Tag: precipitation

“Beast from the East”

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Newly open water in the Arctic — Vladimir Lugai

The April snow falling on fruit blossoms in Europe these days may be directly connected to the loss of the sea ice in the Barents Sea in the Arctic. That was certainly the case in 2018 when the sudden cold spell known as “Beast from the East” descended on the mid-latitudes of the continent…

They are diligently stoking thousands of bonfires on the ground close to their crops, but the French winemakers are fighting a losing battle. An above-average warm spell at the end of March has been followed by days of extreme cold, destroying the vines with losses amounting to 90 percent above average. The image of the struggle may well be the most depressingly beautiful illustration of the complexities and unpredictability of global climate warming. It is also an agricultural disaster from Bordeaux to Champagne.

It is the loss of the Arctic sea-ice due to climate warming that has, somewhat paradoxically, been implicated with severe cold and snowy mid-latitude winters…

“What we’re finding is that sea-ice is effectively a lid on the ocean. And with its long-term reduction across the Arctic, we’re seeing increasing amounts of moisture enter the atmosphere during winter, which directly impacts our weather further south, causing extreme heavy snowfalls. It might seem counter-intuitive, but nature is complex and what happens in the Arctic doesn’t stay in the Arctic.” says Dr. Hanna Bailey.

And it gets more complex than that. RTFA, and understand as diverse and divergent from our “common sense” on the ground as many of these events may seem, cause and effect still happens and can be analyzed. Remedies for harmful change is the difficult bit.

NASA Spots “Hot Towers” in Tropical Storm Frank — which you should start learning about

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❝ As tropical storm Frank was forming in the Eastern Pacific Ocean, NASA analyzed rainfall and cloud heights and found “hot towers” that indicated intensification was likely.

After the Global Precipitation Measurement mission or GPM core satellite passed over System 99E, it quickly strengthened into Tropical Depression 07E and then a tropical storm. The…satellite flew directly above the increasingly organized stormy area on July 21, 2016 at 4:51 a.m. EDT. GPM found some powerful thunderstorms contained intense showers. Rain was measured by GPM’s Dual-Frequency Precipitation Radar instrument falling at a rate of over 7.2 inches per hour in a few of these convective storms.

WTF? Ever been in a tropical downpour? They average about 1½ inches/hour rainfall – up to 6″ max. I’ve been in cities with superb drainage, lots of paving leading to storm drains – at 2″ hour and experienced flooding.

❝ GPM data also provided a 3-D look at the storms. GPM’s radar…slicing through these storms found that some tall thunderstorms were reaching heights of over 9.9 miles…

A “hot tower” is a tall cumulonimbus cloud that reaches at least to the top of the troposphere, the lowest layer of the atmosphere. It extends approximately 9 miles high in the tropics. These towers are called “hot” because they rise to such altitude due to the large amount of latent heat. Water vapor releases this latent heat as it condenses into liquid. Those towering thunderstorms have the potential for heavy rain. NASA research shows that a tropical cyclone with a hot tower in its eyewall was twice as likely to intensify within six or more hours, than a cyclone that lacked a hot tower…

❝ Frank was moving toward the northwest near 12 mph and the NHC forecast a turn to the west-northwest with a decrease in forward speed during the next couple of days. On the forecast track, Frank is expected to move away from the southwest coast of Mexico and pass well south of the Baja California peninsula over the weekend.

Maximum sustained winds are near 50 mph with higher gusts. NHC said some strengthening is forecast during the next 48 hours, and Frank could become a hurricane during the weekend.

I’m not posting this to give you the weather forecast over the eastern Pacific. Just pointing out what’s happening in weather systems during a fairly normal La Nina year. Maybe even lightweight at this point. As a matter of habit in the high desert Southwest we watch for orange tops with hopes of getting a bit of precip. For you folks, elsewhere, it’s a different story.

I’d suggest you start paying attention. “Nobody told me this was coming” ain’t a terrific excuse anymore.

Growing seasons are longer – not necessarily better

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Are leaves and buds developing earlier in the spring? And do leaves stay on the trees longer in autumn? Do steppe ecosystems remain green longer and are the savannas becoming drier and drier? In fact, over recent decades, the growing seasons have changed everywhere around the world. This was determined by a doctoral candidate at the Goethe University as part of an international collaboration based on satellite data. The results are expected to have consequences for agriculture, interactions between species, the functioning of ecosystems, and the exchange of carbon dioxide and energy between the land surface and the atmosphere.

Will they make any difference in nations where politicians are bought and sold like secondhand video games at a local thrift shop run by lobbyists?

“There is almost no part of Earth that is not affected by these changes,” explains Robert Buitenwerf, doctoral candidate at the Institute for Physical Geography at the Goethe University. He has evaluated satellite data from 1981 to 2012 with regard to 21 parameters on vegetation activity, in order to determine the point in time, the duration, and the intensity of growth from the northernmost conifer forests to tropical rain forests. His conclusion: On 54 percent of the land surface, at least one parameter of vegetation activity has moved away from the mean value by more than two standard deviations.

As reported by researchers from Frankfurt, Freiburg and New Zealand in the current edition of the professional journal “Nature Climate Change,” leaves are now sprouting earlier in most of the climate zones of the far north. Although they are also dropped somewhat earlier in autumn, the overall vegetation period has grown longer. On the other hand, in our latitudes, trees and shrubs are losing their leaves later than they have up to now…

The study is clear about relevancy limited to the northern hemisphere. Whether the same factors are changing in the southern hemisphere isn’t a question. There simply isn’t sufficient data.

Meanwhile, the effects of climate change measurably affect large enough geographies to analyze and begin to understand. That is – for people and nations interested in knowing their world, managing their future for the betterment of all.

Strange clouds form when aircraft inadvertently cause precipitation

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As turboprop and jet aircraft climb or descend under certain atmospheric conditions, they can inadvertently seed mid-level clouds and cause narrow bands of snow or rain to develop and fall to the ground, new research finds.

Through this seeding process, they leave behind odd-shaped holes or channels in the clouds, which have long fascinated the public.

The key ingredient for developing these holes in the clouds: water droplets at subfreezing temperatures, below about 5 degrees Fahrenheit (-15 degrees Celsius). As air is cooled behind aircraft propellers or over jet wings, the water droplets freeze and drop toward Earth.

“Any time aircraft fly through these specific conditions, they are altering the clouds in a way that can result in enhanced precipitation nearby,” says Andrew Heymsfield, a scientist with the National Center for Atmospheric Research (NCAR) and lead author of a new study into the phenomenon.

“Just by flying an airplane through these clouds, you could produce as much precipitation as with seeding materials along the same path in the cloud…”

As far back as the 1940s, scientists have wondered about the causes of these clouds with gaps seemingly made by a giant hole punch. Researchers have proposed a number of possible aviation-related causes, from acoustic shock waves produced by jets, to local warming of the air along a jet’s path, to the formation of ice along jet contrails.

Indeed, the earliest observations implicated jet aircraft, but not propeller aircraft, as producing the holes.

Researchers in the 1980s observed that propeller aircraft could transform supercooled droplets into ice crystals, and experiments were launched in the 1990s to characterize the phenomenon.

RTFA – for the tale of how one group of researchers had the data they needed to understand this process – fall into their laps.