During the winter monsoon, large areas of high pressure remain persistently over Asia pushing cool, dry air south to the tropics providing the region with its dry season. While the Asian monsoon is the most widely known, monsoon conditions also occur also though to a lesser degree in northern Australia, parts of western, southern and eastern Africa, and parts of North and South America. You might also like. A storm surge is possibly one of the most dramatic weather events in the UK, resulting from low pressure, high winds and tidal conditions.
This a very abrupt shift and is caused by the increasing heating on the TP, causing a low pressure system to form and strengthen to a point where it is effectively pulled north over the Himalayas. There is however much uncertainty when it comes to understanding the impact of teleconnections and the mechanisms which link them to monsoon systems and inevitably more work is needed in part to the high signal to noise ratio and a lack of robust spatiotemporal observational data.
Currently, there is still much debate with regards to how monsoons will change in the future in terms of the magnitude of change and even the sign of change with many models not always agreeing.
This can be dependant on the monsoon region itself due to the complex dynamic and thermodynamic interactions and teleconnections which will also evolve and have their own uncertainties under greenhouse gas forcing through the 21st century, however some regions show greater consensus than others. In a simple model of a warming world Sea Surface Temperatures SST should increase strengthening the meridional temperature gradient with the adjacent land surface allowing greater flux of evaporated moisture from the ocean to land from a strengthened monsoons circulation.
However in a warmer world the higher latitudes extratropics are more sensitive and warm up faster than the lower latitudes tropics. This reduces the pole to equator temperature gradient weakening the large-scale atmospheric circulation. However different rates of warming between the southern and northern hemisphere is suggested to in-turn strengthen the Hadley circulation.
Again uncertainty in the response of not only the monsoon circulation but the large-scale circulation under warming conditions.
Further, as the world warms humidity and precipitable water scale with Clausius-Clapeyron at 6. However the repercussion of this is a weakening of vertical temperature gradients and the mass flux from the boundary layer to the free troposphere further weakening large-scale convection.
The disagreement in the multi-model mean the average climatology of all the models used in the IPCC is down to many models not being able to predict the basic state of the monsoon which has hampered many older models although not all, cref. This is why it is critically important to properly evaluate a model when preforming analysis on monsoons. By the time AR5 was released significant progress had been made with more models showing agreement in the sign of change figure 6 , again wetter, but instead measure the change relative to natural variability.
Even at RCP8. Furthermore long-term observations of the monsoon are scant and spatially inconsistent globally, particularly over the oceans. Uncertainty in the response of the monsoon may be a result of decadal variability or more simply a lack of spatio-temporal data converge in the monsoon over the observational record. A confusing signal of change is presented based on past and present and future reports as to what exactly the response of monsoon systems will be in the future.
Paleoclimate data may provide some important insights into the long-term behaviour of monsoons, especially under warmer conditions that were prevalent in the past, for instance such as in the Pliocene warm period, often use an an analogue for your own future. However difficulty arises due to the lack of proxy-data the further back in time you go to not only evaluate the monsoon but the wider global climate signal itself. Alex Farnsworth.
Friday 12th November This is only one of many possible definitions of monsoon regimes around the globe. Data are from GPCP version 2. How are monsoons formed? Monthly precipitation mm is is contoured.
Figure 3: Simple model showing the simple wind reversal mechanism and varying heat capacities of the land and ocean during the winter and summer leading to the different temperature and thus the resulting pressure differentials and resultant wind patterns. A positive phase sees greater-than-average sea-surface temperatures and greater precipitation in the western Indian Ocean region, with a corresponding cooling of waters in the eastern Indian Ocean.
In the summer following a positive negative phase in the IOD transmitted through the subsurface dipole signature which remains long after the surface feature has already dissipated from the year before leads to an intensification reduction of the South Asian High SAH and greater lesser eastward extent of the eastern ridge and an associated westward extending shift in the enhanced weakened western Pacific subtropical High leading to a weaker stronger monsoon.
There has been some suggestion that this relationship may have stalled due to increasing global temperature over the last years. However this may be a result of natural variability leaving an open debate as to the relationship of ENSO in a warmer world. The summer monsoon fills well s and aquifers for the rest of the year. Rice and tea are some crop s that rely on the summer monsoon. Dairy farms, which help make India the largest milk producer in the world, also depend on the monsoon rains to keep cows healthy and well-fed.
Industry in India and Southeast Asia also relies on the summer monsoon. A great deal of electricity in the region is produced by hydroelectric power plants, which are driven by water collected during the monsoons.
Electricity powers hospitals, schools, and businesses that help the economies of these areas develop. When the summer monsoon is late or weak, the regions economy suffers. Fewer people can grow their own food, and large agribusinesses do not have produce to sell. Governments must import food. Electricity becomes more expensive, sometimes limiting development to large businesses and wealthy individuals.
The summer monsoon has been called Indias true finance minister. Heavy summer monsoons can cause great damage. Residents of such urban area s as Mumbai, India, are used to the streets flooding with almost half a meter 1. However, when the summer monsoon is stronger than expected, floods can devastate the region. In cities like Mumbai, entire neighborhood s can be drown ed. In rural areas, mudslide s can bury villages and destroy crops.
In , a strong monsoon devastated western India. As the summer monsoon blew in from the southwest, it first hit the state of Gujarat. More than people died. Then, the monsoon rains hit the state of Maharashtra.
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