Question

At which of the following locations in the atmosphere is the anvil of a towering cumulonimbus cloud usually located?

• A. Top of the surface layer
• B. Top of the boundary layer
• C. Tropopause
• D. Stratopause

Hint:

Think “cap of the troposphere”: deep convection rises until it hits the stable lid at the \textbf{tropopause}, then spreads sideways to form the anvil. Overshooting domes may poke above, but the \emph{anvil} resides at the tropopause.

Answer 1

The Correct Option is C

Step 1: Vertical structure relevant to deep convection.
From the ground upward: \emph{surface layer} (lowest \(\sim\)10–100 m), \emph{planetary boundary layer} (PBL; \(\sim\) 0.5–2 km over land by day), the free troposphere (\(\sim\) up to 12–17 km in the tropics), capped by the \emph{tropopause}—a strong stability/inversion layer that separates the troposphere from the stratosphere. Above that lies the stratosphere up to the \emph{stratopause}.


Step 2: Growth of a cumulonimbus and equilibrium level.
Deep moist convection accelerates upward while the parcel is warmer (positively buoyant) than its environment. The ascent continues to the \emph{equilibrium level (EL)}, typically very near the tropopause in the tropics. There the environment becomes warmer/stable, vertical motion weakens, and the cloud spreads laterally. The expansive, flat, fibrous top is the anvil.


Step 3: Clarify overshooting and why options (A), (B), (D) are wrong.
Strong storms can produce an \emph{overshooting top} that briefly intrudes into the lower stratosphere above the anvil, but the broad, persistent anvil sheet still spreads at the tropopause. - (A) \emph{Surface layer} and (B) \emph{top of PBL} are far too low for anvil formation. - (D) \emph{Stratopause} (~50 km) is well above any convective cloud top.
Final Answer:
\[ \boxed{\text{Tropopause}} \]