Sentences with phrase «used as proxies for temperature»

Further, since no - one appears to be able to show convincingly exactly why and how this divergence occurs, this taints the entire record — at least in terms of it's use as a proxy for temperature.

Historical records of glacier length can be used as a proxy for temperature.

The divergence problem itself is explained here [blogspot.com]- in short, tree - ring data used is used as a proxy for temperature but data for North America «diverges» from other readings around the middle of the 20th century.

Wish he would explain the basis for using them as proxies for temperature.

Although it is the longest instrumented series, CET is not very useful for scientific work and can not be used as a proxy for temperature variations world - wide.

The tree ring data was used as a proxy for temperature.

Not exact matches

Update: as suggested by the academy in its 2006 report, Michael Mann and his colleagues have reconstructed northern hemisphere temperatures for the past 2000 years using a broader set of proxies than was available for the original study and updated measurements from the recent past.

That article discussed Eddy's use of the tree - ring 14C record as an inversely correlated proxy indicator for sunspot activity, but does not appear to be relevant to a discussion of tree - rings as a temperature proxy.

Van Oldenborgh used both modern and early temperature records, as well as sources like tree rings, which can act as a proxy for very old temperatures, to observe Europe's temperature records back to 1500 and determined that 2014 will almost certainly be the warmest year Europe has experienced during the past 500 years.

Species with larvae that are likely to be particularly exposed to sea surface warming (i.e., obligatory broadcast spawners and / or brooders) were regarded as having lower tolerance to warming, and we used evidence of past mass high temperature mortality as a proxy for measuring adult colonies» tolerances.

It uses Ammonium concentration from an ice core in tropical South America (the eastern Bolivian Andes) as a proxy for temperature.

Isotopic composition can therefore be used as a proxy for historical air temperatures before the period for which we have instrumental measurements.

For example, due to the lack of ocean data, secondary data is often used to infer what the ocean is doing — thus, the AMO analysis relies not on ocean temperature measurements, but rather on air pressure measurements as a proxy for ocean behavior — iffy at beFor example, due to the lack of ocean data, secondary data is often used to infer what the ocean is doing — thus, the AMO analysis relies not on ocean temperature measurements, but rather on air pressure measurements as a proxy for ocean behavior — iffy at befor ocean behavior — iffy at best.

This would completely invalidate the use of tree ring data as proxies for past temperature reconstruction.

The same holds for the specific global mean EIV temperature reconstruction used in the present study as shown in the graph below (interestingly, eliminating the proxies in question actually makes the reconstruction overall slightly cooler prior to AD 1000, which — as noted in the article — would actually bring the semi-empirical sea level estimate into closer agreement with the sea level reconstruction prior to AD 1000).

The SSTs temperatures are used here, with success over certain regions of the globe, as a proxy and cross-check for cloud variability.»

The graph uses American network evening news coverage as a proxy for broader news interest, so it's a sketch, akin to using borehole temperature or tree rings as substitutes for thermometers:

The unforced temperature estimate is used as a proxy for what cumulative emissions should be given the current level of warming.

The authors conclude that minimum temperatures should no longer be used as a proxy for global atmospheric warming.

I think that using tree - rings as a proxy for temperature could be considered incorrect science.

For mush less academic reasons, I agree that tree rings are not good proxies for temperature, since tree rings are also used as proxies for precipitatiFor mush less academic reasons, I agree that tree rings are not good proxies for temperature, since tree rings are also used as proxies for precipitatifor temperature, since tree rings are also used as proxies for precipitatifor precipitation.

By Steve McIntyre who hasn't come up with an explanation for why his supposedly diabolical Bristlecone proxies don't have any significant effect on Temperature reconstructions using the 1450 proxy network as shown by Wahl and Ammann in their figure 5c.

The «hockey stick» describes a reconstruction of past temperature over the past 1000 to 2000 years using tree - rings, ice cores, coral and other records that act as proxies for temperature (Mann 1999).

Using SW US drought as a proxy for global temperature, we therefore must conclude that it is already warmer than at any time during the MWP.

Lofgren, B. M., T. S. Hunter, and J. Wilbarger, 2011: Effects of using air temperature as a proxy for potential evapotranspiration in climate change scenarios of Great Lakes basin hydrology.

So, the thickness of the tree rings in each year could be used as a proxy for local summer temperatures.

His position: • No evidence of increasing lake clarity as a result of secchi measurements since 1946 • The interplay of stratification and plankton productivity are not «straightforward» • Challenges O'Reilly's assumption on the correlation of wind and productivity - the highest production is on the end of the lake with the lowest winds • A strong caution using diatoms as the productivity proxy (it is one of two different lake modes) • No ability to link climate change to productivity changes • More productivity from river than allowed for in Nature Geopscience article • Externally derived nutrients control productivity for a quarter of the year • Strong indications of overfishing • No evidence of a climate and fishery production link • The current productivity of the lake is within the expected range • Doesn't challenge recent temp increase but cites temperature records do not show a temperature rise in the last century • Phytoplankton chlorophylla seems to have not materially changed from the 1970s to 1990s • Disputes O'Reilly's and Verbug's claims of increased warming and decreased productivity • Rejects Verburgs contention that changes in phytoplankton biomass (biovolume), in dissolved silica and in transparency support the idea of declining productivity.

But for years prior to that, scientists can only infer temperatures using what's called «proxies,» such as ice cores or tree rings, whose annual growth can be correlated with annual temperature variations.

They looked at global temperature anomalies — deviations from an average or standard temperature — for 73 sites distributed across the planet, using fossils in sediments as a proxy for temperature.

It all seems to depend on whether you want to assume that proxies which show a signal that shows a trend in the 20th century actually also show a good correlation with local temperature at any other time, paired with the assumption that the measured global temperature is indeed accurate enough to be used as a training - set for the procedure

I like using CO2 as a proxy for the temperature a few months earlier.

Moreover, as I have believed all along, there is just not enough of a scientific basis for even attempting to use tree rings for temperature proxies.

As others have noted, the IPCC Team has gone absolutely feral about Salby's research and the most recent paper by Dr Roy Spencer, at the University of Alabama (On the Misdiagnosis of Surface Temperature Feedbacks from Variations in Earth's Radiant Energy Balance), for one simple reason: both are based on empirical, undoctored satellite observations, which, depending on the measure required, now extend into the past by up to 32 years, i.e. long enough to begin evaluating real climate trends; whereas much of the Team's science in AR4 (2007) is based on primitive climate models generated from primitive and potentially unreliable land measurements and proxies, which have been «filtered» to achieve certain artificial realities (There are other more scathing descriptions of this process I won't use).

And to the extent that sea level might be used as a proxy for global temperature, it would show the same for the latter.

The difference over time of temperature measured at a consistent location has much lower systematic error than the use of that single location's temperature as a proxy for the overall temperature of the region.

As I pointed out, lgl's use of the same method I developed for using TSI or SSN as a proxy for ocean heat content also fits Steinhilber's TSI reconstruction quite well to the Mann08 temperature reconstructioAs I pointed out, lgl's use of the same method I developed for using TSI or SSN as a proxy for ocean heat content also fits Steinhilber's TSI reconstruction quite well to the Mann08 temperature reconstructioas a proxy for ocean heat content also fits Steinhilber's TSI reconstruction quite well to the Mann08 temperature reconstruction.

Mr McIntyre: Im sorry that this commenter's language was too intemperate... However, the use of tree rings as a proxy for temperature, when one can not control for the myriad of other factors that influence tree growth, brings into question the entire enterprise, no?

Now if he can show good evidence for using the min temperature differences for windy and calm conditions as a proxy for the UHI effect and how he selected his weather stations, he might sway some skeptical minds.

Judith Curry is using ENSO data as a proxy for PDO, and arguing that PDO is potentially a signficiant forcing for global temperatures.

The «sceptical» blogosphere had in fact been excercised for much longer by temperature records - the much - discussed hockey stick controversy, allegations that data and methods were being kept secret, the use of temperature proxies such as tree - rings, and so on.

A number of criticisms may arise from this inference, such as the realism of the LGM CMIP simulations, uncertainty in the temperatures inferred from proxies, and the use of paleoclimates as a surrogate for global warming (differences in temperature patterns, albedo feedback etc.).

The problem is compounded by the fact that sea surface temperatures are used as a proxy for marine air temperatures due to problems in the measurement of marine air temperatures.

If only treeline trees can react to temperature, then it becomes of paramount importance to establish that these trees have remained «the treeline trees» for all the 2000 years period they are used as temperature proxies.

Maybe there really isn't any fixed volume to the eartyh atmosphere; My ancient Radio - Physics training says that the ionosphere keeps moving up and down, in response to the sun's action; so I am not used to thinking of the atmosphere as being constant Volume; so how can pressure possibly be a proxy for Temperature; well other than in the Michael Mann approximation of proxy?

However, the temperature anomoly is used as a proxy for this.

Sections 2 and 3 at the same link provide estimates of the timing and extent of the coming cooling based on the natural 60 and 1000 year periodicities in the temperature data and using the 10be and neutron count data as the most useful proxy for solar activity.

We can't measure the evaporation rate or rainfall pattern, but we are allowed to look at the number of tourists who stay in nearby hotels, some of whom state if they have fishermen or windsurfers staying, and so one can use these as proxies for sunlight / rainfall patterns (CO2 partitioning into temperature dependent aquatic bodies).

For earlier times, we adopt Greenland temperature estimated as follows (33): For the period 128,700 B.P. to 340,000 B.P., this temperature was derived from a proxy based on Antarctic ice core methane data using the relation T = − 51.5 + 0.0802 [CH4 (ppb)-RSB- from a linear regression of Greenland temperature estimates on Antarctic methane for the period 150 B.P. to 122,400 B.P.. For the remaining period of 122,400 B.P. to 128,700 B.P., data from a variety of climate archives indicate that Greenland warming lags that of Antarctica, with rapid warming commencing around 128.5 ky B.P. in the northern North Atlantic and reaching full interglacial levels by about 127 ky B.P. (5For earlier times, we adopt Greenland temperature estimated as follows (33): For the period 128,700 B.P. to 340,000 B.P., this temperature was derived from a proxy based on Antarctic ice core methane data using the relation T = − 51.5 + 0.0802 [CH4 (ppb)-RSB- from a linear regression of Greenland temperature estimates on Antarctic methane for the period 150 B.P. to 122,400 B.P.. For the remaining period of 122,400 B.P. to 128,700 B.P., data from a variety of climate archives indicate that Greenland warming lags that of Antarctica, with rapid warming commencing around 128.5 ky B.P. in the northern North Atlantic and reaching full interglacial levels by about 127 ky B.P. (5For the period 128,700 B.P. to 340,000 B.P., this temperature was derived from a proxy based on Antarctic ice core methane data using the relation T = − 51.5 + 0.0802 [CH4 (ppb)-RSB- from a linear regression of Greenland temperature estimates on Antarctic methane for the period 150 B.P. to 122,400 B.P.. For the remaining period of 122,400 B.P. to 128,700 B.P., data from a variety of climate archives indicate that Greenland warming lags that of Antarctica, with rapid warming commencing around 128.5 ky B.P. in the northern North Atlantic and reaching full interglacial levels by about 127 ky B.P. (5for the period 150 B.P. to 122,400 B.P.. For the remaining period of 122,400 B.P. to 128,700 B.P., data from a variety of climate archives indicate that Greenland warming lags that of Antarctica, with rapid warming commencing around 128.5 ky B.P. in the northern North Atlantic and reaching full interglacial levels by about 127 ky B.P. (5For the remaining period of 122,400 B.P. to 128,700 B.P., data from a variety of climate archives indicate that Greenland warming lags that of Antarctica, with rapid warming commencing around 128.5 ky B.P. in the northern North Atlantic and reaching full interglacial levels by about 127 ky B.P. (51).

Ice core samples are used as proxy indicators for past global climate temperatures and atmospheric CO2 concentrations.

If Mann et al. had simply cobbled together all the proxies available and presented their result as a proposed reconstruction of paleo - temperature, the validity of the reconstruction and the methods used to make it would be the subject of everyday debate, and the generally low opinion of statisticians for the work would perhaps have prompted the field to move to correct the deficiencies.