The North Atlantic Meridional Overturning Circulation (MOC) is associated with deep water formation at high latitudes, and climatically‐important ocean‐atmosphere heat fluxes, hence the current substantial effort to monitor MOC. While it expected that, on sufficiently long time scales, variations in MOC would be coherent across latitudes south of region, not clear whether coherence should shorter timescales. In this paper, we investigate a range ocean models. We find model physics,...

A synthesis is provided of dissolved organic nitrogen (DON) and phosphorus (DOP) distributions over the Atlantic Ocean based upon field data from eight recent transects, six meridional between 50°N 50°S two zonal at 24° 36°N. Over entire tropical subtropical Atlantic, DON DOP provide dominant contributions to total pools for surface waters above thermocline. Elevated concentrations (>5 >0.2 μ mol L −1 , respectively) occur in on eastern side North gyre equatorial sides both South...

The effect of the Southern Ocean on global climate change is assessed using Earth system model projections following an idealized 1% annual rise in atmospheric CO 2 . For this scenario, plays a significant role sequestering heat and anthropogenic carbon, accounting for 40% ± 5% uptake 44% 2% carbon over ocean (with defined as south 36°S). This fraction however less than historical scenarios with marked hemispheric contrasts radiative forcing. inter-model differences are strongly affected by...

This paper describes the seasonal characteristics of Mediterranean Sea general circulation as simulated by a primitive equation model. The forcing is composed climatological monthly mean atmospheric parameters, which are used to compute heat and momentum budgets at air‐sea interface allows fluxes be determined realistic interaction physics. Strait Gibraltar open, model resolution in horizontal 19 levels vertical. results show large cycle its transient characteristics. budget surface...

The total heat gained by the North Atlantic Ocean over past 50 years is equivalent to a basinwide increase in flux of across ocean surface 0.4 +/- 0.05 watts per square meter. We show, however, that this basin has not warmed uniformly: Although tropics and subtropics have warmed, subpolar cooled. These regional differences require local changes (+/-4 meter) much larger than average. Model investigations show these can be explained large-scale, decadal variability wind buoyancy forcing as...

Nutrients are transferred from the nutricline into winter mixed layer through a combination of vertical and lateral advection, referred to here as induction, reverse subduction process. This advective supply nutrients maintains high productivity at latitudes over timescales several years longer. Climatological diagnostics North Atlantic reveal that induction is dominated by advection even in subpolar gyre where there significant Ekman upwelling. The flux itself sustained nutrient streams,...

Abstract Basin-scale thermal anomalies in the North Atlantic, extending to depths of 1–2 km, are more pronounced than background warming over last 60 years. A dynamical analysis based on reanalyses historical data from 1965 2000 suggests that these formed by ocean heat convergences, augmented poorly known air–sea fluxes. The convergence is separated into contributions horizontal circulation and meridional overturning (MOC), latter further Ekman MOC transport minus (MOC-Ekman) cells....

Abstract The variability in mean sea level (MSL) during 1950–2009 along the northeast American Atlantic coast north of Cape Hatteras has been studied, using data from tide gauges and satellite altimetry information Liverpool/Hadley Centre (LHC) ocean model, thereby providing new insights into spatial temporal scales variability. Although a relationship between overturning circulation can be identified (an increase approximately 1.5 cm MSL for decrease 1 Sv transport), it is effect nearshore...

Numerical simulations reveal that variations in wind stress and heat fluxes can induce significant interannual fluctuations the circulation of upper layers Mediterranean. From January 1980 to November 1988, atmosphere shows changes structure magnitude surface winds air temperatures which modifications ocean currents. The model prediction Sicily Strait baroclinic westward volume transport is agreement with observations variability explained as a function curl forcing region. current anomalies...

[1] The Gulf Stream provides a 'nutrient stream,' an advective flux of nutrients carried in sub-surface waters, redistributing from the tropics to mid latitudes. There is dramatic downstream strengthening full depth, volume and nitrate transport diagnosed synoptic measurements along three sections: 32 Sv 300 kmol s−1 at 27°N, increasing 66.7 940 35.5°N, 149.5 2100 36.5°N; estimates have uncertainties reaching 10% their values. transport-weighted concentration by generally decreases light...

Climate projections reveal global-mean surface warming increasing nearly linearly with cumulative carbon emissions. The sensitivity of to emissions is interpreted in terms a product three terms: the dependence on radiative forcing, fractional forcing from CO 2 , and Mechanistically each term varies, respectively, climate ocean heat uptake, contributions, terrestrial uptake. fossil-fuel examined using an ensemble Earth system models, forced either by annual increase atmospheric or RCPs until...

Abstract The concentration of phosphate and dissolved organic phosphorus (DOP) is chronically low limits phytoplankton growth in the subtropical North Atlantic relative to other ocean basins. Transport DOP from productive flanks gyre its interior has been hypothesized as an important supply pathway. During a cruise eastern spring 2011, rates uptake, alkaline phosphatase activity (APA), production were measured northwest African shelf region, subtropics, tropics. Rates sixfold higher region...

Global surface warming projections have been empirically connected to carbon emissions via a climate index defined as the transient response (TCRE), revealing that is nearly proportional emissions. Here, we provide theoretical framework understand TCRE including effects of all radiative forcing in terms product three terms: dependence on forcing, fractional contribution from atmospheric CO2 and cumulative This used interpret over next century for two Earth System Models differing complexity,...

The North Atlantic Ocean contributes approximately 30% of the global ocean carbon uptake. This region plays a vital role in anthropogenic uptake and hosts significant natural cycle driven by physical biogeochemical processes. study focuses on understanding inter-annual variability air-sea CO2 fluxes, storage, Gulf Stream transporting water masses with low concentrations into subpolar Atlantic. We present development application our forward adjoint biogeochemistry models within Estimating...

Abstract The ‘warming stripes’ are an iconic climate data visualisation, adopted globally as a symbol of our warming world. We discuss their origin and uses for communication, including understanding long-term changes in the consequences future emission choices. also extend stripes concept to explore observed temperature variations throughout system, revealing coherent troposphere upper ocean, cooling stratosphere, consistent with human influences on climate.

A simplified cycling and transport model for inorganic nutrients dissolved organic nitrogen (DON) phosphorus (DOP) is applied to the Atlantic, on basis of recent measurements along a meridional transect. The DON DOP are separated into semilabile pools with lifetime 6 months refractory pool which conserved in interior, but photochemically breaks down euphotic zone 6–12 years. typically only makes up 10% surface DON, 95% DOP. preferentially produced over upwelling zones zone. Elevated...

Abstract In the North Atlantic, there are pronounced gyre-scale changes in ocean heat content on interannual-to-decadal time scales, which associated with both sea surface temperature and thermocline thickness; subtropics often warm a thick when subpolar gyre is cool thin thermocline, vice versa. This climate variability investigated using semidiagnostic dynamical analysis of historical salinity data from 1962 to 2011 together idealized isopycnic model experiments. On scales typically 5 yr,...

Abstract Projected changes in ocean heat and carbon storage are assessed terms of the added redistributed tracer using a transport-based framework, which is applied to an idealized climate model suite six CMIP5 Earth system models following annual 1% rise atmospheric CO 2 . Heat budgets for used explain opposing regional patterns anomalies, such as tropics subpolar North Atlantic, relatively reduced within Southern Ocean. Here takes account net source advection by circulation, while...

Abstract The Southern Ocean provides dominant contributions to global ocean heat and carbon uptake, which is widely interpreted as resulting from its unique upwelling circulation. Here we show a large asymmetry in these contributions, with the accounting for 83 ± 33% of uptake versus 43 3% over historical period state-of-the-art climate models. Using single radiative forcing experiments, demonstrate that this due suppressed by northern oceans enhanced aerosol forcing. In future projections,...

The relationship between changes in sea‐surface height, bottom pressure, and overturning is explored using isopycnal model experiments for the North Atlantic. Changes high‐latitude forcing are communicated rapidly over basin through boundary wave propagation along continental slope, involving a hybrid mixture of Kelvin topographic Rossby waves, as well spreading more slowly advection western boundary. This communication leads to coherent signals height pressure variability extending several...

Abstract The climate response after cessation of carbon emissions is examined here, exploiting a single equation connecting surface warming to cumulative emissions. multicentennial an idealized pulse considered by diagnosing 1,000 year integration Earth system model (Geophysical Fluid Dynamics Laboratory ESM2M) and ensemble efficient simulations. After cease, temperature evolves according (i) how much the emitted remains in atmosphere (ii) additional radiative forcing warms rather than ocean...

Abstract The Transient Climate Response to Emissions (TCRE), the ratio of surface warming and cumulative carbon emissions, is controlled by a product thermal contributions. contribution involves airborne fraction ocean saturated atmospheric inventories, with this carbonate chemistry. evolution TCRE illustrated in hierarchy models: box model atmosphere‐ocean an Earth system model, both integrated for 1,000 years, suite models 140 years. For all models, there same generic chemistry response:...