Bhaskar-- With respect to your message, I would very much like to see the evidence for the oxygen content ever being as high as 35% when life was present as fire would have run rampant (and since lightning would have been needed to provide the nitrate source, there would not have been a lack of a natural match). If that supposedly high oxygen content is what underpins your assurance that there are plenty of nutrients, then that conclusion would also seem to come into question.
It really is not so much whether the full ocean waters contain adequate nutrients, but how much (or few) make it up to the upper ocean and at what rate. With warming of surface waters likely to tend to stabilize the oceans (so reducing the bottom water formation that presumably forces colder, nutrient rich waters up), it would seem to me much more likely that the nutrient supply of the upper ocean would be headed down instead of up. Now, Kerry Emanuel has suggested that the restraint on the thermohaline circulation may not be the problem of getting cold waters to sink, but of getting them to come back up, and that tropical cyclones likely play an important role in this. While the number of tropical cyclones is projected to decrease, what the net effect (fewer tropical cyclones, perhaps more powerful, more stable ocean, etc.) on drawing up deeper colder waters remains, as I understand it, a bit murky, so it seems to me postulating a lot more nutrients reaching the surface layer is not at all well-established, and how the marine biological pump would work in the face of ocean acidification is also unclear‹the notion of a great increase seems to me quite premature, at best. Mike MacCracken On 7/23/12 7:31 AM, "M V Bhaskar" <bhaskarmv...@gmail.com> wrote: > Morton > > Iron fertilization is planned to be used in HNLCs, i.e., areas that have high > nutrient levels year after year. > So it appears that there is a abundance of nutrients in the oceans. > > In the past the CO2 levels of atmosphere and oceans were lower due to natural > factors and diatom growth higher, so nutrients to support this were available. > > O2 levels of atmosphere is today ~ 21 %, peak was ~ 35%. > So nutrients to support more than 50% higher photosynthesis was available at > that point in time. > > P is available only as a solid or dissolved in water, never as gas. > N may exit lakes and oceans as N2 gas but not P. > > So P to support much higher level of photosynthesis was and is available on > land or in water, if it has to be transported it can be done - whether 100 > tankers are required or 1000 tankers are required will be known only if we > experiment. > > Excess carbon in the atmosphere is about 200 billion tons - 390 ppm - 280 ppm. > At 100 : 1, total P requires is less than 1 billion tons. > > Annual carbon emissions are 10 billion tons of C, P required is about 50 > million tons. > > Global Rock Phosphate production is 256 million tons. > Rock Phosphate reserves in Western Sahara alone are about 50 Billion tons. > http://minerals.usgs.gov/minerals/pubs/commodity/phosphate_rock/mcs-2012-phosp > .pdf > > There seems to be no danger of running out of phosphorus. > > Before you ask how many tankers are required, please read - > > African dust leads to large toxic algal bloom > http://eospso.gsfc.nasa.gov/ftp_docs/African_Dust.pdf > > "Each year, several hundred million tons of African dust are transported > westward over the Atlantic > to the Caribbean, Gulf of Mexico, Central America, and South America." > > "Plant-like bacteria use the iron to set the stage for red tide, a toxic algal > bloom. When iron levels > go up, these bacteria, called Trichodesmium, process the iron and release > nitrogen in the water, > converting it to a form usable by other marine life. The increased nitrogen in > the water makes the > Gulf of Mexico a friendlier environment for toxic algae. The image on the left > shows a red tide > event that was seen by the SeaWiFS sensor on August 26, 2001. A huge bloom of > toxic red algae, > called Karenia brevis (K. brevis), appears on the true-color image as a black > area hugging the > Florida Gulf Coast from the Keys to Tampa Bay." > > The dust contains P, Si and Fe. > N is fixed from atmosphere by cyanobacteria - Trichodesmium. > > The key is to ensure bloom of useful algae and not harmful algae. > We have the key. We can prevent this dust from causing toxic algal bloom by a > very scientific fertilization to cause a controlled bloom of diatoms instead > of dinoflagellates (red tides). > > regards > > Bhaskar > > On Saturday, 21 July 2012 17:31:15 UTC+5:30, O Morton wrote: >> The reported ratio of C:Fe for IEFEX is >10,000:1. The redfield C:P ration is >> about 100:1. So you'd need your 100 tankers to be carrying pure phosphate, >> not sewage, no? >> >>> -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
