An empirical primary production model for the East China Sea 東海基礎生產力經驗模式 Gwo-Ching Gong*, Gong-Jen Liu Reporter: 廖怡婷 09/04/13

國科會「黑潮與東海陸棚交換過程研究 」 (ROC-KEEP) 全球海洋通量聯合研究

1. Introduction

基礎生產力（ primary production ）： 單位面積或體積、時間中自營性生物所合成的有機質的量， 稱為基礎生產力。 primary production

北緯 23 度至 32 度，東至琉球島弧，西至大陸沿岸 km 2

三峽大壩對東海的影響

1995 年 5 月 ~ 1998 年 10 月 2. Material and methods 春春 春 冬 秋夏 夏 夏

E 0 ：可利用於光合作用的 輻射 水面上可見光 偵測計 (QSR-240, Biospherical Inc.) K d ：海水透光層內光消散 係數 水面下可見光 偵測計 (QSP-200L, Biospherical Inc.)

Primary productivity ： 基礎生產力 C 14 assimilation method Chlorophyll a ：葉綠素 濃度 現場螢光檢測 計 (10-AU-005, Turner Design) 2. Material and methods RsRs RBRB

IP ：透光層總基礎生 產量 梯形法則 2. Material and methods

3. Results and discussion We used optimal daily-integrated specific primary productivity （ P B opt ） within the euphotic zone to replace the term of the product of maximum specific primary productivity and day length in the scale factor. optimal daily-integrated specific primary productivity (P B opt ) product of maximum specific primary productivity HOUR DAY

3.1. Variations in the parameters used in the model IP E0E0 SST CSCS KdKd P B opt Fig.2. 各個參數在不同季節的變動

Fig.3. 各個參數的範圍及 頻率分布

Table.1. 各參數的平均數和最大、最小值 3.21 < 4.54

3.2. Primary production model Fig. 4. 八個航次的總基礎生產力和各參數的相關性

Fig.5. (A)IP 和 C S *P B opt *K -1 d 的相關性 (B) Model IP 和 IP 實測值 的相關性

3.3. P B opt model The relative difference between P B opt and the surface water specific primary productivity was, on average, less than 10%. The primary factors regulating P B opt are seawater temperature and the availability of solar irradiance (Li, 1980; Cullen, 1990).

SST 和 P B opt 的相關性 Model IP and IP 實測值 的相關性 SST–P B opt relationship Falkowski Megard

3.3.2 E 0 –P B opt relationship E 0 和 P B opt 的相關性 Model IP and IP 實測值 的相關性

We found fairly good correlations between euphotic zone-IP and the products of sea surface chlorophyll a concentration ， P B opt and K -1 d. These findings may have been because of the nature of the ECS which is considered a highly dynamic region by virtue of the seasonal fluctuations of different water masses. IP chlorophyll a P B opt K -1 d

Earlier, a variety of empirical relationships, mostly based on SST, has been described for P B opt. The one developed here, however, is distinct in that it can also be based on sea surface irradiance. R 2 =0.82 R 2 =0.70 >

4. Conclusions This implies that the unique empirical production model that is presented here can be further applied for the estimation of primary production based on satellite information.

In future, a more mechanistic model for P B opt ; one that not only accounts for observed variations but that also highlights the primary driving factors which lead to changes in the assimilation efficiencies, should be sought.

Such a model would provide guidance for future remote sensing missions and for other observational programs whose common mission is to determine the critical physical and chemical characteristics of various water masses and thereby evaluate carbon fixation.