8. What do you notice on the map about the pattern of the gyres in the Northern Hemisphere as compared to the gyres in the Southern Hemisphere?

When examining a map of ocean gyres in both the Northern and Southern Hemispheres, several distinct patterns emerge: 1. **Rotation Direction:** - **Northern Hemisphere Gyres:** These gyres rotate **clockwise**. This clockwise motion is primarily driven by the Coriolis effect, which deflects moving objects to the right in this hemisphere. - **Southern Hemisphere Gyres:** In contrast, gyres in the Southern Hemisphere rotate **counterclockwise**, as the Coriolis effect deflects moving objects to the left. 2. **Number and Location:** - **Northern Hemisphere:** There are typically **four major subtropical gyres** in each of the major ocean basins (North Atlantic, North Pacific, North Indian, and Arctic Oceans). These gyres are prominently featured due to the extensive continental margins that help define their boundaries. - **Southern Hemisphere:** The Southern Hemisphere also hosts **subtropical gyres** in the South Atlantic, South Pacific, and Indian Oceans. However, the presence of the vast Southern Ocean (Encircling Antarctica) influences gyre formation differently, often leading to larger and less confined gyres compared to the Northern Hemisphere. 3. **Western Boundary Currents:** - **Northern Hemisphere:** Gyres in this hemisphere often exhibit **strong western boundary currents** such as the Gulf Stream in the North Atlantic and the Kuroshio Current in the North Pacific. These currents are swift, deep, and narrow, playing a crucial role in heat distribution. - **Southern Hemisphere:** While western boundary currents exist here as well (e.g., the Brazil Current in the South Atlantic and the East Australian Current in the South Pacific), they are generally less intense compared to their Northern counterparts. This difference is partly due to the more uniform wind patterns and fewer land barriers in the Southern Hemisphere. 4. **Influence of Landmasses:** - **Northern Hemisphere:** The presence of extensive continental landmasses disrupts gyre circulation, leading to more defined and constrained gyre boundaries. - **Southern Hemisphere:** With fewer large landmasses interrupting the ocean basins, Southern Hemisphere gyres can circulate more freely and are often broader and more expansive. 5. **Interplay with Other Oceanic Features:** - **Northern Hemisphere Gyres:** These gyres interact significantly with coastal ecosystems and can influence weather patterns due to their interaction with land. - **Southern Hemisphere Gyres:** The interaction with the Southern Ocean and Antarctic Circumpolar Current adds complexity to their behavior, often making Southern gyres more stable and less variable seasonally. **Summary:** Overall, the primary distinction between Northern and Southern Hemisphere gyres lies in their **direction of rotation**—clockwise in the North and counterclockwise in the South—driven by the Coriolis effect. Additionally, Northern Hemisphere gyres tend to have more pronounced western boundary currents and are more influenced by continental landmasses, resulting in more defined circulation patterns. In contrast, Southern Hemisphere gyres are generally larger, rotate in the opposite direction, and circulate more uniformly due to the expansive Southern Ocean and fewer land interruptions.