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�ꡡ�ܡ�û�ȳ��Υ졼���ˤ�뽡ë��ή�δ�¬ \\ Observation of the Soya Warm Current using HF Ocean Radar

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û�ȳ��Υ졼���ˤ�뽡ë��ή�δ�¬ \\ Observation of the Soya Warm Current using HF Ocean Radar (��ʥ ľ��) ȯɽ�׻� :

  
  ��ǯ�Ƥ���¬��³���Ƥ����㲹�����Υ졼�������ƥ�γ��פ���Ӵ�¬���� 
 ��Ҳ𤹤�ȤȤ�ˡ���ë������ˤ����ƹԤä�ɺή�֥��Ȥ���Ӽ¸��η�̡� 
 ������� ADCP ��¬�ǡ����Ȥ���ӷ�̡�����ӽ�ë��ή�ε�����ư�˴ؤ� 
 �������Ϸ�̤ˤĤ�����𤹤롥 
  
 ����ë������ΥΥ���å�̨����ë��̨����ʧ�Σ��ս�����֤��� 13 MHz û�� 
 ���Υ졼�������ƥ�ϡ���ǯ�����ꡤ�ۤܽ�Ĵ�˴�¬��³���Ƥ��롥��¬���� 
 �ֳ֤ϣ����֡�����ʬ��ǽ�� 3 km����¬��󥸤� 60��70 km �ǡ��дߤΥ��� 
 ���ޤǤν�ë��������򥫥С��Ǥ���褦�����ꤵ��Ƥ��롥��¬���줿ή®�� 
 ���ȥ��ʬ�ۤˤϡ���ë���������ʧ��������������ή��뽡ë��ή��ª����� 
 �Ƥ��ꡤOhshima (1994) �����ͥ�ǥ�¸��Ǽ��������ϥ�����ߤ������ë�� 
 �����̲᤹��ή������Ƥ˸���Ƥ��롥�ޤ�������Υ٥��ȥ�λ������Ĵ�²� 
 �Ϥ��顤��ë�������ճ����Ĭή��������Ĵ�٤뤳�Ȥ��ǽ�Ǥ��롥 
 ����¬���줿ή®�٥��ȥ�����٤�ɾ�����뤿�ᡤɺή�֥������ ADCP �δ�¬ 
 �ͤȤ���Ӥ�Ԥä������η�̡����ˤ褤���פ򼨤������������̳���ʬ�λ� 
 ����ɸ���к��ϥ֥��Ȥ���Ӥ� 10 cm/s ���١�ADCP �Ȥ���Ӥ�20 cm/s ���� 
 �Ǥ��ä���ɺή�֥��Ȥ���ӷ�̤���٤� ADCP �Ȥ���Ӥ�ɸ���к����礭���� 
 �ϡ�ADCP �ȳ��Υ졼���δ�¬���ΰ㤤�ˤ���Τȹͤ����롥 
 ����ǯ12��ܤޤǤ�����줿�ǡ������Ȥˡ���ë��ή�ε�����ư�ˤĤ��Ƥ� 
 ͽ��Ū���Ϥ�Ԥä������η�̡��͵����̲��Υ饤��Ǥϡ���ë��ή����40��50 
 km �ˤ錄�ꡤ����ή®�ϴߤ���20��30 km ��¸�ߤ��뤳�Ȥ������줿���ޤ����� 
 �κ���ή®�ϡ�����ܡ������ܤ˺���Ȥʤ� 1 m/s ��Ķ���뤬��11����ܤ� 
 ��޷��ή®���������ʤ롥��������ħ�ϡ�����������¬����α��¬������ 
 ���Ƥ��뽡ë��ή����ħ�Ȥ褯���פ��Ƥ��롥���Υ饤����ڤ�����ή��ʬ�� 
 ���᤿��ë��ή��ɽ��ή�̤������������Ĭ�̺�����Ӥ����Ȥ�����10������ 
 ��û��������ư����ӵ�����ư�ʤɤˤĤ������ˤ褯���פ��뤳�Ȥ������줿�� 
  
 Three HF ocean radar stations were installed at the Soya/La Perouse Strait 
 in the Sea of Okhotsk in order to monitor the Soya Warm Current. Frequency 
 of the HF radar is 13.9 MHz, and range and azimuth resolutions are 3 km and 
 5 deg., respectively. It covers a range of about 70 km from the coast. Surface 
 current velocity observed by the HF radar is compared with data from drifting 
 buoys and shipborne ADCPs (Acoustic Doppler Current Profilers). The current 
 velocity derived from the HF radar shows good agreement with that observed 
 by the drifting buoys without drogues. The rms (root-mean-squared) differences 
 are about 10 cm/s. In the comparison with the shipborne ADCP observations, 
 the rms differences increase to 20 cm/s. It might be explained by the fact that 
 the shipborne ADCPs measure the current velocity at 5 to 10 m below the 
 surface, while the HF radar observe the velocity within a few meters beneath 
 the surface. It is shown that the HF radar clearly captures seasonal and short- 
 term variations of the Soya Warm Current. The surface transport across the 
 strait shows a significant correlation with the sea level difference along the 
 strait derived from coastal tide gauge records. 
  
  

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