Abstract. Isca is a framework for the idealized modelling of global circulation planetary atmospheres at varying levels complexity and realism. The an outgrowth models from Geophysical Fluid Dynamics Laboratory in Princeton, USA, designed Earth's atmosphere, but it may readily be extended into other regimes. Various forcing radiation options are available, dry, time invariant, Newtonian thermal relaxation to moist dynamics with radiative transfer. Options available dry scheme account effects...

Abstract We examine the midlatitude jet stream responses to projected Antarctic and Arctic sea‐ice loss global ocean warming in coordinated multi‐model experiments from Polar Amplification Model Intercomparison Project. cause an equatorward shift of winter southern northern hemisphere, respectively, on average across models. Models with stronger eddy feedback simulate farther shifts response both loss. The models too weak compared real world, particularly resulting underestimation boreal...

Polar vortices on Mars provide case-studies to aid understanding of geophysical vortex dynamics and may help resolve long-standing issues regarding polar Earth. Due the recent development first publicly available Martian reanalysis dataset (MACDA), for time we are able characterise thoroughly structure evolution vortices, hence perform a systematic comparison with The winter atmospheric circulations two planets compared, specific focus vortices. residual meridional overturning circulation is...

Abstract A key feature in polar atmospheric dynamics, vortices are found on many planets, with those Mars the most studied beyond Earth. We review current understanding of physical processes that give Martian their barotropically unstable annular structure, latent heating from condensation CO 2 to be major forcing mechanism. summarise previous work investigating spatial variability vortices, and outline some unanswered questions about potential causes this how it impacts cross‐vortex...

Abstract The atmospheric response to SST anomalies is notoriously difficult simulate and may be sensitive model details biases, particularly in midlatitudes. Studies have suggested that the a model’s background wind field its variability. dependence on such factors has meant it know what responses, if any, are robust, whether system itself or models themselves failing. Our goal this work better understand geographical seasonal of anomalies, with particular attention role state. We examine an...

A longstanding mystery about Jupiter has been the straightness and steadiness of its weather-layer jets, quite unlike terrestrial strong jets with their characteristic unsteadiness long-wavelength meandering. The problem is addressed in two steps. first to take seriously classic Dowling-Ingersoll (DI) 1-1/2-layer scenario supporting observational evidence, pointing toward deep, massive, zonally-symmetric zonal underlying dry-convective layer. second improve realism model stochastic forcing...

The continental distribution and surface conditions of a planet strongly impact its climate. Continents on Earth are believed to have emerged above sea level in the Archean Eon, although exact timing area widely debated. We use Isca climate model, framework for modelling idealised planetary atmospheres, explore climatic various land-ocean configurations 2.7 Ga Earth. find that addition land consistently produces global cooling introduces hemispheric asymmetry large-scale atmospheric...

This study investigates the impact of Arctic Amplification (AA) on midlatitude temperature extremes using aquaplanet simulations within ISCA intermediate complexity modeling framework. We use a mixed-layer ocean as boundary condition and grey radiation. Simulations are run with two setups: zonally symmetric control asymmetric experiment. In experiment localized oceanic heating is prescribed in midlatitudes to mimic western current generate eddy transient kinetic energy maximum (or storm...

Polar vortices are observed in the atmospheres of most solar-system planets, arising as a single cyclone centred on or close to pole. In contrast, Jupiter’s polar have an unprecedented structure. As revealed by NASA’s Juno spacecraft, they consist geometric patterns cyclonic surrounding central vortex at These crystalline structures were not predicted prior being observed, and mechanisms explaining their formation evolution remain poorly understood. One possible mechanism...

The time averaged winter polar vortex on Mars has been observed to have an annular structure, with a potential vorticity (PV) local minimum at the pole and surrounding region of higher PV. This structure is known be barotropically unstable; latent heat released by condensation atmospheric CO2 thought major forcing mechanism responsible for maintaining it. Whilst time-averaged seen take smooth reanalysis data suggest instantaneous spatially patchy localised regions lower PV rotating around...

Abstract Skill in seasonal forecasts the Northern Hemisphere extratropics is mostly limited to winter. Drivers of summer circulation anomalies over North Atlantic–European (NAE) sector are poorly understood. Here, we investigate role Atlantic sea surface temperatures (SSTs) driving atmospheric changes. The Oscillation (SNAO), leading mode observed variability NAE sector, correlated with a distinct SST tripole pattern Atlantic. An general model used test whether there robust responses...

Abstract Arctic amplification has been proposed to promote temperature extremes by slowing the midlatitude jet and increasing amplitude of its meanders. Observational modeling studies have used a variety metrics quantify waviness. These show conflicting changes in waviness depending on metric period examined. Here, we evaluate common for dry idealized model simulations which apply polar warming varying depth meridional extent. In all simulations, increases spatial extent meanders, but...

The climate and circulation of a terrestrial planet are governed by, among other things, the distance to its host star, size, rotation rate, obliquity, atmospheric composition gravity. Here we explore effects last these, Newtonian gravitational acceleration, on atmosphere climate. We first demonstrate that if obeys hydrostatic primitive equations, which very good approximation for most atmospheres, radiative forcing is unaltered, changes in gravity have no effect at all except vertical...

Abstract Among the great diversity of atmospheric circulation patterns observed throughout solar system, polar vortices stand out as a nearly ubiquitous planetary‐scale phenomenon. In recent years, there have been significant advances in observation planetary vortices, culminating fascinating discovery Jupiter's vortex clusters during Juno mission. Alongside these observational has major effort to understand dynamics using theory, idealized and comprehensive numerical models, laboratory...

The winter polar vortices on Mars are annular in terms of their potential vorticity (PV) structure, a phenomenon identified observations, reanalysis and some numerical simulations. Some recent modeling studies have proposed that condensation atmospheric carbon dioxide at the pole is contributing factor to maintaining annulus through release latent heat. Dust topographic forcing also known be causes internal interannual variability vortices. However, coupling between these factors remains...

Abstract In this paper and its companion, Part I, we explore the response of atmosphere to sea surface temperature anomalies in different geographical locations seasons. focused on Northern Hemisphere winter (DJF), whereas paper, II, focus summer (JJA) interseasonal comparisons. We use two configurations same idealized atmospheric model, constructed using continents topography. These give rise slightly background wind fields variability within season therefore a measure how robust is small...

We describe the use of Isca for hierarchical modeling Solar System planets, with particular attention paid to Earth, Mars, and Jupiter. is a framework construction models planetary atmospheres at varying degrees complexity, from featureless model planets an atmosphere forced by thermal relaxation back specified temperature, through aquaplanets no continents (or ocean) simple radiation scheme, near-comprehensive multi-band convection configurable topography. By judicious choice parameters...

Abstract The Arctic is estimated to have warmed up four times faster than the rest of globe since 1980s. There significant interest in understanding mechanisms by which such warming may impact weather and climate at lower latitudes. One mechanism “stratospheric pathway”; proposed induce a wave‐driven weakening stratospheric polar vortex, subsequently large‐scale tropospheric circulation. However, recent comprehensive model studies found systematic differences both magnitude sign response...

Explorationists are increasingly concerned with finding more difficult targets such as those under cover. Significant developments in Airborne Electromagnetic (AEM) technology now providing advanced tools for exploration these scenarios. Recovering the magnetic field B rather than dB/dt from a towed sensor boosts response high-conductance target, is readily shown model calculations. The advantage of B-field data presence noise illustrated GEOTEMDEEP™ example over known conductive body that...

Abstract. Isca is a framework for the idealized modelling of global circulation planetary atmospheres at varying levels complexity and realism. The an outgrowth models from Geophysical Fluid Dynamics Laboratory designed Earth's atmosphere, but it may readily be extended into other regimes. Various forcing radiation options are available, dry, time invariant, Newtonian thermal relaxation to moist dynamics with radiative transfer. Options available in dry scheme account effects obliquity...

Orebodies, mineralised zones, faults, folds, contacts, etc. may represent localised electrical conductors that create airborne electromagnetic (AEM) responses of interest to explorationists. However, typical AEM datasets in conductive regimes exhibit numerous features besides those and it is left the interpreter identify ones are significance interpretation task at hand.Synthetic data can be used illustrate effects host medium overburden on target responses, how these might identified...

The Bristol CMIP6 Data Hackathon formed part of the Met Office Climate Challenge series during 2021, bringing together around 100 UK early career researchers from a wide range environmental disciplines. purpose was to interrogate under-utilised but currently most advanced climate model inter-comparison project datasets develop new research ideas, create networks and outreach opportunities in lead up COP26. Experts different science fields, supported by core team scientists data specialists...

Abstract. A simple diagnostic cloud scheme (SimCloud) for general circulation models (GCMs), which has a modest level of complexity and is transparent in describing its dependence on tunable parameters, proposed this study. The large-scale clouds, form the core scheme, are diagnosed from relative humidity. In addition, marine low stratus typically found off west coast continents over subtropical oceans, determined largely as function inversion strength. “freeze-dry” adjustment based specific...

Coupled climate model simulations designed to isolate the effects of Arctic sea-ice loss often apply artificial heating, either directly ice or through modification surface albedo, constrain in absence other forcings. Recent work has shown that this approach may lead an overestimation response loss. In study, we assess spurious impacts ice-constraining methods on idealised aquaplanet general circulation (GCM) with thermodynamic sea-ice. The true effect is isolated by inducing reduction...

Abstract Coupled climate model simulations designed to isolate the effects of Arctic sea-ice loss often apply artificial heating, either directly ice or through modification surface albedo, constrain sea in absence other forcings. Recent work has shown that this approach may lead an overestimation response loss. In study, we assess spurious impacts ice-constraining methods on idealised aquaplanet general circulation (GCM) with thermodynamic ice. The true effect is isolated by inducing...