Climatology Help (Koppen Classification)
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Koppenclassification4.docxPhoenix, AZ:
|
|
Jan |
Feb |
Mar |
Apr |
May |
June |
July |
Aug |
Sep |
Oct |
Nov |
Dec |
|
T |
12.3 |
14.5 |
17.0 |
21.2 |
26.2 |
31.4 |
33.8 |
33.0 |
30.0 |
23.7 |
16.4 |
12.4 |
|
P |
2.1 |
2.0 |
2.7 |
0.6 |
0.4 |
0.2 |
2.5 |
2.4 |
1.9 |
2.0 |
1.9 |
2.3 |
Step 1: Calculate the yearly average of temperature, annual total precipitation, as well as summertime precipitation. Summertime is the months of April, May, June, July, August, and September. Average annual temperature: 22.7 °C
Annual total precipitation: 21.0 cm
Summertime precipitation: 8.0 cm
Step 2: Determine if the climate is classified as Type B: Dry This is done by suing the appropriate inequality between annual average temperature T, and total precipitation P.
a. If summertime precipitation is more than 70% of P, use
P<2(T+14)
b. If summertime precipitation is less than 30% of P, use
P<2T
c. Otherwise, use
P<2(T+7)
If the appropriate inequality is true, then the Climate is classified as dry.
For Phoenix, summertime precipitation is not more than 70% of P, and is not less than 30% of P, so we use P<2(T+7)
21.0<2(22.7+7)
21.0<59.4
The inequality is true, so Phoenix is a dry climate.
Since it is a dry climate, we need to differentiate between a true desert climate and an arid climate. This is done by using the same inequality as before, but without the multiple of 2 on the temperature side of the inequality
P<(T+7)
21.0<29.7
The inequality is true, so Phoenix is a true desert climate and gets assigned the classification of BW. If the inequality had not been true, it would have been classified as an arid or “steppe” climate and assigned the label BS.
Step 3: If not a group B dry climate, determine the 1st order classification based on temperature:
|
Abbreviation |
Classification |
Criteria Specifics |
|
A |
Tropical (Equatorial) |
Coolest month >18°C (64°f) |
|
C |
Mesothermal (AKA Midlatitude mild or Warm) |
Coldest month >0°C but <18°C (64°F) Warmest month >10°C (50°F) |
|
D |
Microthermal (AKA Midlatitude cold or Snow) |
Coldest month <0°C Warmest month >10°C (50°F) |
|
E |
Polar |
Warmest month <10°C (50°F) |
Phoenix was classified as dry, so we can skip this step.
Step 4: If not a group B dry climate, determine the 2nd order climate classification based on precipitation:
|
Abbreviation |
Criteria Specifics |
|
f |
Constantly moist – rainfall through all months of the year |
|
m |
Monsoon rain, short dry season Total rainfall sufficient to support rain forest |
|
s |
Summer dry season |
|
w |
Winter dry season |
Phoenix was classified as dry, so we skip this step as well.
Step 5: Determine the 3rd order climate classification based on temperature extremes:
|
Abbreviation |
Criteria Specifics |
|
a |
Warmest month >22°C (72°F) – hot summers |
|
b |
Warmest month <22°C (72°F) – warm summers |
|
c |
Fewer than 4 months >10°C (50°F) – mild summers |
|
d |
Fewer than 4 months >10°C (50°F) – cool summers Coldest month <-38°C (-36°F) |
|
h |
Only for “W” or “S” – Hot and dry year round Average annual temperature >18°C (64°F) |
|
k |
Only for “W” and “S” – Cold and dry year round Average annual temperature <18°C (64°F) |
|
k' |
Same as k but mean temperature of warmest month <18°C (64°F) |
For Phoenix, it was classified as dry with annual temperature average over 18 °C, so it gets classified as 3rd order grouping h.
Final classification for Phoenix is BWh, Dry true desert, hot year round.
Detroit, MI:
|
|
Jan |
Feb |
Mar |
Apr |
May |
June |
July |
Aug |
Sep |
Oct |
Nov |
Dec |
|
T |
-4.2 |
-2.7 |
2.7 |
8.9 |
15.4 |
20.6 |
23 |
22.1 |
17.7 |
11.1 |
4.8 |
-1.3 |
|
P |
4.9 |
4.8 |
6.4 |
7.7 |
7.7 |
9.0 |
8.0 |
7.9 |
8.3 |
5.7 |
6.8 |
6.4 |
Step 1: T=9.8 °C P=83.5 cm Summer Precipitation: 48.6 cm
Step 2: Is it a dry group?
Summer precipitation is not more than 70% of P, and not less than 30% of P, so use p<2(T+7)
85.3<2(9.8+7)
85.3<36
Inequality is not true, so Detroit is not a dry climate, and we move on to step 3.
Step 3: Which 1st order classification?
Coldest month >18 °C? (no, not “A”) Coldest month >0 °C? (no, not “C”) Coldest month <0 °C? (yes) Warmest month >10 °C? (yes) therefore D group
We stop as we move down the list as soon as we get a yes answer.
Step 4: Which 2nd order classification?
Precipitation steady throughout year? (yes) therefore f secondary group
Step 5: Which 3rd order classification?
Warmest month >22 °C? (yes) therefore a group
Detroit gets classified as Dfa, Microthermal climate, with consistent precipitation and hot summers
Given the following precipitation and temperature data for 5 stations, classify them using
the Köppen Climate classification system (abbreviations and description).
Station 1:
Köppen Classification is:
Station 2:
Köppen Classification is:
Station 3:
Köppen Classification is:
Station 4:
Köppen Classification is:
Station 5:
Köppen Classification is:
