Does the magnificent Himalayas let the monsoon system go shallow ?

As we mentioned in the previous post, about 1.3 billion people living in the Himalayan river basins rely on monsoon rainfall and glacier meltwater for their livelihoods. Monsoon ( in this blog referring to Indian Summer monsoon) as seasonally reversing winds over the Indian Ocean sustains 1/5 populations on earth for their irrigation, drinking, sanitation, infrastructure, industrial uses and economic development.

Map source http://www.meteo.co.in/Monsoons/image004.jpg

However, does the magnificent Himalayas let the monsoon system go shallow?

The Monsoon has inter-annual and inter-decadal change, temporal and spatial variation factored into their respective onset and retreating rates and dates.The Monsoon-rainfall on set during June to September is a complex system. The Himalayas have significant influence on the Monsoon system by virtue of high altitude, intercept two branches of summer monsoon coming from Bay Bengal and Arabian sea, release latent heat of evaporation originally travelling from the ocean causing precipitation in the form of rain and snow. Without Himalayan, Asian continent like Indian would be a desert otherwise.

Map by Saravask, based on work by Planemad and Nichalp https://blog.education.nationalgeographic.com/2014/09/08/monsoon-floods-kill-hundreds/

The land-sea thermal contrast forms the fundamental mechanism of Indian Summer Monsoon. In addtion to this thermodynamic system at lower troposphere, monsoon rainfall and rhythm may be controlled by a more dynamic and large-scale circulation at upper troposphere where the Himalayas also play a significant role:

Graphic: NOAA

• 
  During winter, a sub-tropical westerly Jet Stream blows in eastwards along southern slopes of Himalayas, it is bifurcated by the Himalayan range into two branches, the northern branch blows over the north Tibetan Plateau, and the southern branch to the southern edge of Himalayan, the southern arm is much more powerful, while the air is subsiding it couples with lower tropospheric monsoon, establishes the dry north-easterly winter monsoon, out-blowing from Northwest Indian plains to the sea
• Many studies, also show the westerly Jet Stream brings in western disturbances from Mediterranean coast, Black Sea, Persian Gulf, causes occasional winter rain over Northwest India and western Himalaya, an intense western disturbance may even lead to heavy snowfall and trigger avalanches particularly over western Himalayan regions 
• As winter progresses to summer, the westerly Jet Stream shifts northward along the northern edge of Himalaya during early summer in April and May. When the southern arm breaks and shifts over Himalaya to the north of Tibet Plateau, it makes way for monsoon winds to accelerate over Indian continents. The Himalayas help to allow sudden Monsoon burst in summer

Is Tibetan Plateau having dominant control of the Monsoon?

As established by Dr P. Koteswaran in 1958, the summertime heating of Tibetan Plateau is the most important factor in monsoonal circulation, acting as a sensible heat source at middle-upper troposphere. Associated with abundant latent heat rising and condensing from the surface, further warming the middle-upper troposphere, the high temperature eventually produces thermal anticyclone, and assists in the formation of tropical easterly Jet Stream caused by the pressure gradient between the subtropics and the equatorial Indian Ocean in the upper troposphere. This easterly Jet Stream induces summer heat low over North India upward to the top of the atmosphere, draws in low-level flow from ocean to India, kicks the start of monsoon. The monsoon bursts suddenly over India when westerly Jet Stream is breaking (as mentioned above) and replaced by easterly Jet Stream.  

Fig. 1. The terrain of the Tibetan Plateau and its surroundings. Major atmospheric circulation systems around the Plateau are shown, with yellow arrows for summer and blue arrows for winter.http://www.sciencedirect.com.libproxy.ucl.ac.uk/science/article/pii/S0921818113002713#f0005

In the contrast to this well-established theory,  a recent research of Boos and Kuang, 2010, published on Nature has viewed the monsoon is insensitive to the absence of plateau heating: 

'......although Tibetan plateau heating locally enhances rainfall along its southern edge in an atmospheric model, the large-scale South Asian summer monsoon circulation is otherwise unaffected by removal of the plateau, provided that the narrow orography of the Himalayas and adjacent mountain ranges is preserved....'

Thermodynamic structure, precipitation and wind from the atmospheric model June–August, run with a. standard topography. b. no elevated topography, and c, surface elevations north of the Himalayas set to zero.