Are Sea Surface Temperatures and Global temperatures really increasing?

Teleconnection in the Atlantic.

I posted the other day on my Facebook weather page on the current weather pattern. In the post I talked about the cool SST in the Atlantic, and the developing El Nino Modoki.  The Atlantic Multi-Decadal Oscillation (AMO) looks to be heading into its negative (cool) phase. In my post I also talked about how the increase in Northern Hemisphere sea ice extent is increasing support the idea of a negative AMO developing.  The AMO is a long-term ocean oscillation that typically last for an estimated period of 40-80 years. We've been in a positive (warm) phase since the mid 1990's.  The AMO is based upon the average SST anomalies in the North Atlantic characteristically  between 0-80N. It's been 23 years since we officially started into the AMO positive phase. So given that the AMO has a general period of 40-80 years, we're clearly within range for a switch to negative phase. We've seen in the past how the AMO can quickly go from one phase to another.

The AMO cycle involves changes in the north to south circulation and overturning in the Atlantic Ocean. The warm Gulf Stream Current off the East Coast of the CONUS is an important part of this overturning process. When the overturning circulation decreases, the North Atlantic SST become cooler. When I mentioned how the sea ice and Greenland ice and snow are increasing, it caused confusion and doubt for some who read it.  All of this led to me deciding to post on global temperatures.  I've posted in this blog more than a few post involving global warming and climate change. I've stated how I'm not convinced that humankind is the primary driver in any global warming process.  The post is going to be on SST and global temperatures. The post isn't meant  to show how/or how not global warming is occurring. But it deals with global climate so it does touch on the same subject. The following is a very complex subject. But I've tried to put it into plain speak.

Part one: the basics of how all this works.

We're seeing a rapid change in the Atlantic SST. Both the tropical Atlantic and the far north Atlantic have cooled off dramatically. But the Atlantic isn't the only place we're seeing ocean cooling.  The Pacific and the Indian Oceans have also seen cooling. Here are comparisons between SST in 2015 and 2018.

 

It's plain to see there has been a big reversal. Over 70% of the Earth's surface is covered by water; that is a lot of surface area. 97% of all surface water is in the oceans. Clearly the oceans are important.  The climate is driven by the Sun and the oceans. The Sun's energy comes to Earth through solar radiation. As the radiation reaches the atmosphere, radiation is absorbed by upper atmospheric molecules; these molecules transfer this and warm other molecules and so on ( a process called conduction) .  At some point, all of this reaches the surface containing land and water.  The oceans have control over the vast majority of the thermal energy on Earth; The total amount available is 99.9 %. Thermodynamics is a complex subject. But for our purpose we will just say, thermal energy is energy that comes from heat. Heat is the process that occurs when thermal energy is transferred from one object to another.  Looking back at the 99.9%, it is clear that the oceans have control of a lot of energy potential. This is important to remember.

The oceans and atmosphere work together in two very important ways. 1st, is through an exchange of heat, water momentum. Because of their size oceans store enormous amounts of energy in the form of heat. Most of the heat is collected along the equator; because of the Earth's rotation ocean currents transfer the warm water poleward. In this way the ocean transports an enormous amount of heat toward the poles. In the Atlantic this is called the Atlantic Meridional Overturning Circulation (AMOC); the northward flow of warmer water and the southward flow of cooler water is part of the Thermohaline Circulation (which is beyond the scope of this post). Anyway, the ocean heat rises and eventually warms the atmosphere. 

 

 

 

 

The atmosphere is also a fluid and air currents (wind) transfers heat toward the poles as well.  The northward movement moves the air through colder and colder air as it moves toward the poles. Because thermal energy transports heat into a colder environment faster than a warm one.  In this way heat is transported from the low latitudes to the middle and high latitudes.  This poleward movement is called Poleward Heat Transport (PHT), and is accomplished through air mass exchanges, storms, and ocean currents. This is where convection comes in; convection is the rising and falling of air molecules and water particles in the atmosphere and water. When we look in the sky, clouds are a visual aspect of the convective process.  A lot of this heat ultimately goes into outer space.

Part two:  Applying what I  just went over to what's going on.

I know what I posted above was a review of your Earth Science in High School, but I thought it  necessary. OK with the basic science out of the way; I will talk how all that fits into the current pattern.

Referring back to those SST images above, there has been a turnaround in worldwide ocean surface temperatures. Surface temperatures are cooler, but what about the sea temperature underneath the surface? Here is a chart done by, Dr. David Thornalley, department of Geography, University college London. The chart shows how much Ocean Heat Content (OHC) in the North Atlantic has cooled from the Surface down to 2296 feet over the last five decades.

 

Here is another Chart done by Dr. David Smeed, National Oceanography Centre, Southampton, UK. This shows how much the surface and subsurface temperatures in the North Atlantic have cooled over 30+ years.

 

Yet another chart, this one done by Dr. Christopher Piecuch, which shows the cooling trend in the Sub-polar North Atlantic (SPNA). We can see how the upper ocean and SST's have reversed from the mid 90's to Mid 2000's to the cooling trend that started around 2005 to 2015.

 

Clearly this is a huge amount of water, add in the cooling Pacific and Indian oceans and the amount is just plain gargantuan. Appling the processes I talked about, we can see how the PHT and AMOC distribution of the cool water would have an influence on atmospheric heat distribution and in turn the weather.  Those of us who live in the Northeast understand cold, snow, and ice. To me, that cool OHC has to have an impact on arctic ice conditions. 

Here is a chart from the Danish Meteorological Institute (DMI) showing Arctic sea ice volume is at its 4th highest level since June 30,2018. We can see how the volume increased through June.

This chart shows how there has be a huge spurt of ice growth in Greenland. The red line turning sharply to the right is 2018

 

Looking at this chart shows that the Arctic temperature has been below the mean all Summer.

 

Here is a chart showing the higher than average amount of snow falling on Greenland since late 2017. Also because of the cooler than average surface temperatures, there has been an average to below average melt season.

 

In Conclusion:

This brings me back to my original Facebook post  and the confusion and doubt it raised.  I've shown how the ocean and atmosphere transport heat. And how they work in concert.  Colder ocean temperatures logically lead to cooler air temperatures, which translates to a greater potential for snow and ice growth.  So the idea that ice loss has stabilized and started to reverse shouldn't be that surprising, at least to me. 

The oceans absorb CO2 and heat . The ocean has an incredibility high temperature and resistance to change, relative to the atmosphere.  The ocean circulation system is very slow.  A  storm can make atmospheric changes  in hours and then dissipate. But ,the Oceans  take months, years, and even decades to accomplish the same type of change. The heat content of the oceans is the product of centuries.

 

Also these ocean oscillation cycles have been around for millennia if not throughout history, much longer than recorded weather history, which only goes back a few centuries; Accurate weather records go back only around 150 years. The science of Meteorology is in its infancy, clearly we have a lot more to learn, about how the process of climate and weather coexist.

Again this is not about global warming for say. But it does show how the science of meteorology and climatology work and how they should be applied. This isn't meant to make you a meteorologist or climatologist; but it should give you a good working understanding how all of this works with each other.