csnavywx

Incidentally, this isn't the first setup like that this year. The one in January that produced a forced line of low-topped showers had a somewhat similar evolution (CAA and dry slotting aloft with some surface heating). It lacked the more beefy mid-level CAPE or it would have produced a similar result wrt wind damage.

Normally with that much shear and low cape, updrafts are simply tilted and sheared out of existence before they can do much. Yesterday was different. The total amount of cape was low (~500J/kg), but it was very low topped (around 450-500mb top, around -20 to -25C, just cold enough for charge separation and lightning) and concentrated. A more "normal" sounding with a higher top would've resulted in values 2-3x that large. That didn't matter in this case. The amount of instability was concentrated vertically and parcel acceleration was large enough to balance the shear somewhat and thus these shallower, but stronger updrafts could tap into the extremely high ambient helicity.

Should have a few more days of big gains from the remnant open water area in the Laptev, then a marked slowing as the Pacific side OHC remains high and the weather pattern turns hostile for growth.

Yeah, the transition time from supersaturated to undersaturated is very short, on the order of ~20 years and every one of those papers focuses on the 2030s as the onset date. 450ppm seems to be the threshold. It starts small in areal extent and depth, but once onset begins, it takes very little time to overtake virtually the entire Southern Ocean in wintertime and begins to encroach on mid-latitude waters with rather alarming speed. I can't imagine that's going to be good for some species (as the authors rightly point out). It also kind of forms a pincer, in that, species will be migrating towards the poles as acidification migrates towards the equator, putting the squeeze on species adaption.

You can always use Sci-hub! Chances are your taxes were used to fund the research anyways. (This paper has the following comment listed in acknowledgements: We acknowledge support from the National Science Foundation Ocean AcidificationProgram (OCE-1314209). This is IPRC publication no. 1152 and SOEST publicationno. 9508. )

Additional paper: https://www.nature.com/articles/nclimate2844

https://www.eurekalert.org/pub_releases/2019-03/uoaf-soa031119.php This is just concerning the appearance of a widespread undersaturation horizon near/in the mixed layer in the next 20 years or so. https://www.pnas.org/content/105/48/18860 It's an older paper, but we are very closely following the emissions scenario used (IS92a), so these dates probably aren't far off. Once aragonite undersaturation appears at the surface, it takes just 20-30 years for it to encompass basically entire Southern Ocean south of 50-60S. If we screw around long enough, by near the end of the century, that will spread towards the tropics and then calcite undersaturation will appear in the Southern Ocean. Once calcite is knocked out, you can kiss most shelled creatures goodbye. The thresholds for this seem to be at ~450 and ~650ppm. We're rapidly coming up on the first one.

I'm still reading through that paper. From what I've read so far, the change is on the order of 0.25 pH post-impact. We've had around 0.15 of change so far, but this hasn't eaten into the aragonite buffer enough to cause undersaturation at the surface or in the mixed layer in most locales so far. That is due to change sometime in the 2030s in the Southern Ocean and the waters next to Antarctica (where colder SSTs allow more gas to dissolve). From there it will spread rapidly across seasons and area. It's not talked about much and my suspicion is that it won't be until that starts to occur.

Looks like the ESS and Laptev are finally starting to freeze from both sides. That usually results in a quick jump in extent numbers as two ice fronts develop temporarily. Once that's done (by first or second week of Nov), the Pacific side will be the place to watch. Lots of heat to bleed off in the Chukchi and western Beaufort seas. Depending on how the weather goes, those might not freeze over until the new year. The southern Chukchi has a chance of not completely freezing over at all or only for a brief period in Jan-Mar. The warm water there is particularly deep this year.

And a frost free period of 85 days. Remarkable. One wonders what that's doing to the permafrost this year. Last few years the situation further south (near Fairbanks) has been bad enough that the active layer isn't completely refreezing during the winter, creating a layer of permanent thaw sandwiched in between. A situation which wasn't expected until quite a bit later in the century.

Best chance is going to be late tonight through tomorrow. Outflow channel opens up to the north, SSTs jump and shear is low for a while. However, that's going to be dependent on how the inner core looks by that time.

Starting to lose definition on radar. Probably due to both upwelling and partial concentric ring around the old eye. It's starting to move, but it might be a tad too late to salvage the inner core. Time will tell this evening.

Keep an eye on the steering flow above 500mb as well. The upper level anticyclone to the west of the storm (visible on the 250mb streamline charts) is going to influence the track as well and may provide enough steering influence to be a deciding factor (through 96hr or so). That light northeasterly flow in the upper levels may be just enough to keep it moving at a slow pace (3-5kt) vs a near stall. Dorian's strength will also come into play as well (via diabatic effects). These are normally small factors, but with the loss of major steering currents, they become the drivers and can make a notable difference when it's a marginal case like this.

Nuclear would be significantly cheaper than trying to build out massive storage systems. While daily storage seems like a solvable problem in the medium term, seasonal storage does not. Baseload nuclear takes care of that pretty neatly and much sooner. Part of the reason solar and wind are so cheap is that they displace generation only at the margin and are at relatively low penetration. Once you get past a certain penetration (I believe 10-15% for solar atm), it becomes significantly more expensive because of the aforementioned intermittency problem. Wind is even worse, because (at least here in the US), climo wind peaks are in November and March, not exactly the time of year where you need power the most. As part of a legit climate plan, I'd be up for subsidizing and standardizing nuclear in a hurry. Build a bunch of standardized current-gen reactors and work on getting a standardized design for 20-30 years from now. It's probably the fastest way to bring emissions down. And we need speed -- the hour is late. We seem to be screaming along at 2.5-3ppm/yr, which is putting us dangerously close to a RCP 6.0-8.5 scenario through mid-century.

A pretty strong argument, imo. Not much support for anything below 2C at this point, especially after the corrections to the lower-end estimates in the recent past.