Can human emissions of Carbon Dioxide be blamed for the retreat of Arctic Ice?
The retreat of Arctic Ice has been one of the signature claims from the The IPCC and its supporters, and was a major feature of that heavily flawed documentary from Al Gore, as being attributable to human carbon dioxide emissions. Yet there is ample evidence that in fact the ice retreats and advances fairly regularly.
Evidence readily available, principally from Russian sources, shows that the Arctic had as little ice in the period 1920-1940 as it has today. It is interesting to consider the following information. I am convinced that a lot of the evidence adduced by IPCC supporters of the effects of human emitted greenhouse gases are in fact cyclical. And hence due to natural causes
|This is the abstract of a paper presented in Report on Study of the Arctic Change Workshop held November 10-12, 1997 University of Washington Seattle, Washington This report is available in full on the Internet at http://psc.apl.washington.edu/publication/Arctic_Change/arctic.pdf.|
“Arctic Warming” During 1920-40: A Brief Review of Old Russian Publications
Sergey V. Pisarev and P.P. Shirshov Institute of Oceanology Russian Academy of Science Moscow, Russia
The idea of Arctic Warming during 1920–40 is supported in Russian publications by the following facts:
- retreating of glaciers
- melting of sea islands
- retreat of permafrost
- decrease of sea ice amounts
- acceleration of ice drift
- change of cyclone paths
- increase of air temperature
- biological indications of Arctic warming
- ease of navigation
- increase in temperature and heat content of Atlantic Waters, entering Arctic Basin.
2. The reasons of Arctic Warming (according to old Russian publications)
3. Cooling in 1950–1960.
Retreating of glaciers, melting of islands, and retreat of permafrost
During the Persey cruise in 1934 Zubov noticed that the glaciers of Jan-Mayen and Spitsbergen were considerably reduced, relative to their sizes adduced in British sailing directions of 1911. Retreat of glaciers was observed also at Spitsbergen, Franz-Joseph Land, and Novaya Zemlya. The ice bridges between some of Franz-Joseph islands melted. Alman explored the glaciers of Spitsbergen in 1934 and came to the conclusion that they were melting. The observations of 1935–1938 showed that Iceland glaciers were melting too. According to Sumgin, the south boundary of permafrost shifted to the north by 40 km during 1905–1933.The disappearance of Vasilievsky Island in the Laptev Sea and washing away of the Lyakhovsky islands were phenomena of the same type.
The decrease of sea ice amounts in 1920–1940
The area of ice in the Greenland Sea in April–August of 1921–1939 was 15–20% less than in 1898–1920 (data of Karelin). In the Barents Sea. the area of ice was 12% less in 1920–1933 than in 1898–1920 (data of Zubov).Vise pointed out that since 1929 the south part of the Kara Sea in September was free of ice, while in 1869– 1928 the possibility of meeting ice there in September was about 30%.
The polar ice very often came close to the coast of Iceland in the last century and in the beginning of this century. During 1915–1940 the situation changed: no ice was observed in that region; negligible amounts of polar ice were noticed there only in 1929.
The thickness of ice determined during the Fram cruise was 655 cm; during the Sedov cruise it decreased to 220 cm (the reason for this was more intensive summer melting of ice).
Before Arctic warming, the strait of Jugorsky Shar froze near the 24th of November, but in 1920–1937 it became frozen two months later—in January.
The acceleration of ice drift
In spite of the fact that the amount of Arctic ice transported to the Greenland sea increased (established by Soviet expeditions in 1920–1940), the amounts of ice in that sea decreased because of the influence of factors promoting destruction and melting of ice: an increase in the velocity and temperature of the Norway and Spitsbergen currents; an increase in the velocity of winds, connected with common intensification of atmospheric and hydrospheric circulation. The velocity of the drift of North Pole station in 1937 was 2.4 times greater than the velocity of Fram’s drift.
The increase of air temperature
According to Vise, in Varde (northeast of Norway) since 1918 the average annual air temperatures were higher than the average air temperature of the previous century (the exception was 1926, when the average temperature was lower by 0.2°C). Beginning with 1930, not one negative anomaly of average yearly or monthly temperature was observed in the whole Arctic sector from Greenland to Cape Tcheluskin, and during the same time the positive anomalies reached significant values: 1934/35 ± (4–10)°C, November in Spitsbergen ± 10°C.
Vise noticed, that the average annual temperatures observed during the Fram cruise (for the period of November 1893–August 1895) were lower by 4.1°C than those observed during the Sedov cruise (for the period of November 1937–August 1939), although the Fram and Sedov locations more or less coincided (Fram, 81°59’/113°26′; Sedov, 82°43’/121°30).
At the station Tikhaya (Franz-Joseph Land), temperatures below – 40°C were never observed after 1929. But 10 expeditions in the archipelago before 1929 observed such temperatures every winter, except 1896.
According to Vise, near Dicson and Franz-Joseph Land the amplitudes of tides increased by 20–30% as a result of a decreasing amount of ice
Biological indications of Arctic warming
Knipovich, in 1921, was the first who paid attention to the changes of Arctic fauna. Marketable species of fish spread to the north after the beginning of the 20th century and fisheries in the north became more intensive. Some benthos species spread to the north.
The ornitofauna of the Arctic region changed: some species of birds (White Gulls) left their places of habitation, and some southern species were noticed in the far north (swans in Iceland).
Uspensky stated that 40–50 species of birds moved to the North during 1890–1930.
Ease of navigation
The sailing conditions in the Arctic region became much more favorable in 1920–1940. This can be proved by the following cruises:
- Knipovich, 1932 (round Franz-Joseph Land)
- Sibiryak, 1932 (round Severnaya Zemlya)
- sailing of non-icebreaking ships along North Sea Route in the 1930s no ice met
- possibility for non-icebreaking ships to double Novaya Zemlya every year since 1930.
The severe conditions of navigation in previous years can be proved by the following cruises:
- In 1912, the ship Foka, a member of the Sedov expedition, could not reach Franz-Joseph Land.
- In 1912, the ship St. Anna, a member of the Brusilov expedition, was trapped in ice near Yamal and carried out with the ice to the central Arctic.
- In 1901, the icebreaker Ermak failed to double Novaya Zemlya.
Increase of temperature and heat content of Atlantic Waters entering the Arctic Basin
- The waters of Nordcape Current (Zubov) became warmer by approximately 0.7°C in 1940–45 compared to the beginning of this century.
- In the regions adjacent to Spitsbergen and Franz-Joseph Land, the lower boundary of the cold intermediate layer rose from 150–200 m in the beginning of the century to 75–100 m in 1940–45.
- Not one station made during the Fram cruise showed Atlantic Waters exceeding a temperature of 1.13°C, but in 1935 (Sadko cruise) Zubov observed Atlantic Water temperatures reaching 2.68°C, and in 1938 (Sedov cruise) even in the places situated to the north and east of Fram’s drift (it must be colder there) the temperatures reached 1.8°C.
- According to Shokalsky, “the temperature of surface waters of the Gulfstream steadily rises from the beginning of our century.” The increase of surface waters’ temperature can also be seen (Shokalsky) in the other regions of the ocean subjected to the influence of the Gulfstream and the Atlantic Current.
The variation in the extent of Arctic ice is thus clearly cyclic. It appears to be governed by a number of interacting natural cycles. One of these involves the Multidecadal North Atlantic Oscillation (AMO), the other the Pacific Decadal Oscillation (PDO).
|It appears certain that the main factors controlling the advance and retreat of Arctic Ice and two critical ocean currents: the Atlantic Multidecadal Oscillation and the Pacific Decadal Oscillation.
The AMO is an ongoing series of long-duration changes in the sea surface temperature of the North Atlantic Ocean, with cool and warm phases that may last for 20-40 years at a time and a difference of about 1°F between extremes. These changes are natural and have been occurring for at least the last 1,000 years.
During the positive phase relatively more warm water is carried north from the tropics, and the ice retreats. During the negative phase, less warm water is carried north and the ice advances.
The website of the US National Oceanic and Atmospheric Adminsitration (Available at http://www.aoml.noaa.gov/phod/amo_faq.php#faq_10 )
has the following section:
Is the AMO a natural phenomenon, or is it related to global warming?
Instruments have observed AMO cycles only for the last 150 years, not long enough to conclusively answer this question. However, studies of paleoclimate proxies, such as tree rings and ice cores, have shown that oscillations similar to those observed instrumentally have been occurring for at least the last millennium. This is clearly longer than modern man has been affecting climate, so the AMO is probably a natural climate oscillation. In the 20th century, the climate swings of the AMO have alternately camouflaged and exaggerated the effects of global warming, and made attribution of global warming more difficult to ascertain.
On the Pacific Decadal Oscillation, Thayer Watkins of San Jose University in the United States (Available at http://www.applet-magic.com/AGT_PDO.htm ) makes the following statement:
The record of average global temperatures from 1880 to 2008, as given below by the National Oceanic and Atmospheric Administration (NOAA) in terms of temperature anomalies (deviations from the long term average), shows a pattern of a cycle combined with a long term upward trend.
The profile of the cycle and the slope of the long term trend can be estimated by means of regression analysis. The details of the estimation procedures are given elsewhere.
The coefficient of determination (R²) for this regression is 88 percent. This means that 88 percent of the variation in average global temperature is explained by a long term trend of 0.5°C per century and a cycle which consists of an approximately thirty-year upswings and downswings.
The regression analysis provides the basis for forecasts and backcasts which given in Cycles and Trends in Average Global Temperature and Their Projection and confidence limits for those forecasts and backcasts are given in Confidence Limits. The forecasts and backcasts are based upon the duration of the upswings and downswings being thirty two years and thus the cycle period being sixty four years. The cycle has persisted for the 155 years for which the global temperature data is available.
The long term trend of 0.5°C per century quite likely is due to human activities, but from a variety of them rather than solely the production of carbon dioxide. The clearing of land for agriculture and city building goes back into the 19th century and is probably the major source. The increase in water vapor in atmosphere in arid and semi-arid areas due to irrigation, landscape watering, hydro projects and the burning of hydrocarbon fuels fuels is another. The increase in water in the atmosphere leads to a greater greenhouse effect and also the effect of more clouds on the climate. The other result of burning hydrocarbon fuels and of burning carbon (coal) is the increase in the carbon dioxide content of the air and its effect on the greenhouse effect. The long term trend is discernable but not catastrophic. The catastrophic predictions derive from an unjustified extrapolation of the short term cycle.
The immediate question is what natural phenomenon can account for the approximately thirty-year cycle of upswings and downswings. One plausible candidate for this cycle is the Pacific (Multi)Decadal Oscillation (PDO). The Pacific Decadal Oscillation is a climate index based upon patterns of variation in sea surface temperature of the North Pacific. It is available from the Northwest Fisheries Science Center, a division of the NOAA Fisheries Service. It has been tabulated for the period 1900 to 2009 and is maintained by Dr. Nathan Mantua. It is the principal component of sea surface temperatures in the northern Pacific Ocean. According to ther Northwest Fisheries Science Center,
The term Pacific Decadal Oscillation was coined by Fisheries scientist Steven Hare in 1996 as a result of his work on the connections between Alaska salmon production cycles and Pacific climate. The Pacific (Multi)Decadal Oscillation is sort of the big brother of El Niño, the Southern (Pacific) Oscillation (ENSO). The ENSO occurs sporadically with a time interval between episodes of something on the order of ten years. When an El Niño occurs there is often a spike in the average global temperature and weather is affected around the world. The perturbations due to ENSO events typically last only six to eighteen months. The oscillation is between warming phases (El Niño) and cooling phases (La Niña). The perturbations due to ENSO events typically last only six to eighteen months.
The PDO involves a much bigger area of the ocean than the ENSO and the switch between warming and cooling phases takes a correspondingly longer time. Also because of the larger oceanic area involved the effect of the cycle of the PDO is also correspondingly larger spatially.
Here is the graph of the annual average for the PDO. The quantity plotted is a simple annual average of the monthly data on the PDO as tabulated by the Northwest Fisheries Science Center.
There is a good deal more noise for this data than for the average global temperature (AGT) data but the PDO index has a declining phase from 1900 to about 1919, as does the AGT. Then there is an upswing that lasts until the late 1930’s, as does the AGT. From there there is a downswing lasting until about 1970, as there is for the AGT. From cerca 1970, for both the PDO index and the AGT there is an upswing. For the AGT the upswing lasts until about 2005 whereas for the PDO the downswing begins before 1990.
When a bent-line regression is fitted to the PDO index the result is as shown below. In the analysis the turning points were varied and selected to maximize the coefficient of determination.
The coefficient of determination (R²) for this equation is 0.325. This indicates that there is a good deal of the variation in the PDO index that is not explainable by a pattern over time.
As can be seen the slopes of the upswings are nearly equal and the slopes of the downswings are nearly equal. A regression line was fitted to the data in which the slopes of all the upswings are the same and all the slopes of the downswings are the same. As can be seen below the result looks nearly the same as the unconstrained regression shown above.
The coefficient of determination (R²) for this equation is 0.316, nearly the same as that for the unconstrained regression.
The big question is how closely can the cyclic profile of average global temperature (AGT) be related to that of the PDO index. The two profiles are shown together below.
Or, to more easily view the correspondences and non-correspondences:
There appears to a lag between the turning points of the PDO index and those of the AGT. This is as would be expected. However the magnitude of the lag varies which considerably weakens the use of the PDO as a predictor of the AGT. Although the correspondence is intriguing it is impossible to make it precise. The periods of the upswings and downswings for the PDO index is variable and is roughly 26 or 27 years. The corresponding period for the AGT is about 32 years. It is to be noted that a spectral analysis of average global temperatures comes up with a cycle period of about 52 years, corresponding to trends of 26 years in either direction.
Thus while the Pacific (Multi)Decadal Oscillation appears to be involved in the cycles of the average global temperature there has to be other factors also involved. The strong possibility is that the other oceanic oscillations such as the Atlantic Multidecadal Oscillation are involved as well as the Pacific one. It is already accepted that the ENSO accounts for significant perturbations in the AGT record.
The results of the above indicates that there is anthropogenic global warming but of a non-catastrophic 0.5° per century and probably only partially due to due to increased carbon dioxide in the atmosphere. The more perceptible changes in average global temperature are undoubtedly due to oceanic oscillations, one major one being the Pacific (Multi)Decadal Oscillation. More work needs to be done on the PDO index to remove the apparent noise in the data. More work also needs to be done on the matter of cycle lengths and time lags. And finally the other oceanic oscillations have to be examined as supplements to the effect of the PDO.
Over all the result is so reasonable and should have been obvious from the beginning. Average global temperature is driven by oceanic cycles and a secular trend of non-catastrophic proportions probably due to human activities. Once the tunnel vision focus on carbon dioxide is given up the truth emerges easily.
Data has recently emerged about the North Atlantic Multidecadal Oscillation, in a paper published on Icecap (http://www.icecap.us/).
AMO, THE KEY GLOBAL CLIMATE INDICATOR
The AMO is an ongoing series of long-duration changes in the sea surface temperature of the North Atlantic Ocean, with cool and warm phases that may last for 20-40 years at a time and a difference of about 1°F between extremes. These changes are natural and have been occurring for at least the last 1,000 years. [per NOAA].
The AMO index is calculated at NOAAPSD by using the Kaplan SST data set [5×5], determining the area weighted average over the North Atlantic over 0-70N and then detrending this data.
The average AMO index or the Atlantic Multidecadal Oscillation index went negative or cool in January 2009 The average for the first 5 months this year is about [-0.06] . It has been cooling since 2003. In the past, the very cold seasons of North America and especially the East coast happened when the annual average AMO went cool [ as low as -0 .405] in the 1970’s. It seems that this level of cool AMO may be several years off as the AMO cooling rate appears to be still slow. Back in 1964 it took about 8 years before the AMO went to [- 0.3] by 1971.Review of other periods for similar rates of decline of the AMO show a spread of about 2-8 years. However the solar activity was much higher during 1964-1972 and things may cool down faster currently with extended solar minimum and anticipated low future solar cycles. If AMO does drop faster, then the cold weather like 1964-1979 may be the norm here much sooner and the East Coast will cool down as well as will the globe. The most sustained number of low AMO levels was during the cold spell of 1902 -1925 and again the 1970’s.
The graph below shows how closely Annual Global Air Temperature Anomalies [Crutem3] follow the Atlantic Multidecadal Oscillation Index [AMO].
GRAPH OF ANNUAL AMO INDEX VS GLOBAL ANNUAL AIR TEMPERATURE ANOMALY[CRUTEM3] 1964-2008-0.5-0.4-0.3-0.2-0.100.10.20.30.40.54567891970123456789198012345678919901234567892000123456789YEARSANNUAL AMO INDEX-0.4-0.3-0.2-0.100.10.20.184.108.40.206GLOBAL ANNUAL AIR TEMP ANOAMLY[C]ANNUAL AMO INDEXGLOBAL AIR TEMP ANOAMLY[CRUTEM3]
Extreme AMO levels both cool and warm have clearly affected each of the following warm and cool global periods to account for the extreme global temperature anomalies
Note that all AMO levels shown are annual average figures.
RECORD AMO LEVELS DURING RECENT EXTREME WARM AND COLD PERIODS
1900-1926 COOL PERIODS [AMO NEGATIVE]
Lowest global temperature anomalies ever especially 1902-1913
1904 -0.345[ 4th lowest ever
1913 -0 .386[ 2ND lowest ever]
1920 -0.330[6th lowest ever
1926-1944 WARM PERIOD [AMO POSITIVE]
[Last global warming period prior to the 1994-2008 warming, the period of the 1930’s drought & dust bowl]
1944 0.360 2nd warmest]
1937 0.304 6th warmest ever]
1964-1976 COOL PERIOD [AMO NEGATIVE]
[Latest cool phase post early 1900’s especially 1964-1976]
1974- 0.405[lowest ever]
1976-0.349 [ 3rd lowest ever]
1972 –0.338[ 5th lowest]
1994 -2008 WARM PERIOD [AMO POSITIVE]
[Latest global warming period]
1998 0.402[highest ever]
2005 0.326[3rd highest]
2006 0.306[ 4th highest
2003 0.266[8th highest]
2004 0.240[10th highest
YEARS WITH THE WARMEST SINGLE MONTH AMO
1998 0.562 WARMEST YEAR EVER
2003 0 .504 YEAR OF EUROPEAN HEAT SPELL
2005 0.503 SECOND WARMEST YEAR
YEARS WITH THE COLDEST SINGLE MONTH AMO
1913 -0.563 10 Th COLDEST YEAR GLOBAL
1974 -0.495 2ND COLDEST YEAR IN LAST 30 YEARS
1904 -0.474 4TH COLDEST YEAR GLOBAL
1976 -0.464 COLDEST YEAR IN LAST 30 YEARS
1972 -0..460 COLDEST YEAR IN CANADA 1948-2008
GLOBAL WARMING EXPLAINED
IPCC said that “Eleven of the last twelve years [1995-2006] rank among the twelve warmest years in the instrumental record of global surface temperature [since 1850]”
However, 13 OF THE WARMEST GLOBAL AIR TEMPERATURES happened during the 14 year period JAN 1995- DEC 2008 when PDO and AMO were essentially both warm or positive * and accounts for the global warming and the temperature records . Five of the 10 highest ANNUAL AMO levels occurred during this recent global warming period
The numbers below show how the 3 highest monthly global temperature records were accompanied by 3 of the 5 highest single AMO index readings ever .Only1878 and 1937 had the higher monthly AMO levels. The single PDO readings were also high [around 2.0] during these peak periods.
1998 Highest Temperature anomaly [0.546C] AMO [0.562 3rd highest]
2005 Second Highest Temperature anomaly [0 .482C] AMO [0.503 5TH highest]
2003 Third Highest Temperature anomaly [0.473C] AMO [0.504 4th
As one can see there was a similar warming period in 1926-1944.
So global warming existed well before manmade green house gases started to rise after the 1940’s
OUTLOOK FOR THE FUTURE
Unlike the PDO, numerical models have been unable to predict AMO cycles with any accuracy. There are only about 130-150 years of data based on instrument data which are too few samples for conventional statistical approaches. With aid of multi –century proxy reconstruction, a longer period of 424 years was used by Enfield and Cid –Serrano to develop an approach as described in their paper called, The Probabilistic Projection of Climate Risk. [See reference below.] Their histogram of zero crossing intervals from a set of five re-sampled and smoothed version of Gray et al(2004) index together with the maximum-likelihood [MLE] gamma distribution fit to the histogram, showed that the largest frequency of regime interval was around 10 –20 year. The cumulative probability for all intervals 20 years or less was about 70 % .
The last interval change was 1994 or about 15 years ago and according to their work, the probability that AMO will switch to cool in 15 years is about 80 % .
Based on this analysis , there is a high probability that the current cooling phase of AMO which started in 2009 is real and likely sustainable for the next 20 years at least.
The graph below shows the decline of the AMO index from warm to cool between 2005 and 2009
PLOT OF UNSMOOTHED MONTHLY AMO PER KAPLAN SST V2[NOAA/ESRL/PSD1] YEARS 2005-2009-0.2-0.100.10.20.220.127.116.110052006200720082009MONTHS AND YEARSMONTHLY UNSMOOTHED AMOMONTHLY UNSMOOTHED AMOLinear (MONTHLY UNSMOOTHED AMO)Linear (MONTHLY UNSMOOTHED AMO)Linear (MONTHLY UNSMOOTHED AMO)Linear (MONTHLY UNSMOOTHED AMO)
The main climate indicator in my opinion in the near term] is likely going to be the cool AMO, cool PDO. ENSO events and the changing polar jet stream which swings more often now north before coming south or heading east, bringing cold air to most of North America, and specially the western half and subsequently east, as the our climate moves from west to east.
The graph below shows the relationship between AMO and GLOBAL [ land and marine] TEMPERATURE ANOAMLIES [Hadcrut 3]. AMO appears to be like a thermostat or predictor of global temperatures. ENSO events if moderate or strong seem to modify, amplify or over-ride the AMO effects.
GRAPH OF MONTHLY AMO INDEX VS MONTHLY HADCRUT3 GLOBAL LAND AND MARINE TEMPERATURE ANOMALY 2005 -200900.10.20.30.18.104.22.1680052006200720082009MONTHSAMO INDEX -0.2-0.100.10.20.22.214.171.124HADCRUT 3 GLOBAL MONTHLY TEMPERATURE ANOMALY[C]hadcrut3 global monthly land +marineamo monthly indexLinear (amo monthly index)Linear (hadcrut3 global monthly land +marine)EL NINO>>>>>-ELNINOLA NINA SEPT-MAYxxxxxxxxxxxxxxxxxxxxxJAN-FEBAUG-JAN
This pattern will continue to bring cool yearly temperatures and colder and snowy winters like 2008 and 2009. My best guess is that the climate of the 1960’and 1970’s will be our climate for the next several decades [2-3] at least, and inter-dispersed with periodic warm years. PDO and AMO readings are of limited value for short term use but quite useful and accurate for decadal forecasts .Currently 2009 looks something like 1971 [cool PDO, low cool/ near neutral AMO] and the rest of this decade looks like the 1970’s if you had pick one decade from the past . The 1960’s and the 1950 are also close behind .I also see that during the next few years, the AMO may go down to – 0.4 to -0.5 and PDO’s down to -2 to -2.5. La Nina’s may return and more often than El Nino’s [like in 1970-1976]. If this happens, then the polar jet stream often splits into two parts with the lower branch bringing more rain, snow and cooler weather to the US North west and the upper or north branch which still goes north to Alaska and Yukon and then south, bringing cold air to the western half Canada and the US.
POSSIBILTY OF AN EL NINO 2009-2010
There has been an El Nino within about 12 months after each of the last four solar minimums. The same pattern seems to be developing again now.
If an El Nino does develop later this year or early 2010, it may be a moderate or weak and short lived [about a year].It may have a minor effect on global temperatures , like in the period 1965-1966 when US temperatures continued to drop despite the El Nino.
This latest period of cooler weather is not the start of some modern ice age or new grand cold minimum but just another cool cycle of the planet that happens about after every 20-30 years more recently when AMO and PDO are both in the cool mode simultaneously. The coldest last such cycle 1902-1925 when AMO hit a single month low of -0.563 and PDO went down to -1.72 and global air temperature anomalies plummeted to -0.581 C [crutem3] in 1911. Other such cool periods occurred 1964-1976 and also much earlier during the Dalton and Maunder Minimums.
BACKGROUNDER ON AMO
FREQUENTLY ASKED QUESTIONS ABOUT THE ATLANTIC MULTIDECADAL OSCILLATION [AMO] PARTIALLY REPRODUCED HERE PER NOAA WEBPAGE
The AMO is an ongoing series of long-duration changes in the sea surface temperature of the North Atlantic Ocean, with cool and warm phases that may last for 20-40 years at a time and a difference of about 1°F between extremes. These changes are natural and have been occurring for at least the last 1,000 years.
How much of the Atlantic are we talking about?
Most of the Atlantic between the equator and Greenland changes in unison. Some area of the North Pacific also seem to be affected.
What phase are we in right now?
Since the mid-1990s we have been in a warm phase.
What are the impacts of the AMO?
The AMO has affected air temperatures and rainfall over much of the Northern Hemisphere, in particular, North America and Europe. It is associated with changes in the frequency of North American droughts and is reflected in the frequency of severe Atlantic hurricanes. It alternately obscures and exaggerates the global increase in temperatures due to human-induced global warming.
How does the AMO affect rainfall and droughts?
Recent research suggests that the AMO is related to the past occurrence of major droughts in the Midwest and the Southwest. When the AMO is in its warm phase, these droughts tend to be more frequent and/or severe (prolonged?). Vice-versa for negative AMO. Two of the most severe droughts of the 20th century occurred during the positive AMO between 1925 and 1965: The Dustbowl of the 1930s and the 1950s drought. Florida and the Pacific Northwest tend to be the opposite – warm AMO, more rainfall.
How does the AMO affect Florida?
The AMO has a strong effect on Florida rainfall. Rainfall in central and south Florida becomes more plentiful when the Atlantic is in its warm phase and droughts and wildfires are more frequent in the cool phase. As a result of these variations, the inflow to Lake Okeechobee – which regulates South Florida water – changes by 40% between AMO extremes. In northern Florida the relationship begins to reverse – less rainfall when the Atlantic is warm. http://www.aoml.noaa.gov/phod/amo_faq.php
AMO EFFECT ON THE 2003 EUROPEAN HEAT WAVE and NORTH AMERICAN CLIMATE
Quotes from paper called Atlantic Ocean Forcing of North American and European Summer Climate by
Rowan T. Sutton* and Daniel L. R. Hodson
..for the particular decadal change considered (1931 to 1960 compared with 1961 to 1990), the Atlantic Ocean was the dominant oceanic influence on summertime climate in the regions
Overall, our results provide strong evidence that during the 20th century the AMO had an important role in modulating boreal summer climate on multi-decadal time scales. We have focused here on time mean anomalies, but some of the most important impacts are likely to be associated with changes in the frequency of extreme events. There is evidence that the frequency of U.S. droughts and the frequency of European heat waves) are both sensitive to Atlantic SSTs.
Our results suggest, for example, that the change in phase of the AMO in the 1960s may have caused a cooling of U.S. and European summer climate; a further change in the AMO[ AMO went warm in 1994] may have contributed to recent warming in these regions.
EL NINO EFFECTS IN CANADA
During the winter of an El Nino event, the air temperature tends to be warm over most of Canada, with the greatest warming centered on Manitoba-western Ontario, where a temperature anomaly of up to +3 degrees Celsius (averaged over the last nine El Nino events) can be found (Hoerling et al., 1997; Shabbar and Khandekar, 1996). Southern Canada also tends to be drier during an El Nino winter (Shabbar et al., 1997). Southern British Columbia tends to receive less snow (Hsieh and Tang, 1999).
THE PROBABALISTIC PROJECTION OF CLIMATE RISK
By David B. Enfield and Luis Cid-Serrano
Quote fro opening paragraph
The last 15 years have seen much research on decadal to multidecadal (D2M)
climate modes and their global and regional impacts. At least some of these D2M
modes suggest compelling climatic and ecological impacts. Both the Pacific
Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO) are
associated with alternating trans-decadal regimes in precipitation and drought
frequency, which appear to be sensitive to small but persistent changes in the
prevalent atmospheric circulation patterns over the continental regions adjacent
to the oceans that mediate the oscillations. They have also been shown to
modulate (render nonstationary) the rainfall signatures of El Niño-Southern
Oscillation (ENSO) in the United States and they are reflected in the
multidecadal changes in North Pacific fisheries. Of concern for climate
applications is the fact that — unlike El Niño-Southern Oscillation (ENSO) —
numerical models have proven incapable of predicting future phase shifts of
D2M climate modes in a deterministic manner.
The alternatives to such predictions are probability-based projections, but these are
hampered because the instrumentally based time series are limited to the last 130-150
Fig. 2: histogram (vertical bars) of zero crossing intervals from a set of five
resampled and smoothed versions of the Gray et al. (2004) index and the maximum
likelihood (MLE) gamma probability distribution (solid curve) fit to the histogram.
You can either go back my no.1 document to access all or any post:
1. Evidence that the IPCC’s case is a fraud.
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12.Significant correlations argue against ther IPCC’s model.