Query: water surface pco2

title: Seasonal and spatial variability in surface p CO 2 and air water CO 2 flux in the Chesapeake Bay

title: Environmental controls of surface water pCO2 in different coastal environments: Observations from marine buoys
abstract: Time series of in situ surface seawater partial pressure of CO2 (pCO2) data collected between 2005 and 2017, together with other environmental variables from field or satellite measurements, along the coasts of the United States of America and its territories at different latitudes, are analyzed to separate the temperature effect from the remaining non temperature effects (i.e. biological and other physical effects) on driving surface pCO2. Similar to the findings in the open ocean, on seasonal time scales, the temperature effect (pCO2_T) tends to override the non temperature effect (pCO2_nonT) in modulating surface pCO2 in tropical and subtropical oceanic waters. However, the balance between pCO2_T and pCO2_nonT tends to shift towards pCO2_nonT in temperate zone waters, with a few exceptions in some specific oceanic environments. On interannual time scales, both atmospheric pCO2 and surface pCO2 show significant increasing trends over short time scales (i.e.

title: Rapid daily change in surface water pCO2 and CO2 evasion: A case study in a subtropical eutrophic lake in Southern USA
abstract: Evasion of carbon dioxide (CO2) from lakes is a significant component in the continental carbon balance, but most current CO2 evasion estimates ignore daily CO2 fluctuations. To test the hypothesis that partial pressure of CO2 (pCO2) and CO2 evasion vary throughout a day due to biological processes driven by solar radiation, we conducted in situ pCO2 and ambient water measurements over eleven 10 h periods in a subtropical, eutrophic shallow lake from November 2017 to May 2018. In situ measurements were performed at 7:00, 10:00, 14:00, and 17:00 Central Standard Time of the United States (CST) and CO2 evasion rates were estimated based on the field pCO2 records. Strong daily declining trends of pCO2 and CO2 flux were found throughout the seasons except for one winter day with unusually low temperatures. At 7:00, 10:00, 14:00, and 17:00 CST of a day, average pCO2 were 1131, 839, 345 and 205 uatm, respectively, while average CO2 fluxes were 80, 67, 10, and 34 mmol m2 h 1. Significant differences were found in average pCO2 between any two measured time points in a day, while significant reductions in CO2 flux were observed between 10:00 and 14:00 CST and between 14:00 and 17:00 CST. pCO2 and CO2 flux dynamics were most likely driven by the air water exchanges during nighttime hours and mainly driven by aquatic metabolism in the daytime. These findings suggest possible large uncertainties in the estimation of carbon emitted from trophic lakes, highlighting the need for further research on diurnal pCO2 fluctuation from different aquatic ecosystems to improve CO2 evasion estimation.

title: Variability of Surface Water p CO 2 in the Canadian Arctic Archipelago From 2010 to 2016

title: Spatio temporal variability of surface water pCO2 and nutrients in the tropical Pacific from 1981 to 2015
abstract: This study presents a synthesis of surface water partial pressure of CO2 (pCO2) and nutrient observations in the tropical Pacific (20degS 20degN) from 1981 to 2015 and characterizes the spatio temporal variability. We used data from the Surface Ocean CO2 Atlas version 5, which include about 2 million pCO2 measurements in the tropical Pacific. Unlike many previous studies that estimated pCO2 fields from relationships with other variables like sea surface temperature, we developed gridded products of monthly means using a technique to interpolate measured pCO2 values. Large seasonal variation of pCO2 appears in the cold tongue region (EQ 20degS, east of 120degW) corresponding to the seasonal variation of coastal upwelling, and in the off equatorial region where the thermodynamic effect on pCO2 dominates. Consistent with previous findings, pCO2 along the equator declines during El Nino due to weakening of the easterly winds and therefore reduced upwelling of CO2 rich subsurface water. We also quantified the spatial distribution of the long term pCO2 trend beyond the area averaged trend presented previously. The long term trend of pCO2 is positive in all regions with an area average of 1.8 0.1 matm yr 1. However, along the equator the trend is 2 matm yr 1 linked to the Pacific Decadal Oscillation forcing. Using the same methodology, we also analyzed about 20,000 surface nutrient measurements from the Global Ocean Data Analysis Project version 2, World Ocean Database 2013, and ship of opportunity sampling by the National Institute for Environmental Studies, Japan. We present the spatial patterns of reduced surface nutrient concentration in the central to eastern tropics along the equator during El Nino, but there are not enough data to characterize the trends of nutrients in the tropical Pacific. Decorrelation analyses are also applied using covariance between pCO2 anomalies separated by a lag increment for zonal, meridional, and temporal directions. The e folding scale of pCO2 is estimated to be 6deg in latitude, 13deg in longitude, and 2 months with a signal to noise ratio of 4, which are used as input for the interpolation as well as an assessment of ideal observation density and frequency. Decorrelation analyses such as this are critical for evaluating existing observing system design and informing future sampling strategies.

title: Remote estimation of surface pCO2 on the West Florida Shelf
abstract: Surface pCO2 data from the West Florida Shelf (WFS) have been collected during 25 cruise surveys between 2003 and 2012. The data were scaled up using remote sensing measurements of surface water properties in order to provide a more nearly synoptic map of pCO2 spatial distributions and describe their temporal variations. This investigation involved extensive tests of various model forms through parsimony and Principal Component Analysis, which led to the development of a multi variable empirical surface pCO2 model based on concurrent MODIS (Moderate Resolution Imaging Spectroradiometer) estimates of surface chlorophyll a concentrations (CHL, mg m 3) diffuse light attenuation at 490 nm (Kd_Lee, m 1) and sea surface temperature (SST, degC) Validation using an independent dataset showed a pCO2 Root Mean Square Error (RMSE) of

title: Temporal Variability in Surface Water pCO2 in Adventfjorden (West Spitsbergen) With Emphasis on Physical and Biogeochemical Drivers
abstract: Seasonal and interannual variability in surface water partial pressure of CO2 (pCO2) and air sea CO2 fluxes from a West Spitsbergen fjord (IsA Station, Adventfjorden) are presented, and the associated driving forces are evaluated. Marine CO2 system data together with temperature, salinity, and nutrients, were collected at the IsA Station between March 2015 and June 2017. The surface waters were undersaturated in pCO2 with respect to atmospheric pCO2 all year round. The effects of biological activity (primary production/respiration) followed by thermal forcing on pCO2 were the most important drivers on a seasonal scale. The ocean was a sink for atmospheric CO2 with annual air sea CO2 fluxes of 36 2 and 31 2 g C*m *year 1 for 2015 2016 and 2016 2017, respectively, as estimated from the month of April. Waters of an Arctic origin dominated in 2015 and were replaced in 2016 by waters of a transformed Atlantic source. The CO2 uptake rates over the period of Arctic origin waters were significantly higher (2 mmol C*m *day than the rates of the Atlantic origin waters of the following year.

title: Suitability of the shallow water hydrothermal system at Ambitle Island (Papua New Guinea) to study the effect of high pCO2 on coral reefs.
abstract: Volcanic CO2 seeps were successfully used to predict coral reef response to ocean acidification, although toxic elements, often characteristic of hydrothermal vents were rarely reported. We measured the physicochemical conditions, seawater carbonate chemistry and trace elements in Tutum Bay, Papua New Guinea. There, intense emission of hydrothermal fluids and CO2 expose the coral reef to a seawater pHT between 7.6 and 7.7. Arsenic and silica were enriched by up to six times in surface seawater, while bottom concentrations were lower and thus similar to coral reefs worldwide. Manganese, cesium, iron and zinc concentrations fell into the range of other coastal environments. Our measurements suggest that Tutum Bay is a suitable site to study the response of coral reefs to high pCO2. Considering that arsenic is a common metal in hydrothermal fluids, its characterization should be included in any study that uses volcanic CO2 seeps as natural laboratories for ocean acidification.

title: A mechanistic semi analytical method for remotely sensing sea surface pCO2 in river dominated coastal oceans: A case study from the East China Sea
abstract: While satellite remote sensing has become a very useful tool contributing to assessments of sea surface partial pressure of carbon dioxide (pCO2) that subsequently allow quantification of air sea CO2 flux, the application of empirical approaches in coastal oceans has proven challenging owing to the interaction of multiple controlling factors. We propose a "mechanistic semi analytic algorithm" (MeSAA) to estimate sea surface pCO2 in river dominated coastal oceans using satellite data. Observed pCO2 can be analytically expressed as the sum of individual components controlled by major factors such as thermodynamics (or temperature) mixing, and biology. With marine carbonate system calculations, temperature and mixing effects can be predicted using thermodynamic principles and by assuming conservative two end member mixing of total dissolved inorganic carbon and total alkalinity (e.g. the Changjiang River and Kuroshio water in the East China Sea, ECS) Next, an integral expression for pCO2 drawdown due to biological effects can be parameterized using the chlorophyll a concentration (chla) We demonstrate the validity and applicability of the algorithm in the ECS during summertime. Sensitivity analysis shows that errors in empirical coefficients and three input satellite parameters (salinity, SST, chla) have limited influence on the algorithm, and satellite derived pCO2 is consistent with underway data, even though no in situ pCO2 data from the ECS shelves was used to train the algorithm. Our algorithm has more physical and biogeochemical mechanistic meaning than empirical methods, and should be applicable to other similar systems.

title: Surface Water pCO2 Variations and Sea Air CO2 Fluxes During Summer in the Eastern Canadian Arctic
abstract: Based on a 2 year data set, the eastern Canadian Arctic Archipelago and Baffin Bay appear to be a modest summertime sink of atmospheric CO2. We measured surface water CO2 partial pressure (pCO2) salinity, and temperature throughout northern Baffin Bay, Nares Strait, and Lancaster Sound from the CCGS Amundsen during its 2013 and 2014 summer cruises. Surface water pCO2 displayed considerable variability (144 364 matm) but never exceeded atmospheric concentrations, and average calculated CO2 fluxes in 2013 and 2014 were 12 and 3 mmol C m 2 d 1 (into the ocean) respectively. Ancillary measurements of chlorophyll a reveal low summertime productivity in surface waters. Based on total alkalinity and stable oxygen isotopes (d18O) data, a strong riverine signal in northern Nares Strait coincided with relatively high surface pCO2, whereas areas of sea ice melt occur with low surface pCO2. Further assessments, extending the seasonal observation period, are needed to properly constrain both seasonal and annual CO2 fluxes in this region.