LinkedIn Insight GATE 2020 Paper with Answer Keys for Atmospheric & Oceanic Sciences (XE-H) - Grad Plus

GATE 2020 Paper with Answer Keys for Atmospheric & Oceanic Sciences (XE-H)

XE: Engineering Sciences – H: Atmospheric and Oceanic Sciences

Q.No.1 In the northern hemisphere, the flow in the middle depths of the ocean is geostrophic. As we go down from that level and start approaching the bottom of the ocean, the flow deflects to the left of the geostrophic current because

(A) friction decreases and Coriolis force increases

(B) friction decreases and Coriolis force decreases

(C) friction increases and Coriolis force increases

(D) friction increases and Coriolis force decreases

Ans: (A) friction decreases and Coriolis force increases

Q.No.2 Which one of the following is the definition of a monsoon?

(A) Seasonal reversal of wind direction

(B) High rainfall

(C) Occurs in the summer

(D) Occurs in the tropics

Ans: (B) High rainfall

Q.No.3 Anthropogenic emission of _ is the main contributor to the ongoing ocean acidification.

(A) Methane

(B) Carbon dioxide

(C) Nitrous oxide

(D) Sulphuric acid

Ans: (C) Nitrous oxide

Q.No.4 What are phytoplankton?

(A) Microscopic animal life floating on surface of water bodies

(B) Pollen floating freely on surface of water bodies

(C) Microscopic plant life floating on surface of water bodies

(D) Microscopic plant life living on the floor of water bodies

Ans: (C) Microscopic plant life floating on surface of water bodies

Q.No.5 Consider the two atmospheric virtual temperature profiles observed in Delhi given in Figures (i) and (ii) below.

XE gate

At what times of the day are you most likely  to see such profiles?

(A) ii) Midnight and (ii) noon

(B) 3 pm and ii) 3 am 

(C) Sunrise and (ii) sunset

(D) 3 am and (ii) 3 pm

Ans: (B) 3 pm and ii) 3 am 

Q.No. 6 A south-easterly wind is blowing towards which direction?

(A) 1350

(B) 157.50

(C) 3150

(D) 2250

Ans: (C) 3150

Q.No.7 Consider a dry parcel at 30°C in an isothermal environment at 25°C. The parcel rises adiabatically by 1 km. Assuming g = 10 ms-2 and air density = 1 kgm-3, the buoyancy force at the new location (rounded off to 2 decimal places) is _ ms-2.

Ans: -0.17 to -0.16

Q.No.8 The emissivity of polluted air that reflects and transmits 20% and 60% of the incoming solar radiation, respectively, at a given wavelength (correct up to 1 decimal place) is __.

Ans: 0.2 to 0.2

Q.No. 9 Given that the angular velocity of rotation of the Earth = 7.3 × 10-5 s-1, the period of inertial oscillations generated in the oceans by surface winds at 300 N latitude (rounded off to the nearest integer) is __ hours.

Ans: 24 to 24

Q.No.10 Consider a high pressure centre in the northern hemisphere with tangential winds of 10 ms-1 at a distance of 500 km from the centre. Assuming solid body rotation principles, what is the relative vorticity of the flow?

(A) 2 ×10-5s-1

(B) -2 × 10-5s-1

(C) 4 × 10-5s-1

(D) – 4 x 10-5s-1

Ans: (D) – 4 x 10-5s-1

Q.No. 11 Which one of the following statements is true for atmospheric and oceanic general circulation model ?

(A) Vertical velocity is ignored in oceanic models but not in atmospheric models.

(B) Boussinesq approximation is adequate in oceanic models but not in atmospheric models

(C) Atmospheric models need a longer spin-up and integration time than oceanic mulls

(D) Atmospheric models need parameterizations for subgrid scale processes but oceanic model do not.

Ans: (B) Boussinesq approximation is adequate in oceanic models but not in atmospheric models

Q.No. 12 Consider a scenario where air temperature increases by 20 C. We know that saturation vapour pressure for water increases with temperature. As a result of this effect. the water vapour content of the atmosphere will _ and the net warming will be _ than 2 °C. The correct pair of words to fill in the blanks (in the right order) is

(A) increase, more

(B) increases, less

(C) decrease, more

(D) decrease, less

Ans: (A) increase, more

Q.No. 13 The prevailing Trade winds over the Equator in the Pacific Ocean result in piling up of waters in the part of the ocean. As a result, the gradients of the thermocline and the ocean surface have _ signs. The correct pair of words to fill in the blanks (in the right order) is

 (A) western, opposite

(B) western, same

(C) eastern, opposite

(D) eastern, Same

Ans:  (A) western, opposite

Q.No. 14 Consider two different cases, shown in Figures (i) and (ii) below, with two layers of water of same density on top of each other.

XE gate

Which one of the following statements is true about convective plumes across the interface of the two layers?

(A) Upward convective plumes in (i) and downward convective plumes in (ii)

(B) Downward convective plumes in (i) and upward convective plumes in (1)

(C) No convective plume in (i) and (ii)

(D) No convective plume in (i) but upward convective plumes in (ii)

Ans: (B) Downward convective plumes in (i) and upward convective plumes in (1)

Q.No. 15 During the Indian summer monsoon, surface outgoing longwave radiation (OLR) over the Arabian Sea is often observed in he low because

(A) of enhanced convection

(B) monsoon winds advect the OLR away into the Indian subcontinent

(C) monsoon clouds limit incoming solar radiation

(D) surface Bowen ratio is low

Ans: (C) monsoon clouds limit incoming solar radiation

Q.No. 16 A tsunami wave in the ocean is approaching the coast. Assuming g = 10 ms-2, the correct group speed of the wave at a depth of 1 km is

(A) 1 ms-1

(B) 10 ms-1

(C) 100 ms-1

(D) 1000 ms-1

Ans: (C) 100 ms-1

Q.No. 17 A tornado is in cyclostrophic balance where the horizontal pressure gradient and centrifugal forces balance each other. Consider a tornado with 100 m radius and a tangential velocity of 100 ms-1 at the edge. Assuming air density = 1 kgm-3, the magnitude of the pressure-drop between the centre and the edge of the tornado is __ kgm-1s-1.

Ans: 10000 to 10000

Q.No. 18 While driving south a distance of 1000 km, the temperature outside your car increases from 10 °C to 20 “C. Assuming the air is completely dry, g = 10 ms-2 and Coriolis parameter = 10-4 s-1. the vertical gradient of the geostrophic wind (rounded off to 2 decimal places) is _ ms-1km-1.

Ans: 3.40 to 3.50

Q.No. 19 A westerly wind of 10 ms-1 is blowing at a location in the Pacific Ocean in the northern hemisphere. Assuming density of sea water – 1000 kgm-1, Coriolis parameter = 10-4s-1 and drag coefficient for sea water = 10-6, the Ekman transport due to the wind at that location _______is kgm-1s-1.

Ans: -1000 to -1000

Q.No. 20 Mx and My represent the ocean mass transport in the x and y directions,  respectively. Lx and Ly are the corresponding east-west and north-south length scales. For a typical equatorial ocean gyre, if the ratio of zonal to meridional mass transport ≈ 10, then Lx__ Ly.

Ans: 10 to 10

Q.NR. 21 Assume that pressure varies exponentially with height: p(z) = P0e-z/H, where p(z) is the pressure at a height z above the surface. Po is the surface pressure, and the scale height H = 7.5 km. Under these conditions, one-fourth of the total mass of the atmosphere lies above a height (rounded off to 1 decimal place) of _ km above the surface.

Ans: 10.3 to 10.5

Q.No. 22 Consider an atmospheric column of depth 300 m at the Earth’s surface with an average temperature of 300 K. If the temperature of the layer rises by ΔT = 10°C, the layer depth h will increase by Δh. Assuming ΔT/T ≈ Δh/h, air density remains unchanged at 1 kgm-3 and g = 10 ms-2, the change in surface pressure is kgm-1s-2.

Ans: -100 to -100 or 100 to 100

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