ICAR AICE-JRF/SRF Atmospheric Science & Agrometeorology: practice questions

ICAR AICE-JRF/SRF (PhD) — Environmental Sciences (subject 71) and Agricultural Meteorology (subject 60) · India · National Testing Agency for ICAR

Original practice questions written to the published syllabus · not past papers

10worked here, free

96written to this exam in this subject

14syllabus units

What this subject covers

Radiation, heat, moisture and motion in the atmosphere, and how weather and climate are measured and used on farms. ICAR AICE subject 60 Agricultural Meteorology examines it in depth.

In the exams: ICAR AICE-JRF/SRF subject 60 (whole paper); ICAR AIEEA-PG 3.1 Agricultural Meteorology; GATE ES Section 6 (meteorology for dispersion)

Layers of the atmosphere and their characteristics
Radiation laws: Planck, Stefan-Boltzmann, Wien, Kirchhoff, Beer-Lambert
Solar radiation, albedo and the surface energy balance
Latent and sensible heat; temperature inversions
Atmospheric humidity: vapour pressure, relative humidity, dew point, VPD
Atmospheric stability and adiabatic processes
Clouds, precipitation processes and forms
Pressure systems, winds and general circulation
Monsoons, air masses, fronts and cyclones
Climatic classification: Köppen and Thornthwaite
Weather instruments and observatories; automatic weather stations
Crop-weather relations: growing degree days, photoperiod, thermal stress
Evapotranspiration estimation and crop water needs
Weather forecasting for agriculture and agromet advisories

What ICAR AICE-JRF/SRF asks from it

ICAR AICE-JRF/SRF (PhD) — Agricultural Meteorology (subject 60)

The whole paper: atmospheric structure, radiation laws and constants, energy balance, humidity measures and psychrometry, lapse rates and stability, clouds and precipitation, general circulation, monsoon dynamics, Köppen and Thornthwaite, instruments and observatories, heat units and photoperiodism, ET methods (Penman–Monteith, Hargreaves, pan) and agromet advisories, with numerical problems.

Where the 96 questions fall

How our questions for ICAR AICE-JRF/SRF spread across the units of Atmospheric Science & Agrometeorology. Difficulty: 25 easy, 53 medium, 18 hard.

Evapotranspiration estimation and crop water needs	9
Weather instruments and observatories; automatic weather stations	8
Crop-weather relations: growing degree days, photoperiod, thermal stress	8
Weather forecasting for agriculture and agromet advisories	8
Radiation laws: Planck, Stefan-Boltzmann, Wien, Kirchhoff, Beer-Lambert	7
Solar radiation, albedo and the surface energy balance	7
Latent and sensible heat; temperature inversions	7
Pressure systems, winds and general circulation	7
Monsoons, air masses, fronts and cyclones	7
Layers of the atmosphere and their characteristics	6
Atmospheric humidity: vapour pressure, relative humidity, dew point, VPD	6
Clouds, precipitation processes and forms	6
Climatic classification: Köppen and Thornthwaite	6
Atmospheric stability and adiabatic processes	4

10 practice questions, worked

Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.

1 · Radiation laws: Planck, Stefan-Boltzmann, Wien, Kirchhoff, Beer-Lambert · medium

Kirchhoff's law states that, for a body in thermal equilibrium,

its transmitted radiation falls exponentially with the depth of the medium
its wavelength of peak emission is inversely proportional to its temperature
its emissivity at a wavelength equals its absorptivity at that wavelength
its emission is proportional to the fourth power of its absolute temperature

Answer and working

C. its emissivity at a wavelength equals its absorptivity at that wavelength

Kirchhoff's law links emissivity and absorptivity at the same wavelength. The other statements are the Stefan–Boltzmann law, Wien's law and the Beer–Lambert law.

Further reading: See the manual sources: FAO-56, WMO Guide to Agricultural Meteorological Practices, and the textbooks named there

2 · Solar radiation, albedo and the surface energy balance · easy

Which surface has the highest albedo?

Fresh snow
Green crop canopy
Deep water under a high Sun
Coniferous forest

Answer and working

A. Fresh snow

Fresh snow reflects about 80–90% of sunlight; green crops about 20–25%; water at high sun about 6%; forests about 10–20%.

Further reading: See the manual sources: FAO-56, WMO Guide to Agricultural Meteorological Practices, and the textbooks named there

3 · Atmospheric stability and adiabatic processes · medium

Surface air temperature is 30 °C and the dew point is 18 °C. Using the approximation of 125 m per °C of dew-point depression, at what height will a rising parcel reach its lifting condensation level?

12 m
2250 m
3750 m
1500 m

Answer and working

D. 1500 m

LCL ≈ 125 × (30 − 18) = 1500 m. 3750 m uses the air temperature alone; 2250 m uses the dew point alone; 12 m forgets the 125 m factor.

Further reading: See the manual sources: FAO-56, WMO Guide to Agricultural Meteorological Practices, and the textbooks named there

4 · Pressure systems, winds and general circulation · medium

Using f = 2Ω sin φ with Ω = 7.292 × 10⁻⁵ s⁻¹, what is the Coriolis parameter at 30° latitude?

7.292 × 10⁻⁵ s⁻¹
3.646 × 10⁻⁵ s⁻¹
1.458 × 10⁻⁴ s⁻¹
0 s⁻¹

Answer and working

A. 7.292 × 10⁻⁵ s⁻¹

f = 2 × 7.292 × 10⁻⁵ × sin 30° = 2 × 7.292 × 10⁻⁵ × 0.5 = 7.29 × 10⁻⁵ s⁻¹. 1.46 × 10⁻⁴ is the polar value; 3.65 × 10⁻⁵ omits the factor 2; 0 is the equatorial value.

Further reading: See the manual sources: FAO-56, WMO Guide to Agricultural Meteorological Practices, and the textbooks named there

5 · Monsoons, air masses, fronts and cyclones · easy

What is the India Meteorological Department's normal date of southwest monsoon onset over Kerala?

1 June
15 May
15 June
1 July

Answer and working

A. 1 June

IMD's normal onset date over Kerala is 1 June, with a standard deviation of about seven days.

Further reading: See the manual sources: FAO-56, WMO Guide to Agricultural Meteorological Practices, and the textbooks named there

6 · Climatic classification: Köppen and Thornthwaite · medium

What is the central concept of Thornthwaite's 1948 climate classification?

Mean wind speed and direction, used to define the exposure of each region
The number of frost-free days, used to define the length of the growing season
The distribution of natural vegetation, mapped from satellite images of land cover
Potential evapotranspiration set against precipitation

Answer and working

D. Potential evapotranspiration set against precipitation

Thornthwaite based his scheme on PE estimated from temperature and day length, and on the water balance of precipitation against PE. Köppen's scheme was designed around vegetation; frost days and wind are not his basis.

Further reading: See the manual sources: FAO-56, WMO Guide to Agricultural Meteorological Practices, and the textbooks named there

7 · Climatic classification: Köppen and Thornthwaite · medium

Why should a Thornthwaite moisture-index boundary always be quoted with the formula used?

The index is defined only for India, so values from other countries cannot be compared
The index uses wind speed, which is measured at different heights in different countries
The 1948 index weights aridity by 0.6 and the 1955 Thornthwaite–Mather one does not
The index was abandoned in 1948 and replaced entirely by the Köppen classification

Answer and working

C. The 1948 index weights aridity by 0.6 and the 1955 Thornthwaite–Mather one does not

Different formulations of Im exist (1948 with a 0.6 weighting of the aridity index; Thornthwaite–Mather 1955 without), so class boundaries and values are not interchangeable. The index is global, uses no wind, and remains in use.

Further reading: See the manual sources: FAO-56, WMO Guide to Agricultural Meteorological Practices, and the textbooks named there

8 · Crop-weather relations: growing degree days, photoperiod, thermal stress · hard

Why was photoperiod insensitivity a key trait of Green Revolution rice and wheat varieties?

They flowered on time across latitudes and seasons, widening where they could grow
It made them flower only in long days, limiting them to high-latitude temperate regions
It made them resistant to all pests by shortening their exposure in the field
It removed their need for water, allowing cultivation without irrigation

Answer and working

A. They flowered on time across latitudes and seasons, widening where they could grow

Insensitive varieties flower according to temperature and age, not day length, so they fit different latitudes and sowing dates. They still need water and are not inherently pest-resistant.

Further reading: See the manual sources: FAO-56, WMO Guide to Agricultural Meteorological Practices, and the textbooks named there

9 · Evapotranspiration estimation and crop water needs · easy

Reference ETo is 6.0 mm day⁻¹ and the mid-season crop coefficient is 1.15. What is crop evapotranspiration?

7.15 mm day⁻¹
6.0 mm day⁻¹
6.9 mm day⁻¹
5.2 mm day⁻¹

Answer and working

C. 6.9 mm day⁻¹

ETc = Kc × ETo = 1.15 × 6.0 = 6.9. Dividing gives 5.2; adding gives 7.15; 6.0 ignores Kc.

Further reading: See the manual sources: FAO-56, WMO Guide to Agricultural Meteorological Practices, and the textbooks named there

10 · Evapotranspiration estimation and crop water needs · hard

Wind speed measured at 10 m is 3.2 m s⁻¹. Using FAO-56, u₂ = uz × 4.87/ln(67.8z − 5.42), what is the wind speed at 2 m?

0.64 m s⁻¹
4.28 m s⁻¹
3.20 m s⁻¹
2.39 m s⁻¹

Answer and working

D. 2.39 m s⁻¹

ln(678 − 5.42) = 6.511; u₂ = 3.2 × 4.87/6.511 = 2.39. 3.20 ignores the height correction; 0.64 scales linearly with height; 4.28 inverts the factor.

Further reading: See the manual sources: FAO-56, WMO Guide to Agricultural Meteorological Practices, and the textbooks named there

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