Question

2. Throughout the year, weather conditions change rapidly in Champaign-Urbana. During the summer months, strong southerly winds often bring high-dewpoint air from the Gulf of Mexico northward into the Midwest. How do these strong southerly winds affect the vapor pressure?

Answer 1

there is a negative variation in atmospheric pressure, so the pressure must decrease in cities and fields

In other words in cities we have a low pressure area

Step-by-step explanation:

We can solve this problem using Bernoulli's equation, let's use an index 1 for the Gulf of Mexico in the South and an index 2 for the countryside and city in the North

P₁ + ½ ρ₁ v₁² + ρ₁ g y₁ = P₂ + ½ ρ₂ v₂² + ρ g y₂

We can assume that the height of the wind does not change or change very little, so y₁ = y₂

P₁ + ½ ρ₁ v₁² = P₂ + ½ ρ₂ v₂²

We see that there is a relationship of the pressures in the two places with the wind speeds and their densities,

The air coming from the Gulf of Mexico loaded with moisture has a greater weight, so a density greater than the air in the city, so its pressure is higher than the air pressure in the city

If we consider that the speed in both airs is the same, we can see that

P₁ - P₂ = ½ (ρ₂ - ρ₁) v²

Therefore there is a negative variation in atmospheric pressure, so the pressure must decrease in cities and fields

In other words in cities we have a low pressure area