To examine the spatial variability and controlling factors of new, regenerated and primary productions, 21 stations were studied during fall monsoon period in the western Indian Ocean under Indian-GEOTRACES program. The primary, new and regenerated productions were estimated based on the incubation of enriched ¹³C_HCO3 and ¹⁵N_NO3, ¹⁵N_NH4 tracers respectively. High nitrate and phosphate concentrations were observed in the upper 30 m of water column in the Arabian Sea (AS) due to advection of upwelled waters from Oman and Somalia coasts. Chl-a in the upper 25 m of water column was low with prominent subsurface Chl-a maximum (0.5–1.3 mg m⁻³) between 25 and 50 m. The mean new production was almost similar in the AS and the South Indian Ocean (SIO; north of 30°S) with higher regenerated production in the SIO than AS. The photic zone integrated nitrate, and phosphate showed positive relation with primary production and negative relation with new and regenerated production. The photic zone integrated primary production was more than double in the AS (1238 ± 626 mg C m⁻² d⁻¹) compared to the SIO (675 ± 431 mg C m⁻² d⁻¹) with significant positive relation with photic zone integrated Chl-a. The range of primary production observed in the Indian Ocean (236–1899 mgC m⁻² d⁻¹) is within the range observed in the tropical Pacific and Atlantic Oceans (210–1887 mgC m⁻² d⁻¹). The contribution of primary production in the upper 25 m to photic zone integrated production was higher in the AS than the SIO due to low nutrients in the upper water column in the latter basin. Depth of nitracline showed inverse relation with primary production and f-ratios (ratio of new to primary production) in the study region. Insignificant differences in mean primary production and f-ratios were observed in the AS during 2015 (present study) as compared to a 1995 study, contradicting the belief that rapid warming may modify primary production.

为了研究新产品，再生产品和初级产品的空间变异性和控制因素，在印度-GEOTRACES计划下，在印度洋西部的秋季季风期研究了21个台站。分别基于富集的¹³ C _HCO3和¹⁵ N _NO3和¹⁵ N _NH4示踪剂的孵育，估算初级，新产品和再生产品。由于来自阿曼和索马里沿岸的上升流的平流，在阿拉伯海（AS）的水柱上部30 m观察到较高的硝酸盐和磷酸盐浓度。Chl-一个在水塔的上部25米低与突出地下Chl-一个25至50 m之间最大（0.5–1.3 mg m ^-3）。南美洲和南印度洋（SIO； 30°S以北）的平均新产量几乎相似，SIO的再生产量高于AS。光合带整合了硝酸盐，而磷酸盐与初级产量呈正相关，与新的和再生的产量呈负相关。与SIO（675±431 mg C m ^-2  d ^-1）相比，AS的光合带综合初级生产力（1238±626 mg C m ^-2  d ^-1）多两倍，与光合带呈显着正相关综合Chl-一个。在印度洋观测到的初级生产范围（236-1899 mgC m ^-2 d^-1）在热带太平洋和大西洋中观测到的范围内（210-1887 mgC m ^-2 d ^-1）。由于后流域上层水柱中的养分含量低，AS区上游25 m的初级生产对光合带综合生产的贡献高于SIO。在研究区域内，硝苯胺的深度与初级生产和f-比率（新生产与初级生产的比率）成反比。与1995年的研究相比，2015年（本研究）在AS中观察到平均初级生产力和f比率的微不足道的差异，这与认为快速变暖可能会改变初级生产力的观点相矛盾。