Hurricanes 2018

There was a lot of press about the 2017 hurricane season. Hurricanes Harvey, Irma, and Maria caused hundreds of billions of dollars in damage, killed thousands, and left untold more injured. By themselves, these three storms caused an estimated $265 billion in damage to the U.S. That figure is from January 8, 2018 and is likely to be even higher by now. Official records show 64 deaths in Puerto Rico, but analysis indicates this number is extremely low and the real number of fatalities lies between 1000 and 5000 people.

The question that was immediately asked was how much manmade global warming had to do with all of this. The deniers in government responded that 'this wasn't the time to talk about that.' Of course not. They didn't want to be held accountable for their actions. But, that didn't stop the conversation and the analysis. The conclusion? Yes, AGW most certainly made these storms worse. Attribution science shows global warming made the storms stronger, slower, and wetter. They are also growing in strength faster. Three independent studies last fall found that human activity made the damage from Hurricane Harvey more intense. The disastrous rainfall from Harvey was three times as likely as from a storm a hundred years ago and 15% more intense. The seven day rainfall was as much as 40% greater than from a similar storm even a few decades ago. The lead researcher on one study, Geert Jan van Oldenborgh, stated,

This multimethod analysis, drawing upon both observed rainfall data and high-resolution climate models, confirms that heavy rainfall events are increasing substantially across the Gulf Coast region because of human interference with our climate system.

[Of course, much of the damage could've been avoided if not for the climate-change denying director for the Harris County Flood Control District, Mike Talbot, who insisted climate change was a hoax and allowed construction in known flood plains for many years. It would be wonderful if Talbot was arrested for his crimes, but it won't happen.]

The problem is that the average hurricane strength has remained pretty constant with the accumulated cyclone energy (ACE) remaining relatively steady. But, while the ACE has remained constant, there has been an increase in storms in recent years of such incredible strength they are being referred to as category 6 storms, which would constitute a new level in the Saffir-Simpson index used to categorize cyclonic storms and would consist of storms with constant winds exceeding 175 or 180 mph.

The science is clear - global warming is resulting in cyclonic storms that develop faster, become stronger, move more slowly, and dump more rain. And, at the same time, the total energy of storms has remained fairly constant. How do you reconcile this contradictory information? One way is that small storms and large storms are both becoming more common. This results in the average remaining nearly the same. Another way is that very active years (2017) alternate with relatively quiet years.

This year, 2018, appears to be one of those slow years. The July forecasts are for below-average activity with eleven named storms and four hurricanes. Despite the fact that we've already had three full-strength hurricanes, it appears this should be a slow year. There are several factors leading to this conclusion.

Take a look at this plot of the sea surface temperature (SST) anomaly:

Source: CCI

This image is showing us three really important things.

First, note the red area in the North Atlantic. The sea surface is hotter than usual here. That is causing a high pressure system in the North Atlantic. This creates a clockwise cycle of wind which goes down past the Iberian Peninsula and westward across the mid-Atlantic. Take a look at this graphic illustrating the wind patterns:

Source: Earth

The result of this is to cool the sea surface. This is indicated by the blue, lower-than-normal temperature region in our SST figure above and is the second thing to note. That area is known as the Main Development Area for hurricanes.

Hurricanes need warm ocean water. The threshold temperature is typically regarded as at least 79 degrees Fahrenheit (about 26 degrees Celsius). The winds blowing across the mid-Atlantic are keeping the sea surface temperature down, which is bad for hurricane formation.

The third thing to note in the image above is the red area west of equatorial South America indicating hotter than usual SSTs. This is an El Nino possibly forming. The July ENSO Diagnostic Discussion estimates a 65% chance of an El Nino this fall and a 70% chance for this coming winter. Even if it doesn't turn into a full-scale El Nino, it has the effect of creating high-altitude wind shear across the Caribbean Sea. Hurricanes gain strength by forming a rising column of air in the eye, resulting in a low-pressure area and sucking in hot, moist air to replace it. This air rises, condenses, releases its energy and then cycles around to continue fueling the storm. High-altitude shear winds crossing over the top of this column will essentially chop it off, robbing the cyclone of its reinforcing wind pattern. This is also bad for hurricane formation.

So, two bad things for hurricane formation. But, there's a third. Take a look at this satellite image:

Source: NOAA/RAMMB, via Weather Underground

What you can see here is a big cloud of dust blowing off Northern Africa across the mid-Atlantic and into the Caribbean. This dust is contributing to the lower SST for the region by shading the sunlight.

So, we have cool SSTs caused by wind and dust, and high-altitude wind shears. This is a bad combination for the formation of tropical cyclones. So, despite having three hurricanes already, the estimate remains that it will be a slow hurricane season in the Atlantic.

The interesting thing is all of those factors are made worse by AGW. The high-SST area in the North Atlantic is the result of ocean warming, as is the El Nino. Manmade global warming makes both of these events more likely and more extreme. The dust blowing off Africa is due to more extreme drought conditions, again made worse by global warming.

So, does AGW make tropical hurricanes worse? Or, better? Apparently, depending on the year, it can be either.

"This multimethod analysis, drawing upon both observed rainfall data and high-resolution climate models, confirms that heavy rainfall events are increasing substantially across the Gulf Coast region because of human interference with our climate system."

Read more at: https://phys.org/news/2017-12-climate-harvey-rainfall-percent-intense.html#jCp

"This multimethod analysis, drawing upon both observed rainfall data and high-resolution climate models, confirms that heavy rainfall events are increasing substantially across the Gulf Coast region because of human interference with our climate system."

Read more at: https://phys.org/news/2017-12-climate-harvey-rainfall-percent-intense.html#jCp

"This multimethod analysis, drawing upon both observed rainfall data and high-resolution climate models, confirms that heavy rainfall events are increasing substantially across the Gulf Coast region because of human interference with our climate system."

Read more at: https://phys.org/news/2017-12-climate-harvey-rainfall-percent-intense.html#jCp

What if Climate Change is Real?

This video is a lecture given by a climate scientist at Texas Tech University. It is the kind of thing people like Tom Harris and Russell Cook would never watch because it shows, graphically, just how wrong they are. Everyone else should watch it. It is about 18 minutes long and worth it. I did not post this because it talks about Texas, but it didn't hurt, either.

What if Climate Change is Real?

Weak El Nino Conditions Exist

The National Weather Service has announced weak El Nino conditions now exist and there is a 50-60% chance it will continue through the Northern Hemisphere summer of 2015.

I have been following the El Nino - Southern Oscillation (ENSO) conditions closely since last spring when it began to look as though the ENSO conditions might come to pass. There are some areas in the equatorial Pacific that are monitored closely - Area 1+2 - located near South America; Area 3- located a little further out; Area 4- located even further west; and Area 3.4, which overlaps areas 3 and 4. It is 3.4, essentially in the middle of the Pacific Ocean, they pay most attention to and is specifically mentioned in the NWS announcement.

At least twice in the last year I thought the ENSO had begun, once in the late spring and once in the fall. In addition to the borderline conditions there were also weak weather patterns consistent with it occurring. Each of those times the conditions came apart, though. My guess is the mechanisms responsible for causing this event (and it is very complicated) were getting close to coming together, but not quite.

So, what does this mean for worldwide weather and the climate? My guess right now (a fool's errand) is that it won't have a very large impact. It looks as though it is a weak system and any impact will be small.

Significantly, it is not likely this system will do much for the California drought. Instead, the data indicate the snowpack in the Sierra Nevada mountains is dangerously low, meaning California will have another terrible summer. Statewide, the snowpack is measured at just 19 percent of the long term average. A weak El Nino will not change that.

According to the NWS, some areas of the planet may see some light affects from this El Nino, but worldwide effects are not expected. How all of this ties together is something for scientists to study and figure out. While I follow it, I am not involved in any kind of research on ENSO so I can't state what this on-again/off-again cycle means. Hopefully, though, it is one more piece of the puzzle to help us figure out this very important system in our climate.

Naturally Occurring Cycles Are Not Responsible For Today's Warming

The claim that there have been naturally occurring warming cycles in the past has become the single most often stated 'proof' that man made global warming is not real. I have discussed this before, but thought it was time to address it again.

There are lots of naturally occurring cycles and the climate has gone through many warming and cooling phases in the past. Take a look at this plot of temperature and CO2 over the last 800,000 years. Today is on the left.

It is very easy to see that there have been lots of warming periods in the last 800,000 years. I count 13 separate times the global average goes above the baseline, including today. You may get a different number based on how you define 'separate.' We also see the level of CO2 in the atmosphere rises and falls with a very high correlation coefficient.

The denier argument goes like this: Evidence of past warming cycles proves today's warming trend is just a naturally occurring cycle. To put it succinctly, it goes like this:

There were warming periods in the past.
We have a warming period today.
The warming periods in the past were natural.
Therefore, today's warming trend is natural.

Does anyone disagree with my characterization of the denier argument?

Does anyone see the fatal flaw in this argument?

Let me give you an identical argument.

Pneumonia kills people.
Gunshot wounds kill people.
Pneumonia is a naturally occurring disease.
Therefore, gunshot wounds are a naturally occurring disease.

The problem with this argument, and the reason it is a false argument, is that it makes a false connection between the first part and the second. It is automatically assumed, without any evidence, that pneumonia and gunshot wounds are related merely because they both kill people. At no time is any evidence presented to link them together or to show that there is only one way to kill people (a naturally occurring disease).

The denier argument makes an equally false connection between past warming trends and today's warming trend. It is automatically assumed, without evidence, that today's trend and all past trends are related simply because they are both warming trends. At no time is any evidence ever presented to link them together and it is assumed, without proof, that there is only one way to cause a warming trend (a natural cycle). All of these are false arguments designed to fool and deceive. There are even multiple ways to have a naturally occurring cycle. They are not all the same simply because they occurred naturally.


This is called the fallacy of four terms. 

The real truth about natural cycles is very disturbing for deniers. There are lots of naturally occurring cycles and they are studied a lot by scientists. There are the Milankovitch cycles, the Pacific Decadal Oscillation (PDO), the Atlantic Multidecadal Oscillation (AMO), the North Atlantic Oscillation (NAO), the El Nino Southern Oscillation (ENSO), the solar cycle, solar activity (not the same as the solar cycle), and more.

Deniers will pull one of these cycles out with an 'Ah ha! Caught you!' type of attitude, as if they are the first person to find them and scientists are ignoring them. Ask yourself one question, who do you think discovered these cycles in the first place? Some denier playing around on his computer? No! They were discovered by scientists and we work these cycles into our calculations.

Two very influential cycles are the AMO and solar activity. Both of these give a lot of correlation to global average temperature. Unfortunately, both of these were in a negative phase throughout the warming trend of the 1980s and 1990s. The AMO has turned positive (warming), ironically during the same period deniers claim global warming has stopped (not true), but the solar activity has continued to be in a negative phase.

The sum of the natural cycles is that we are in a naturally cooling phase, not a warming one. If it was not for man made greenhouse gas emissions, the climate would be much cooler than the long-term average. All of the heating above the long-term average (actually, above what it would be without our emissions) is due to human activity in the form of greenhouse gas emissions which trap heat in the atmosphere that would otherwise escape into space.

So, for anyone claiming manmade global warming is not real because there were naturally occurring cycles in the past, you did not prove manmade global warming is not real.

El Nino 2014

Update: You can read a nice NSF article on El Nino here.

There are many natural climate oscillations, but one of the most important is the El Nino/Southern Oscillation (ENSO).  El Nino is the ocean oscillation where Pacific waters get warmer than usual off the coast of Peru. NOAA defines El Nino as being when the Peruvian waters are at least half of a degree Celsius warmer than average for at least three months. The Southern Oscillation is the atmospheric oscillation that roughly accompanies the ocean component.

ENSO affects the weather virtually everywhere on the planet. It has caused droughts resulting in massive famines as well as widespread floods. The 1997-1998 El Nino caused the worldwide average temperature to rise more than 2.4 degrees Celsius (4.5 degrees Fahrenheit), making 1998 the hottest year ever recorded at the time. It is still the fourth hottest year on record and was so out of line with the rising temperature trend that global warming deniers continue to cherry pick it as the starting point for trend lines to claim there is no global warming. You can clearly see the isolated peak from 1998 in this graph of global surface temperatures.

Source: NASA Goddard Institute for Space Studies

So, it is small wonder that we keep a close eye on the formation of El Nino. The National Weather Service's Climate Prediction Center has a very detailed website with weekly updates on the ENSO conditions, and it is looking more and more likely that 2014 will be an El Nino year. I wrote the other day that El Nino is back. I am a little more lax in my definition of El Nino and jumped the gun in comparison to the official agencies. In fact, forecast centers around the world are saying El Nino, if it occurs, won't occur until later this summer or sometime in the fall. The consensus seems to be about 65% chance of it forming this summer and as much as 80% chance for it this fall. Forecasters are also saying it will be a mild to moderate event and nothing near as strong as some of the large events of the past. I have been reviewing the data and I agree with that assessment. There is a definite warming trend that has been going on this spring. The amount of warming that is being observed in the upper-level of the Pacific Ocean (upper-300 meters) is greater than the weak events of the past, but less than the strongest ones. That is not to say that something couldn't happen that would tip it to being either stronger or weaker. Such an event is certainly possible. But, based on past behavior, this event is proceeding in much the same way that past moderate events have.

What is still unknown is what effect global warming is having on ENSO. That will take some time to figure out.

El Nino is back. What does it mean?

El Nino is the name given to the natural cycle that involves the eastern Pacific getting warmer in the area close to the equator. (La Nina is the name for the alternative cycle when the waters there are cooler. The two together are known as the El Nino Southern Oscillation - ENSO.) This is one of the most significant natural cycles and occurs every few years. It has the potential to change weather around the world. Take a look at this graphic showing the sea surface temperature anomaly. The darker the red, the warmer it is relative to the long-term average.

Source: Climate Reanalyzer

You can clearly see how the water temperature off western South America is warmer than usual, which is the classic definition of El Nino. The name comes from how local fishermen noticed the change  in the water and how it seemed to always arrive in the late fall - about Christmas time. El Nino means 'the boy' and refers to the Christ child of Christmas. The name has stuck.

But, the important thing is to notice how the warm water stretches all the way across the Pacific Ocean. The significance of this lies in the fact that warm water creates atmospheric low-pressure areas which results in thunderstorms. There is now a Pacific Ocean-wide corridor of low pressure which will allow thunderstorms to develop and travel all the way from Asia to South America. One of the things this leads to is a change in the Hadley Cells.

Hadley Cells are circulation patterns in the atmosphere. Warm air near the equator rises and then travels towards the poles at high altitude. When the air reaches the mid-latitudes it sinks back to the surface and travels back towards the equator. This circulates heat and causes the trade winds. A stronger El Nino results in stronger Hadley Cells. Live Science has a nice graphic here showing how this all works.

You can probably see where this is going. More heat is being circulated through-out the world as a result of El Nino. Changes in the heat and water vapor input in a given region will result in changes to the weather in that region. How much of a change and what kind can be expected? That is a big variable. Some regions will experience greater rainfall. Others will experience droughts. Depending on the strength of the El Nino event, the effect could be anywhere from very mild to catastrophic.

Some of the most dramatic example of El Nino effects is a series of famines that have occurred in what is modern-day India, including the Great Famine of 1876-1878 (5.5 estimated dead) and the Bengal Famine of 1770 (10 million estimated dead). These famines occurred when the monsoons did not occur and the crops failed. The famines were greatly aggravated by British mismanagement.

What has been found is that severe droughts in India always occur during El Ninos, but not every El Nino leads to droughts in India. The apparent link seems to be where the Pacific is warmest. When it is warmer in the Central Pacific, India has droughts. When it is warmest in the Eastern Pacific, India is spared. Take a look at the plot of surface temperatures, similar to the plot above.

Source: Climate Reanalyzer

The figure above showed the difference from the average. This plot shows the actual average temperature. The way I interpret this data is that it is warmer in the Central Pacific region than in the Eastern Pacific region off of South America. This could be bad news for India. The good news is that Britain is not handling the management any more.

But, El Ninos are not bad news for everyone. Actually, for us in the U.S. it will be a good thing. A typical El Nino brings mild temperatures and more rainfall for the southern half of the country. This would be particularly welcome in the mid-Plains and the Southwest where drought has been raging for many years. In fact, several states out here are at risk of running out of water.  More rain would be good.

So, let's talk about the White Elephant sitting in the middle of the room. Is global warming affecting the ENSO cycle? Quite simply, we don't know yet. There are some that believe a connection exists, but more data is needed. What is known for sure though, is the El Nino affects the short-term accuracy of our computer models. The models are highly accurate when predictable conditions exist. But, unpredictable events like ENSO and volcanic eruptions disrupt them. The good news is that when the events occur and are included in the models, the models once again become highly accurate - in excess of 95% accurate and getting better. I have not heard what the models are forecasting with the this current El Nino included, but I will keep a look out for any news.