Blue Skies Meteorological Services congratulates Megan Walker Radtke on earning her Certified Consulting Meteorologist designation from the American Meteorological Society (AMS)!
From the American Meteorological Society:
GAINESVILLE, FL: Megan Walker Radtke of Blue Skies Meteorological Services has earned the nationally recognized Certified Consulting Meteorologist (CCM) designation by the AMS.
The CCM designation is issued by the Society to highly qualified meteorologists providing research and services to a wide variety of users of weather information, including agriculture, business, industry, and various sectors of government. These services extend beyond the traditional public service functions and statutory responsibilities of the National Weather Service.
To earn the CCM credential, a meteorologist must make application for the designation, be recommended by three associates, pass a stringent written examination, and pass an oral examination before a national board of examiners. The CCM designation is granted only to those who demonstrate a broad background in meteorology together with detailed knowledge in a particular field of specialization. CCMs must demonstrate exemplary qualities of character and devotion to high professional standards.
CCMs are highly regarded by their peers in meteorology. They are considered experts in the application of weather information to a host of practical challenges ranging from specialized forecasts to engineering design support and expert testimony on weather-related court cases. Certification enables users of meteorological services to select consultants or employees with greater confidence in the quality and reliability of the products or services they will receive.
The AMS promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. Founded in 1919, AMS has a membership of more than 14,000 professionals, students, and weather enthusiasts. AMS publishes 11 atmospheric and related oceanic and hydrologic journals—in print and online, sponsors more than 12 conferences annually, and offers numerous programs and services.
Full press release available here.
What does a birthday mean? A major birthday – the type that warrants a card declaring your exact new age, possibly by spelling it out in macabre black balloons – what does it mean? Why do we care?
It’s not like you wake up on the morning of your birthday feeling dramatically older than when you went to bed. A decade’s worth of wrinkles don’t suddenly appear on your face. Yet you are older, and on your birthday, you are acutely aware of that fact.
A major birthday reminds you that life is short and you don’t have forever to act. It reminds you of all you’ve done and all you have left to do. Then it starts playing the Final Jeopardy countdown music in your ear. Time is ticking. Better get busy.
Reaching a global average carbon dioxide (CO2) concentration of 400 ppm is that type of milestone, and we passed it in March. To put 400 ppm in perspective, consider that maximum pre-industrial CO2 levels were 280 ppm and that 350 ppm is widely considered the upper limit to avoid truly dramatic climate change. Consider that CO2 levels haven’t been as high as 400 ppm in several million years, when the world was much hotter and the oceans much higher than they are today.
Yet, besides the climate scientists who marked the passing of 400 ppm with a mixture of dismay, anger, and sad resignation, few others seem to have noticed (well, besides the United States military who consider climate change a national security risk and key business and insurance leaders who are already taking action to adapt). Nationally and internationally, we’re certainly not getting busy.
It’s as if we believe that if we don’t acknowledge what’s happening, it won’t happen. As if staying in bed with your eyes closed on your birthday somehow stays the hands of time.
But time doesn’t stand still just because we avoid clocks and mirrors – just as CO2 concentrations continue to increase whether we acknowledge it broadly and publicly or not. Of course, the critical difference between the inexorable forward march of time and the increasing concentration of greenhouse gases in Earth’s atmosphere is that we can actually do something about greenhouse gas concentrations.
We very likely can’t undo what we’ve already done (the technology just doesn’t exist to capture and indefinitely store vast quantities of atmospheric CO2). But we can slow down and eventually stop emitting new greenhouse gases, if only we muster the foresight to recognize and the willpower to address a large, costly, complex, global problem that will only get larger, more costly, and more complex with each year of procrastinated action.
Failing to even acknowledge the passage of the 400 ppm milestone doesn’t bode well, though.
So what does 400 ppm mean? What is this new world we’ve created for ourselves and our progeny?
Well, for one thing, 400 ppm means we’ve committed to major climate change – to what we’re already experiencing and more. The average residence time of carbon dioxide in Earth’s atmosphere is hundreds to thousands of years, so even if we stopped emitting CO2 tomorrow, our climate would continue to warm toward a 400 ppm equilibrium.
Of course, we can’t put the brakes on instantaneously. If you’re traveling 100 mph down the highway and slam on the breaks, you keep traveling forward as you slow to a stop. A shift to renewable energy and carbon-neutral fuels, like stopping a speeding car, takes time, and the concentration of CO2 in the atmosphere will continue to increase during that shift.
Right now, though, we’re mashing on the accelerator rather than the brakes. With the exception of 1990-2000, each decade has seen an increase in the rate of CO2 emissions. Not only are we continuing to emit carbon dioxide – we’re emitting it faster and faster each year. If we continue along our current trajectory, we’re on pace for greater than 3° C warming, and that’s just the increase in average temperature. Extremes in both temperature and precipitation tend to increase more dramatically than their respective averages.
Such climatic changes would decrease crop yields and alter agricultural zones, decrease water availability while simultaneously increasing demand, inundate coastal areas with rising seas, extend the season and range of numerous pests and insect-borne diseases, increase heat stress and heat-related illness, and increase the frequency and intensity of flooding rainfall, among many other impacts.
400 ppm means that aspects of our environment that have been our touchstones for thousands of years – food and water availability, weather and climate – will shift in unprecedented ways. The ideal locations for cities, farmland, roads, factories, homes, and military assets will modify. Processes and procedures that have been reliable will become uncertain.
In short: the assumptions upon which we have built our societies may cease to be valid.
Although some progress toward mitigation (emissions reduction) and adaptation has been made on the local level both domestically and internationally, the sort of global-scale agreement and action required to alter our current emissions trajectory remains elusive. Emissions will therefore continue to rise, and the climate will continue to shift. Governments, industries, and individuals will be increasingly impacted by a variable and changing climate, and given the lack of coordinated effort to date, the unfortunate reality is that we must prepare to protect our own interests, assets, and welfare.
Businesses and insurers looking to take the long view of their investments, infrastructure, supply chains, and insured properties need to be aware of climatic changes that impact vulnerability. Blue Skies Meteorological Services is here to help these clients understand and mitigate their climate-related risk and exposure. Contact us at email@example.com for more information.
Weather radar works by emitting microwave radiation into the sky and then listening for the signal that’s reflected back. It’s a meteorological game of Marco Polo.
All sorts of targets reflect the microwaves – raindrops, snowflakes, hailstones, bats, airplanes, and even swarms of insects. How well a given target reflects microwaves depends on its composition, size, and shape. For instance, liquid water is a better reflector of radar energy than ice.
When a meteorologist looks at a radar display, she’s seeing the reflected signal from all those targets in a given slice of sky. The radar doesn’t “know” which piece of reflected energy came from a bird and which piece came from the hailstone that moments later cracked your car windshield. The radar simply aggregates the reflected signal. It’s up to the meteorologist to interpret the results.
Until just a few years ago, the National Weather Service’s network of weather radars collected information about only two quantities: the reflected energy from a given section of sky (reflectivity) and the velocity of the targets within that section (mean radial velocity and spectrum width). In complex meteorological situations like winter weather events or severe storms, these two pieces of information provide only an incomplete picture of the type of precipitation that’s falling. When you’re just looking at reflectivity and velocity data, for instance, it can be difficult to tell the difference between hail and heavy rain. Yet on the ground, knowing the difference can be critical.
Enter dual-polarization radar technology. If you’ve ever owned polarized sunglasses, you’re already familiar with the principle of polarization. The short-n-sweet version is that electromagnetic waves (like radio waves emitted by radar or visible light waves emitted by the sun) can be oriented along a certain axis.
Tilt your head from side to side while wearing polarized sunglasses, and you’ll notice that the image you see changes – the color of the sky darkens and lightens, glare off the pavement appears and disappears. As you tilt your head, you’re actually changing the polarization of the light that’s being let through your sunglasses, and that gives you additional information about the world around you.
The same is true with weather radar. Conventional radar sends out radio pulses polarized only in the horizontal direction, so the reflected signal carries only 1-dimensional information. Dual-polarization (or “dual-pol”) radar, on the other hand, sends out both horizontally polarized pulses and vertically polarized pulses, so the reflected signal carries 2-dimensional data.
This may seem rather trivial until you consider that precipitation types have characteristic shapes. Small raindrops are spherical, while big raindrops flatten out like a Frisbee. Hailstones are roughly spherical when they’re dry but can become oblong as their outer layers melt. The two-dimensional data provides invaluable insight into what types of precipitation are present within a storm.
Here in Florida, we don’t have to worry too much about winter weather, but hail is another matter. In the lightning capital of the United States, thunderstorms are part of the scenery for much of the year, and most thunderstorms, if they are strong enough and reach high enough into the atmosphere, produce hail.
But that hail doesn’t always reach the ground. In warm, moist atmospheres, hail melts as it falls toward the ground. If the hail starts out small or if the freezing level is high in the atmosphere, hail can melt completely before reaching the ground. Dual-pol radar data can reveal whether a storm is producing hail aloft, and by examining radar data at different heights within the storm, meteorologists can determine whether and how much that hail is melting before it reaches the surface (and people’s cars and houses).
Dual-pol radar adds three more tools to the meteorologist’s kit. Each of these tools provides unique information about the size, shape, and mixture of precipitation types within a storm.
Correlation Coefficient (CC)
Correlation coefficient measures how similarly the returned horizontal and vertical pulses are behaving. It’s like looking at the world under a strobe light. From one flash to the next, how much does the image change? When the targets within a given region are of the same shape and type (for example, all medium-sized raindrops), one pulse will look much like the next, and the correlation coefficient will be high. If, on the other hand, precipitation types are mixed (like rain and hail swirling together), correlation coefficient values will be lower. Generally, the larger the hail, the lower the correlation coefficient.
Differential Reflectivity (ZDR)
Differential reflectivity compares the reflectivity values returned in the horizontal and vertical directions, like comparing how much the image through your polarized sunglasses changes as you tilt your head. Targets that are wider than they are tall (like large raindrops) have higher differential reflectivity – they reflect more horizontally polarized energy than vertically polarized energy. Hailstones, on the other hand, are more spherical and tend to tumble as they fall, reflecting roughly equal amounts of horizontally and vertically polarized energy. Hail typically has low to near-zero ZDR values.
Specific Differential Phase (KDP)
Specific differential phase is a bit more complicated than correlation coefficient and differential reflectivity. Physically, KDP measures the phase shift of the returned horizontal and vertical signals. In practice, this means that specific differential phase responds to both the shape and the density of liquid water targets. Frozen precipitation, like dry hail and snow, do not contribute to KDP – KDP “ignores” frozen precipitation and sees only liquid precipitation. Specific differential phase is therefore useful for determining rainfall rate.
As part of the dual-polarization upgrade, National Weather Service weather radars now incorporate an algorithm that estimates precipitation type from the dual-pol variables discussed above. Numerous automated hail report websites use the National Weather Service algorithm or a custom one to identify regions of hail. While such algorithms provide a useful first-pass to identify regions within a storm where hail is likely being produced aloft, they do not provide information about whether that hail is reaching the ground and at what size.
When Blue Skies Meteorological Services investigates the presence of hail for a forensic meteorology case, we don’t just run an algorithm and depend on the radar to “know” what was happening in the storm and to assume what was happening on the ground. We examine official storm reports, severe weather warnings and advisories, the atmospheric profile, and dual-polarization radar data at multiple heights and throughout the lifetime of the storm to reconstruct a comprehensive picture of the weather situation – both high in the storm and on the ground, where it matters.
Even Florida got in on this week’s pre-holiday winter chill, with Blue Skies’ home base of Gainesville, FL, breaking records for lowest maximum temperature (53 degrees on Nov 18) and lowest minimum temperature (24 degrees on Nov 20). (Yes, yes, the world’s tiniest violin is playing the world’s saddest song for the poor, shivering Floridians while upstate New Yorkers roll their eyes and stoically shovel out from 6+ feet of snow.)
This fierce onset of winter caught many people across the country by surprise. After all, it’s not even Thanksgiving. Although temperatures will be moderating over the weekend for much of the US – bringing the risk of flooding to many affected by this week’s snowstorm in the northeast and a welcome and benign warm-up to many others – the annual rollercoaster of winter weather is just beginning.
If you’ve ever wondered why winter weather fluctuates so dramatically, you’re not alone. And you can place much of the blame on the location of the polar jet stream. Yeah, we know – it’s easier to blame the meteorologist messenger. But hear the messenger out on this one.
Jet streams are like fast-moving rivers of air in the upper troposphere, at approximately the same altitudes that commercial aircraft cruise. And just as rivers of water flow faster when the elevation change is dramatic and steep, jet streams become more vigorous during the winter, when the temperature difference (“gradient”) between the poles and the equator is more dramatic (it’s beach weather year round in Key West, but come January in Maine, you’re going to want to be wearing more than just a swimsuit).
As winter progresses, the pool of cold air at the poles expands and sinks southward. Since jet streams are found where the temperature gradient is largest – at the boundary between cold and warm air – the polar jet slides southward along with the expanding pool of cold air. Although in summer, the polar jet is typically pinned near the US-Canada border, in winter it can plunge as far south as Florida.
The polar jet isn’t straight, either, but rather meanders from north to south, bringing that characteristic wintertime rollercoaster of relatively warm and sunny weather (under ridges) followed by cold, dreary, and occasionally downright miserable weather (in troughs).
Where the jet stream ends up draping itself and how strong it is determines much about the winter’s weather. Certain large-scale factors (like the presence of an El Niño or La Niña), can exert a powerful influence on the average position of the jet stream and therefore on seasonal temperatures and precipitation.
Despite indications this summer of a developing strong El Niño, it hasn’t materialized. Forecasters at the Climate Prediction Center are now calling for about a 60% chance of a weak El Niño developing this winter. This lack of a strong climate driver, like El Niño, makes seasonal forecasts somewhat less certain.
Although seasonal forecasts will never be able to predict daily high temperatures or the probability of afternoon precipitation months in advance, they can offer insight into general patterns and trends, like whether this winter is likely to be warmer or cooler than average. The strength of those patterns and trends, and therefore the skill of the seasonal forecast, is highest when strong, large-scale climate drivers dominate.
So, what about this winter’s weather? NOAA forecasters at the Climate Prediction Center are anticipating cooler than average temperatures across much of the Southeast and Southern Plains, with above average temperatures favored in the western US and throughout Alaska. Wetter than normal conditions are more likely throughout the southern US and along much of the East Coast, while drier than normal conditions are favored in the Northwest and Upper Midwest.
Given the fairly weak El Niño signal this year, forecast confidence isn’t particularly high, but for those folks in the northeast still reeling from this week’s snowstorm, take heart. That winter pummeling isn’t likely to be the season’s norm. But for those of us in Florida, it might be worth picking up another couple of ugly holiday sweaters from the sale racks… you know, for layering.
Fresh water is among the earth’s most precious resources – we drink it, cook with it, bathe in it, farm with it, and use it in the generation of much of the world’s electricity. It is fundamental not only to life, but to our way of life.
Yet water availability is not assured for billions of people across the planet, and research has indicated that in the near future, an even larger percentage of people will likely face water scarcity.
The reasons behind the projected increase in water scarcity can be boiled down to supply and demand.
The supply of fresh water comes from precipitation and is stored in lakes, rivers, aquifers, and snowpack. Weather obviously affects the water supply from season to season and from year to year, but over the long term, climate is the main driver.
When the climate is in a relatively steady state (as it was for about the past 12,000 years as humanity developed agriculture, civilization, and technology), so too is water availability. Sure, droughts and very wet periods occur, but over decades and centuries, it tends to even out.
However, when the climate is rapidly changing (as it is now), water availability becomes less certain. Precipitation patterns shift and so too do the locations and levels of lakes and rivers, aquifers and snowpacks. The sources we have depended on for water become undependable.
That’s what we’re facing now. The supply of fresh water is shifting – increasing in some places and decreasing in others. Unfortunately for us, many of the regions that are expected to see a decrease in total water availability are also heavily populated.
And here is where supply predictably meets demand: people use water. Primarily, we use it to grow food and to produce electricity. In the US, these two uses account for over 75% of total water withdrawals.
As the global population grows and becomes more industrialized, we have more mouths to feed and more high-tech lifestyles to power. If we continue with business as usual, we could face a direct conflict between agriculture, electricity generation, and other water uses by 2040. We could literally use up all of the available water in the system.
Judicious and mindful use of water (i.e. not being blatantly wasteful) and adoption of more water-efficient farming practices can go a long way towards conserving water resources (demand side), while the energy sector offers opportunities for a “twofer” — both reducing water use (demand) as well as mitigating climatic changes that threaten to disrupt water availability (supply).
All thermoelectric power systems (like the combustion of coal or natural gas to produce steam that drives turbine generators) require inputs of water, both to create the steam and often to cool it. Meanwhile, if the power plant relies on a hydrocarbon fuel, it’s also emitting carbon dioxide and other greenhouse gases.
Solar and wind power are familiar and growing alternatives to traditional thermoelectric electricity generation methods, and they offer the twin benefits of significantly reduced water use and dramatically reduced greenhouse gas emissions. For people living in developed regions that can provide the supporting infrastructure and dependable maintenance that solar and wind systems typically require, these alternative energy solutions are very promising.
But for people living in less developed or simply less accessible regions, portable gasoline- or propane-powered generators are often their only option — although perhaps not for much longer. Andrew Kazantsev and his team of Russian scientists have reportedly developed a device that collects atmospheric moisture and channels it down to the ground where it can be used for both drinking water and electricity generation.
The device, called Air HES looks like a small dirigible (aerostat) with a fine mesh hanging below it. The aerostat rises to the mid-levels of the atmosphere, where water vapor and water droplets in clouds condense onto the mesh and are funneled to the ground. The water pressure from the descending stream of droplets can then be used to power a generator and create electricity.
Kazantsev reported that the prototype Air HES was able to create approximately 5 liters of fresh water per hour from low level clouds. If the technology scales successfully, it could provide not only portable clean electricity generation but also potable water to inaccessible and/or undeveloped regions where both are sorely needed.
Technology and the need for electrical power have inarguably propelled us into this water scarcity and climate change challenge, but with ingenuity and willpower, technology may well help us out of it as well.