Chlorophyll and phaeopigments from water column samples, collected at selected depths at Palmer Station Antarctica, during the Palmer LTER field seasons, 1991 – 2018.

Phytoplankton chlorophyll sampling was led by Smith from the 1991-1992 season through the 2001-2002 season, and then by Vernet from the 2002-2003 season through the 2006-2007 season. Schofield is the third, and current lead, beginning in the 2008-2009 season. Methods have been kept consistent as much as possible over the full time series and different Principal Investigators. Chlorophyll a (Chl a) is the principal photosynthetic pigment of phytoplankton, and is used as a proxy measurement for estimating phytoplankton biomass in water samples. Chl a concentrations reflect the distribution of active phytoplankton spatially and with depth in the water column and their changes over time. Phaeopigments are non-photosynthetic pigments that are degradation products of phytoplankton chlorophylls which form during and after phytoplankton blooms. Water samples are collected throughout the water column at stations within the Palmer LTER region (primarily B and E, to 50m and 65m respectively). Water samples are filtered onto GF/F filters, and filters kept frozen at -80°C until analysis. Fluorometric chlorophyll and phaeopigment analysis is conducted at Palmer Station through acetone extraction of the GF/F filters and measurement of the extract on a Turner 10AU Fluorometer. The primary source of error for phaeopigment measurement is Chlorophyll b. If high amounts of Chlorophyll b are present in the sample, phaeopigments may be overestimated.1991-1992航次至2001-2002航次期间的浮游植物叶绿素采样工作由Smith主导，2002-2003航次至2006-2007航次期间则由Vernet负责。第三位负责人，同时也是现任负责人Schofield，自2008-2009航次起接手该采样工作。在整个时间序列及不同首席研究员（Principal Investigators）的统筹下，采样方法始终尽可能保持一致。 叶绿素a（Chlorophyll a，缩写Chl a）是浮游植物的核心光合色素，常被用作估算水体样品中浮游植物生物量的替代指标。Chl a浓度可反映活性浮游植物在水体中的空间分布、垂向分布及其随时间的动态变化。 褐藻素（Phaeopigments）属于非光合色素，是浮游植物叶绿素的降解产物，在浮游植物水华发生期间及发生后形成。 帕尔默长期生态研究（Palmer LTER，Long-Term Ecological Research）区域内的所有站位均采集全水柱水样，主要采样站位为B和E，对应采样深度分别可达50米与65米。采集的水样经GF/F滤膜过滤后，将滤膜置于-80℃环境下冷冻保存直至分析环节。 叶绿素与褐藻素的荧光光度分析在帕尔默站（Palmer Station）完成：将保存的GF/F滤膜用丙酮萃取，随后使用Turner 10AU荧光光度计对萃取液进行检测。 褐藻素测量的主要误差来源为叶绿素b（Chlorophyll b），若样品中叶绿素b含量过高，可能会导致褐藻素的测量结果被高估。