Behemoths of the tropical atmosphere and ocean system

So first of all I want to wish everyone a happy thanksgiving and hope that they are have a great weekend. This is one of my favorite holidays, not just because of the turkey!

So I just wanted to give an update on what my plots are showing while my peca pie bakes. It's the first time I make a pecan pie, so I hope it doesn't explode or something!

Also I want to point out that most of the things I write in this blog, particularly on the MJO status,  can be found on my UW-Atmospheric Sciences website (http://www.atmos.washington.edu/~angelf88) , so feel free to take a look at them. I also archive some of these plots. If you want to contact me or something, even if it's to send some hate (I hope not), you can so here!

So first of all, are you familiar with some of the most powerful phenomena of the atmosphere and ocean system. Can you recognize them if I put a picture of them below? Some of them might be at play right now! They range in spatial and temporal scales, from a few hundred kilometers and several days (like a hurricane), to global scale and lasting more than a year (like ENSO).

Hurricane Felix (2007). Tropical cyclones are some of the most impressive phenomenon on Earth. There are stories of them all the way back to the beginning of the last millenium, and them some. They are some of the most studied phenomenon on  Earth, and yet we still struggle to understand them, particularly the way they intensify.

Active MJO, January 2006. MJO's were discovered a little bit more than 40 years ago.  Even though an even lasts 30-90 days and convection is confined in the tropics, their circulation affects the whole globe, providing great challenges for forecasts. The MJO is one of the major challenges in our field at this moment.

The 1997 El Niño. One of the strongest ever recorded. ENSO is probably one of the most important oscillations in the coupled atmosphere and ocean. Its effects are massive and worldwide. Its presence can mean the difference between wet and dry, cold or hot, and so much more!

So the whole point of this short writing is to observe the different scales in which different phenomena can affect weather. This is why tudying this field can be so challenging, and why we still have such a long way to go on forecast improvement and better understanding on how the air we breathe ticks. I will make another blog post talking more about this topic in the future.

Latest GFS runs on the MJO


The latest model runs of the MJO keep showing fairly strong activity over the Indian Ocean, we can see it propagate eastward slowly, and as of yesterday or so you can see some strong activity right over the Maldive islands (about 73 degrees west, 0.2 degrees south or so) where  DYNAMO is happening.  The whole active phase looks very classi, a behemoth of clouds covering a good deal of the ocean. (thanks to Luke Madaus for giving the MJO this wonderful term)



A feature I've been meaning to mention is the tilting with height of moisture convergence over the region, which is likely an indicator of convective and stratiform clouds in the area. The major one in the back has had that shape for a couple of days now, and seems to be in the back end of most cloud activity, according to the model run.

A LOOP of the cross section below shows the feature just suddenly popping up from a lower level convergence feature that was moving eastward and becoming this large, coherent, area that we see below. Also the model indicates strong upward motion preceding it, and downward motion right below the tilt, as pointed in the figure below..

A map of moisture convergence at two levels shows a very well defined feature, with the 500 hPa showing signs of a classic "swallowtail" feature prominent in MJO events.  Notice how inmense convergence is near 80 degrees with the arrows showing a center almost at the equator!. Loops of these images can be found here (on the loop link on the page).