Environmental lapse rate
The Environmental Lapse Rate
Exercise A (Total = 12 marks) The heights of the temperature °c measurements are given in meters (m)
Convert each of these to the appropriate height in Hectopascals (hPa):
Height (m) Temperature°c Hectopacals (hPa)
0 22 1000
1500 18 850
3000 13 700
4000 7 600
5000 -15 500
6000 -22 400
7000 -36 300
8000 -41 200
8500 -49 150
9000 -58 100
a) Plot a simple graph to display these data (3 marks): see attached b) what does the graph tell you about the temperature profile? (1 mark). I can infer that as the height in meters increases along with pressure (Pascal’s) the temperature decreases.
Calculate the environmental lapse rate (ELR) on the basis of the data given (show all stages of your working and the units involved) (4 marks). The environmental lapse rate (ELR) on the data given is
8.8 (recurring)…
I have calculated this by taking away the highest temperature from the lower:
22°c -(-58°c)= 80°c∴ there is a 80°c overall change in temperature over 9000m
9000÷9= 1000
And… 80÷9= 8.88888….
Suggest one cause of error in using only the temperatures at the lowest and highest heights to calculate the ELR (2 marks).
One error in only taking the highest and lowest temperatures only into account when calculating ELR is that there may be fluctuations within the altitudes e.g. a rise at 3500m from 3000m then a fall at 4000m as it is most likely that there isn’t a direct decrease in temperature
Calculating ‘parcel’ lapse rates and cooling
Exercise B (Total = 12 marks)
A parcel of unsaturated air moves upwards from the ground. The temperature measured at the ground is 15. Assuming that the air parcel moves adiabatically through the atmosphere, what will be its temperature at each pressure level up to and including 500 hPa? (Assume ground level is equivalent to 1000 hPa) (4 marks).
Height (hPa) Temperature°c
500 -35
600 -25
700 -15
800 -5
900 5
1000 15
If the parcel is then forced down to
Exercise A (Total = 12 marks) The heights of the temperature °c measurements are given in meters (m)
Convert each of these to the appropriate height in Hectopascals (hPa):
Height (m) Temperature°c Hectopacals (hPa)
0 22 1000
1500 18 850
3000 13 700
4000 7 600
5000 -15 500
6000 -22 400
7000 -36 300
8000 -41 200
8500 -49 150
9000 -58 100
a) Plot a simple graph to display these data (3 marks): see attached b) what does the graph tell you about the temperature profile? (1 mark). I can infer that as the height in meters increases along with pressure (Pascal’s) the temperature decreases.
Calculate the environmental lapse rate (ELR) on the basis of the data given (show all stages of your working and the units involved) (4 marks). The environmental lapse rate (ELR) on the data given is
8.8 (recurring)…
I have calculated this by taking away the highest temperature from the lower:
22°c -(-58°c)= 80°c∴ there is a 80°c overall change in temperature over 9000m
9000÷9= 1000
And… 80÷9= 8.88888….
Suggest one cause of error in using only the temperatures at the lowest and highest heights to calculate the ELR (2 marks).
One error in only taking the highest and lowest temperatures only into account when calculating ELR is that there may be fluctuations within the altitudes e.g. a rise at 3500m from 3000m then a fall at 4000m as it is most likely that there isn’t a direct decrease in temperature
Calculating ‘parcel’ lapse rates and cooling
Exercise B (Total = 12 marks)
A parcel of unsaturated air moves upwards from the ground. The temperature measured at the ground is 15. Assuming that the air parcel moves adiabatically through the atmosphere, what will be its temperature at each pressure level up to and including 500 hPa? (Assume ground level is equivalent to 1000 hPa) (4 marks).
Height (hPa) Temperature°c
500 -35
600 -25
700 -15
800 -5
900 5
1000 15
If the parcel is then forced down to
References: John W. James. (2011). Sierra Nevada. Available: http://www.britannica.com/EBchecked/topic/543431/Sierra-Nevada. Last accessed 11th Nov 2013 Bruce Walters. (2009). lee wave. Available: http://www.britannica.com/EBchecked/topic/334629/lee-wave. Last accessed 11 Nov 2013. N/A. (2010). Topographic lifting. Available: http://apollo.lsc.vsc.edu/classes/met130/notes/chapter6/lift_topo_wave.html. Last accessed 11 Nov 2013. Brian J. Billings. (2007). SIERRA ROTORS. A COMPARATIVE STUDY OF THREE MOUNTAIN WAVE AND ROTOR EVENTS. n/a (N/A), p1-18. Brian J. Billings. (2007). SIERRA NEVADA. CLIMATOLOGY OF WESTERLY WIND EVENTS IN THE LEE OF. n/a (N/A), p1-5.