Can we accurately measure the pH of ocean water?

The accuracy of our pH measurements are difficult to evaluate directly because we have no seawater standard for pH measurements. The accuracy is therefore dependent primarily on the accuracy of the seawater buffers that are used for electrode calibration.

How do you measure pH in the ocean?

The classical potentiometric method for the determination of pH in seawater consists of the measurement of the electromotive force (EMF) of a cell, most commonly composed of a silver/silver chloride electrode and a glass pH electrode.

Why is it difficult to deal with errors in oceanographic measurements?

Two major challenges confront the oceanographer making measurements: the limitations of the instrumentation, and the difficulty in obtaining adequate spatial and temporal sampling.

Why do we measure pH of seawater?

The pH data were used to calculate the partial pressure of carbon dioxide (pCO2) in surface waters, and it was shown that changes in pCO2 could be calculated with an accuracy of ≈ 0.7 ppm.

What is seawater pH?

Today, average ocean pH is about 8.1. This might not seem like much of a difference, but the relationship between pH and acidity is not direct.

What is the pH value of pure water?

7
Pure water has a pH of 7 and is considered “neutral” because it has neither acidic nor basic qualities.

Is the pH of the ocean increasing or decreasing?

The ocean’s average pH is now around 8.1 , which is basic (or alkaline), but as the ocean continues to absorb more CO2, the pH decreases and the ocean becomes more acidic.

What pH is the ocean?

about 8.1
Solutions with low pH are acidic and solutions with high pH are basic (also known as alkaline). Prior to the Industrial Revolution, average ocean pH was about 8.2. Today, average ocean pH is about 8.1.

What factors can cause errors in measurements?

Variables such as temperature, humidity, pressure, gravity, elevation, vibration, stress, strain, lighting, etc. can impact the measurement result. Some tests and calibrations are more sensitive to certain environmental factors than others.

What errors could occur when reading thermometer measurements?

There are many factors that create temperature measurement errors. These include sensor calibration and accuracy, amplifier, lead wire, electrical composition, emissivity, radiation and conduction. Of these sources of error, conduction is the largest source of error in contact type temperature sensors.

What factors affect the pH of seawater?

When carbon dioxide dissolves in seawater, the water becomes more acidic and the ocean’s pH (a measure of how acidic or basic the ocean is) drops. Even though the ocean is immense, enough carbon dioxide can have a major impact.

What is the pH of the ocean going to be like?

Estimates of future carbon dioxide levels, based on business-as-usual emission scenarios, indicate that by the end of this century the surface waters of the ocean could have a pH around 7.8 The last time the ocean pH was this low was during the middle Miocene, 14-17 million years ago.

Who first measured the pH of seawater?

While seawater pH measurements have been made on some oceanographic expeditions starting with the first measurements that were made by Sørensen and Palitzsch (1910), most of the earlier data have proven to be problematic for a number of reasons that we will describe below.

Why is the pH in my database so low?

The lack of information as to whether the pH values were reported as measured versus in situ, and the lack of documentation on measurement temperature will lead to large pH uncertainties in the earlier database.

How has the pH of the ocean changed during the Industrial Revolution?

In the 200-plus years since the industrial revolution began, the concentration of carbon dioxide (CO 2) in the atmosphere has increased due to human actions. During this time, the pH of surface ocean waters has fallen by 0.1 pH units.