A5004492495- Oceanographic and Atmospheric Processes
- Climate variability and models
- Arctic and Antarctic ice dynamics
- Geology and Paleoclimatology Research
- Marine and coastal ecosystems
- Meteorological Phenomena and Simulations
- Atmospheric and Environmental Gas Dynamics
- Methane Hydrates and Related Phenomena
- Geophysics and Gravity Measurements
- Cryospheric studies and observations
- Atmospheric Ozone and Climate
- Paleontology and Stratigraphy of Fossils
- Ocean Acidification Effects and Responses
- Astro and Planetary Science
- Isotope Analysis in Ecology
- Fluid Dynamics and Turbulent Flows
- Scientific Research and Discoveries
- Marine and environmental studies
- Geomagnetism and Paleomagnetism Studies
- Advanced Thermodynamics and Statistical Mechanics
- Quality and Safety in Healthcare
- Tropical and Extratropical Cyclones Research
- Hydrocarbon exploration and reservoir analysis
- Corporate Finance and Governance
- Planetary Science and Exploration
University of Reading
2016-2025
New York Academy of Sciences
2024
Middle East Institute
2024
Liechtenstein Institute
2024
Hudson Institute
2024
John Wiley & Sons (Germany)
2024
Moss Landing Marine Laboratories
2024
Instituto Politecnico de Setubal
2023
National Institute of Meteorology
2021
Centre for Polar Observation and Modelling
2020
We review recent observations and models concerning the dynamics of Cryogenian global glaciation their biological consequences.
Abstract The authors quantify the relationship between location of intertropical convergence zone (ITCZ) and atmospheric heat transport across equator (AHTEQ) in climate models observations. observed zonal mean ITCZ varies from 5.3°S boreal winter to 7.2°N summer with an annual position 1.65°N while AHTEQ 2.1 PW northward 2.3 southward 0.1 southward. Seasonal variations are highly anticorrelated observations a suite state-of-the-art coupled regression coefficients −2.7° −2.4° PW−1...
Through study of observations and coupled climate simulations, it is argued that the mean position Inter-Tropical Convergence Zone (ITCZ) north equator a consequence northwards heat transport across by ocean circulation. Observations suggest hemispheric net radiative forcing at top atmosphere almost perfectly symmetric about equator, so total (atmosphere plus ocean) small (order 0.2 PW northwards). Due to Atlantic ocean's meridional overturning circulation, however, carries significantly...
Abstract The response of the Southern Ocean to a repeating seasonal cycle ozone loss is studied in two coupled climate models and found comprise both fast slow processes. similar interannual signature southern annular mode (SAM) on sea surface temperature (SST), onto which hole forcing projects summer. It comprises enhanced northward Ekman drift, inducing negative summertime SST anomalies around Antarctica, earlier ice freeze-up following winter, expansion edge year-round. however, results...
Abstract A global ocean circulation model is formulated in terms of the “residual mean” and used to study eddy–mean flow interaction. Adjoint techniques are compute three-dimensional eddy stress field that minimizes departure coarse-resolution from climatological observations temperature. The resulting 3D maps residual-mean yield a wealth information about role eddies large-scale circulation. In eddy-rich regions such as Southern Ocean, Kuroshio, Gulf Stream, stresses have an amplitude...
Abstract An eddy-resolving numerical model of a zonal flow, meant to resemble the Antarctic Circumpolar Current, is described and analyzed using framework J. Marshall T. Radko. In addition wind buoyancy forcing at surface, contains sponge layer northern boundary that permits residual meridional overturning circulation (MOC) exist depth. The strength MOC diagnosed for different strengths surface stress. It found eddy largely compensates changes in Ekman circulation. extent compensation thus...
In recent decades, the Arctic has been warming and sea ice disappearing. By contrast, Southern Ocean around Antarctica (mainly) cooling sea-ice extent growing. We argue here that interhemispheric asymmetries in mean ocean circulation, with sinking northern North Atlantic upwelling Antarctica, strongly influence sea-surface temperature (SST) response to anthropogenic greenhouse gas (GHG) forcing, accelerating while delaying it Antarctic. Furthermore, amplitude of GHG forcing similar at poles,...
Abstract Multiple equilibria in a coupled ocean–atmosphere–sea ice general circulation model (GCM) of an aquaplanet with many degrees freedom are studied. Three different stable states found for exactly the same set parameters and external forcings: cold state which polar sea cap extends into midlatitudes; warm state, is free; completely ice–covered “snowball” state. Although low-order energy balance models climate known to exhibit intransitivity (i.e., more than one given governing...
Abstract Quantifying global trends and variability in sea surface temperature (SST) is of fundamental importance to understanding changes the Earth’s climate. One approach observing SST via remote sensing. Here we use a 37-year gap-filled, daily-mean analysis satellite SSTs quantify trends, persistence between 1981–2018. The mean warming trend 0.09 K per decade globally, with 95% local being −0.1 + 0.35 K. Excluding perennial sea-ice regions, 0.11 decade. After removing long-term calculate...
Abstract Precipitation and circulation patterns of Northern Hemisphere monsoons are investigated in Coupled Model Intercomparison Project phase 5 simulations for mid‐Holocene future climate scenario rcp8.5. Although both climates exhibit warming enhanced interhemispheric thermal contrast boreal summer, changes the spatial extent rainfall intensity smaller than all except Indian monsoon. A decomposition moisture budget thermodynamic dynamic contributions suggests that under global warming,...
While the Atlantic Ocean is ventilated by high-latitude deep water formation and exhibits a pole-to-pole overturning circulation, Pacific does not. This asymmetric global pattern has persisted for past 2–3 million years, with evidence different ventilation modes in deeper past. In current climate, Atlantic-Pacific asymmetry occurs because more saline, enabling convection. To what extent salinity contrast between two basins dominated atmospheric processes (larger net evaporation over...
Abstract Antarctic shelf ocean warming affects melt of ice shelf/sheets and sea but projected changes vary vastly across climate models. A increase in El Niño variability has been found to slow future mid-latitude Southern Ocean how this impacts the is unknown. Here we show that a accelerates warming, hastening shelf/sheet slowing reduction.
The Hadley circulation (HC) is a global-scale atmospheric feature with air descending in the subtropics and ascending tropics, which plays fundamental role Earth's climate because it transports energy polewards moisture equatorwards. Theoretically, as consequence of anthropogenic change, HC expected to expand polewards, while indications on strength are equivocal, weakening strengthening response different mechanisms. In fact, there general agreement among reanalyses simulations that has...
Abstract Air‐sea fluxes are a crucial component in the energetics of global climate system. The largest air‐sea occur regions high sea surface temperature variability, such as ocean boundary, frontal currents and eddies. In this paper we explore importance model resolution to resolve flux relationships these areas. We examine temperature‐wind stress relationship high‐pass filtered observations two versions Met Office with eddy‐permitting eddy‐resolving resolutions. Eddy‐resolving shows...
Abstract The authors study the role of ocean heat transport (OHT) in maintenance a warm, equable, ice-free climate. An ensemble idealized aquaplanet GCM calculations is used to assess equilibrium sensitivity global mean surface temperature and its equator-to-pole gradient (Δ T ) variations OHT, prescribed through simple analytical formula representing export out tropics poleward convergence. Low-latitude OHT warms mid- high latitudes without cooling tropics; increases by 1°C Δ decreases...
Abstract. Although estimation of turbulent transport parameters using inverse methods is not new, there little evaluation the method in literature. Here, it shown that extended observation broad-scale hydrography by Argo provides a path to improved estimates regional rates. Results from 20-year ocean state estimate produced with ECCO v4 (Estimating Circulation and Climate Ocean, version 4) non-linear modeling framework provide supporting evidence. Turbulent parameter maps are estimated under...
The formation of sea ice in polar regions is possible because a salinity gradient or halocline keeps the water column stable despite intense cooling. Here, we demonstrate that unique property central to maintenance halocline, namely, thermal expansion coefficient (TEC) seawater increases by one order magnitude between and tropical regions. Using fully coupled climate model, it shown that, even with excess precipitations, would not form at all if near-freezing temperature TEC was well below...