Autonomous Flow-Thru (AFT) pH data of the West Florida Shelf: USGS Cruise 11BHM04

The United States Geological Survey (USGS) is conducting a study on the effects of climate change on ocean acidification within the Gulf of Mexico; dealing specifically with the effect of ocean acidification on marine organisms and habitats. To investigate this, the USGS participated in two cruises in the West Florida Shelf and northern Gulf of Mexico regions aboard the R/V Weatherbird II, a ship of opportunity lead by Dr. Kendra Daly, of the University of South Florida (USF). The cruises occurred September 20 - 28 and November 2 -4, 2011. Both left from and returned to Saint Petersburg, Florida, but followed different routes (see Trackline). On both cruises the USGS collected data pertaining to pH, dissolved inorganic carbon (DIC), and total alkalinity in discrete samples. Discrete surface samples were taken during transit approximatly hourly on both cruises, 95 in September were collected over a span of 2127 km, and 7 over a trackline of 732 km line on the November cruise. Along with the surface samples, another set of samples were taken at various depths at stations; 27 in September at four stations and 15 in November at five stations. In addition to the discrete samples flow-through data was also collected on both cruises in a variety of forms. Surface CTD data was collected every five minutes which includes temperature, salinity, and pH. In addition, two more flow-through instruments were setup on both cruises that recorded pH and CO2 every 15 minutes. Corroborating the USGS data is the vertical CTD profiles collected by USF, using the following sensors: CTD, oxygen, chlorophyll fluorescence, optical backscatter, and transmissometer. Additionally, discrete depth samples for nutrients, chlorophyll, and particulate organic carbon/nitrogen were collected.

美国地质调查局（United States Geological Survey, USGS）正开展一项针对气候变化对墨西哥湾海洋酸化影响的研究，重点聚焦海洋酸化对海洋生物及其栖息地的效应。为推进此项研究，该局与由南佛罗里达大学（University of South Florida, USF）肯德拉·达利博士牵头的机遇性考察船R/V Weatherbird II号团队合作，在西佛罗里达陆架与墨西哥湾北部海域完成了两次科考航行。两次航行分别于2011年9月20日至28日、11月2日至4日开展，均从佛罗里达州圣彼得斯堡出发并返回，但航线各异（详见航迹线）。
两次航行中，美国地质调查局均采集了离散样本的pH值、溶解无机碳（dissolved inorganic carbon, DIC）及总碱度数据。航行过程中，每间隔约1小时采集一次表层离散样本：9月航次在2127千米的航程中共采集95份样本，11月航次在732千米的航迹线上采集7份样本。
除表层样本外，科考站位还采集了不同深度的分层样本：9月航次在4个站位采集27份样本，11月航次在5个站位采集15份样本。
除离散样本外，两次航行还采集了多种形式的流通式监测数据。表层温盐深（Conductivity-Temperature-Depth, CTD）数据每5分钟采集一次，涵盖温度、盐度及pH值。此外，两次航行均部署了另外两套流通式监测仪器，每15分钟记录一次pH值与CO₂浓度。
与美国地质调查局数据相互佐证的，还有南佛罗里达大学采集的垂直CTD剖面数据，所用传感器包括CTD、溶解氧、叶绿素荧光、光学后向散射仪及透射率计。
此外，团队还采集了营养盐、叶绿素及颗粒有机碳/氮的分层离散样本。