I’ve been struggling with a model error for over a week now, and it all seemed to revolve around this Fortran subroutine “shr_sys_flush()”. The error usually showed up in the log file as a “floating point exception”, but other times I got a “segmentation fault”. I had an epiphany this afternoon that will hopefully help other people with similar errors. Continue reading
When serving as a reviewer of a journal article I usually do not reveal my identity, but some people in my field choose to self identify on a regular basis. I’ve been reconsidering my stance on this and thought I’d share my list of pros and cons. Continue reading
In spite of considering myself a “climate expert” I still struggle a bit with understanding how climate sensitivity is estimated. Admittedly, part of my confusion is because the climate system has multiple definitions of sensitivity depending on the timescale of interest. That’s why a thought experiment from a recent RealClimate.org article caught my eye. The post was written by Gavin Schmidt and describes why the earth system sensitivity (ESS) cannot be estimated by regressing temperature and radiative forcing estimates across ice-age cycles. Continue reading
This is just a personal update. I’m wrapping up my work on African easterly waves at NC State and heading out to California to start a new job at Lawrence-Livermore National Lab (LLNL). I’ll be working on a relatively new climate model called ACME for the US Department of Energy. I’m not sure how the recent political environment will affect the funding for climate work at National labs. There seems to be sufficient evidence to be concerned, but I’m not too worried at the moment. Continue reading
Understanding the various sources of heating in the atmosphere, like convection and radiation, is critically important in Tropical meteorology. Unfortunately we cannot just go out and directly measure the temperature tendency from convection. However, we can measure the temperature and estimate how it changes as a result of air flowing over an area, and then calculate the “leftover” residual temperature tendency to get an idea of how diabatic processes (i.e. convection and radiation) are heating the atmosphere. In practice, there are two widely used approaches to produce these estimates, and the goal of this article is to provide a brief comparison of them. Continue reading
I still struggle with using potential vorticity (PV) to think about atmospheric phenomena, but many extremely smart people find it very useful, so it’s a good thing to study. PV is perhaps most often used to discuss circulations on very large scales, but there has been a lot of work to make “PV thinking” work for mesoscale circulations as well. This paper describes such a theory to utilize PV to understand the maintenance of long-lived mesoscale systems in which convection plays a substantial role.
Raymond, D. J., and H. Jiang, 1990: A Theory for Long-Lived Mesoscale Convective Systems. J. Atmos. Sci., 47, 3067–3077.
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On my Global Climate page I have some long term time series of the annual global temperature, but these plots are a bit too coarse to see the recent variations in global temperature. So I created a new plot that covers that last couple years of monthly data to be able to look at this. I also included breakdowns of land vs ocean and hemispheric averages. Continue reading
I added a map of current surface temperature anomalies from the last 3 months of NASA GISS data on my climate data page. I might add maps of other data sets, but right now NASA seems to provide the “cleanest” in the sense that there is less missing data. I’m not sure if they are just faster with their data processing or if they incorporate more data than other datasets. Either way, the differences don’t bother me much, since the time series of various datasets shows reasonable agreement. Continue reading
When I’m finalizing figures I like to go through and make sure they are adequately annotated. For example, it’s nice to have the units and variable name[s] mentioned somewhere on the plot for the casual reader that’s just skimming through and doesn’t want to take the time read through the figure captions. However, lately I’ve been running into the issue of NCL incorrectly positioning the titles of the x-axis and the colorbar (see example below). Continue reading
Myron Ebell is a climate denialist who was recently appointed as an advisor to Donald Trump’s presidential campaign. Ebell’s background is in economics, which explains why most of his thoughts about global warming are about economic policy and not science. But Ebell still claims that the science behind global warming is a hoax perpetrated to harm the US economy. How does a non-scientist get so much credit for trying to dis-credit actual science? Continue reading