Sentences with phrase «ph units»

Model forecasts suggest that average pH may decrease by as much as 0.5 pH units in total by 2100 [17].

Changes in the watershed can, for example, lead to changes in alkalinity and CO2 fluxes that, together with metabolic processes and oceanic dynamics, yield high - magnitude decadal changes of up to 0.5 units in coastal pH. Metabolism results in strong diel to seasonal fluctuations in pH, with characteristic ranges of 0.3 pH units, with metabolically intense habitats exceeding this range on a daily basis.

Open - ocean time series show that surface ocean pH has decreased on average by 0.1 pH units since the industrial revolution (Caldeira and Wickett 2005; Orr et al. 2005; Doney et al. 2009), with open - ocean pH decreasing steadily over the last few decades at a rate of 0.0019 per year (Doney 2010).

Whereas these effects on open - ocean pH are calculated to be minor, they can be higher, at rates of 0.02 — 0.12 × 10 − 3 pH units per year (< 10 % of OA by anthropogenic CO2), in coastal ecosystems (Doney et al. 2007), where atmospheric deposition is intense and the waters can be more weakly buffered.

The Bermuda plot (BATS station) is here (Fig. 5): http://www.biogeosciences.net/9/2509/2012/bg-9-2509-2012.pdf It shows a pH drop of 0.04 pH units within the huge seasonal noise over a period of nearly 30 years.

The «30 %» or the «0.09 pH units», in other words, is NOT AN OBSERVATION.

It cites the 2003 paper, and it just repeats the model result, which is a reduction of 0.09 pH units (Table 1).

Thanks Wayne, I was looking for the accuracy of the early glass electrodes... If we put the ancient electrodes and procedures at 0.1 units (best result) and the pH drop at a fixed place in the oceans with a growth of 40 % CO2 is not more than 0.1 pH units over 100 years, what then is the value of the historical data, taken at a lot of different places in different seasons?

What was done In a study designed to explore these assumptions, the authors tested the effects of seawater acidification by CO2 addition, leading to reductions of 0.3 and 0.6 pH units, on six - month - old juvenile mussels (Mytilus galloprovincialis), which they obtained from a mussel raft on the Ria de Ares - Betanzos of Northwest Spain, focusing their attention on growth, calcification and mortality.

«Since 1990, surface ocean pH has directly been measured or calculated at several locations, with the average recent decrease estimated as 0.0019 pH units per year at the Hawaii Ocean Time - series (HOT; close to the site of long - term atmospheric CO2 measurements at Mauna Loa)[12]; 0.0017 per year based on transects in the North Pacific [13]; 0.0012 per year at the Bermuda Atlantic Time - Series (BATS)[14] and 0.0017 per year at the European Station for Time - Series in the Ocean at the Canary Islands (ESTOC)[15].

Say the ocean pH is 8.1 and drops to 8.0 for a change of 0.1 pH units.

From preindustrial levels, contemporary surface ocean pH is estimated to have dropped on average from 8.2 to 8.1, or by about 0.1 pH units (a 26 % increase in hydrogen ion concentration), and further decreases of 0.22 to 0.35 pH units are projected over this century unless carbon dioxide emissions are significantly reduced.

From preindustrial levels, contemporary surface ocean pH is estimated to have dropped on average from 8.2 to 8.1, or by about 0.1 pH units (a 26 % increase in hydrogen ion concentration), and further decreases of 0.22 to 0.35 pH units are projected over this century unless carbon dioxide emissions are significantly reduced (Orr et al., 2005; Bopp et al., 2013).

If it varies by 4 - 5 pH units, not at all.

However, I know from experience that problems with equilibration of the solution and separately with the pH probe itself can often lead to uncertainties of up to + / - 0.1 pH units.

Onyx Sand is not chemically coated or treated but does have a slight buffering capacity that may raise pH by 0.1 - 0.5 pH units.

Ocean pH is projected to drop an additional 0.4 pH units by 2100 under a high CO2 emission scenario, ref with carbonate saturation levels potentially falling below those required to sustain coral reef accretion.

The pH of the surface ocean has fallen by 0.1 pH units since the beginning of the Industrial Revolution.

«It's projected to fall another 0.3 to 0.4 pH units by the end of this century.

Based on samples, we've found that acidity has increased significantly — by about 0.002 pH units a year since the industrial revolution.

As the team reported here on 12 December at a meeting of the American Geophysical Union, the acidity near the corrals plunged by more than 1.0 pH units, to 6.5 and below — far more extreme than the reduction of 0.1 to 0.3 units forecast for a program of gradual deep - sea CO2 injection.

In humans, a difference of only 0.2 pH units in the blood can lead to extreme health problems.

I also wanted to share this screen from beefproducts.com own video called «Ammonia in Foods» that shows how they need to raise the pH from 6 to 11 to combat E. coli in «pink slime», 5 pH units = 100,000 fold increase in alkalinity (since it's a log scale) http://oi40.tinypic.com/2zishfk.jpg

For the high mitigation scenario RCP2.6, corresponding changes are +0.71 °C, − 0.07 pH unit, − 1.81 % and − 2.0 % respectively, illustrating the effectiveness of extreme mitigation strategies.

For the «business - as - usual» scenario RCP8.5, the model - mean changes in 2090s (compared to 1990s) for sea surface temperature, sea surface pH, global O2 content and integrated primary productivity amount to +2.73 °C, − 0.33 pH unit, − 3.45 % and − 8.6 %, respectively.

Yes, the pH scale is logarithmic and the concentration of H + (written as [H +] or [H3O +]-RRB- is 10 times greater if 1 pH unit lower.

In some lagoons, pH has been measured to vary as much as 1 pH unit in a day (e.g., 7.6 to 8.6).

The pH range is over one pH unit, so I am more than highly skeptical of anyone claiming to have measured a change of a few hundredths of the natural variability locally, and extrapolating to the «world's oceans.»

Since the preindustrial period, pH has declined by approximately 0.1 pH unit corresponding to a 30 percent increase in acidity.

Roy, I doubt that the pre-1985 data have any value if they were taken with glass electrodes (+ / -0.1 pH unit), different places and different seasons.

So every one of these creatures experiences a pH change of half a pH unit, twice a day!

Can someone post a link to an article a couple years back that demonstrated the ocean around San Francisco fluxuated a full pH unit daily.

Further the influence of CO2 on pH is very small: In Hawaii a drop of 0.05 pH unit with a (mainly seasonal) variability of 0.05 pH unit for an increase of 45 ppmv CO2 in the atmosphere (Bermuda has a double seasonal amplitude).

I suspect that the spread is enormous compared to the 0.1 pH unit / century where we are looking for...

the real accuracy of the historical data, which may have been too variable because of place, time and method and too inaccurate to conclude anything about a (theoretical, but based on ocean chemistry) trend of 0.1 pH unit over a century...

So the whale is experiencing a drop in pH of nearly three quarters of a pH unit in 5 minutes or so...

If that is better than 0.01 pH unit still is questionable, but anyway easier to obtain than direct pH measurements.

We are searching for a (theoretical) trend of about -0.1 pH unit over the first 100 years of human emissions...

Yes, but Wallace didn't publish the error bars of the GEpH data... If you are looking for a trend of -0.1 pH unit over a period of 100 years and your instrument is accurate to 0.1 pH unit and ocean pH can vary 0.5 pH unit (and more) at different parts of the oceans and in different seasons, any such compilation of pH data taken at different places and seasons has no meaning at all.

Thus I don't think that he historical data have much value, as one need a series of data with very high accuracy (better than 0.01 pH unit) at the same place at high (at least monthly) frequency over many years to have a clear picture of any pH trends...

Kasuha, I agree on that point: pH measurements with glass electrodes may have been accurate to 0.1 pH unit in the early days, while we are looking for a trend of 0.1 pH unit over (the first) 100 years of human emissions.

Time - series and survey measurements [4 — 6] over the past 20 years have shown that surface ocean pH has reduced by 0.1 pH unit relative to pre-industrial levels, equating to a 26 % increase in ocean acidity [3].

Not exact matches

Unfortunately these units can't ve used to check the pH on hot sauce — unfortunately, way more expensive is required for testing liquids.Testing Soil NutrientsBesides pH meters, soil test kits with color indicators are another method of checking the acidity.

When I tested the soil in our pepper patch, the results were amazingly accurate — all three units showed a pH of 6.3 to 6.5, i.e. no actions necessary here to adjust the pH. One shop that has the Rapitest unit is here, another one here (please note I am not endorsing any of these shops here — just found them using Google).

TAML treatment at this pH caused BPA to assemble into larger units called oligomers, which clump together and precipitate out of the water.

In a secondary analysis of a multicenter randomized study of fetal pulse oximetry, of 4,126 nulliparous women who reached the second stage of labor, none of the following neonatal outcomes was found to be related to the duration of the second stage, which in some cases was 5 hours or more: 5 - minute Apgar score of less than 4, umbilical artery pH less than 7.0, intubation in the delivery room, need for admission to the neonatal intensive care unit, or neonatal sepsis (27).

Members of OIST's Information Processing Biology Unit, led by Prof. Ichiro Maruyama, have recently uncovered the sensor for alkaline environments, or high pH, in C. elegans.

But since 1800, the beginning of the Industrial Revolution, the pH of the ocean has dropped by 0.1 unit.

As its concentration rises in the atmosphere, carbon enters the ocean through chemical reactions, causing its pH at the surface to drop by 0.1 units since the preindustrial era.

Or they might decrease the water's pH by 0.4 units to study the effects of ocean acidification.