Sentences with phrase «forcing over ocean»

In terms of the LGM forcings only WMGHGs effect a significant forcing over the oceans.

Not exact matches

A plague of oxygen - deprived waters from the deep ocean is creeping up over the continental shelves off the Pacific Northwest and forcing marine species there to relocate or die.

The Himyarites conquered Saba in 280 C.E., took over the frankincense monopoly, and became key players in the expanding Indian Ocean trade between the Roman Empire and India until Ethiopian forces overthrew them in 525 C.E.

The waves that run along shallow continental shelves are much larger than those over the deep ocean, and so the force applied by the standing waves is also larger in shallow water.

Upper ocean temperatures have warmed significantly in most regions of the world over recent decades, with anthropogenic greenhouse gas forcing very likely being the main contributor21.

If it was just being heated by tidal forces within the ice, the ocean would freeze over in less than 30 million years.

The observed patterns of warming, including greater warming over land than over the ocean, and their changes over time, are only simulated by models that include anthropogenic forcing.

As proposed by Andrew Goldsworthy in 1987, cyanobacteria and later chloroplast - related protists and plants developed after microbes that used a purple pigment bacteriorhodopsin that absorbs green light dominated the oceans, and so the new photosynthetic cyanobacteria were forced to use the left - over light with chlorophyll that reflects green light, which was too complex to change even after purple - reflecting photosynthetic lifeforms were no longer dominant (Debora MacKenzie, New Scientist, September 10, 2010 — more on the evolution of photosynthetic life and plants on Earth).

If it is true, as some studies suggest for example, that El Nino events become more frequent and greater in magnitude due to anthropogenic forcing (this is not yet a settled issue), then, given the established relationship between the El Nino / Southern Oscillation (ENSO) and the extratropical Pacific / North American atmospheric circulation, we might expect increased baroclinicity and greater storminess over a substantial region of the mid-latitude North Pacific ocean and neighboring western U.S..

We can estimate this independently using the changes in ocean heat content over the last decade or so (roughly equal to the current radiative imbalance) of ~ 0.7 W / m2, implying that this «unrealised» forcing will lead to another 0.7 × 0.75 ºC — i.e. 0.5 ºC.

Similarly, if as a number of recent studies suggest, anthropogenic climate forcing leads to a greater tendency for the positive phase of the North Atlantic Oscillation (NAO)[or related «Arctic Oscillation» (AO)-RSB- pattern, we would expect increased baroclinicity and storminess over a substantial region of the mid-latitude North Atlantic ocean and neighboring western Europe..

«[B] y making use of 21 CMIP5 coupled climate models, we study the contribution of external forcing to the Pacific Ocean regional sea level variability over 1993 — 2013, and show that according to climate models, externally forced and thereby the anthropogenic sea level fingerprint on regional sea level trends in the tropical Pacific is still too small to be observable by satellite altimetry.»

Probably because wind and moisture coming off the Pacific Ocean are forced to rise over our region's tallest peak.

After his plane crashed into the ocean, he survived for over 40 days with little food or water but was later rescued by the enemy and taken prisoner by Japanese forces, where he was severely beaten and mistreated.

Then as they seemingly crash into the ocean, it's becomes very clear, very quickly these ain't no meteors but rather an alien force, intent on taking over our planet by using our water to fuel their machines.

After flying for what seems like forever over endless ocean views, the mountains surrounding Queenstown quickly force their way into view and as your plane hastily maneuvers itself toward the tiny landing strip you start to question if this is supposed to be happening - don't worry it is.

As we continued to swing out over the ocean, we caught a glimpse of Robbeneiland (Robben Island), which is of course where Nelson Mandela was held for 18 of the 27 years he was forced to serve in prison.

In addition, since the global surface temperature records are a measure that responds to albedo changes (volcanic aerosols, cloud cover, land use, snow and ice cover) solar output, and differences in partition of various forcings into the oceans / atmosphere / land / cryosphere, teasing out just the effect of CO2 + water vapor over the short term is difficult to impossible.

Given those assumptions, looking at the forcing over a long - enough multi-decadal period and seeing the temperature response gives an estimate of the transient climate response (TCR) and, additionally if an estimate of the ocean heat content change is incorporated (which is a measure of the unrealised radiative imbalance), the ECS can be estimated too.

Corresponding time for surface + tropospheric equilibration: given 3 K warming (including feedbacks) per ~ 3.7 W / m2 forcing (this includes the effects of feedbacks): 10 years per heat capacity of ~ 130 m layer of ocean (~ heat capacity of 92 or 93 m of liquid water spread over the whole globe)

Nowadays we would use an ensemble of runs with slightly perturbed initial conditions (usually a different ocean state) in order to average over «weather noise» and extract the «forced» signal.

The key points of the paper are that: i) model simulations with 20th century forcings are able to match the surface air temperature record, ii) they also match the measured changes of ocean heat content over the last decade, iii) the implied planetary imbalance (the amount of excess energy the Earth is currently absorbing) which is roughly equal to the ocean heat uptake, is significant and growing, and iv) this implies both that there is significant heating «in the pipeline», and that there is an important lag in the climate's full response to changes in the forcing.

The pace is very slow pace over many centuries, and given ocean acidification, there will be forces cancelling out this process by dissolving calcium.

http://www.springerlink.com/content/lm0024kv72t3841w/ «The simulated magnitude of hydrological changes over land are much larger when compared to changes over oceans in the recent marine cloud albedo enhancement study since the radiative forcing over land needed (− 8.2 W m − 2) to counter global mean radiative forcing from a doubling of CO2 (3.3 W m − 2) is approximately twice the forcing needed over the oceans (− 4.2 W m − 2).

On the other hand, there is a simple explanation for such a temporary cooling in a model: an artifact known as «coupling shock» (e.g. Rahmstorf 1995), which arises when the ocean is switched over from a forced to a coupled mode of operation, something that has no counterpart in the real world.

Solar forcing has increased over the 20th century and given that the oceans have not yet had time to equilibrate to the new levels of forcing, it must have contributed some to the recent warming, in fact, that equlibration was further delayed by the cooling period, so the unrealized climate commitment would have been greater than ordinarily expected given that most of the increase in solar activity occurred in the first half of the century.

Andresen, C. S., F. Straneo, M. H. Ribergaard, A. A. Bjork, T. J. Andersen, A. Kujipers, N. Norgaard - Pedersen, K. H. Kjaer, K. Weckstrom, and A. Alhstrom, 2011: Enhanced calving of Helheim Glacier over the last century forced by the ocean and atmosphere.

By comparing modelled and observed changes in such indices, which include the global mean surface temperature, the land - ocean temperature contrast, the temperature contrast between the NH and SH, the mean magnitude of the annual cycle in temperature over land and the mean meridional temperature gradient in the NH mid-latitudes, Braganza et al. (2004) estimate that anthropogenic forcing accounts for almost all of the warming observed between 1946 and 1995 whereas warming between 1896 and 1945 is explained by a combination of anthropogenic and natural forcing and internal variability.

You conclude that the present rate of increase in forcing is 2 to 3x the average rate over 55 years of 0.39 W / m ^ 2 (per unit area of the world ocean), as estimated by Leviticus et al..

Over that period, solar forcing was net negative, volcanic forcing was net negative, and oceanic fluctuations can not give the ocean heat, merely shift it around.

This was my mental equation dF = dH / dt + lambda * dT where dF is the forcing change over a given period (1955 - 2010), dH / dt is the rate of change of ocean heat content, and dT is the surface temperature change in the same period, with lambda being the equilibrium sensitivity parameter, so the last term is the Planck response to balance the forcing in the absence of ocean storage changes.

«The forcing should not balance the ocean heat content increase, and it should apply over the same period anyway (1955 - 2010) which 1.6 W / m2 doesn't.»

Temperatures over part of Pacific are forced to the observed values by a heat flux from the atmosphere to the ocean (or from ocean to the atmosphere).

This ongoing debate over the ultimate cause of the Younger Dryas has led to a search for other potential forcing mechanisms, such as an abrupt discharge of meltwater to the Arctic Ocean (Tarasov and Peltier, 2005) and a bolide impact (Firestone et al., 2007).

If there has been only a fairly small change in ocean heat flux over the last century and the ratio of global increase in surface temperature to increase in forcing is low (as the evidence certainly suggests), then it follows that climate sensitivity is low — perhaps of the order of 1.5 C.

With a rise in the overall temperature of the ocean, ocean - borne storms such as tropical storms and hurricanes, which get their fierce and destructive energy from the warm waters they pass over, could increase in force.

I brought up ENSO, Jim D, because the forcing chart and AR5 models with - then - without anthro forcing graphs of temperature over time are not reflective of what is actually happening in the oceans and the atmosphere.

In the first one, the authors use an optimal flux perturbations framework and an adjoint approach to estimate the AMOC sensitivity to ocean surface buoyancy forcing over the Arctic and globally.

The AMO during the Little Ice Age was characterized by a quasi-periodicity of about 20 years, while the during the Medieval Warm Period the AMO oscillated with a period of about 45 to 65 years... The observed intermittency of these modes over the last 4000 years supports the view that these are internal ocean - atmosphere modes, with little or no external forcing... However, the geographic variability of these periodicities indicated by ice core data is not captured in model simulations.»

Of course the slow changing Milankovitch forcing can also emerge from the short - term noise over several millennia (or faster when ocean circulation or glacial - melt tipping points are reached).

Then the authors use the observed, or more accurately described «reconstructed,» flux anomalies over the Arctic for the past three decades to force a forward ocean model.

The study published in Nature Climate Change finds that equatorial trade winds have been blowing harder over the Pacific for the past two decades, forcing more heat down into the ocean.

«The Walker circulation is caused by the pressure gradient force that results from a high pressure system over the eastern Pacific ocean, and a low pressure system over Indonesia.

The Pavlakis et al (2008) paper «ENSO Surface Shortwave Radiation Forcing over the Tropical Pacific» identifies the variations in surface downward shortwave radiation over portions of the Pacific Oceans caused by El Nino - produced cloud cover changes.

The response of atmospheric CO2 and climate to the reconstructed variability in solar irradiance and radiative forcing by volcanoes over the last millennium is examined by applying a coupled physical — biogeochemical climate model that includes the Lund - Potsdam - Jena dynamic global vegetation model (LPJ - DGVM) and a simplified analogue of a coupled atmosphere — ocean general circulation model.

The global annual mean top of the atmosphere DMS aerosol all sky radiative forcing is − 2.03 W / m2, whereas, over the southern oceans during SH summer, the mean DMS aerosol radiative forcing reaches − 9.32 W / m2.»

Ice albedo feedback change is mainly limited to high latitude NH * land * during deglaciation, and its effects — though strong — are limited compared to those of a radiative forcing over the global ocean.

Frankclimate, dpy6629, Nic, and stevefitzpatrick: Given the uncertainty in aerosol forcing and the uncertainty it produces in the output of EBMs, perhaps BC17 should have added the ability to reproduce CERES measurements of aerosol reflection of SWR (through clear skies over the oceans) to their predictors.

I always believed that the oceans were an important element in localised weather conditions over the short term but feel that relatively sudden shifts in climate occur through external forcings such as volcanic eruptions, meteor strike and the effects of changes in cosmic rays and sun spot activity, which are, unfortunately, all chaotic by nature and unpredictable.

The notion that over the longer timescales, forced responses dominated (at least for the second half of the past century) is reinforced by data on Ocean Heat Uptake since 1955.