Urban Size
lm = 10 (Urban 20%)
lm = 20 (Urban 40%)
lm = 40 (Urban 80%)
Temperature
High T (Summer)
Defualt
Low T (Winter)
-
Surface Temperature
- Difference Max: 2.66 K
- Diff Max occur time:
6:00 PM
-
U Wind
- Collision time:
6:30PM
- Average Velocity change:
0.052 m/s (Before Collision)
> 0.114 m/s (After Collision)
-
Surface Temperature
- Difference Max: 1.65 K
- Diff Max occur time:
6:30 PM
-
U Wind
- Collision time:
9:00PM
- Average Velocity change:
0.232 m/s (Before Collision)
> 0.160 m/s (After Collision)
-
Surface Temperature
- Difference Max: 2.78 K
- Diff Max occur time:
6:00 PM
-
U Wind
- Collision time:
7:00PM
- Average Velocity change:
0.029 m/s (Before Collision)
> 0.120 m/s (After Collision)
-
Surface Temperature
- Difference Max: 3.04 K
- Diff Max occur time:
6:00 PM
-
U Wind
- Collision time:
7:00PM
- Average Velocity change:
0.017 m/s (Before Collision)
> 0.076 m/s (After Collision)
-
Surface Temperature
- Difference Max: 1.73 K
- Diff Max occur time:
6:30 PM
-
U Wind
- Collision time:
11:00PM
- Average Velocity change:
0.259 m/s (Before Collision)
> 0.208 m/s (After Collision)
-
Surface Temperature
- Difference Max: 1.89 K
- Diff Max occur time:
6:00 PM
-
U Wind
- Collision time:
00:30AM
- Average Velocity change:
0.141 m/s (Before Collision)
> 0.171 m/s (After Collision)
As Temperature Increases;
1. Increased Maximum
Temperature Difference
2. Faster Collision Time
(Comparing Default & Summer)
-
Surface Temperature
- Difference Max: 1.82 K
- Diff Max occur time:
8:30 PM, 10:00 PM
-
Surface Temperature
- Difference Max: 1.45 K
- Diff Max occur time:
3:00 PM
-
U Wind
- No Significant Pattern
As Land Size Increases;
1. Decreased Maximum
Temperature Difference
2. Maximum Difference occur
faster
As Land Size Increases;
1. Increased Maximum
Temperature Difference
2. Late Collision time
3. Decreased Velocity of before
and after Collision
-
Surface Temperature
- Difference Max: 1.76 K
- Diff Max occur time:
10:30 PM
-
U Wind
- Collision time:
8:00PM
- Average Velocity change:
0.504 m/s (Before Collision)
> 0.292 m/s (After Collision)
-
U Wind
- Collision time:
8:30PM
- Average Velocity change:
0.427 m/s (Before Collision)
> 0.080 m/s (After Collision)
In the simulation of default and high atmosphere temperature cases,
1. The city size consistently affects the atmospheric temperature near the surface, U wind, and W wind.
2. As the land size gets larger, the maximum surface temperature deviation increases.
3. The divergence time point at the center increases and each convergence and divergence velocity seems to decrease as the city size increases.
In the simulation of low atmosphere temperature,
1. No significant wind pattern was observed by the change in urban size.
2. Maximum temperature difference (Max-Min) decreases, as the urban size increases.
3. Maximum temperature difference appears faster
- Therefore, we concluded that the U wind is stronger and faster convergence occurs in the smaller city.
Comparing the temperature modification case with a unified urban size,
1. Generally, under the same land size condition, the increase of atmosphere temperature affects the factors (atmosphere temperature near the surface, U wind) linearly with the temperature change.
2. However, low-temperature case showed different aspects from other cases.
- Therefore, we concluded that the U wind is stronger and faster convergence occurs in the hotter city.
2023-2 Numerical Weather Prediction
Team 4
Ideal Urban Heat Island Simulation