Gravity Waves Help With Weather Prediction

 

Gravity waves form in the atmosphere as a result of destabilizing processes, like during weather fronts, storms or when air masses stroke over mountain ranges. They can occasionally be seen in the sky as bands of cloud, however, they are mostly “invisible” due to their short wavelength.

Although gravity waves have comparatively short wavelengths of between just a few hundred metres and several hundred kilometres, at times they influence the transport of water vapour as well as large-scale winds and temperature distributions to a considerable degree. This effect is strongest in the upper layers of the atmosphere. These, in turn, have such a strong effect on the lower layers too that a realistic modeling of weather and climate in the atmosphere is impossible without giving due consideration to gravity waves. They also play a significant role for air traffic in predicting turbulence and are an important factor in weather extremes, such as heavy rain or storms.

The development of gravity waves can now be reproduced much more reliably in high-resolution numerical models, which has been used to improve parameterizations, which serve to describe the influence of gravity waves, in weather and climate models with typically coarser resolution. The weather and climate model ICON has been refined and is used by Germany’s National Meteorological Service (DWD) and the Max Planck Institute for Meteorology.

The new model, UA-ICON, allows more precise predictions for the upper atmosphere and can be operated with different resolutions, so that gravity waves can either be simulated in it for test purposes or must be parameterized in the operational mode. The advanced parameterizations are now being integrated and tested in this model.

The project will also focus on impacts on weather prediction and climate modeling. An important aspect in this context is a better description of the interaction between gravity waves and ice clouds (cirrus), undertaken in cooperation with the University of Mainz. It could well be that this plays an important role for the climate.

Paths To Forest Restoration Discovered

    

Recognizing the incredible value of forests in providing habitat, storing carbon dioxide, purifying water and more- people around the world are working to restore forests destroyed in the past by human activities, however, in some places, it’s practically impossible.

Among the toughest forests to regenerate are tropical dry forests, species-rich ecosystems found near the equator in regions that experience alternating wet and dry seasons. Most of these forests, which help keep water clean and provide valuable habitat for wildlife, have been replaced by farms and cattle pastures. Now, as conservationists work to replant deforested areas, they’re finding that the already challenging, high-clay soils underlying them have been degraded to an extent that makes it hard for tree seedlings to sink their roots.

To find out what works best for reestablishing tropical dry forests, researchers planted seedlings of 32 native tree species in degraded soil or degraded soil amended with sand, rice hulls, rice hull ash or hydrogel (an artificial water-holding material). After two years, they found that tree species known for traits that make them drought tolerant, such as enhanced ability to use water and capture sunlight, survived better than other species. Some of the soil amendments helped get seedlings off to a good start, but by the end of the experiment there was no difference in survival with respect to soil condition.

The study demonstrates that it is possible to grow trees on extremely degraded soils, which provides hope that we can indeed restore tropical dry forests. It also provides a general approach to screen native tree species for restoration trails based on their functional traits, which can be applied widely across the tropics.

In follow up, the researchers have planted additional plots using the 12 top-performing species identified in the study. They are using these additional study sites to explore the appropriate mixes of species to plant at different stages of a forest’s life.

This continued work will help to further develop best practices for the restoration of tropical dry forests.

California May Ban Gas Car Sales

California is world renowned for it’s progressive climate policies, but Governor Jerry Brown isn’t satisfied to rest on his laurels. The four term Governor (by law, this current term is his last) wants to ban gasoline powered cars in the near future, a statement of intent that has been popular with climate-conscious nations recently.

China recently vowed to phase out the sale of gas cars by the year 2040, and they’re only following in the footsteps of India, France, Britain, and Norway, among others. And, because the United States under the leadership of climate-change-denier President Donald Trump does not look likely to make such a commitment nationwide any time soon, Brown feels that California should lead the way.

Mary Nichols, chair of the California Resources Board, has been party to Brown’s wish, though there isn’t any formal legislation to back it up – yet. “I’ve gotten messages from the governor asking, ‘Why haven’t we done something already? [Governor Brown] has certainly indicated an interest in why China can do this and not California.”

Californians buy an estimated two million gasoline powered cars per year, roughly 20% of national automobile sales. If Californians suddenly insisted those cars were powered by alternative energy, it would be a huge boost towards getting the rest of the country on board with making the switch as well. Brown is said to be considering implementing the ban as early as 2030.

A Midwestern Farmer’s Dilemma

The Keystone XL Pipeline remains an incredibly divisive project, and usually those divisions fall along party lines in predictable patterns. This is why the subject of Ted Genoways’ new book, “This Blessed Earth: A Year in the Life of an American Farm Family,” is so interesting. Rick Hammond’s Nebraska farm is on the pipeline’s pathway, and he’s not happy about it.

You’d think this would put him square in the camp with organic, sustainable and cruelty-free farming, but Hammond also uses satellite guided machinery, chemicals, and GMO seeds to grow his products and raise his cattle. In other words, he’s not the type of Midwest farmer you’d think would complain about having an oil pipeline bring jobs into his neighborhood.

Hammond rebels against this characterization and the idea that his position on the pipeline should be reflected in his farming. “The people in the food movement have a lot of ideas about how farming should be reformed, and I think a lot of them are correct,” Genoways says, “but they’re not grounded in very much knowledge of the pressures farmers face and the reasons they aren’t reforming.”

In other words, Hammond lives in the real world, where ideals aren’t always practical in the present. This reflects how many in the current political and economic climate feel in America. They have lofty convictions that they’d like to live by, but that they don’t have the luxury of following through on currently. The world is changing, but for many in middle America, it isn’t changing fast enough.

Finally, Good News About CO2!

We have some welcome and rare news on the climate change front: folks, carbon emissions did not grow for the year of 2016! This marks the third year in a row that carbon emissions have stayed the same instead of steadily increasing, according to the Netherlands Environmental Assessment Agency! Now that’s cause for celebration!

The stabilization is likely due to the slow decline of coal and the increased usage of natural gas to produce energy; it produces more electricity at a more efficient rate than it’s sooty counterpart. However, the real winner here is renewables, such as solar and wind power, which are changing the game in the energy sector (as I’m sure you’re tired of hearing).

However, not all the news is good news. Methane increased this year, raising the overall greenhouse emissions for 2016 by .5%. Methane comes largely from cattle, as we recently reported, but also from leaks at natural gas facilities like Aliso Canyon. Also, we should note that this report does not take into account the natural resources (like forests and peatlands) lost during the year.

Still, says climate economist Nicholas Stern, the report shows we’re headed in the right direction. “These results are a welcome indication that we are nearing the peak in global annual emissions of greenhouse gases.” The numbers are slowing to a halt, and with any luck we’ll hopefully soon start to see them slide backwards!