풍어를 만드는 캘리포니아 upwelling은 어떻게 형성되는가?

참고자료

 

Understanding the California Current.pdf

다운로드

 

 

 

 

Upwelling의 3대 요소는

wind, Coriolis effects, and Ekman transport.

 

 

 

 

 

전세계에서도 가장 productive한 바다입니다.

 

브리티쉬 컬럼비아부터, 바자(Baja)까지 이르는 저 푸른 녹색이 그 증거입니다.

 

캘리포니아 해류는 무슨 비밀을 갖고 있길래 바닷가를 온통 녹색으로 만들었을까요?

 

 

 

그 비밀은

 

 

 

breezes often blow from land to sea and push ocean surface waters away from the coast. As a result, cooler, nutrient-rich water rises up from the depths to take its place—a process known as upwelling.

 

 

 

The combination of cool water and abundant nutrients promotes the growth of plant life in the sea, from microscopic phytoplankton to dense kelp forests. Those plants—primary producers—become the center of a food web that includes highly productive fisheries, sizable populations of marine mammals (whales, seals, dolphins), and vast numbers of sea birds. This productive ecosystem can extend as much as 500 kilometers (300 miles) out from the coast.

 

 

 

 

 

 

This graphic shows how displaced surface waters are replaced by cold, nutrient-rich water that “wells up” from below.
Winds blowing across the ocean surface push water away. Water then rises up from beneath the surface to replace the water that was pushed away. This process is known as “upwelling.”

 

 

 

Upwelling occurs in the open ocean and along coastlines. The reverse process, called “downwelling,” also occurs when wind causes surface water to build up along a coastline and the surface water eventually sinks toward the bottom.

 

Water that rises to the surface as a result of upwelling is typically colder and is rich in nutrients. These nutrients “fertilize” surface waters, meaning that these surface waters often have high biological productivity.  Therefore, good fishing grounds typically are found where upwelling is common.

 

 

 

If the wind blows parallel to the coast in the northern hemisphere (such as the coast of California, where the wind blows South), then Ekman transport can produce a net movement of surface water 90° to the right. This may result in coastal upwelling.

 

 

If the wind blows parallel to the coast in the southern hemisphere (such as along the coast of Peru, where the wind blows North), then Ekman transport can produce a net movement of surface water 90° to the left. This may result in coastal upwelling.

 

 

2002년 7월 ~ 2012년 6월까지 관측 값

 

 

 

에크만(Ekman) 수송 원리 (북반구의 경우)

 

 

 

Understanding Weather And Climate by Edward Aguado, James E. Burt (6th) (2012) Pearson - 231page

 

 

 

Essentials of Oceanography by Alan P. Trujillo, Harold V. Thurman (12th) (2016) Pearson - 215page

 

 

Essentials of Oceanography by Alan P. Trujillo, Harold V. Thurman (12th) (2016) Pearson - 215page

 

 

 

 

 

 

 

 

참고로

 

Finding Life in the Benguela Current (November 1, 2017)

 

https://earthobservatory.nasa.gov/IOTD/view.php?id=91198

 

 

 

 

 

 

 

Oceanology - The Secrets of the Sea Revealed (2020) DK - 250page