Sentences with phrase «monsoon circulations»

Changes in global monsoon circulations since 1950.

Using eight AOGCMs, Ueda et al. (2006) demonstrate that pronounced warming over the tropics results in a weakening of the Asian summer monsoon circulations in relation to a reduction in the meridional thermal gradients between the Asian continent and adjacent oceans.

Following a minimalistic philosophy, the model comprises the necessary processes for a positive feedback and thereby demonstrates the possibility of an abrupt transition of monsoon circulations from a state with strong rainfall to a weak precipitation state.

Monsoon depressions are cyclonic atmospheric vortices with outer radii near 1000 km that form within the larger - scale monsoon circulations of India and other regions.

Though details of monsoon circulations are complicated, observations reveal a defining moisture - advection feedback that dominates the seasonal heat balance and might act as an internal amplifier, leading to abrupt changes in response to relatively weak external perturbations.

A minimal conceptual model for monsoon circulations that captures the moisture - advection feedback is presented.

Similarly, a colder climate with generally decreased humidity q O could be closer to the critical threshold, which might be the reason for less - stable monsoon circulations during glacial periods.

Slowing such overturning by reducing the horizontal differential heating could tend to allow heat to build up at lower levels until the lapse rate is more favorable to localized vertical overturning (LVO)(The two forms of overturning are not always completely distinct or separate; for example, the Hadley cell, Walker, and monsoon circulations, as well as extratropical storm track activity (developing from baroclinic instability (Rossby wave phenomena)-RRB- are driven and organized in part by horizontal differential heating, but in the ascending portions of these circulations, cumulus - type convection can occur).

But Kristjánsson said their result could be explained by a monsoon circulation that shifts to land when only ocean areas get cooled down.

The other (much smaller) major pathway for transporting air from the lower atmosphere to the stratosphere is the Asian monsoon circulation, which prevails in the summer.

Wang and his colleagues, however, found that over the past 30 years, the summer monsoon circulation, as well as the Hadley and Walker circulations, have all substantially intensified.

This dynamic similitude may be helpful in understanding past and future variations in monsoon circulation.

We derive a minimal conceptual model of a monsoon circulation (Fig. 1 A), comprising merely conservation of heat and moisture, knowingly neglecting a large number of relevant physical processes in order to distill the fundamental nonlinearity of monsoon circulations.

The strong monsoon circulation then played a role in the Russian heat wave from mid-June to mid-August 2010 (Barriopedro et al. 2011; TF12), perhaps not unlike that in 2003 (Black and Sutton 2007) although influences from the Atlantic likely also played a role.

Sea level rise in the Indian Ocean increases as monsoon circulation weakens & heat transport decreases.

The dimming by sulfates, nitrates, and carbonaceous (black and organic carbon) species has been shown to disrupt and weaken the monsoon circulation over southern Asia.

It can also strengthen the Asian summer monsoon circulation and cause a local increase in precipitation, despite the global reduction of evaporation that compensates aerosol radiative heating at the surface (Miller et al., 2004b).

Andreae et al., 2004) and monsoon circulation transition (Zhang et al., 2009, Bevan et al., 2009) due to inputs of smoke from agricultural burning.

The dust - induced thermal contrast changes between the Eurasian continent and the surrounding oceans are found to trigger or modulate a rapidly varying or unstable Asian winter monsoon circulation, with a feedback to reduce the dust emission from its sources (Zhang et al., 2002).

Consequently, any perturbation that tends to weaken the driving pressure gradient has the potential to destabilize the monsoon circulation.

He said though the Indian summer monsoon circulation will weaken, rainfall will increase due to higher atmospheric moisture resulting from a rise in temperatures.

Weather systems tend to wax and wane but the anticyclones that move through stall and strengthen systematically in the same region because of the influence from SE Asia through the overturning monsoon circulation and the associated wave patterns.

Irrigation effects on climate may also be indirect, especially in monsoon regions where alteration of the thermal contrast between land and ocean may produce changes in monsoon circulation and the accompanying climatic variables.

Not exact matches

The greening of Sahara strengthens the West African Monsoon, which triggers a change in the atmospheric circulation over the entire tropics, affecting tropical cyclone activity.

The Tibetan Plateau in China experiences the strongest monsoon system on Earth, with powerful winds — and accompanying intense rains in the summer months — caused by a complex system of global air circulation patterns and differences in surface temperatures between land and oceans.

However, with the onset of the monsoon the new ocean circulations patterns began to emerge that were not favorable to the islands» coral reefs.

The researchers have also identified smaller circulations that could significantly affect atmospheric chemistry such as the North American monsoon and convections over Africa.

They will look for evidence of temperature changes caused by ocean circulation patterns in both the North Atlantic and tropical Pacific Oceans, which drive precipitation in Tibet as well as the Indian monsoons.

They also manifest as perturbations in the tropical weather induced by anomalous middle latitude circulation patterns (e.g., mid-latitude blocking anticyclone), such as cold surges or monsoon breaks.

Links between monsoon - related events (rainfall over South Asia, rainfall over East Asia, NH circulation, tropical Pacific circulation) weakened between 1890 and 1930 but strengthened during 1930 to 1970 (Kripalani and Kulkarni, 2001).

[A] tmospheric circulation over South America and monsoon intensity have been tightly correlated throughout most of the Holocene, both directly responding to solar precession.

and the examples that he thinks have the potential to be large scale tipping elements are: Arctic sea - ice, a reorganisation of the Atlantic thermohaline circulation, melt of the Greenland or West Antarctic Ice Sheets, dieback of the Amazon rainforest, a greening of the Sahara, Indian summer monsoon collapse, boreal forest dieback and ocean methane hydrates.

Since El Nino also has an important impact on the Asian Summer Monsoon in particular, its hard to know precisely what large - scale changes in atmospheric circulation are due to the radiative forcing of the eruption itself, and the secondary response to that eruption of ENSO.

Althoug absent ice age - integlacial response, orbital forcing still affects low - latitude circulation patterns (monsoons).

So while the monsoon winds might weaken the precipitation nonetheless increases (more bang for the buck) as a weaker circulation carries more water vapor (and latent energy).

Bordoni, S., and T. Schneider, 2008: Monsoons as eddy - mediated regime transitions of the tropical overturning circulation.

Schneider, T., and S. Bordoni, 2008: Eddy - mediated regime transitions in the seasonal cycle of a Hadley circulation and implications for monsoon dynamics.

«The Sensitivity of Monsoon Climates to Orbital Parameterization Changes for 9000 Years BP: Experiments with the NCAR General Circulation Model.»

Previous general circulation models have suggested that the monsoons were simply shifting later, with decreased rains through July but increased precipitation in September and October.

Current state - of - the - art general circulation models have difficulty simulating the regional distribution of monsoon rainfall, the 24 June review in Nature Climate Change says.

Within the restrictions of the model, we compute R c for current monsoon systems in India, China, the Bay of Bengal, West Africa, North America, and Australia, where moisture advection is the main driver of the circulation.

Overview of the tropical atmosphere, monsoons, intraseasonal variability, hurricanes, theory of tropical convection and the large - scale circulation

monsoon wind in the genereal atmospheric circulation typified by a seasonal persistent wind direction and by a pronounced change in direction from one season to the next

For example, the northern East Asian summer monsoon (NEASM) is, for the years of highest SST anomalies in the tropical eastern Pacific (TEP), affected by the Pacific - East Asian (PEA) teleconnection pattern, which consists of a wave creating an anomalously strong western North Pacific (WNP) anticyclonic circulation and anomalously strong cyclonic circulation in the NEASM region, creating more monsoon rainfall.

Current global multi-decadal predictions are unable to skillfully simulate regional forcing by major atmospheric circulation features such as from El Niño and La Niña and the South Asian monsoon, much less changes in the statistics of these climate features.

This shift is caused by global climatic warming that leads to higher energy in the general circulation: The Intertropical Convergence Zone (ITCZ)-- known more commonly as monsoon — increases in strength due to increased convection and convergence.

The Walker circulation usually brings areas of high pressure to the western Indian Ocean but, in years when El Niño occurs, this pattern gets shifted eastward, bringing high pressure over India and suppressing the monsoon, especially in spring when the monsoon begins to develop.

The major climate system indices that are operationally used at ICPAC include evolution of monsoons, medium and upper level winds, Madden - Julian Oscillation (MJO), Quasi Biennial Oscillation (QBO), El Niño Southern Oscillation, Indian Ocean dipole (IOD), tropical cyclones, sea surface temperature gradients among many others that have been derived from general circulation.

The cool, dry westerly and northwesterly winds — driven by the East Asian winter monsoon (pdf) circulation — typically blow pollutants away from the city.

This study evaluates the forecast skill of the fourth version of the Canadian coupled ocean — atmosphere general circulation model (CanCM4) and its model output statistics (MOS) to forecast the seasonal rainfall in Malaysia, particularly during early (October — November — December) and late (January — February — March) winter monsoon periods.