Downward migration in the tropical circulation!
Published:
Just submitted to Geophysical Research Letters, our paper on “Downward migration of the zonal-mean circulation in the tropical atmosphere”, led by Kevin DallaSanta.
News
2020
Improving our climate models, one bias at a time
Published:
Just submitted to the Journal of Climate, our paper on “The impact of SST biases in the tropical east Pacific and Agulhas current region on atmospheric stationary waves in the Southern Hemisphere”.
Extreme variability of the stratosphere in a warming world
Published:
A quick update on an earlier post: our paper exploring the impact of global warming stratosphere-troposphere coupling, was just accepted for publication in the Journal of Geophysical Research: Atmospheres. Look here for more details!
The building blocks of Northern Hemisphere stationary waves
Published:
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.
2019
How will global warming change the coupling between the troposphere and stratosphere?
Published:
Please see our new paper exploring the impact of global warming stratosphere-troposphere coupling, just submitted to the Journal of Geophysical Research: Atmospheres.
The Impact of Numerics on Circulation and Transport in Atmospheric GCMs
Published:
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!
How does the numerical formulation of an atmospheric model affect trace gas transport?
Published:
Please see our new paper exploring the role of model numerics on trace gas transport, just submitted to the Quarterly Journal of the Royal Meteorological Society.
The generic nature of the tropospheric response to sudden stratospheric warmings
Published:
Please see our new paper on the tropospheric response to extreme events in the stratosphere, just submitted to the Journal of Climate. Update: this paper was accepted for publication in January 2020!
Imagining Simpler Worlds to Understand the Complexity of Our Own
Published:
Our commentary for the Journal of Advances in Modeling Earth Systems, “Imagining Simpler Worlds to Understand the Complexity of our Own”, was just accepted for publication. It follows on a nice paper by Zhihong Tan, Orli Lachmy, and Tiffany Shaw that recently appeared in the same journal.
Extratropical Stratosphere-Troposphere Coupling
Published:
Please see our chapter on extratropical stratosphere-troposphere coupling, just submitted as Chapter 6 of the SPARC Reanalysis Intercomparison Project, S-RIP. I’m quite pleased by the final (or at least, submitted) product! Kudos to Patrick Martineau, my co-lead on this 17 author effort which started over 6 years ago. Six years ago, a far away time when I only had one kid. To say that I’m very relieved to have this submitted is an understatement!
Speakers at Atmospheric Circulation in a Changing Climate
Published:
An updated on our workshop on the Atmospheric Circulation in a Changing Climate, 22-25 October 2019, Madrid, a joint DynVarMIP, SPARC DynVar, and SNAP meeting, hosted by Universidad Complutense Madrid, Instituto de Geociencias.
Check out our line up of invited speakers!
- Rolando Garcia NCAR, USA (Keynote talk on the history of stratospheric research modeling!)
- Blanca Ayarzaguena Porras UCM, Spain,
- Elisabeth Blanc, CEA, France,
- Paulo Ceppi Imperial College London, UK,
- Peter Hitchcock Cornell, USA,
- Martin Jucker UNSW, Australia,
- Sarah Kang UNIST, Korea,
- Andrea Lang SUNY Albany, USA
- Michael Sigmond CCCma, Canada
Imagining Simpler Worlds to Understand the Complexity of Our Own
Published:
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!
Atmospheric Circulation in a Changing Climate
Published:
Please come to our workshop on the Atmospheric Circulation in a Changing Climate.
22-25 October 2019, Madrid
A joint DynVarMIP, SPARC DynVar, and SNAP meeting, hosted by Universidad Complutense Madrid, Instituto de Geociencias. A substantial amount of travel support is available for Early Career Scientists and participants from underrepresented nations!
Now in press: model hierarchies for understanding atmospheric circulation
Published:
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. 
Why is Rome so much warmer than New York?
Published:
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?
Coast to coast speaking tours!
Published:
The whole group is hitting the road. Check out talks in Boulder, Palo Alto, and uptown, to be helf over the next couple weeks!
See you at the AMS Annual Meeting!
Published:
Coming to the AMS Annual Meeting in Phoenix next week (6-10 January)? Check out these presentations!
2018
What limits our ability to characterize the variability of the large scale circulation of the extratropics?
Published:
Please see our paper Quantifying the variability of the annular modes: Reanalysis uncertainty vs. sampling uncertainty, just accepted in Atmospheric Chemistry and Physics. Patrick Martineau and I show that reanalyses have gotten quite good, and we are chiefly limited by the finite length of the observational records. In this sense, we are starved for data, not model physics!
Can we make useful forecasts beyond a couple weeks?
Published:
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 only some Sudden Stratospheric Warmings bring stormy weather?
Published:
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!