Guest post by: Dr. Philip Klotzbach, Research Scientist, Department of Atmospheric Science, Colorado State University
As an author on the Colorado State University (CSU) seasonal hurricane forecast, I read with interest the blog regarding “Global Tropical Cyclone Activity still at 30 year low” posted yesterday. I have started to receive questions from the media asking where the hurricanes in the Atlantic are. We forecast a very active season, calling for a total of 18 named storms, 10 hurricanes and 5 major hurricanes (compared with the climatological average of 11 named storms, 6 hurricanes and 2 major hurricanes). Before I go into more detail describing why I think it is too early to think that this is a seasonal forecast bust, I wanted to briefly address the global storm component.
I completely agree that tropical cyclone (TC) activity is very quiet so far for this year’s Northern Hemisphere season. The Northeast Pacific had no named storms during the month of July, which is the first time that this has happened since 1966. The Joint Typhoon Warning Center did not name its fifth storm in the Northwest Pacific until August 8, which is also a record. The North Atlantic has also been very quiet since Hurricane Alex in late June. Alex was the strongest storm in terms of wind speed in the month of June in the North Atlantic since Alma (1966).
With a moderate La Niña event, it is typical to expect reduced activity in the Northwest Pacific and the Northeast Pacific. It has been well-documented that storm formations in the Northwest Pacific shift northwestward in La Niña years (Camargo et al. 2007). Consequently, these storms have less time to track over warm ocean water before making landfall and therefore have less time to reach their maximum potential intensity.
Northeast Pacific storm activity is also typically reduced in La Niña years, due to anomalous upper-level easterly winds that develop at upper levels associated with the strengthening and westward-shifting of the Walker Circulation (Figure 1). From a climatological point of view, upper-level winds in the Northeast Pacific blow out of the east (Figure 2), so stronger upper-level easterly winds increases vertical wind shear, which is detrimental for storm formation. Upper-level winds in the North Atlantic’s Main Development Region (MDR) (defined as 10-20°N, 20-70°W) blow out of the west in a climatological average (Figure 3), so anomalous upper-level easterlies reduces vertical wind shear (Wang and Lee 2009).
Figure 1: Correlation between the August-October Nino 3.4 index and 200 mb zonal winds. These correlations imply that a La Niña event increases vertical shear in the Northeast Pacific while reducing vertical shear in the North Atlantic.
Figure 2: Climatological upper-level winds in the Northeast Pacific during the months of August-October. Note that the climatological upper-level winds are easterly (so upper-level easterly anomalies associated with La Niña increases vertical wind shear).
Figure 3: Climatological upper-level winds in the MDR of the North Atlantic during the months of August-October. Note that the climatological upper-level winds throughout most of the MDR are westerly (so upper-level easterly anomalies associated with La Niña reduce vertical wind shear).
I want to begin addressing the North Atlantic component of the TC activity by examining historical hurricane seasons in La Niña years. I selected years that had an August-October averaged Nino 3.4 index less than -0.5°C since 1950. I calculated August-October averages from the Climate Prediction Center’s dataset available here:
http://www.cpc.ncep.noaa.gov/data/indices/sstoi.indices
I thought that an easy way to examine the typical progression of these seasons was to see when the 2nd hurricane formed. So far in 2010, the North Atlantic has had only one hurricane (Alex). Table 1 displays the La Niña years since 1950 along with the date of 2nd hurricane formation and the seasonal Accumulated Cyclone Energy (ACE) index for that year. ACE is defined as the sum of the square of a named storm’s maximum wind speed (in 104 knots2) divided by 10000. The 1950-2000 average of this index was 96, and for the 2010 season, we are predicting a value of 185.
Table 1: La Niña years since 1950 along with the date of 2nd hurricane formation and the seasonal ACE accumulated in each year.
| Year | ASO Nino 3.4 | 2nd Hurricane Formation Date | Seasonal ACE |
| 1995 | -0.66 | 8/1 | 227 |
| 1970 | -1.04 | 8/2 | 40 |
| 1956 | -0.63 | 8/10 | 54 |
| 1955 | -1.39 | 8/12 | 199 |
| 1971 | -0.63 | 8/15 | 97 |
| 1973 | -1.20 | 8/20 | 48 |
| 1950 | -0.75 | 8/20 | 243 |
| 1999 | -1.01 | 8/22 | 177 |
| 1998 | -1.17 | 8/25 | 182 |
| 1954 | -0.98 | 8/27 | 113 |
| 1975 | -1.34 | 8/30 | 76 |
| 1974 | -0.53 | 8/31 | 68 |
| 2007 | -0.92 | 9/2 | 74 |
| 1964 | -0.86 | 9/3 | 170 |
| 1961 | -0.52 | 9/3 | 205 |
| 1988 | -1.55 | 9/9 | 103 |
The average date of 2nd hurricane formation for all of these years is August 21, and you will note that five years with very high ACE values of 170 or greater did not have their 2nd hurricane formation until August 20th or later. The 2nd storm in 1961 did not form until September, and that September went on to have four major hurricanes, a record for the month. So, from a climatological perspective, it is not time to write off the TC season yet.
With regards to sea surface temperature (SST) anomalies, they are still running at record levels across the MDR, based on data from the NCEP/NCAR Reanalysis. I calculated the July SST over the MDR and have plotted the timeseries from 1948-2010 below (Figure 4). July 2010’s value was at record levels, approximately 0.1°C greater than it was in 2005. Calculations were made from the following website:
http://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries1.pl
Figure 4: July SST averaged over the MDR. The value of 27.5°C reached in 2010 is the warmest on record, beating out 2005 and 1958 by approximately 0.1°C.
I tend to disagree with the SST analysis given by Steve Goddard yesterday. Other SST datasets that I look at in real-time tend to agree with the fact that the MDR is running at record or near-record levels right now. Here’s an additional analysis from NOAA (Figure 5):
Figure 5: Real-time SST anomaly analysis from NOAA.
In addition, analysis from the Advanced Very High Resolution Radiometer of the difference in SST between 2010 and 2005 indicates comparable SSTs throughout the MDR (Figure 6).
Figure 6: SST difference between 2010 and 2005. Note that there are only small differences between the two years.
The sea level pressure anomaly and low-level wind pattern in July would also tend to reinforce the very warm SST anomalies that were already in place from the spring. Figure 7 displays the SLP anomaly pattern in July, while Figure 8 displays the 925-mb wind anomalies. The trades were very weak in July, which is to be expected from the pressure gradient pattern observed in Figure 7. Very weak trades were observed over the MDR, which feeds back into continued warmth due to reductions in mixing and upwelling.
Figure 7: Anomalous sea level pressure in July. This pressure gradient pattern drives anomalous low-level westerly flow, thereby weakening the trades across most of the MDR.
Figure 8: Anomalous 925-mb winds in July. Note the anomalous westerly flow across most of the MDR, implying weaker trade winds (which feed back into warmer SSTs).
With that being said, it does appear that TC activity in the Atlantic should increase over the next couple of weeks. There are a couple of systems that currently have a high chance of formation into TCs in the next 48 hours according to the National Hurricane Center’s website. In addition, we should be heading into a more favorable large-scale regime for TC formation according to the latest Madden-Julian Oscillation forecasts. I showed in a paper published earlier this year that when the MJO is located in Phases 1 and 2 (convectively active over the Indian Ocean), it reduces vertical wind shear in the tropical Atlantic, thereby providing a more conducive environment for formation on a shorter time-scale basis (Klotzbach 2010). The GFS ensemble is hinting that the MJO may be amplifying in the Indian Ocean in the next couple of weeks (Figure 9).
Figure 9: Ensemble GFS forecast for the MJO over the next two weeks.
To summarize, I would say that it is too early to discount seasonal forecasts issued by CSU, NOAA and other agencies. Our August forecast has shown significant skill over the period from 1984-2009, with our average real-time forecast error over that time period being ± 2.2 named storms, ± 1.7 hurricanes and ± 1.1 major hurricanes. Correlations between our early August predictions and post-31 July TC activity are approximately 0.60 for most predictands over that same period. Full forecast verifications from CSU are available here:
http://tropical.atmos.colostate.edu/
NOAA’s forecasts show similar levels of skill. While seasonal forecasts do bust on occasion, these forecasts show moderate skill in real-time and should not be dismissed this early in the TC season.
References:
Camargo, S. J., A. W. Robertson, S. J. Gaffney, P. Smyth, and M. Ghil, 2007: Cluster analysis of typhoon tracks. Part II: Large-scale circulation and ENSO. J. Climate, 20, 3654-3676.
Klotzbach, P. J., 2010: On the Madden-Julian oscillation-Atlantic hurricane relationship. J. Climate, 23, 282-293.
Wang, C. and S.-K. Lee, 2009: Co-variability of tropical cyclones in the North Atlantic and the Eastern North Pacific. J. Geophys. Res., 36, L24702,doi:10.1029/2009GL041469.
I’d point out that every hydro-electric generator in the world is run by gravitational energy that can be traced back to water which evaporated at sea level and condensed at some higher altitude. It falls as rain to some collection point higher than sea level and the potential (gravitational) energy is then extracted by having it drive some kind of bladed contraption as it flows to a lower level. That is definitely a heat engine. Without any manmade contraptions extracting gravitational energy I’d point out that all erosion from flowing water is actually mechanical work accomplished by the water cycle and that too is a heat engine. One might also consider the substantial damage done by winds in hurricanes, thunderstorms, and tornadoes. That damage is essentially mechanical energy extracted from the flow of gases in the heat pump which also qualifies it as a heat engine. Or the storm surge in a hurricane which lifts boats higher is another example of work being accomplished.
PolishG asked…
“…Then suddenly there is the same temperature difference, and hurricanes! I ask — why? The message I gathered from the PT article is because heat input has increased due to high wind speeds — and high wind speeds are due to high heat input — but, my apologies, this is exactly what Baron Münchhausen did when getting out of a swamp by pulling his own hair…”
If I may, the thing that separates a mass of showers/thunderstorms from an organized tropical cyclone is the Upper-Level High (ULH) at the top of the storm. The ULH is what is driving the cyclone and causing the pressure drop at the surface. It is fed by the latent heat released from the moisture drawn up from below.
The airflow in the lower levels into an organized storm is a fairly long path, round in circles, compaired to the slightly curved path out & away from the storm at the top. The ULH is pushing the exhaust air out away from the storm faster than is being supplied from below. Since it cannot draw air from above the tropopause, it must draw (lift) air from below. This lowers the pressure at the surface since the entire column of air across a relatively broad area is being lifted.
The ability of the ULH to do this is governed by the temperature contrast from the center to the outer edges. The warmer the center of the ULH is, the greater it’s ‘pumping’ action is and since this heat is brought up from the surface, the warmer the water is, the stronger the ULH can be which translates to a stronger tropical cyclone.
The upper levels if the tropical cyclones have always been neglected from monitoring mainly due to the difficulty of reaching it but I believe *that* is where the ‘engine’ of the tropical cyclone resides and everyplace else below that we look, we are just seeing the effects of the storm (low pressure, high winds, eye wall, etc.) but not the cause and that is why I think this new NASA project to discover the cyclone genesis may miss the mark because they are looking in the wrong area. I notice the NASA ER-2 (U-2) is not involved with the project.
I have more details to this genesis theory if you are interested.
Jeff
To All (slightly OT):
I cannot but comment on the discussions here. Contrary to EVERY other Weblog on this topic (and most other topics, in fact), it is worth noting there are ZERO instances of the following terms: stupid, ignorant, idiot, moron, [profane and vulgar expletives deleted], and a whole host of others.
Now that I’m in my seventh decade, it is refreshing to see such an anachronistic multilogue ongoing. (I’m NOT a climatologist, but have earned degrees in engineering, physics and management, so I consider myself an intelligent but untutored observer)
THNX! to all participants.
It seems that some people are distracted by normal temperatures, anomalies near-.5 to .5, and thinking this means low hurricane count. If temps are normal, then you would expect a “normal” number of storms. (9 trop storms, 5 hurricanes). It would be other factors that influence above or below the norm.
Dear Dr. Klotzbach,
Having correlated sunspot activity to Accumulated Cyclone Energy, temperatures, number of hurricanes, precipitation and lack of significant glacier growth since the mid-1980s, the biggest nemesis to your prediction this year is the lack of sunspot activity.
You may wish to enter upper atmosphere humidity to your calculations. That measurement and critical ozone production have dropped in the last few years.
The earth is cooling. We are now in a solar sunspot minimum.
My work is at nationalforestlawblog.com
Oct. Newsletter under my name.
Most Sincerely,
Paul Pierett
Ric Werme says: August 11, 2010 at 3:34 pm I agree with your assertion that hurricanes are removing heat from the ocean. I don’t have a picture on hand, but watching SSTs with the passage of a hurricane, shows a trail of cooler water in its wake.
Steve Keohane says:
August 13, 2010 at 7:22 am
See http://journals.ametsoc.org/doi/pdf/10.1175/1520-0493%281997%29125%3C2716%3ASIOSST%3E2.0.CO%3B2 for a photo of Hurricane Edouward’s track which decreased SST by as much as 5° C. The effect is from both evaporation and mixing. Hurricanes that stall generally weaken after a day or two thanks to the losing warm water fuel.
The same image is on page 76 of Kerry Emanuel’s Divine Wind, see my next comment.
polishG says:
August 11, 2010 at 7:09 pm
Fair enough – I hope you didn’t expect me to write the book. It has been done already, See Kerry Emanuel’s Divine Wind at amazon.com. (More in a bit)
Given warm water on the surface and cold overhead, the next step is convection. Warm moist air is lighter than warm dry air and lighter still than cold dry air. Surface convects upward, condensing water vapor keeps the temperature warm as it jumps from the dry adiabatic lapse rate to the wet adiabatic lapse rate. If convection is strong enough, you’ll get a thunderstorm. Apparently you also need more than the typical mid-level humidity to get more than a thunderstorm.
This still isn’t enough for a tropical storm, it needs a source of rotation around a core, this comes from things like Saharan waves off Africa, old extratropical storms, etc. Now the updrafts and rotation provide more air inflow, more wind, more evaporation. With an upper level ridge or anticyclonic system above, that provides ventilation to get the upwelling air out of the developing storm.
The eyewall appears to be a point where radial force pulling in air can’t pull any further because it all goes into bending the wind. That forces air up, enhancing the convective forces. It also allows dry air above the storm to sink into the eye, hence the clearing and warm core nature of tropical storms.
Emanuel’s book goes into all this in much greater detail and even has equations that let you estimate the top winds a hurricane can reach. (Including some stuff about “hypercanes” that pass a tipping point and enter the realm of the movie “The Day after Tomorrow” but let’s not go there!)
If this link works – http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dstripbooks&field-keywords=diven+winds+emanuel&x=0&y=0&ih=36_3_0_1_0_0_1_0_1_1.152_769&fsc=-1 click on the “Look inside” link and search for terms like genesis, carnot, and Edouard for information starting at pages 93, 54, and 76.
Steve Keohane says:
I agree with your assertion that hurricanes are removing heat from the ocean. I don’t have a picture on hand, but watching SSTs with the passage of a hurricane, shows a trail of cooler water in its wake.
My observation is that any rain produces some cooling at the surface. Aren’t raindrops falling from a certain height in the atmosphere much colder than the surface? Hurricanes carry heavy showers, it does not surprise me they leave cold sea surface behind.
If you have a heater in the room, try to remove heat from it by mixing the air. All you will get is a more uniform (higher) temperature of the room, no mechanical output.
JKrob says:
If I may, the thing that separates a mass of showers/thunderstorms from an organized tropical cyclone is the Upper-Level High (ULH) at the top of the storm. The ULH is what is driving the cyclone and causing the pressure drop at the surface.
This makes good sense to me as a general idea. My point is we need a pressure drop somewhere to drive wind. If we have a pressure gradient, we are there. My next question would be — what makes the high pressure at the top of the storm?
I like the work of Makarieva and Gorshkov (2009) because they answer this question for the surface. If you know what a heat pipe is, the idea is amazingly clear. The pipe is filled with saturated vapor. Due to the temperature difference between the pipe ends (the cold and the hot) there is a pressure difference that can theoretically lead to vapor velocities comparable to the speed of molecules. This high vapor velocity makes heat pipes very efficient in conducting (latent) heat.
Now let’s look at the hurricane as a (crooked, hockey-stick like) heat pipe. It has a long nearly horizontal part and a shorter nearly vertical end. The warm, vapor-rich air streams upward along the pipe to the center where it condenses at some height. The temperature difference between the pipe ends should be in the order of several dozen degrees. Most vapor condenses. If at start we have about 4% standard pressure of vapor, at finish we have nearly nothing. This accounts for the pressure drop along our crooked pipe and yields air velocities up to square root of 0.04 times the speed of molecules = 60 m/sec. To me, the hurricane is there.
I like these numbers. It is ok to propose a qualitative idea, but to prove that it really means something one would need to bother about some rough zero-order estimates. If the physics is clear, to demonstrate such estimates to educated guys from the street would make no difficulty.
JKrob says:
If I may, the thing that separates a mass of showers/thunderstorms from an organized tropical cyclone is the Upper-Level High (ULH) at the top of the storm. The ULH is what is driving the cyclone and causing the pressure drop at the surface.
This makes good sense to me as a general idea. My point is we need a pressure drop somewhere to drive wind. If we have a pressure gradient, we are there. My next question would be — what makes the high pressure at the top of the storm?
I like the work of Makarieva and Gorshkov (2009) because they answer this question for the surface. If you know what a heat pipe is, the idea is amazingly clear. The pipe is filled with saturated vapor. Due to the temperature difference between the pipe ends (the cold and the hot) there is a pressure difference that can theoretically lead to vapor velocities comparable to the speed of molecules. This high vapor velocity makes heat pipes very efficient in conducting (latent) heat.
Now let’s look at the hurricane as a (crooked, hockey-stick like) heat pipe. It has a long nearly horizontal part and a shorter nearly vertical end. The warm, vapor-rich air streams upward along the pipe to the center where it condenses at some height. The temperature difference between the pipe ends should be in the order of several dozen degrees. Most vapor condenses. If at start we have about 4% standard pressure of vapor, at finish we have nearly nothing. This accounts for the pressure drop along our crooked pipe and yields air velocities up to (0.04)^1/2 times the speed of molecules = 60 m/sec. To me, the hurricane is there.
I like these numbers. It is ok to propose a qualitative idea, but to prove that it really means something one would need to bother about some rough zero-order estimates. If the physics is clear, to demonstrate such estimates to educated guys from the street would make no difficulty.
Ric Werme says
Fair enough – I hope you didn’t expect me to write the book. It has been done already, See Kerry Emanuel’s Divine Wind at amazon.com. (More in a bit)
Thanks for taking the effort to explain things. It appears the paper I read in Physics Today was of K. Emanuel so I now realize my concerns are not about a marginal view.
Surface convects upward, condensing water vapor keeps the temperature warm as it jumps from the dry adiabatic lapse rate to the wet adiabatic lapse rate.
I am trying to get the point. Wet adiabatic lapse rate is smaller than the dry one, right? An air parcel will continue moving upward as long as it is warmer than the surrounding air. But if the adiabatic lapse rate is already wet (minimal?), what will enhance the upward movement of the air at the surface?
If convection is strong enough, you’ll get a thunderstorm.
To me, this is circular. It is here that I see the problem: what makes convection strong? Over a calm sea surface there is suddenly strong convection. I ask: why? Logically, I am ready to accept the answer of JKRob: because there is a strong pressure gradient in the upper atmosphere. If the cause of this gradient is identified and quantified, I am happy. I am also ready to accept the answer of Makarieva and Gorshkov, because they show a positive feedback between condensation, pressure drop formation and velocity. But with the heat engine concept my logic fails to be satisfied.
polishG says:
August 15, 2010 at 4:24 am
I’m not certain we see the same things here. Convection starts at the surface due to warm water heating the air and adding water vapor (note water’s molecular weight is 1*2+12 = 14, N2 is 2*14=28, so water vapor is a lot lighter than air). That heat input is what initiates convection. As long as the air column is marginally stable, adiabatic cooling won’t be enough to stop convection.
Heat initiates convection, unstable air allows it to continue.
Check out Jeff Haby’s http://theweatherprediction.com/ which I probably should have though of first. He has notes on tropical storm development (I meant to include a plug for the Coriolis effect). A lot of stuff about convection centers on the “skew-T” chart which can keep you busy for a long, long time. Note especially comments about “CAPE” – Convective Available Potential Energy.
If convection is strong enough, you’ll get a thunderstorm.
It’s a positive feedback loop – of course it’s circular. 🙂 Daytime sun heats the surface, and that heats the air. A typical tropical day has afternoon thunderstorms, so it’s more an issue of gathering a tropical wave into a depression and spinning that up in to a storm, and there’s nothing sudden about that. So far this year that seems to be a challenge even for nature.
Watch some of the tropical waves as they develop, the NHC discussion is fairly decent, see http://www.nhc.noaa.gov/ and click on “Tropical Weather Discussion.” They spend a lot of time talking about convection and cyclonic winds. The surface analysis map, e.g. http://www.nhc.noaa.gov/tafb/ATSA_06Z.gif , is cluttered, but helps make the discussion comprehensible.
I see the current discussion notes (downcased because I hate shouting):
Tropical wave extends from 19N53W to 13N51W to 8N46W moving W 20 kt. Wave exhibits weak low level cyclonic curvature along the wave axis as observed on satellite imagery and satellite derived winds. A large area of dry air and Saharan dust is E of the wave axis to west Africa. Scattered moderate convection is 15N-16N between 50W-52W.
Saharan dust is important – it blocks sunlight at mid-level altiudes and that both heats the air (reducing convective potential) and reduces sea surface heating (reducing energy input to surface air and reducing convective potential).
Ric Werme says
It’s a positive feedback loop – of course it’s circular. 🙂 Daytime sun heats the surface, and that heats the air.
First of all, thanks for further comments and links. I wish I could give more time to this than I have.
But at the point above I have to disagree. And this is precisely where I see the problem. There is no positive feedback, the feedback is negative. Of course if the temperature drops sharply with height then some vertical movement (not necessarily ascending, by the way) can be initiated due to the convective instability of the fluid in the presence of gravity.
The upward movement of the air volume we keep an eye on continues as long as the volume is warmer than the surroundings. But this very movement changes the initial sharp temperature profile and makes it close to wet adiabatic. What I mean, the movement that starts due to the fact that there is a sharp temperature gradient makes this gradient shallower. The movement does not sustain the instability that has caused the movement. It wipes it out instead.
To me this is an obvious point. Enhanced mixing destroys the temperature difference on which a heat engine operates.
In the hurricane like heat pipe model of Makarieva and Gorshkov the positive feedback loop is clear to me. Cooling rate and condensation rate are both proportional to vertical velocity. Vertical motion leads to condensation, condensation creates a pressure drop to elevate velocity and, in turn, raises the condensation rate.
Very good and interesting article, but …
I quickly learned to just ignore these forecasts in general. Anyone can take a long shot the year before, then keep readjusting towards the end of the season, as the numbers are already on the table! Instead of listing the “Final Forecast” from previous years as reference, play open cards and start listing “First Forecast” from previous years for comparison. Maybe then I’ll start taking the good ones more seriously. From my analysis of these earlier numbers, most of these predictions are akin to playing Russian Roulette, and no better than “Aunt Sally’s best guess”.
Also, the forecasts may be interesting and meaningful to meteorologists, or others interested in pure academics. For 99% of the population, there is a geographical interest that is more important than any of these numbers. As example, the year 2005 went down as the busiest season in recent memory in terms of numbers (as well as intensity). Yet, for the Carolinas it was about as quiet as 2009 (which meteorologically was an average year!)! In contrast, 1989 had only 11 storms … of which one was Hugo … and Charleston still shivers at the thought. It only takes ONE storm, and for the average citizen the importance of numbers is insignificant compared to location. If the forecast can one day nail the probability to be affected in a specific location, in a particular year … now THAT has value! But we already have that probability as an average over the years, right? Problem is, it is a constant … and I do not see us able to ever simplify complex environmental systems over time enough to make a sensible forecast possible. Until then, we will have to continue preparing for storms as if it is going to hit us next week … and be thankful that the track forecasts on individual storms improved dramatically in recent years 🙂
Jaco,
There are a lot of theories on the table and a lot of factors being played out as to the causes of a hurricane, which is a global warming event.
Hurricanes can only happen for a short time each year over a period of a few thousand years during between ice ages before we slide into the next ice age.
We have advanced only a little bit in the last 150 years in our understanding of this event. Unfortunately, global warming alarmists have muddied the water with miss-information.
Fortunately, we have people like Dr. Klotzbach who have dedicated life long study to these events and their efforts should be recognized.
As for predictions, I guessed this past spring, 7 named storms with a 50/50 mix of tropical storms and hurricanes and several tropical depressions.
Why is that? Historically, during limited sunspot activity, the named storm numbers drop to reflect a slow global cooling that is constantly debated in the blogs.
It is not a theory. It was observed in the 1878, Jan. Issue of Popular Science that fewer sunspots means fewer hurricanes. This could be a turning point in the science world if the hurricane numbers actually drop and show continued correlation to sunspot activity.
Our science world needs to strongly minimize global warming due to sunspot activity so as to keep the masses stupid and those who thought up “Cap and Tax” and have invested in the carbon trading, happy.
You will find sunspot activity ignored and or rejected by some of the popular science magazines and contributing scientists. It was downplayed by the IPCC in one of their recent reports
And… They run the show.
Most Sincerely,
Paul Pierett