Floating Oasis in the Bays; Oyster Farms and Their Ecological Benefit

Floating Oasis in the Bays; Oyster Farms and Their Ecological Benefit

You might have seen a floating oyster farm while driving over Garcon Point Bridge or along Scenic Highway. Many people know them for the beautiful, tasty oysters they produce, but those farms have a major ecological benefit that many aren’t aware of. First, the oysters in those cages act as a very efficient water filter, filtering upwards of 30 gallons per day. The floating farms also act as an oasis for other marine creatures, from crustaceans to finfish, and can help increase the biodiversity in the area. Oysters are also great at sequestering carbon into their shells. Today, we will go over these ecological benefits and proper etiquette when maneuvering around the farms to enjoy some of the ecological benefits of the oyster farm.

Pompano on an oyster farm
Florida Pompano Caught Off an Oyster Farm – Thomas Derbes II

Besides being tasty, oysters are very well known for their ability to filter massive amounts of water in a single day. Research has shown rates of up to 50 gallons per day in a laboratory setting, but they filter upwards of 30 gallons per day in the wild. With most oyster farms in the area having more than 500,000 oysters on their farm, that’s more than 15,000,000 gallons of water per day per farm! Oysters can filter out any excess sediments from the water, forming them into small packets and depositing the sediment on the bottom of the bay, keeping the sediments from being re-suspended. This is very beneficial to any bay or estuary as eutrophication (More Here on Eutrophication) has been an issue in almost every bay in the southern United States.

Another benefit to oyster farms is that it is a floating oasis for all types of marine creatures. Blue crabs and stone crabs are a common threat to oysters, and they love to congregate around oyster farms waiting for an easy meal from a dropped oyster or oyster spat on cages. Common bay fish, like the Spotted Seatrout, Sheepshead, and Red Drum, have been known to hang out under the cages consuming smaller finfish and crabs, but some uncommon fish like Tripletail and Florida Pompano also patrol the cages looking for a meal. Because of its ability to hold all types of fish, fishermen love to fish around the oyster farms. Fishing around oyster farms is allowed, but most farmers want the boats to stay on the boundary of the farm and not inside of it. This is due to there being lines under the surface of the water that could potentially damage any lower unit and can cut free a line of cages. Also, it is against state law to be within the boundary of the farm if you are not an authorized harvester of that lease, and I have personally seen FWC enforce those rules. As a seasoned oyster farmer once told me “We know our farm holds fish and it is okay for them to fish the farm, heck put out some blue crab traps around it, but do not mess with the cages and stay outside of the boundary and we can all live in harmony.”

Oyster Farmer holding a Tripletail fish
Tripletail Caught Off An Oyster Farm – Brandon Smith

Last but not least is the ability of oysters to sequester carbon and excess nitrogen into their shells and pseudofaeces (aka bio-deposits). Carbon and nitrogen sequestration is a crucial service provided by oysters that helps battle global climate change. Just as they do with excess sediments, they deposit excess carbon and nitrogen into bio-deposits that accumulate on the bottom, keeping them from being re-suspended into the waters. Oyster reefs are currently on the decline around the world, and their decline has “resulted in a forfeiture of several ecosystem services” including carbon and nitrogen sequestration and water filtration. (More Here on Carbon Sequestration)

While oysters might be tasty, we have learned about some of the ecological services oysters provide to an estuarine environment. From water filtration to increasing biodiversity to carbon/nitrogen sequestration, oysters are a major benefit to any estuary and can help fight climate change and eutrophication. Next time you see an oyster farm or reef, give oysters (and farmers) a little appreciation for their hard work in helping make the world a healthier place!

El Nino and This Winter Cold

El Nino and This Winter Cold

I am sure everyone has noticed how cold this winter has been.  We have had multiple days in the 20’s here in the Florida panhandle, even some snow flurries near Pensacola.  I was first told this may happen by a Sea Grant colleague of mine who works with oyster farmers.  Six months ago, he said the Farmer’s Almanac mentioned this would be a colder than normal winter.  A few weeks later a Master Naturalist mentioned that if it was heavy “mast season” (lots of acorns on the ground) it would be a colder winter.  We certainly had a heavy mast season in Pensacola this year, acorns were EVERYWHERE.  And here we are.  As I type this it is 27°F outside. 

Though we do not see snow as often as Colorado, the panhandle does see snow from time to time. Photo: Rick O’Connor

This past week I was at a Sea Grant meeting.  We were discussing this cold and another colleague mentioned that it was an El Nino year.  That’s right… it is an El Nino year, and many know that the weather does change when this occurs. 

I first heard of the El Nino shortly after receiving my bachelor’s degree.  I was teaching at Dauphin Island Sea Lab, and we had a video series on oceanography and one episode discussed it.  It explained that commercial fishermen in Peru were the first to notice it over a century ago. 

Off Peru’s coast is a large ocean current that originates in the Antarctic, flows north towards the equator passing the west coast of South America along the way.  The water is cold and full of life.  The Andes Mountains also run north-south along the coast.  Cold air at the top of the mountains runs down towards the coast and offshore.  As it blows offshore, it “pushes” the surface water of the ocean offshore as well.  This generates an upwelling current moving from the ocean floor towards the surface, bringing with it nutrients from the sediments below.  This nutrient reach seawater, mixing with the highly oxygenated cold water, and the sun at the surface creates the perfect environment for a plankton bloom, and a large bloom she is.  This large bloom attracts many plankton feeding organisms, including the commercially sought after anchovies and sardines.  This in turn supports the tuna fishery that comes to feed on the small fish.  These are some of the most productive fisheries on the planet.

Based on records kept by Peruvian fishermen, every three to seven years the surface waters would warm, and the fish would go away.  It was lean times for them.  When it did occur, it would do so around Christmas time.  So, the fishermen referred to it as the El Nino – “the child”. 

Based on the video episode we showed the students, others began to notice warming along the western Pacific and realized it was a not a local event, but a global one.  A high school friend of mine does sound for nature films and one of his first projects was to video the effects of the El Nino on the seal nesting season in California.  As in Peru, the cold waters become warm, the bloom slows and the fish go away, with less fish the mother seals have no food so, cannot produce milk for their newborns waiting on the beach.  As horrible as it sounds, and was to watch in Mike’s film, the mothers eventually abandon the newborns to starve. 

The video we showed at Sea Lab followed marine biologists studying corals along the western coast of Central America.  Here the waters were warming as well, warmer than normal, and the corals were stressed and dying.  With orbiting satellites now in place oceanographers were able to view this event from space and watch the entire thing unfold.  These images showed that during a normal year the western Pacific had cold water along California and much of South America.  The waters along western Central America were warm.  But during an El Nino year, warm water replaced the cold, particularly near Peru.  Scientists were able to connect several events to El Nino seasons.  Increases in wildfires in the western US, people were viewing the northern lights at lower latitudes, droughts occurred where it was usually wet, floods occurred where it was usually dry, and during one El Nino season the Atlanta Falcons made it to the NFL playoffs.  Weird things were happening. 

The obvious question for science is what drives these El Nino events? 

It is understood that our weather and climate are driven by ocean currents.  The “dry air” everyone talks about in the western US is driven by the cold California Current.  Likewise, the “humid air” of the southeastern US is driven by the warm Gulf Stream.  If you alter these currents, you alter the weather and climate of the region.  How do you alter ocean currents? 

Warm water in the eastern Pacific indicates an El Nino season. Graphic: NOAA

In the 1980s, when I was teaching at Dauphin Island Sea Lab, the video suggested a connection to sunspots on the surface of the sun.  At the time, they were not sure whether the increased sunspot activity triggered the El Nino, or whether there was something else going on, but there was a correlation between the two. 

One explanation comes from a textbook on oceanography I used when I was teaching marine science during the 1990s1.  It explains the event as such…

  • During “normal years” cold water from the Arctic and Antarctic runs along the western coasts of North and South America – both heading towards the equator.  Once there, the earth’ rotation moves this water westward towards Australia and Indonesia, warming the water as it goes. 
  • Apparently, the ocean currents cannot transport and disperse these warm waters effectively once they reach the western Pacific.  Thus, warm water begins to build there. 
  • This accumulating warm water seems to reverse the trade winds that normally flow from the eastern Pacific to the western along the equator.  This wind reversal occurs between November and April.  It mentions that in the late 1990s the cause of this wind reversal was not well understood.   
  • This wind reversal is often followed by the development of twin “super typhoons” (very strong typhoons) north and south of the equator. 
  • The extreme warm water in the western Pacific affects the weather in the region and this “heat mass” expands spatially.  During this expansion, the high-pressure system that sits over the eastern Pacific, bringing them the dry air we know California for, weakens.  At the same time, the normal low-pressure system over the western Pacific weakens and, in a sense, things are flipped.  This atmospheric change is called the Southern Oscillation, and the entire event was termed the El Nino Southern Oscillation (ENSO)
  • The power of the typhoons moves warm water from the western Pacific across the equator to the America’s.  The waters there warm and the historic El Nino occurs.  This movement takes several months. 
  • The El Nino will persist for one to two years.  When the warm water eventually releases its heat, the waters cool, and normal conditions return.  Until the next El Nino forms. 
  • In the 1990s they had already noticed an increase in the frequency of El Ninos (based on old fishermen’s logs).  They suggest climate change may be driving this. 
  • During El Nino years weather patterns change globally, as mentioned above.  This altering of the weather impacts all sorts of biological processes, as mentioned above. 
  • Often, the “return” of colder water along the western Pacific “overshoots” normal temperatures and the ocean becomes colder than normal.  This has been termed the La Nina.

I kind of imagine the whole process like a sloshing pool of water flowing towards one end of the pool, bouncing off and sloshing back to the other.  But instead of water “sloshing around” it is temperatures. 

But this was 1996.  Have scientists learned anymore about this event?

Not much has changed in their explanation, other than we are much better at predicting when they will happen and alert the public so that farmers, fishermen, fire fighters, etc.  are prepared.  They do seem to be increasing in frequency. 

For the 2024 El Nino, which NOAA began alerting the public in the summer of 2023, they are predicting it to continue for several seasons2.  There is no doubt that this winter is colder than normal.  The Florida panhandle also experienced a drought this past fall.  But… during most El Nino years, hurricanes are few in the Gulf of Mexico.  We will see, and watch, how the rest of the year rolls out.


1 Gross, M.G., Gross, E. 1996. Oceanography; A View of Earth. 7th edition.  Prentice Hall.  Upper Saddle River, New Jersey.  Pp 472.   

2 El Nino / Southern Oscillation (ENSO) Diagnostic Discussion. Jan 11, 2024. National Weather Service Climate Prediction Center.  National Oceanic and Atmospheric Association.


The 2023 Year in Review – Water Quality

The 2023 Year in Review – Water Quality

Based on an annual evaluation recent competed, and feedback from my advisory committee, water quality issues are the number one natural resource concern for those who follow my extension programs.  It makes sense.  Poor water quality can negatively impact businesses who depend on clean water, waterfront property values, tourism, and the untold numbers of Florida panhandle residents who recreate in our estuaries and bays.  The water quality issues I provided education on in 2023 are focused on the Pensacola Bay system, but these issues are probably similar across the Florida panhandle.  Those issues include excessive nutrients, fecal bacteria (and other microbes), and salinity.  We also wrote one article on the increasing water temperatures occurring in the summer. 

Let’s begin with the fecal bacteria issue.  In the Pensacola Bay area, it may be our number one concern.  The Florida Department of Health posts local health advisories each week and some bodies of water are issued advisories for over 30% of the samples that are taken.  Frequently Bayou Chico (in Pensacola Bay) is issued an advisory over 50% of the samples taken.  However, in 2023 (in the Pensacola area) the number of advisories never exceeded 30% for any body of water.  Seven of the 13 swimming beaches monitored did not post an advisory at all.  This is one of the best years we have had since I began monitoring them. 

Closed due to bacteria. Photo: Rick O’Connor

In 2023 eight of the 13 water quality articles I wrote were on this subject.  Three additional articles were posted by other extension agents on our panhandle e-newsletter team.  But my annual follow up survey showed very few adopted best management practices (BMPs) they could adopt to help reduce fecal bacteria in area waterways.  The reduction was more likely due to the effort by our local city and county to improve sewage infrastructure and the fact that we were in a drought for much of the year – there is a positive correlation between rainfall and the number of advisories issued for local waterways.  Despite the fact that few readers adopted BMPs this year, and advisories declined – at least in Pensacola – we still believe adopting these practices would help reduce this issue.  We will be developing a fact sheet in 2024 to help homeowners better understand these practices and help reduce health advisories.    

Another local water quality issue that is high on everyone’s mind is excessive nutrients.  This is actually one of the largest concerns nationwide.  Excessive nutrients can lead to algal blooms, which can lead to harmful algal blooms or low dissolved oxygen, which can lead to fish kills.  In the Pensacola Bay area large fish kills have not occurred in decades, but nutrient monitoring continues.  The UF IFAS Lakewatch program trains local volunteers how to collect water samples and measure water clarity.  The samples are analyzed in the Lakewatch lab on campus in Gainesville and the results sent back to the community.  In the Pensacola Bay area, we are currently monitoring six bodies of water (three stations in each).  Nutrients values are stable, or improving, in four of the six locations.  They are slightly elevated in Bayou Chico and one station in Bayou Texar is quite high in total nitrogen.  Despite the values at those stations, no algal blooms or fish kills occurred in either Bayou Chico or Bayou Texar (or anywhere else in the Pensacola Bay area) in 2023.  There are numerous sources for nutrients in local waterways and many behavior practices businesses and residents can adopt to help reduce nutrient pollution.  In 2023 I wrote only one article on this topic but plan to provide more education in 2024.     

A body of water receiving excess nutrients can turn green and unhealthy from too much algae growth. Photo Credit: UF IFAS FFL program

A third topic that caught attention this year was the warm water that occurred this past summer.  Extreme water temperatures can decrease dissolved oxygen below levels where most estuarine creatures can survive.  Many creatures have a thermal tolerance that could have been exceeded this year.  Industries like oyster farming are negatively impacted.  Many varieties of harmful algae thrive in warm conditions.  My extension program does not conduct any citizen science project that monitors water temperatures within the bay.  Working with our local oyster farmers, the local estuary program is beginning to monitor such, and more folks are taking notice of the issue.  Extension agents posted four articles on the subject this year.  Whether the summers of high-water temperatures will become more common is unknown.  The first thought on cause is climate, and management practices on how to reduce climate change are well documented.  It is also understood that adopting such practices will not reduce intense warm summers immediately but should still be adopted for the long term.  It is also possible that the current extreme heat summers are cyclic, and things will cool down (relatively) in coming seasons.  2023 was an El Nino year.  Monitoring and time will tell how this issue will play out.  That said, it would be smart to consider behavior changing practices for the future.  Extension will post more information on this topic in 2024.   

The Gulf of Mexico at sunrise. Photo: Rick O’Connor

One issue of concern personally was the impact of increased rain on the salinity of our bay.  There has been a noticeable (and measured) increase in rainfall in recent years.  For Pensacola, we historically received about 60 inches of rain each year – one of the wetter locations in the southeast.  But over the last decade this has increased to 70 inches per year.  Along with the increase in rainfall, there has been a noticeable increase in development.  This increase in development reduces the surface area of land that would naturally absorb this rainwater and recharge the much-needed aquifer.  Instead, this rainwater is diverted from the new developments to stormwater management projects – some that work well, others that do not.  The question I have on the table is whether this increase in stormwater run-off is decreasing the salinity of area waterways?  And, if so, is it to a level where local marine species (and those we are trying to restore) will be negatively affected?  To answer this question, I have trained volunteers to monitor salinity at locations around the bay area.  They are monitoring once a week, at the surface, near the shoreline.  Though the sampling location is not ideal, it is what our volunteers are able to do.  I had determined that the data would be collected until each volunteer reached 100 readings (about two years).  As of the end of 2023, five of the 13 monitoring locations (38%) have reached that 100-reading mark.  We know that the turtle grass and bay scallops, both species we would like to see increase in our bay, require salinity be at (or above) 20 parts per thousand.  Though there are many more weeks of monitoring needed to reach our mark, current data suggests that salinities have not altered from data posted decades ago and are high enough for these species to return in areas where they historically existed. 

I will finish this review with a comment that articles were posted in 2023 on issues I am not directly involved with, but know they are a concern in many areas of the panhandle.  Private drinking wells being one.  There were several articles posted by Dr. Andrea Albertin addressing this issue in 2023 and for those interested in this topic I recommend they read these, and/or reach out to her directly (albertin@ufl.edu.).  There was also an article that focused on water quality improvement BMPs in general posted by Khadejah Scott (Wakulla County) that may be of interest.  https://nwdistrict.ifas.ufl.edu/nat/2023/10/05/simple-steps-to-improve-local-water-quality/.

With this being a large issue with many in the Florida panhandle, extension will continue to publish articles and have programs on this topic.  Reach out to your local county extension office for more information. 

How Hot Can You Go?  Warmer bay waters and the thermal maximums of estuarine creatures

How Hot Can You Go?  Warmer bay waters and the thermal maximums of estuarine creatures

I attended a meeting recently where one of the participants stated – “We have been looking at a lot of water quality parameters within our bay in recent years, and plan to look at more, but has anyone been looking at temperature?”

What he was referring to was that the focus of most monitoring projects has been nutrients, dissolved oxygen, etc.  But most agencies and universities who have been conducting long term monitoring in our bays are collecting temperature data as well.  His question was not whether they have or not but has anyone looked at this long-term temperature data to see trends. 

I know from some of the citizen science monitoring I have been involved with that temperature is collected but (anecdotally) does not vary much.  It is like pH, we collect it, it is there, but does change drastically (anecdotally) over time.  However, it has been a very hot year.  This “heat dome” that has been sitting over the Midwest and southeast this summer has set records all across the region.  Someone monitoring water temperature in East Bay recently reported surface water temperature at 96°F (36°C).  Many have stated that swimming in our waters at the moment feels like swimming in bath water.   It’s not just warm in your yard, it is warm in the bay.  And this brings up the question of thermal tolerance of estuarine species.

All creatures have a temperature tolerance range.  They resemble a bell curve where you have the thermal minimum at one end, the thermal maximum at the other, and the “preferred” temperatures near the top of the bell curve (see image below).  Many creatures have a large tolerance for temperature shifts (their bell curves extend over a larger temperature range).  You find such creatures in the temperate latitudes where temperature differences between summer and winter are larger.  Others have a lower tolerance, such as those who are restricted to polar or tropical latitudes.  Within an estuary you can find creatures with varying thermal tolerances.  Some have a larger tolerance than others.  Ectothermic (cold-blooded) creatures often have a wider range of temperatures they can survive at than endothermic (warm-blooded) ones.  Homotherms (creatures who maintain their body temperature near a fixed point – such as humans 98.6°F/37°C) expend a lot of energy to do this.  When environmental temperatures rise and fall, they have to expend more to maintain it at their fixed temperatures. 

Image provide by Research Gate.

It is also true that most creatures prefer to exist near their thermal maximum.  In other words, the bell curve is sort of skewed towards the warmer end of their range.  But what is their thermal maximum?  What happens when they reach it?  How hot can they go?

Local waters are warmer this year. Photo: Rick O’Connor

The studies I reviewed suggested that the thermal maximum is dependent on other environmental factors such as salinity and dissolved oxygen.  In most cases, the higher the salinity, the higher the thermal maximum was.  I looked at studies for the eastern oyster (Crassostrea virgincia), the brown shrimp (Farfantepenaeus aztectus), the blue crab (Callinectes sapidus), the Spot Croaker (Leiostomus xanthurus), and the pinfish (Lagodon rhomboides).  The oyster, shrimp, and blue crab support important commercial fishery.  The spot croaker is a dominant fish species in the upper estuary where the pinfish is a dominant species in the lower sections.  These studies all suggested that again, depending on salinity, dissolved oxygen, pressure, and rate of temperature increase, the thermal maximum could happen as low as 30°C (86°F) and as high as 40°C (104°F), with many having a thermal maximum between 35-40°C. 

At these temperatures proteins begin to denature and biological systems begin to shut down.  Most of the studies determined the endpoint at “loss of equilibrium” and not actually death.    Our estuaries can certainly reach these temperatures in the summer.  Again, one recent reading in East Bay (within the Pensacola Bay system) was 96°F (36°C). 

So, what do these creatures do when such temperatures are reached?

The most obvious response is to move, find cooler water.  These are often found in deeper portions of the bay below the thermocline (a point in the water column where water temperatures significantly change – usually decreasing with depth).  However, many sections of our estuaries are shallow and deep water cannot be found.  In these cases, they may move great distances to seek deeper water areas, or even move to the Gulf of Mexico.  In some cases – like with oysters – they cannot move, and large die-offs can occur.  Other responses include lower metabolic rates and decline in reproduction. 

We know that throughout history, there have been warmer summers than others and heat waves have happened.  In each case, depending on other environmental factors, estuarine creatures have adapted, and some members have survived, to keep their populations going. 

We know that large scale die-offs have occurred in the past and the tougher species have continued on. 

We also know that the planet is warming, and it would be interesting to look at how the water temperatures have changed over the last few decades.  Are they increasing?  Are they reaching the thermal maximums of the creatures within our bay?  How will these creatures respond to this? 

How hot can they go?

Beat the Heat – Avoid Heat Related Illnesses

Beat the Heat – Avoid Heat Related Illnesses

It’s no surprise that it gets hot in Florida during this time of year. We are the “Sunshine State” of course. The National Weather Service issues heat advisories when the heat index is forecast to be over 100°F for at least 2 days and nighttime temperatures are forecast to be above 75°F. The Excessive Heat Warning is when the heat index is forecast to be above 105°F for at least 2 days and nighttime temperatures are not expected to drop below 75°F. If you are like me, I have received many notices of heat advisories and excessive heat warnings over the last few weeks. Just because we are accustomed to this heat does not mean we should not heed these advisories and warnings. 

Heat related illnesses include sunburn, heat rash, heat cramps, heat exhaustion, and heat stroke. Heat rash and sunburn can happen even when temperatures are not extreme like now. Remember to apply sunscreen and wear lightweight clothing to protect your skin from the sun’s UV rays. For heat rash, do not allow moisture to stay close to your skin. Wear loose fitting clothing and try to minimize sweating. 

Heat cramps, heat exhaustion, and heat stroke are progressive stages of effects of excessive heat on your body. The first stage is muscle cramps or spasms. Once you notice this, you should remove yourself from the heat and physical activity. Drink water or a sports drink and wait for the cramping to subside before returning to physical activity. The next stage is heat exhaustion. The symptoms include heavy sweating, clammy skin, fast heart rate, nausea, dizziness, and fainting. If you experience these symptoms, move to a cool place, and loosen clothing. You can also put cool cloths on your body or take a cool shower or bath. Sip water. If you ignore these symptoms, you can progress to heat stroke. Symptoms of heat stroke include high body temperature, dizziness, headache, nausea, confusion, loss of consciousness. If you find someone with heat stroke, call 9-1-1 at once and move the person to a cool place. 

graphic with sun, thermometer, and water bottle

Here are a few steps you can take to avoid heat related illness: 

  1. Wear loose fitting, lightweight clothing. 
  1. Drink plenty of fluids and stay hydrated. 
  1. Avoid excessive caffeine and alcohol intake. 
  1. Schedule outdoor activities during the cooler parts of the day. 
  1. Plan for breaks in cooler places when enjoying the outdoors. 
  1. Don’t forget your sunscreen. 

For more information on heat related illnesses and extreme heat in Florida: 

NWS – Heat Safety 

CDC – Extreme Heat 

Our Intense Weather and Climate Change

Our Intense Weather and Climate Change

Everyone has noticed the intense weather that crossed the United States in recent years.  Tornadoes are hitting communities throughout the Midwest, but are also hitting places like Seattle, southern California, and even recently Pensacola Beach.  Thunderstorms, though common, are occurring in waves.  Typical summer days here in the panhandle include afternoon thunderstorms, but recently there have been daily squall lines beginning as early as 9:00am.  I was recently camping out west and we encountered three hailstorms.  Though these do occur out there, they were becoming a common thing and were also encountered in multiple states.  And of course, there are hurricanes.  Some are more intense and increase intensity as they come ashore, instead of decreasing as has been the rule over the decades. 

This squall line formed early in the morning. One of many morning thunderstorms formed over a period of a week in the summer of July 2023. Photo” Rick O’Connor

Many have pointed the finger at climate change as being part of the reason why these intense weather events are increasing, and climatologists have said for decades this could happen.  To better understand what is driving these storms, I decided to grab one of my old college textbooks from the shelf and read what actually forms and fuels these weather events.  The Nature of Violent Storms was published in 1961, and reprinted in 1981, by Dr. Louis Battan.  Though many things that were unclear at the time of the writing have been discovered, the mechanisms that generate and fuel these storms were understood. 

The mechanism that begins storms is convection cells within the air rising from the earth’s surface.  The air moving over warm land or water warms as well and begins to rise.  The rising air lowers the air pressure at the surface and is called a low pressure system.  We associate low pressure systems with storms.  These storms form due to unstable air masses in this rising column of air.  The greater the temperature difference between the warmer air near the ground, and the cooler air in the upper atmosphere, the more unstable the air becomes and the faster the column of air rises.  As the air rises it begins to cool, become denser, and falls back to earth like a water fountain shooting water into the air.  This is the convection cell we have heard about. 

However, if the air mass holds a lot of moisture (humidity) the release of heat from this humid air mass rising in the column can warm the environmental air mass surrounding it enough to cause the rising air mass to continue higher into the atmosphere increasing its speed while doing so.  We can see this as cumulus clouds building over the landscape and, if humid enough, you can literally watch the thunderhead build.  If supplied with enough water vapor and heat, these thunderheads will grow all the way to the tropopause (the lower layer of the stratosphere where the atmosphere itself begins to warm, not cool) and form the “anvil” shape of a thunderhead we are all familiar with.  As a college student taking coastal climatology (the class this book was associated with) we would sit outside of Dauphin Island Sea Lab at mid-afternoon and bet on which thunderhead would reach the tropopause first. 

The upper layer of the lower atmosphere is quite cold.  Here the releasing water vapor condenses into rain droplets, ice, and often hail.  They fall back towards earth.  Much of the ice and hail melt before reaching us but under intense conditions this frozen precipitation can reach the earth’s surface as hailstones, some being as large as three inches across.  One storm we encountered in Colorado this year had hailstones about the size of a large marble.  We heard that at a nearby amphitheater the hail reached the size of golf balls and many who were there to see a concert (and there was no cover to hide) were taken to the hospital. 

A hail storm encountered by the author in Colorado. Photo: Rick O’Connor

The one common denominator in the formation of such storms is the presence of a warm landmass or water body.  The warmer these land masses and water bodies are, the more energy there is for the enhanced convection and severe storm formation.  And these land masses, and water bodies are getting warmer. 

Hail stones are formed from ice that manages to remain solid as precipitation in very unstable air masses. They can reach three inches across. Photo: Rick O’Connor

What has changed is the atmosphere itself.  There are gases within the atmosphere that allow solar rays to pass through reaching the surface of the earth, but do not allow the warmed air caused by the warming of land and sea from this solar radiation to escape back into space – the so called “greenhouse effect”.  This is actually good; it keeps our planet at a warmer temperature than it would be if these gases were not present and allows life to exist here.  However, an increase in these “greenhouse gases” can increase the overall temperature and create problems – intense storms being one of them.  The surface of the planet Venus is around 900°F.  Even though the planet Mercury is closer, Venus is warmer due to the heavy amount of greenhouse gases in its atmosphere.  At temperatures like this, it is understandable that life does not exist there, and scientists do not believe it could.  Getting scientific instruments to the surface of Venus is difficult due to the large amount of sulfuric acid in the clouds, much of this coming from intense volcanic activity there. 

The greenhouse effect. Image: NOAA

On Earth, our temperatures are climbing – slowly, but climbing.  As the atmosphere warms due to the greenhouse effect, it increases the temperature of the land mass and water bodies.  Increased temperatures in Pensacola Bay have triggered some die offs of oysters, and the warming Mobile Bay has increased the number of jubilee’s occurring there.  Remember, high water temperatures mean low dissolved oxygen levels.  Increased surface temperatures will create more unstable air masses and a breeding ground for the formation of vortices that can, and do, lead to more intense thunderstorms and tornadoes.  Surface temperatures are increasing in locations where historically such weather events have not been common, like Seattle.  Recently, I had to make a trip to a department store at one of our local malls.  Leaving the house, as I crossed our wooden deck and walked through the yard to the truck, it was definitely warm – it was July.  However, when I arrived at the store, where all was concrete and asphalt, the temperature difference was striking.  It was MUCH warmer.  Actually, at the store front it was almost unbearable.  In many of our large cities, and even in smaller ones, we have converted much of the natural landscape to concrete and asphalt, which is increasing the surface temperatures even more, and enhancing unstable air even more.  We have all heard that large cities create their own weather, and it is true. 


How do we turn this around?

I see two paths.  (1) Reduce the source of the heating – greenhouse gases.  (2) Mitigate the impacts of the heating. 

There are several sources of greenhouse gases, and these have been discussed in other articles, but certainly the use of fossil fuels is a major one and reducing our dependency on these would be a good start.  But we are moving very slowly on this, the will to do it just is not strong enough. 

To mitigate the impacts, we would need to re-think how we grow and develop the landscape.  Even today, many of the new subdivisions I see clear all of the vegetation, place the houses close together with little or no green space, use asphalt roofs, and replace little or none of the vegetation.  It seems our development plan does not have the will to make some much needed changes in planning either.  There are many ways in which we can develop our landscape to help mitigate the warming that is occurring.  Many researchers at the University of Florida have been working on this for many years.  For ideas and suggestions, just contact your county extension office. 

Based on the 2021 Intergovernmental Panel on Climate Change’s report, we may be past the tipping on sea level rise, but we are not on other negative impacts of climate .  It is understood that with any mitigation efforts right now, there will be a lag time of several years before things begin to turn around, it is not too late.  We can do this.