- Karnataka More rain than MH/Kerala?
- Tibetan plateau: Meteorological importance of
- Natural aerosol and their effect on Monsoon
Why Karnataka gets more Rainfall?
Topic in news Oct. 2014, Hindu; Relevance: GS1-Geography
Mains-GS1 Q. Examine the reasons why Western ghats in Karnataka receive more rainfall than Maharashtra and Kerala, during Monsoon? 200 words.
Ans: #1: More than Maharashtra because:
- Karnataka’s Mountain topography broader than Maharashtra. Since Mountain width greater => Rain clouds need to travel longer distance => more time for water to coalesce and precipitate as rainfall.
- Compared to this, Narrower width of W.Ghats in Maharashtra=> Rain bearing winds cross over to the leeward side quickly before rainfall can occur.
#2: More than Kerala because:
In Kerala, W.Ghats = isolated mountains. Rain-bearing winds can easily cross over leeward side through the gaps, without precipitation occurring.
#3: Other reasons:
- Karnataka Mountains = gentle slope than Kerala and Maharashtra. Gentle slope= Air parcel can retain energy and speed for a long time, allowing cloud droplets to grow and precipitate as rainfall.
- In Karnataka, mountains are continuous. No gaps= Clouds can’t easily escape to leeward side.
Tibetan plateau: Meteorological importance of
Topic in news Oct. 2014, Hindu; Relevance: GS1-Geography.
- Tibet is the largest and highest plateau in the world.
- Given its altitude and topography, Tibet gets more sunlight, becomes hotter than land at sea level.
- This heating of Tibetan plateau leads to following events
#1: Traditional thermal theory
- Hot Tibetan surface: Increases land-ocean temperature differences, causes pressure gradients.
- Low pressure around Tibet, NW India and Pakistan=> attracts trade winds from Southern hemisphere
- These winds pickup moisture from ocean surface=> finally burst of Monsoon.
#2: Jet stream theory
- Hot Tibetan surface=> intense low Pressure => air pumped upwards in the upper troposphere.
- This air travels southwards and descends at Mascarene High basin near horn of Africa through Tropical Easterly jet (TEJ) stream.
- Surface air from Mascarene High move towards ITCZ (low pressure) developed in North India =>monsoon.
Sidenote: Tibetan plateaus is also called third pole, because of third-largest ice-stock the world. Heavy winter snow on Tibetan plateaus increases surface albedo. It retards spring warming and delays summer monsoon over Northern India.
Yes, but Why in News?
- Despite its meteorological significance, very few weather stations in Tibet, because of its remoteness, altitude and harsh conditions.
- But China Meteorological Administration began putting temperature and moisture detectors, and sensor-towers to measure cloud properties. (Aug 2014)
- This data will understanding relation between land surface heating, its impact on rainfall, snow cover and vegetation changes.
Mains-GS1: Discuss the meteorological importance of Tibetan plateau in 200 words.
Natural aerosol and their effect on Monsoon
Topic in news: March, 2014; Relevance: MCQ about examples of aerosols and scientific principle behind their role in monsoon:
- Aerosols: tiny particles of either soli/liquid, suspended in atmosphere.
- Natural aerosols: sea-salt, water vapour, dust, ash from volcanoes, organic material: spores, bacteria, pollen.
- Artificial aerosols: particles of pollutants like, smoke, ashes.
How aerosols effect rain fall?
- Dust absorbs sunlight and heats the atmosphere=> low pressure condition over land.
- These pockets of low pressure attract south-west monsoon winds into the region.
- Scientists found that dust from West Asia to India=>helps in monsoon.
- IF more dust particles from W.Asia and N.Africa blow towards India, then more rain to India.
Mrunal sir thanks for d such wonderful and exact explanation.There is no satifactory moment than when we understand d concet from mrunal.God bless u sir.
@ Raku too good man…
Mrunal Bhai, Political Science ka guidance chahiye ..
2013 ka koi topper hai kya ye phir koi player
hats off sir, u made such an selflesseffort…
Sir, a slight modification
1. Tibeten low pressure creates a cyclonic low pressure on the ground
2. This leads to an upper air anticyclonic high pressure (due to convection), and a subsequent divergence
3. The limbs of the diverging anticyclonic gyre fall on mascernes is. in Indian ocean, another circulates to gangetic plain due to presence of ITCZ …. thereby accelerating the Bay of Bengal branch of S-W mansoon
4. This mascernes high accelerates the incoming S-W monsoon winds towards Indian subcontinent.
5. These events lead to increased rainfall or a normal year rainfall
AS FAR AS QUESTION OF AEROSOL IS CONCERNED.
1. The cloud formation in the upper atmosphere gets intensified due to convection
2. But for condensation to occur, the humid air needs HYGROSCOPIC nuclei to condense otherwise there will be no condensation.
3. These aerosols ( salt -from ocean, or industrial effluents) provide ample of ground for condensation to occur and then to precipitate.
looking at diagram and article its totally clean in mind why it happen.ver good. diagram was amazing,
Well said @ Vaibhav…. wanted to tell the same…
Answer to the question :
1) It is the third largest reservoir of ice in the world and feeds the lifeline rivers of Asia (eg. Ganges, Yangtze etc.). As such, it provides water to more than more than 2 billion people. Any variation in ice quantity can be directly linked to flood/drought like situation in the rivers. In view of recent floods in Kashmir and Pakistan, the meteorological importance of this region stands vindicated.
2) It plays an important role in the onset of Monsoon. It is the highest plateau in the world at an altitude of about 15000ft. and almost as large as Western Europe at 2,500,000 sq. km. As such it gets heated more than land at sea level during summer and creates a low pressure zone. This, in turn, sets in motion, a circulation pattern in which, moisture laden winds are sucked towards the Indian land mass. So, the temperature and pressure readings of this area can be used for weather forecasts.
3) Due to global warming, the glaciers (over 37000 in number), are receding. Immediate climatic effects of this development could be variation in precipitation over the Indian subcontinent. So, the study of this area is important for gauging the effects and extent of Climate change. (204 words)
Please comment and correct.
vooooooo……… thanks mrunal sir…………………….
many toppers ( motivation story of mrunal org ) suggest gk today notes. how I get gk today note through internet.Anyone can help me to answer this question.
why are tropical cyclones are more frequent in bay of bengal than in arabian sea..mrunal bhai plz throw some light on it..
1. Most of India’s coastal region falls under tropical region(0 to 23 1/2 latitude),
2. there are two tyoes of cyclones temperate and tropical .
3.The tropical cyclones have tendency to move from east to west similar to the counter equatorial current due to influence of rotation of earth is maximun in these regions(equatorial>tropical>temperate)
4.so cyclones arising in bay of bengal will move westwards i.e towards the eastern coast
5.While those arising in arabian sea will move westwards towards african coast
6.The arabian sea is relatively cold hence it decreases the intensification of pressure gradient for formulation of cyclone
no more words to expres about your efforts. thank u bhayya… my confidence levil is increased due to your creation mrunal.org
I have started surfing mrunal notes very recently. can anybody tell me how to download the entire gs material
Thank u mrunal team
Sir i m confused abt aerosol
It create hp or lp high pressure or Low pressure?
Dust particles and pollutant particle creats the fog or smog over region such delhi in winter . More cloud over an area >>>obstruct the sun rays >>>> less heating >>>>> High pressure zone
More useful notes and I get clarity about how to write the descriptive answers in the GS papers