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Messages - frethack

Pages: [1] 2 3 ... 20
1
Marine Science / What is Western Pacific Warm Pool, and How did it formed?
« on: 15/08/2011 18:53:31 »
Quote from: JimBob on 14/08/2011 19:33:45
Are not the winds of the earth steered in their direction of initial movement by by the Coriolis Effect?

Absolutely they are, which pushes the WHWP into the western pacific, but its northern extent is is greatly influenced by other factors as well. 

2
Marine Science / What is Western Pacific Warm Pool, and How did it formed?
« on: 12/08/2011 20:17:03 »
Quote from: JimBob on 12/08/2011 03:36:39
INDEED THEY ARE - There is only one physical cause, however.

Be careful with absolutes.

The WHWP is indeed located in the Western Pacific because the trade winds (caused by coriolis) blow warm surface water westward, creating a shoaling of the thermocline and upwelling of cool water in the east. 

There are other major factors that are in play however.  The position, average temperature, sea level height, and sea level pressure of the WHWP oscillates on seasonal and interannual time scales because of shifts in the Walker circulation, position of the ITCZ, intensity and latitude of the Hadley Cell, etc.


3
The Environment / Do you still believe climate change is not mainly due to mankind?
« on: 17/07/2011 01:55:14 »
Quote from: CliffordK on 16/07/2011 02:11:25
At some point in the film they said:
   "Climate change in the past was very gradual."
   "Now it is very rapid."

Yet, that is certainly hotly debated with some theories indicating that the Cretaceous Period may have ended with catastrophic climatic change occurring in a single day.

I dont think that rapid climate change is that hotly debated anymore.  Most paleoclimate studies that have been published in the past 10 years have shown episodic warming and cooling - sometimes beneficial, sometimes catastrophic, sometimes both.  In the past 10,000 years, there have been more than a few that happened in the span of just a decade (Younger Dryas, 8.2 ka event, etc.).


Quote from: CliffordK on 16/07/2011 02:11:25
Yet, that is perhaps the core of the entire climate debate, that we have diverged from actual evidence, and the new science is now models rather than evidence.  And while there are significant improvements in the models, there are still a few significant holes in them. 

The NCEP Renalysis data set is pretty funky before 1950, and still not trustworthy before the late 70s or early 80s.  Until the satellite era, ocean data was taken by ships crossing, and while there were quite a few ship, they mostly stick to certain shipping lanes.  So we have strong data for those areas, but the rest of the "data" for the reanalysis set is modeled from the data that exists.  Until after WWII, the dataset is *horrible*, I toss it out automatically unless Im interested in a specific region that is well covered.  Before 1979, the stratospheric portion of the data is weak, so youre really restricted to 30 years of data that you can actually trust - from a dataset that spans 153 years.  This set is one of the most popularly used datasets in climate science, and even I have to use it because it (and the Met Offices similar sets) is really the best option available at this point.

Quote from: CPT ArkAngel on 15/07/2011 21:34:48
What is the natural cause according to you?

Humans produce 7 times more CO2 than nature. We produce heat too. When you will admit it, it may be too late. The sun is not more active now than before... Some large and very powerful companies see this as a treat to their growth and their power.

I have no disagreement with you that humans produce a LOT of CO2, and that it has warmed the atmosphere.  However, Ive watched and studied the sun for the past four years, and there is a reason that it is classified as a variable star.  Weve launched a pretty hefty arsenal of solar satellites over the past 10 years, and our understanding of the sun has increased exponentially.  Just the last 3 years have nullified the Lean Model, the solar model used in most GCMs and other regional models.  We discovered that ultraviolet light can vary 400-600% more than expected, which has significant implications for ozone and the stratosphere as a whole (which in turn effects the troposphere...where the weather is).


4
The Environment / Humidity, CO2, and cloudcover. And cosmic rays ?
« on: 15/07/2011 17:46:23 »
Cloud microphysics is a very active area of current research.  Svensmarks work has problems, but I am very interested to see the results from his experiments at CERN.

Quote from: yor_on on 05/07/2011 16:42:59
What happens with water molecules when they move faster, I've seen some ideas where those molecules are expected to find it harder to coalesce and form clouds? We have some very hot areas meeting water like India, Thailand etc. Naively speaking now, they must have a high humidity, but, do they have more cloud covers? And when if so, relative the humidity (and season/temperature)?
Soils of UK and Europe drying out.

South/Southeast Asia have very heavy cloud cover and precipitation throughout the boreal summer monsoon months (the highest in the world), but there is more than just temperature and humidity involved.  Atmospheric pressure regimes, orographic effects (which prevent the monsoon from crossing north of the Himalayas), position of the ITCZ, etc. are all major factors...among others.

Quote from: yor_on on 05/07/2011 16:42:59
"Smos is an experimental mission of the European Space Agency (ESA), and is providing some novel information to meteorologists, hydrologists and other scientists interested in how water moves around the globe. The 760km-high satellite carries an 8m-wide interferometric radiometer that senses the natural emission of microwaves coming up off the planet’s surface. Variations in the water content of soils will modify this signal." It was launched 2009.

Soils of UK and Europe drying out.

Soils in the Southwest US are drying as well.  Im beginning a study now that is meant to quantify the feedback effects of soil moisture on drought severity.  Ill post some information as I get it.

5
The Environment / Do you still believe climate change is not mainly due to mankind?
« on: 15/07/2011 17:33:02 »
Yep...I still believe that our changing climate (that has *never* been at equilibrium) is mainly natural, with some effect from man that has yet to be quantified.

6
The Environment / What are the consequences of weather-engineering?
« on: 16/05/2011 18:01:54 »
Quote from: imatfaal on 16/05/2011 17:10:37
I realise there are better scientific paper search engines - but this one is easily accessible. If it has missed any academic papers please post links.

At present the case does not rest as proven - and no proof has been given to be torn up. 

No worries imatfaal, I checked on Web of Science, which IS a comprehensive search engine (google scholar is still very good) and still no hits on C. E. Carnicom.  Nada...zilch...nothing.

Chemtrails are likely just contrails, made more visible by increases in atmospheric water vapor due to warming.  Extraordinary claims require extraordinary evidence.

7
Geology, Palaeontology & Archaeology / How do you know what specific field in Geology you should specialize?
« on: 16/05/2011 16:40:44 »
Quote from: JimBob on 16/05/2011 03:34:25
Forget Seismic - He can't even read a MAP!!!! Dead serious on this.

JimBob is as senile as he is boorish (hard to believe, but its true).  He forgets that I am actually a competent field geologist and cartographer, and I have the A's in my field geology courses to prove it.  Just because I didnt chisel my maps into stone tablets and suffer through mapping without the use of GIS doesnt mean I cant read a map...it only means that I was lucky enough to have been born in the very late Holocene.


8
Geology, Palaeontology & Archaeology / How do you know what specific field in Geology you should specialize?
« on: 15/05/2011 18:43:18 »
Heya olivine, welcome to the forum!

A good background in chemistry will be very helpful in most geoscience fields.  I started out loving paleontology as a kid, went through various paths before attending college, and settled on geology as my major.  Im like you in that I currently work in the paleomag lab, but really only do it for money.  My real love and area of research is in the atmospheric sciences, which requires a great deal of chemistry and physics.  This probably means that I am a bit of a substandard geologist (I cant even read seismic), but Im okay with that.

I suggest talking to as many potential advisors as possible and get an idea of what research in their field involves.  The one that interests you most should be the one that you pick.  For a good salary, petroleum geology and hydrogeology are good paths, as well as environmental geology.  Paleoclimatologists and oceanographers use micropaleontologists quite a bit to get a first order impression of the age of sediment cores through the microbiology they contain, but I am unsure of their salary.  Pretty interesting stuff.




9
The Environment / Is there new observational evidence for solar-climate coupling?
« on: 15/05/2011 18:10:01 »
Quote from: yor_on on 15/05/2011 12:04:52
So the Ozone might be stronger driver than the IPCC considers. Not that it surprise me, they seem to be very wary of stepping out of 'bounds' extrapolating. In this case I don't know if that's the best approach, to me it's a little like not wanting to see, hoping it to go away if one just ignore it.

The IPCC serves a good purpose as a scientific body that uses established and well tested research to make policy recommendations, but because it is large and cumbersome, the body as a whole has a difficult time adjusting quickly to new information, especially in rather controversial fields.  To my knowledge, Judith Lean is the only solar physicist that contributes to IPCC reports...at least for the reports up to AR4...maybe AR5 will be different, I dont know.

A little more info.  The two plots below are the result of multiple regression analysis of NCAR-NCEP reanalysis data sets from 1979 to 2002.  They do not include the most recent deep solar minimum.  Multiple regression analysis is basically finding the equation of a line [y = mx + B], but with multiple x values [y = m1x1 + m2x2 + ...mnxn].  It is used to determine the contribution of multiple independent variables on one dependent variable.  In this case to save space, Ive included only the effects of solar activity from 1979 - 2003 on temperature and zonal wind (average latitudinal wind).  the X axis is latitude, and the y axis is atmospheric pressure level in mb (or hPa).

The unshaded areas are those that are within the 95% confidence level.  As solar maximum is approached (the "11 year" cycle), the lower equatorial stratosphere warms, and two vertical columns of warming extend from the tropopause into the lower troposphere at mid-latitudes.


In this study on zonal wind, done by the same author, it shows that the subtropical jet cores weaken, expand, and shift poleward as solar maximum is approached.  A similar study done on vertical wind (convection) detects a weakening and expansion of the Hadley Cell, and poleward movement of the Ferrel Cell, which is in line with the study shown below.


These two studies were done before the current solar minimum and it is possible that the effect is more pronounced with drastic changes in UV radiation, but we will not know that until longer data sets are available.  The effect on the jet cores, Hadley Cell, and Ferrel Cell were attributed solely to increases in CO2 before, but it is now known that solar variability is also a significant contributor to this change.  What are the contributions of each?  There is no way to tell at the moment.  Paleoclimate evidence suggests that the solar effect could be large...we will see.




10
The Environment / Is there new observational evidence for solar-climate coupling?
« on: 14/05/2011 20:18:01 »
Quote from: yor_on on 14/05/2011 18:17:24
"Since 2000, water vapor in the stratosphere decreased by about 10 percent...

This is another enigma that is currently under heavy research.  The stratosphere in the equatorial regions extends from about 17 to 50 km above the surface, and though water vapor is scarce in the stratosphere, it does create a surface warming effect through polar stratospheric clouds.  These clouds are transparent to incoming solar radiation, but translucent/opaque to outgoing longwave radiation. 

Over the decline of the past solar cycle, the stratospheric ozone peak abundance shifted locations from about 35km to nearly 50km (top of the stratosphere).  This has the effect of cooling the lower stratosphere and reducing its capacity to carry water vapor.  Whether this can entirely explain the water vapor decline, there is not enough information to say, but it is certainly a contributor.  It is likely to take decades to determine all of the mechanisms for water vapor loss in the stratosphere. 

As for the solar-geomagnetic conduits, Ill see what else I can find.  I cant speak competently on this subject, but Im sure there is someone at the university who will know much more than me.  At the end of the summer Im meeting with one of the solar physicists from the astronomy department, and maybe he will have a better idea.

11
The Environment / Is there new observational evidence for solar-climate coupling?
« on: 14/05/2011 16:08:07 »
Quote from: yor_on on 14/05/2011 03:41:20
It seems obvious that the energy transfers possible by such magnetic 'tunneling' should contribute, but to make it correlate to this warming we will need to find evidence for it having either increased in magnitude, or coming much more often.

The magnetic tunneling is a completely different subject.  I dont know of any evidence that this contributes to climate change, though that doesnt necessarily mean that it isnt a factor is some way.  Its just not my area of expertise.

Quote from: yor_on on 14/05/2011 03:41:20
1a. Assuming that we're talking a energy transfer here, that builds up heat, directly or indirectly? How much would be needed for making a discernible impact on the gas layer surrounding Earth, (1b) also put in perspective relative the absolute output of solar radiation we receive from the sun every year?

There is very little change in solar output over the course of a solar cycle, on the order of 0.1%.  It isnt the change in total output that is important, but instead it is the change in output in specific wavelengths across the radiation spectrum.  For example, the following is a plot of spectral irradiance anomalies from the previous solar maximum until the current deep solar minimum.  The data comes from the SOLSTICE and SIM instruments on board the SORCE satellite.  The plot marked "Lean model" is the current solar anomaly model used worldwide in GCMs and by the IPCC.  The Lean model underestimates changes in the ultraviolet spectrum by as much as 600% or more, something we had never detected before.  Because ozone absorbs radiation in this band, this has implications on ozone organization and abundance, which is the main driver of stratospheric circulation. 

In explanation, visible light is in the range of about 700nm wavelengths to about 400nm.  Ultraviolet begins at around 400nm.


This is another plot showing changes in ultraviolet over the past three solar cycles.  Note that the most recent solar minimum is very deep, something we had not detected before.  Until the past few years, it was comepletly unknown to us that the sun reacted in this way.

It is thought by some researchers that we may be ending a Gleissberg cycle, which is about a 100 - 120 year cycle (previously thought to be about 87 years).  It forces us to rethink what the range of solar variability may be, especially extreme events like grand minima such as the Maunder, Sporer, Wolf, and Oort Grand Minima of the Little Ice Age.


Ill post more as I have time. 

12
The Environment / Can Water Run Uphill?
« on: 13/05/2011 19:21:52 »
The Eastern Pacific sea level is not always significantly higher than the Western Pacific...mostly during La Nina events.  The easterly trade winds are much stronger over the equatorial pacific during a La Nina, which equates to stronger surface currents and a pile up of warm water in the Western Pacific Warm Pool.  During a strong El Nino, the equatorial surface currents reverse (because of a reverse in the atmospheric Walker Circulation), and pile warm water into the Eastern Pacific.

The sea level difference, in large part, is dependent on the wind strength and direction of the Pacific ITCZ.

13
The Environment / Is there a relation between changes in the earth's magnetic field and climate?
« on: 13/05/2011 17:20:11 »
Quote from: yor_on on 13/05/2011 16:44:29
I just stated that I could see no direct forcing or correlation between the sun and the temperature.

See the next topic

14
The Environment / Is there new observational evidence for solar-climate coupling?
« on: 13/05/2011 15:34:13 »
Didnt want to hijack the geomagnetic activity thread.

Yes...there is evidence from instrumental data.  No...the sun is not the only determinant factor in regards to the climate system.
As a disclaimer, positive evidence for a solar effect on climate is not negative evidence for the effect of CO2 on climate.  These are two separate subjects, and the validity of one is not dependent upon the invalidity of the other (except among ideologues).

yor_on...if you cannot access these through google scholar, please let me know and I will be happy to email the .pdf files to you (or anyone for that matter).  I cant openly post copyrighted material without risking trouble.  These are all from well respected, peer reviewed journals and are leading authors in the field of solar-climate coupling.  None of these authors believes that because the sun has an effect on climate that CO2 does not, however some (not all) of the recent climate changes attributed to CO2 are now being shown to be attributable to solar variability...not because previous authors were dishonest, but because CO2 and solar activity were increasing at the same time...this is the scientific method.  To dig deeper, just look up more papers by the lead authors...it will help if you have access to a scientific search engine such as Web of Science...if not, google scholar will do.

Bond, G., B. Kromer, J. Beer et al. (2001), Persistent solar influence on North Atlantic climate during the Holocene, Science, 294, 2130–2136.

Gleisner, H., and P. Thejll, (2003). Patterns of tropospheric response to solar variability. Geophys. Res. Lett., 30, 1711.

Haigh, J. D. (2003), The effects of solar variability on the Earth’s climate, Philos. Trans. R. Soc. A, 361, 95–111.

Haigh, J. D., M. Blackburn, and R. Day (2005), The response of tropospheric circulation to perturbations in lower stratospheric temperature, J. Clim., 18, 3672–3685.

Lockwood, M., C. Bell, T. Woollings, R. G. Harrison, L. J. Gray, J. D. Haigh (2010b), Top down solar modulation of climate: Evidence for centennial scale change, Environ. Res. Lett., 5, 034008.

Poore, R.Z., Quinn, T.M., and Verardo, S., (2004), Century-scale movement of the Atlantic Intertropical Convergence Zone linked to solar variability: Geophysical Research Letters, v. 31, p. L12214.

Roy, I., Haigh, J.D. (2010) Solar cycle signals in sea level pressure and sea surface temperature. Atmos. Chem. Phys. 10, 3147-3153.

van Loon, H., Meehl, G.A., Shea, D.J., (2007). Coupled air-sea response to solar forcing in the Pacific region during northern winter. J. Geophys. Res. 112.

There are literally hundreds of papers on the subject...keep digging.


15
The Environment / Is there a relation between changes in the earth's magnetic field and climate?
« on: 13/05/2011 15:05:59 »
Quote from: yor_on on 12/05/2011 05:28:01
Why does the temperature curves just keep climbing?

You are assuming in this line of thought that the sun is the ONLY factor on climate, disregarding "ocean memory", greenhouse gasses, climate oscillations, etc.  This is a fallacious argument.  As this post is about the geomagnetic field and climate, Ill start a new thread on solar influences on climate instead of hijacking this one for yet another futile debate. 

As the on topic part of this post, and to show direct interaction between the geomagnetic field and the solar magnetic field:

http://science.nasa.gov/science-news/science-at-nasa/2008/30oct_ftes/

Look these papers up with google scholar:

Evidence for a flux transfer event generated by multiple X-line reconnection at the magnetopause
Concerning the occurrence pattern of flux transfer events on the dayside magnetopause
Cluster observations of "crater" flux transfer events at the dayside high-latitude magnetopause

As for the decline in geomagnetic intensity and the overall increase in solar activity, there is surprisingly little in the peer reviewed literature.  As stated before:

Quote from: frethack on 11/05/2011 03:40:27
...geomagnetic field strengthens/weakens.  It could also be entirely coincidental.  It would be good to know a little more about the data sets used to create these plots...resolution, dating methods, error, etc.  Longer records would be great as well, but unfortunately, this is about as far back as decently resolved paleoclimate records can conceivably go.

There is a lot to discover...more than we can conceive.

16
The Environment / Is there a relation between changes in the earth's magnetic field and climate?
« on: 12/05/2011 01:38:31 »
Quote from: yor_on on 11/05/2011 22:40:42
Frethack, can you give us a link with some facts too?

It will take me a day to post a few papers, but I will be happy to do so. (working on final papers for classes currently)

Quote from: yor_on on 11/05/2011 22:40:42
By the way, when I asked about the radiation I really was thinking of the closest 250 years to us, as that is where we see a statistical anomaly appear, and accelerate, not seen before in Earths history.

There would be very little way to demonstrate whether the current magnetic field degeneration is an anomaly or not without looking much deeper than 250 years.  The earth operates on time scales much larger than this.

Quote from: yor_on on 11/05/2011 22:40:42
Global warming today is a anomaly, not a phase we have found anywhere else in Earths history. That as I assume that this was what the thread was about? Treated otherwise it's not connected to the warming, instead becoming a question of geomagnetism. When it comes to the suns importance I would be surprised if it didn't play a role. But if you read Changing Sun, Changing Climate? you can see why it's only a very few scientists expecting it to be the sole culprit.

Our current warming is not anomalous...there are many instances when the earth has warmed/cooled at this rate (and even faster).  No need to read the book...solar-terrestrial climate coupling is my area of research (along with drought occurrence and severity).  I dont know of a climate scientist that believes that the sun is solely responsible for the current warming, but the magnitude of the sun's influence is not insignificant.  Ill post recent research on this as well if you like.  Give me a day or so.

17
The Environment / Is there a relation between changes in the earth's magnetic field and climate?
« on: 11/05/2011 03:40:27 »
Quote from: CliffordK on 08/05/2011 23:50:18
I made this chart a while ago.
Ice Core temperatures (bottom) compared to inverted or negative magnetic field strength (top) (from Wikipedia).

This is a really interesting relationship.  The geomagnetic field has been in an overall decline for about the past 200 years, which is coincidentally about the same time that the solar dynamo has been intensifying.  Im not stating this because I believe that solar variability is responsible for glacials, but there is a hypothesis that the geomagnetic field may be at least partially induced by the solar dynamo.  Recently there has been observational evidence of direct interaction through magnetic conduits between the two. 

If I remember correctly, the magnitude of the solar dynamo has an inverse cubed relationship with distance from the sun.  As a first order hypothesis, it is possible that as milankovich cycles increase/decrease the earths average distance from the sun, the geomagnetic field strengthens/weakens.  It could also be entirely coincidental.  It would be good to know a little more about the data sets used to create these plots...resolution, dating methods, error, etc.  Longer records would be great as well, but unfortunately, this is about as far back as decently resolved paleoclimate records can conceivably go.

18
Geology, Palaeontology & Archaeology / extracting zinc ions from the soils
« on: 05/05/2011 14:18:13 »
I know you can extract the ions and recover them through zinc chelation, but Im not sure of the procedure.

Look up 'zinc chelation' and see what comes up.

19
Geology, Palaeontology & Archaeology / Help! Can anyone help identify these pictures please?
« on: 27/04/2011 15:28:29 »
Dont make me dig through your posts JimBo! 

20
Geology, Palaeontology & Archaeology / Are Ica Stones believed to be fakes?
« on: 20/04/2011 23:16:20 »
Yeah, they are.  The only dinosaurs that have survived the past 65 million years are birds, but there were some pretty ferocious birds up until a few thousand years ago.  Unfortunately, they looked nothing like the Cretaceous dinosaurs on the Ica Stones.  If South American indians had actually seen dinosaurs of this kind, they would know that they do not stand upright (like the Tyrannosaur) or drag their tails on the ground.  They would also not depict dinosaurs that only lived in North America.  Instead of a Trex, it would have a Giganotosaurus.

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