The kitchen has been busy: two papers are now in press. First, Marianna Linz’s paper on mixing in the stratosphere was just accepted by the Journal of Geophysical Research: Atmospheres. We show how the vertical gradients in age allow us to quantify the exchange of air between the tropics and extratropics. Increased mixing leads to better baking, right? In this case, it’s very important for transporting ozone and water vapor through the stratosphere, two trace gases that impact us on the surface, protecting us from UV radiation and keeping us a bit warmer, respectively.
As my family and I cannibalize each other on our solitary descent into the abyss that is remote elementary education, intrepid collaborators will be hitting the virtual road to present at the vEGU this April! Check out these presentations:
Despite tremendous advances in our understanding of the atmosphere and our capability to simulate it with numerical models on the fastest computers in the world, their remain processes that we can not accurately represent from basic physical principles. In some cases, it is an issue of computational power: we cannot resolve all relevant scales for climate prediction, from planetary scale weather systems (10^6=1,000,000’s of meters) to cloud and aerosol particles on the microscale (10^-6=0.000001 m). In other cases, we do not yet know all the relevant physics! We still need to do our best to represent these processes based on what we can simulate. Traditionally this has been done with physically motivated schemes, but there’s growing in interest in using machine learning to help. Here we take the first steps of using an artificial neural network to help parameterize atmospheric gravity waves.
Suppose you could build your own planet: create continents, lift mountains, carve out the bathymetry of the ocean to help direct its currents! What would you need to do to create the monsoonal circulation on Earth, the sharp seasonal transitions in rainfall that play such a huge role in the climate of South and East Asia?
Our review article on Sudden Stratospheric Warmings, led by Mark Baldwin and Blanca Ayarzuguena, was just accepted for publication in Reviews in Geophysics. We’ve learned a great deal about “explosionartigen Stratosphärenerwärmungen” since they were first discovered by Prof. Dr. Scherhag almost 70 years ago!
A number of postdoctoral positions are available through a project funded by NSF’s Cyberinfrastructure for Sustained Scientific Inquiry (CSSI) program. This highly collaborative project between four institutions will develop data-driven parameterizations of atmospheric gravity waves and explore their impact on climate variability and change. The project will involve novel balloon-based observations, high-resolution atmospheric model simulations, machine learning, and atmospheric modeling.
I am aware that things have been rather quiet on my blog in the last months. In addition to my new found profession as an elementary school teacher (alas, not a very good one, but our efforts to get the kids transferred to another class were fruitless), we’ve been hard at work on revisions. Some very detailed and careful reviews allowed us to make two good papers even better!
Please see our new paper exploring stationary waves in the Northern Hemisphere, just accepted in the Journal of Climate. What are stationary waves, you ask? In laymen’s terms, they are variations in climate with longitude, for example, the reason why the weather in Madrid is quite different from that here in New York, even though we’re both situated at nearly the exact same latitude.
Aman Gupta is defending his thesis on Wednesday 18 December at 1:15 in Warren Weaver 1302. Come see the world’s leading expert on trace gas transport through the stratosphere by the dynamical cores of atmospheric models!
Just submitted to JAMES: our commentary on a nice paper by Zhihong Tan, Orli Lachmy, and Tiffany Shaw that recently appeared in the same journal. We make the case that models of simpler atmospheres – which are distinct from simple models of our atmosphere – can help us understand the circulation response of our atmosphere to global warming, and enable us to build better climate prediction models!
Our manuscript for Reviews of Geophysics, Model hierarchies for understanding atmospheric circulation, was just accepted! Way to go Penny! In particular, I like our new figure illustrating the web of models around state-of-the-art Atmospheric General Circulation Models (AGCMs). These hierarchies of simpler models enables us to understand and improve our weather and climate prediction systems.
While Rome and New York receive the same amount of energy from the sun (being situated at the same latitude), the former experiences a much warmer climate, particularly in the winter months. This is due to large variations in the atmospheric flow with longitude, known as “stationary waves”. It has long been known that these variations are generated by differences between land and sea, topography, and variations in sea surface temperatures. But just how do these different components add up to produce our climate?
Deterministic weather forecast are only possible for one to two weeks. (Or in other words, we just can’t predict whether it will be sunny or rainy 14 days from now.) But can we say something about the weather over the next few weeks, for example, will it be warmer and drier than average, even if we can’t say exactly which days will be sunny?
Why do some Sudden Stratospheric Warmings appear to influence the troposphere, shifting the jet stream equatorward over the next 2-3 months, while others don’t? Much of the issue is tropospheric variability, which can overwhelm the influence of the stratosphere. However, our recent study, The Downward Influence of Sudden Stratospheric Warmings: Association with Tropospheric Precursors shows that there are regional patterns that can help us predict whether a Sudden Warming is more likely to have an influence on the troposphere!