703-720

PL Read, J Barstow, B Charnay, S Chelvaniththilan, PGJ Irwin, S Knight, S Lebonnois, SR Lewis, J Mendonca, L Montabone


Consequences of twenty-first-century policy for multi-millennial climate and sea-level change

NATURE CLIMATE CHANGE 6 (2016) 360-369

PU Clark, JD Shakun, SA Marcott, AC Mix, M Eby, S Kulp, A Levermann, GA Milne, PL Pfister, BD Santer, DP Schrag, S Solomon, TF Stocker, BH Strauss, AJ Weaver, R Winkelmann, D Archer, E Bard, A Goldner, K Lambeck, RT Pierrehumbert, G-K Plattner


A regime diagram for ocean geostrophic turbulence

QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY 142 (2016) 2411-2417

A Klocker, DP Marshall, SR Keating, PL Read


How to decarbonize? Look to Sweden

Bulletin of the Atomic Scientists 72 (2016) 105-111

R Pierrehumbert


CONVECTION IN CONDENSIBLE-RICH ATMOSPHERES

ASTROPHYSICAL JOURNAL 822 (2016) ARTN 24

F Ding, RT Pierrehumbert


Dynamics of atmospheres with a non-dilute condensible component.

Proceedings. Mathematical, physical, and engineering sciences 472 (2016) 20160107-

RT Pierrehumbert, F Ding

The diversity of characteristics for the host of recently discovered exoplanets opens up a great deal of fertile new territory for geophysical fluid dynamics, particularly when the fluid flow is coupled to novel thermodynamics, radiative transfer or chemistry. In this paper, we survey one of these new areas-the climate dynamics of atmospheres with a non-dilute condensible component, defined as the situation in which a condensible component of the atmosphere makes up a substantial fraction of the atmospheric mass within some layer. Non-dilute dynamics can occur for a wide range of condensibles, generically applying near both the inner and the outer edges of the conventional habitable zone and in connection with runaway greenhouse phenomena. It also applies in a wide variety of other planetary circumstances. We first present a number of analytical results developing some key features of non-dilute atmospheres, and then show how some of these features are manifest in simulations with a general circulation model adapted to handle non-dilute atmospheres. We find that non-dilute atmospheres have weak horizontal temperature gradients even for rapidly rotating planets, and that their circulations are largely barotropic. The relative humidity of the condensible component tends towards 100% as the atmosphere becomes more non-dilute, which has important implications for runaway greenhouse thresholds. Non-dilute atmospheres exhibit a number of interesting organized convection features, for which there is not yet any adequate theoretical understanding.


New use of global warming potentials to compare cumulative and short-lived climate pollutants

NATURE CLIMATE CHANGE 6 (2016) 773-+

MR Allen, JS Fuglestvedt, KP Shine, A Reisinger, RT Pierrehumbert, PM Forster


Exploring the Venus global super-rotation using a comprehensive general circulation model

PLANETARY AND SPACE SCIENCE 134 (2016) 1-18

JM Mendonca, PL Read


Galactic cosmic rays on extrasolar Earth-like planets II. Atmospheric implications

ASTRONOMY & ASTROPHYSICS 587 (2016) ARTN A159

J-M Griessmeier, F Tabataba-Vakili, A Stadelmann, JL Grenfell, D Atri


Atmospheric effects of stellar cosmic rays on Earth-like exoplanets orbiting M-dwarfs

ASTRONOMY & ASTROPHYSICS 585 (2016) ARTN A96

F Tabataba-Vakili, JL Grenfell, J-M Griessmeier, H Rauer


Predictability of the thermally driven laboratory rotating annulus

QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY 142 (2016) 911-927

RMB Young, PL Read

Pages