日本以南黑潮流量对西北太平洋柔鱼渔场重心影响的滞后性分析

为研究西北太平洋海域黑潮流量对柔鱼Ommastrephes bartramii渔场的影响,本研究中结合1994—2010年西北太平洋海域黑潮流量和柔鱼渔场重心数据,采用阿尔蒙法建立了多项式分布滞后模型,通过分析黑潮流量异常与渔场重心偏移的互相关系数和模型的AIC值,确定了模型的最佳滞后期数,并添加了一阶滞后残差项以消除残差序列的自相关。结果表明:在经度方向上,黑潮流量异常在一年内对柔鱼渔场重心偏移没有明显的影响;而在纬度方向上,模型中黑潮流量异常变量的第12~15期系数均显著,分别为0.003 72(P0.05)、0.004 93(P0.01)、0.006 29(P0.01)和0.007 81(P0.05),说明黑潮流量异常会在6个月后的两个月内对渔场纬度重心产生正向的影响,模型调整后的相关系数为0.549。本研究中考虑了渔场对黑潮流量响应的时滞性,研究结果对延长西北太平洋柔鱼渔场预报的有效期限具有一定的参考意义。

Effect of Kuroshio transport off southern Japan on fishing ground gravity of neon flying squid Ommastrephes bartramii in northwest Pacific Ocean based on time lag analysis

Polynomial distribution lag model was established by Almon method and the data of Kuroshio transport a-nomaly and squid fishing ground gravity offset during 1994 and 2010 to study the effect of Kuroshio transport on fishing ground of neon flying squid Ommastrephes bartramii in the northwest Pacific Ocean. The optimal lag time pe-riod of the model was determined by Akaike information criterion ( AIC) resulting from the regression model and the analysis of the cross correlation between the variables of Kuroshio transport anomaly in different periods and the off-set of fishing ground gravity. Meanwhile, first order lag residuals were appended in the model to eliminate the auto-correlation of error terms. The regression analysis indicated that there was no significant effect of anomaly of Kuro-shio transport on meridional offset of fishing ground gravity during a whole year period. However, the coefficients of Kuroshio transport anomaly in the zonal model showed significant effect, with value of 0. 00372 (P<0. 05) in the 12th, 0. 00493 (P<0. 01) in the 13th, 0. 00629 in the 14th(P<0. 01) and 0. 00781 in the 15th(P<0. 05), indi-cating that the Kuroshio transport anomaly has continuing influence on the fishing ground gravity in north and south direction for 2 months with the lag of 6 months, with adjusted correlation coefficient of 0. 549. Since the time lag of fishing ground variance behind the change in Kuroshio transport was considered, the findings provided a reference to extend the validity of fishing ground forecast of neon flying squid in the northwest Pacific Ocean.