Meteoclima

Portale di meteorologia e climatologia

Articoli Scientifici (22)

Tempesta di neve in USA che si è scatenata a Marzo inoltrato come in pieno inverno: colpa del GW? La solita BUFALA del millennio

 

In questo mese di marzo e più precisamente in questi giorni di metà mese primaverile dal punto di vista meteorologico, ha visto l’arrivo rapido di una intensa tempesta di neve in USA orientale, con gelo e nevicate abbondanti che hanno superato anche i 30cm.

Naturalmente i mass media hanno come sempre minimizzato l’evento eccezionale per il periodo stagionale, per non affrontare l’argomento cambiamenti climatici naturali e trovarsi in difficoltà con gli utenti  nel  trovare giustificazioni ad un freddo e neve record in conclamata fase di riscaldamento globale.

Come sempre la natura con queste manifestazioni atmosferiche sta mettendo in seria difficoltà tutto l’apparato mediatico e politico dell’AGW e dell’IPCC che indecorosamente, sta continuando a raccontare frottole e falsità sui cambiamenti climatici, dando la colpa alla CO2 e all’inquinamento ambientale.

Posso comprendere che la salvaguardia dell’ambiente sia un bene per tutti e sicuramente essenziale per l’umanità e il Pianeta, causa nobile ma servirsi della scienza raccontando frottole sul clima solo per catastrofizzare e sensibilizzare l’essere umano, risulta un processo sbagliato e controproducente.

 

The forgotten Milankovitch effect – Tides

The obliquity of the earth’s spin axis varies over a 41000y cycle between 24.5 and 22.2 degrees. The canonical work on calculating Milankovitch cycles has been done by J. Laskar and his team at the Observatoire de Paris[1]. Changes in obliquity have been the main driver for glacial cycles for over 2 million years. Larger obliquity increases summer insolation to both poles. Eccentricity and precession just modulate the seasonal balance at each pole. For the last 800,000 years obliquity alone has been insufficient to end glaciations, and the reason for this is still not fully understood.

Total-compare

Top graph: Obliquity and Eccentricity of the earth’s orbit for the last million years ( Laskar2010 ). Bottom graph shows just how small eccentricity affects net annual insolation.

However, increased obliquity has another effect. It changes the amplitude of the lunar orbital precession. The lunar orbit is inclined at 5 degrees to the solar ecliptic and precesses with

Articolo in lingua inglese del collaboratore prestigioso Fisico e climatologo UK Dr.Clive Best pubblicato sul suo blog http://clivebest.com/blog/?p=7278 dove presenta la nostra ricerca climatica mondiale unica nel suo genere, sulla correlazione fra Tides e Jet Stream, con l'importantissima scoperta di anticorrelazione fra picchi gravitazionali e valori della Artic Oscillation, sotto la direttrice del Polar Vortex JS., con un propagamento di effetto del JS sotto i picchi della forza gravitazionale da 1 a 5 gg.  Una grande soddisfazione personale di avere finalmente la ricerca con una pubblicazione scientifica a livello mondiale sulla rivista internazionale peer review IJEGE della UNiversità la Sapienza di Roma(Scienza della Terra). Una ricerca scientifica sul clima e la meteorologia la prima al mondo pubblicata sulla correlazione fra forza gravitazionale (Tides) e componente  a  getto (Jet Stream).

 

Evidence of a tidal effect on the Polar Jet Stream

 

Preamble: Our  paper has finally been published in Italian Journal of Engineering Geology and Environment. It proved to be controversial with ACP, but I am 95% certain that lunar tides affect both weather and medium term climate.

C.H. Best and R. Madrigali

Abstract

Variations in the Polar Jet Stream directly affect weather across Europe and North America (Francis et al., (2012)). Jet Stream dynamics are governed by the development of planetary Rossby waves (Dickinson, (1978)) driven by variation of the Coriolis force with latitude. Here we show that increasing atmospheric tides can induce the development of Rossby waves, especially during winter months. This changes the flow and position of the Jet Stream, as measured by the Arctic Oscillation (AO) (Higgins 2002). Although horizontal tidal forces are tiny (107 smaller than gravity), they act over vast areas dragging the Jet Stream flow southwards in regular pulses as the earth rotates. This induces a changing Coriolis torque, which then distorts the Jet Stream flow. The data from eight recent winters are studied indicating that the AO is anti-correlated to the horizontal “tractional” component of tides acting between latitude 45N and 60N. The observed 28 day cycle in Jet Stream flow and extent has a statistical significance > 99%. A cross-correlation between all daily AO data since 1950 and the tractional tidal strength shows a small but statistically significant anti-correlation with a lag time of ~5 days. The strongest correlation and largest excursions of the AO are observed during winter 2005/6 – a maximum lunar standstill year. This declination dependence of tidal forces at high latitudes is the proposed cause of many previous reports of an 18.6-year dependence of continental rainfall and drought (Currie, 1983/84).

1        Introduction

Varying tidal forces act both on the oceans and atmosphere particularly at high latitudes. A detailed study (Lindzen, 1981) of atmospheric tides finds that gravitational lunar tidal winds are more important at high altitudes. The horizontal or so called “tractional” component of net tides is responsible for tidal currents in the ocean and for tidal winds in the upper atmosphere. During northern winters the Jet Stream strengthens and shifts northwards. Meanders or Rossby waves (Dickinson 1978) develop near the eastern edges of continental landmasses and oceans. Solar insolation falls each winter to zero inside the Arctic Circle and consequently the diurnal solar ‘expansion’ tide disappears over Polar Regions. Gravitational atmospheric tides now dominate near the poles.

There are two ‘spring’ tides each sidereal month, namely that coincident with the new moon and that coincident with the full moon. Seasons modulate the difference between both spring tides depending on latitude. The larger the latitude the larger is the asymmetry during the summer or winter solstice. At the equator both spring tides are always equal, but for the northern hemisphere the new moon tide is largest during winter, whereas that coincident with the full moon is largest during summer. Twice a year at the spring and autumn equinoxes both spring tides are approximately equal at all latitudes. This seasonal change causes a 6 monthly phase shift of ~14 days in the maximum tractional tidal force. Superimposed onto this is an 18.6 year cycle of the lunar precession which modulates the latitude dependence of this amplitude. The tractional tidal force therefore varies in magnitude, latitude and time, and so is not a single frequency harmonic.

Winter storms in the North Atlantic form at the interface where warm Gulf air meets cold Polar air near Newfoundland. This temperature gradient produces baroclinic instability spawning storms that move westward across the Atlantic. The track of these storms follows the Jet Stream and their impact on Europe depends both on their strength and the relative position of the Jet Stream (Francis, 2012). Previous studies (Currie, 1983, Agosta, 2014, Currie, 1934, Clegg, 1984) have shown an 18.6-year cycle in rainfall across large continental zones implying a dependence of storm formation on the lunar precession. Others have speculated about a tidal influence on climate over decadal timescales (Ray 2007). Changes in lunar declination through the 18.6-year cycle mainly affect the strength and sidereal rate of change of tidal forces with latitude.

The cold winter of 2010 resulted from a Jet Stream positioned below the UK drawing cold air down from the North and East. A negative value of the North Atlantic Oscillation (NAO) is related to a negative AO (Thompson, 1998) and corresponds to a low-pressure difference between the Icelandic Low and the Azores High resulting in a weaker Jet Stream with larger meandering loops. This allows cold air to spill down from the Arctic and Siberia into mid latitudes. During the winter of 2013/14 a strong Jet Stream was positioned directly over the UK and a string of powerful storms caused extensive coastal flooding. It was striking how several of these storms also coincided with high spring tides, for example those of December 5th 2013 and January 5th 2014.

Studio ghiacciaio Drolamabu e Ripimo Glacier confermano un avanzamento significativo glaciale.

La spedizione del Team Explora Extreme Malangur Expedition 2015 –Rowaling Himalaya con il capo esploratore e presidente Davide Peluzzi, è rientrata in Italia, portando notizie importanti climatiche sullo stato di salute dei ghiacciai della zona.

La spedizione esplorativa aveva il compito importante di monitorare e fare ricerca climatica della zona del Rowaling con l’ausilio per le riprese video anche con due droni, che hanno registrato lo stato glaciale del Drolambau e Ripimo Glacier.

STUDIO SUI CAMBIAMENTI CLIMATICI
DEL GHIACCIAIO DROLAMBAU  diretta su RAIUNO mattina nell'ultima settimana di Ottobre per un collegamento satellitare con il Team in Himalaya

 

La spedizione Extreme Malangur Expedition 2015 Rolwaling Himal avrà una rilevanza scientifica importante poiché effettuerà il monitoraggio climatico della zona esplorata, con osservazioni sullo stato dell'innevamento di tutta la zona e dell'importante ghiacciaio del Drolambau.

Le operazioni di osservazione e ricerca saranno condotte dal Team EXPLORA con l'aiuto di due droni fornendo un supporto diretto allo studio e alla ricerca scientifica sui cambiamenti climatici naturali e alla meteorologia, già pubblicati nel documento scientifico mondiale consultabile al seguente link:

http://www.atmos-chem-phys-discuss.net/15/22701/2015/acpd-15-22701-2015.html

In questa pubblicazione gli autori e scienziati indipendenti Dr. Clive Best (fisico e climatologo inglese) e Roberto Madrigali (esperto sul clima e la meteorologia) espongono per la prima volta al mondo scientifico un collegamento diretto tra maree atmosferiche (forza gravitazionale/Tides)  e modifiche importanti di velocità e di direzione del flusso polare (Jet Stream). 


Could the moon have played a role in UK’s heat wave ?

An ‘Omega’ pattern of Jet Stream Rosby waves developed in early July dragging hot air up from Spain. This  coincided with a full moon with maximum summer tides.

20150701-jetstream-heatwave-France-Spain-England

Jet stream flow on 2 July 2015

I am no meteorologist but even I can understand how this ‘Omega pattern’ in the Jet Streams  must drag hot Spanish/N. African up air over the  UK.  So let’s look at the ECMWF charts from  the neap tide on June 25 and the full moon tide on Feb 3rd.

25th June - neap tide

25th June – neap tide

A  full moon generates the largest tides in the northern hemisphere in summer, whereas a new moon dominates in winter.

Full moon spring tide

Having studied this for about a year I am convinced that statiscally the data now prove that there is an effect, particlularly in winter.

Full moon spring tide Feb 2-3

So how could the Jet Stream flow possibly be disturbed by an increasing atmospheric tide? The main effect of tides is the tractional (horizontal) N-S component which is unaffected by gravity. The rotation of the earth generates a variable torque whose strength depends on the lunar cycle of neap and spring tides.

 Having studied this for about a year I am convinced that statiscally the data now prove that there is an effect, particlularly in winter.

Dr. Clive Best link articolo Could the moon have played a role in UK’s heat wave ?

 

 

 

Sabato, 30 Maggio 2015 00:00

The Global Warming Hiatus" Dr. Clive Best

Scritto da

The Global Warming Hiatus

Global surface temperatures have essentially remained static since 1998 – a record el Niño year. The hiatus in land surface warming is real, unexpected, and puzzling. Recent anomaly data are shown below.

Comparison of CRUTEM4, CRUTEM3 and GHCN V3C

Comparison of CRUTEM4, CRUTEM3 and GHCN V3C. Error bars are those quoted for CRUTEM3.

Until 2010  CRUTEM3 was the IPCC reference land temperature data, and was used for the IPCC 4th assessment report in 2007. It is still updated and shows 1998 as the warmest year with no warming trend since then. GHCN V3C is  in agreement with that conclusion. CRUTEM4 was released in 2010, and the main difference to CRUTEM3 was the addition of 628 stations near the Arctic where warming has been strongest. GISS also added a significant number of new Arctic stations. This sampling effect alone has moved the land temperature anomaly to slightly warmer values post 2000.

Map-stations

The blue dots show locations of the 176 stations that were removed in the transition from CRUTEM3 to CRUTEM4. The red dots shows the location of the  628 stations that were added

Marotzke & Forster Revisited

Marotzke & Forster(2015) found that 60 year trends in global surface temperatures are dominated by underlying climate physics. However, the  data show that climate models overestimate such 60 year decadel trends after 1940.

The recent paper in Nature by Jochem Marotzke & Piers Forster ‘Forcing, feedback and internal variability in global temperature trends’ has gained much attention because it makes the claim that climate models are just fine and do not overstimate warming despite the observed 17 year hiatus since 1998. They attempt to show this by demonstrating that 15y trends in the Hadcrut4 data can be expected in CMIP5 models through quasi random internal variability, whereas any 60y trends are deterministic (anthropogenic). They identify ‘deterministic’ and ‘internal variability’ in the models through a multi-regression analysis with their known forcings as input.

\Delta{T} = \frac{\Delta{F}}{(\alpha + \kappa)} + \epsilon

where \Delta{F} is the forcing, \alpha is a climate feedback and \kappa is fraction of ocean heat uptake and \epsilon is random variation.

This procedure was criticised by Nic Lewis and generated an endless discussion on Climate Audit and Climate-Lab  about whether this procedure made statistical sense. However for the most part I think this is irrelevant as it is an analysis of the difference between models and not observational data.

Firstly the assumption that all internal variability is quasi-random is likely wrong. In fact there is clear evidence of a 60y oscillation in the GMST data probably related to the AMO/PDO – see realclimate. In this sense all models are likely wrong because they fail to include this non-random variation. Secondly as I will show below the observed 15y trends in Hadcrut4 are themselves not quasi-random. Thirdly I demonstrate that the observed 60y trends after 1945 are poorly described by the models and that by 1954 essentially all of the models predict higher trends than those observed. This means that the ‘deterministic’ component of all CMIP5 models do indeed overestimate  the GMST response from increasing greenhouse gas concentrations.

Evidence of regular climate oscillations

Hadcrut4 anomaly data compared to a fit with a 60y oscillation and an underlying logarithmic anthropogenic term.

Hadcrut4 anomaly data compared to a fit with a 60y oscillation and an underlying logarithmic anthropogenic term.

Figure 1 shows that the surface data can be well described by a formula (described here) that includes both an net CO2 forcing term and a 60y oscillation as follows:

DT(t) = -0.3 + 2.5\ln{\frac{CO2(t)}{290.0}} + 0.14\sin(0.105(t-1860))-0.003 \sin(0.57(t-1867))-0.02\sin(0.68(t-1879))

The physical justification for such a 0.2C oscillation is the observed PDO/AMO which just like ENSO can effect global surface temperatures, but over a longer period. No models currently include any such  regular natural oscillations. Instead the albedo effect of aerosols and volcanoes have been tuned to agree with past GMST and follow its undulations. Many others have noted this oscillation in GMST, and even Michael Mann is now proposing that a downturn in the PDO/AMO is responsible for  the hiatus.

15y and 60y trends in observations and models

I have repeated the analysis described in M&F. I use linear regression fits over periods of 15y and 60y to the Hadcrut4 data and also to the fitted equation described above. In addition I have downloaded  42 CMIP5 model simulations of monthly surface temperature data from 1860 to 2014, calculated the monthly anomalies and then averaged them over each year. Then for each CMIP5 simulation  I calculated the 15y and 60y trends for increasing start year as described in M&F.

Figure 2 shows the calculated  15y trends in the H4 dataset compared to trends from the fit. For comparison we first show Fig 2a taken from  M&F below.

READ THE REST LINK PHYSICST CLIVE BEST>>>>Marotzke & Forster Revisited

IPCC Scientist’s dilemma

Posted on March 3, 2015 by Clive Best

The headlines used by most politicians and green pressure groups are based on the IPCC attribution of the human impact on the climate. Climate change policy and political soundbites can usually be traced back to the ‘Attribution statements’ contained in each of the 4 yearly asessment reports. The political pressure on scientists to forever increase their “certainty” about  man-made global warming is intense. The stumbling block is that the pause in warming since 1998 is getting harder to explain away and  is beginning to undermine this process. The more scientists try to explain the pause the more difficulties they find themselves getting into . The latest to make this mistake is Michael Mann who can now ‘explain’ the pause as being due to a natural cooling trend of the AMO/PDO since 2000, thereby masking underlying anthropogenic warming.

Mann’s identification of a natural oscillation component in global temperature data. NMO is a net combination of AMO and PDO. Note the amplitude of the oscillation is 0.4C

Mann is quite right that the PDO/AMO may likely be the cause of the hiatus, but by accepting this possibility he unfortunately  drives a coach and horses through the AR5 attribution analysis described in chapter 10. This is because the probability analysis used there depends on natural variability being precisely zero since 1951.

First let’s look at the ever growing IPCC certainty about AGW since the first assesment in 1990

  • 1990 AR1: ‘The unequivocal detection of the enhanced greenhouse effect from observations is not likely for a decade or more. ‘
  • 1995 AR2: “The balance of evidence suggests a discernable human influence on global climate”
  • 2001 AR3: “most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations.”
  • 2007 AR4: “Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations”
  • 2013 AR5: “It is extremely likely that human activities caused more than half of the observed increase in GMST from 1951 to 2010. The best estimate of the human-induced contribution to warming is similar to the observed warming over this period.”However is this increased confidence actually justified in view of the fact there has been essentially no surface warming at all  since 1998?  The AR5 attribution analysis is all based on figure 10.5 shown below and the seemingly small error bar on the Anthropogenic component ANT. Despite the much higher uncertainty in the two individual anthropogenic components GHG and aerosols, the ‘fingerprinting’ analysis can supposedly isolate ANT with a high degree of certainty. This fingerpriniting is extremely obscure and is not at all well explained in the text of chapter 10. Even Science of Doom is not convinced by their arguments. However let’s be generous and assume that they are correct and the error on ANT can  indeed be shown to be that small. The real problem they now have is that the probability that ANT and Observed agree depends on the assumption that Internal Variability is 0.0 ± 0.1 C – but we just saw that this is now increasingly unlikely.
  • So 23 years of intense research has supposedly increased scientific consensus from an agnostic position (AR1), a discernable signal (AR2), through likely (66%-90%)  in AR3, to very likely (90-99%) in AR4, and finally to extremely likely (>99% certain) in AR5. This ratcheting up in scientific certainty, egged on by various pressure groups has underpinned the  increasing political pressure on worldwide governments to abandon fossil fuels. Taking a step backwards now is unthinkable.>>>>>>>READ THE REST LINK PHISICS Dr. Clive Best

  •  Central England Temperature Anomalies "Physicst Dr. Clive Best"

    Posted on January 4, 2015 by Clive Best

    The Met Office reports  that 2014 was the warmest year in the 354 year series of temperature measurements in central england. Ed Hawkins also has a post on this.

    So is it true and what does it really mean?

    annual mean temperatures since 1990 to 2014. The red line is a long term trend fit described below.

    Well 2014 does indeed scrape through  above 2006 as the warmest year, but the quoted measurement error is 0.1C.  So statistically it would be more correct  to say that it is  60% probable that 2014 broke the record. However in this post I want to understand better the full time series and identify a  long term warming trend in CET.

    This gives a rather different narrative than the simplistic one of just CO2 induced warming of the UK climate.

     

    The data shows that there has definitely been a slow but continuous warming trend since 1660 until the present time staring well before the industrial revolution. Furthermore there is no obvious evidence of any CO2 induced acceleration in warming as emissions increased post 195o.

    So let’s do something a little different and calculate temperature anomalies relative to that long term trend instead of relative to 1961-1990. The result of this procedure is shown below

     

    Relative to the 350 year long term trend there is no real evidence for any recent anthropogenic warming. Now let’s simply put a spline through the anomaly data to see if there are  shorter time scale trends.>>>>>>>

    READ THE REST>>>>link >>Clive Best

    InizioIndietro12AvantiFine
    Pagina 1 di 2

    Supporta MeteoClima.net

    Donate using PayPal
    Amount:
    Un tuo piccolo contributo volontario sulla diffusione della ricerca sul scienza del clima e della meteorologia. Grazie ;)

    Libro Sulla Tesi Madrigali e Scoperta Rivoluzionaria

    Osservatorio Astronomico di Grosseto

    Energia & Clima

    Clima/Glaciologo-geologo