Dr. Amy H Butler
@drahbutler.bsky.social
Atmospheric Scientist, atmos dynamics/chemistry-climate, polar vortex expert. Views expressed are mine.
Please consider submitting an abstract to our AGU session "A092 - Stratospheric Dynamics, Aerosol Processes, and Interactions with the Troposphere". There's a lot of new interesting science on this topic to share! agu.confex.com/agu/agu25/pr...
July 9, 2025 at 11:01 PM
Please consider submitting an abstract to our AGU session "A092 - Stratospheric Dynamics, Aerosol Processes, and Interactions with the Troposphere". There's a lot of new interesting science on this topic to share! agu.confex.com/agu/agu25/pr...
Out today, our paper on "Key gaps in models' physical representation of climate intervention and its impacts". We had 3 working groups evaluate where models can be improved to reduce uncertainties in simulating SAI, MCB, and CCT. agupubs.onlinelibrary.wiley.com/doi/10.1029/...
June 20, 2025 at 3:28 PM
Out today, our paper on "Key gaps in models' physical representation of climate intervention and its impacts". We had 3 working groups evaluate where models can be improved to reduce uncertainties in simulating SAI, MCB, and CCT. agupubs.onlinelibrary.wiley.com/doi/10.1029/...
(2/2) Currently still a small #polarvortex heavily displaced towards Europe but in the next 5 days, it will become almost entirely mixed out and replaced by a large and quite strong anti-cyclone over the pole.
March 24, 2025 at 7:46 PM
(2/2) Currently still a small #polarvortex heavily displaced towards Europe but in the next 5 days, it will become almost entirely mixed out and replaced by a large and quite strong anti-cyclone over the pole.
A wavenumber 1 (displacement type) sudden stratospheric warming or possibly final warming is forecast to occur this weekend. The difference between these two outcomes? In the former, the vortex recovers for at least 10 days; in the latter it does not. Similar surface impacts associated with both.
March 3, 2025 at 8:32 PM
A wavenumber 1 (displacement type) sudden stratospheric warming or possibly final warming is forecast to occur this weekend. The difference between these two outcomes? In the former, the vortex recovers for at least 10 days; in the latter it does not. Similar surface impacts associated with both.
Getting into some uncharted territory with very low polar cap #ozone over the Arctic, cold polar vortex temperatures, and high PSC ice volumes. This will soon be mitigated by a slight weakening of the vortex in the next few days. But #vortex will restrengthen after so worth watching. (1/2)
February 7, 2025 at 6:11 PM
(2/) Remember, a strong polar vortex is generally associated with anomalous persistent *warmth* in the mid-latitudes... if it's signal is communicated down to the surface. GFS at least does not seem to want to play that game in Feb... troposphere is doing its own thing.
January 27, 2025 at 4:54 PM
(2/) Remember, a strong polar vortex is generally associated with anomalous persistent *warmth* in the mid-latitudes... if it's signal is communicated down to the surface. GFS at least does not seem to want to play that game in Feb... troposphere is doing its own thing.
(1/) Forecasts for a stronger than normal #polarvortex into mid-Feb have been remarkably consistent (with the next week seeing likely daily records in strength).
January 27, 2025 at 4:52 PM
(1/) Forecasts for a stronger than normal #polarvortex into mid-Feb have been remarkably consistent (with the next week seeing likely daily records in strength).
The frigid temperatures moving in for the central US this coming weekend have a stronger hint of a #polarvortex connection than the last one. Read about it at NOAA climate .gov here: www.climate.gov/news-feature...
January 16, 2025 at 10:58 PM
The frigid temperatures moving in for the central US this coming weekend have a stronger hint of a #polarvortex connection than the last one. Read about it at NOAA climate .gov here: www.climate.gov/news-feature...
Was the #polarvortex to blame for the recent cold weather over the central-eastern US? New on the NOAA Polar vortex blog, we discuss why we don't think so. www.climate.gov/news-feature...
January 8, 2025 at 10:34 PM
Was the #polarvortex to blame for the recent cold weather over the central-eastern US? New on the NOAA Polar vortex blog, we discuss why we don't think so. www.climate.gov/news-feature...
Latest ECMWF forecasts for the #polarvortex are quite remarkable and show the ensemble-mean forecast staying near record strong from mid-January well into mid-February. If this were to transpire, it could rival the exceptionally strong polar vortex of 2020.... (1/3)
January 7, 2025 at 11:53 PM
Latest ECMWF forecasts for the #polarvortex are quite remarkable and show the ensemble-mean forecast staying near record strong from mid-January well into mid-February. If this were to transpire, it could rival the exceptionally strong polar vortex of 2020.... (1/3)
(5/5) Same story using zonal-mean diagnostics- the stratosphere and troposphere are not at all coupled right now. Sometimes, cold and snowy weather is just... weather. It's not related to the #polarvortex every time we get some Arctic air down here.
January 6, 2025 at 6:19 PM
(5/5) Same story using zonal-mean diagnostics- the stratosphere and troposphere are not at all coupled right now. Sometimes, cold and snowy weather is just... weather. It's not related to the #polarvortex every time we get some Arctic air down here.
(4/5) For completeness, here is the current (Jan 1-4 2025) 500mb anomaly pattern. Does not match with a P1 (strong) vortex state, but also doesn’t match with a P4 (stretching vortex) state (row C in thread 2/5 above).
January 6, 2025 at 6:17 PM
(4/5) For completeness, here is the current (Jan 1-4 2025) 500mb anomaly pattern. Does not match with a P1 (strong) vortex state, but also doesn’t match with a P4 (stretching vortex) state (row C in thread 2/5 above).
(3/5) Here is what current (Jan 1-4 2025) 100 hPa geop. anomalies look like (shading on left is anomalies, contours on right are full field). The current pattern looks closest to a P1- a strong vortex state.
January 6, 2025 at 6:15 PM
(3/5) Here is what current (Jan 1-4 2025) 100 hPa geop. anomalies look like (shading on left is anomalies, contours on right are full field). The current pattern looks closest to a P1- a strong vortex state.
(2/5) From Cohen et al. 2023 (www.science.org/doi/10.1126/...): P4, row A, is what a stretched polar vortex at 100 mb (lower stratosphere) looks like (shading is anomalies). This is associated with cold over N. America.
January 6, 2025 at 6:14 PM
(2/5) From Cohen et al. 2023 (www.science.org/doi/10.1126/...): P4, row A, is what a stretched polar vortex at 100 mb (lower stratosphere) looks like (shading is anomalies). This is associated with cold over N. America.
(1/5) Is #polarvortex stretching responsible for the current (Jan 5-6) US cold air outbreak and winter weather? I remain unconvinced.
January 6, 2025 at 6:12 PM
(1/5) Is #polarvortex stretching responsible for the current (Jan 5-6) US cold air outbreak and winter weather? I remain unconvinced.
Final thought: if this plays out as forecast, this tropospheric “boulder” could potentially wobble the vortex enough to make for some interesting times for the #polarvortex ahead… as indicated by the current wavenumber-1 magnitude forecast in the stratosphere. (9/9)
December 30, 2024 at 10:57 PM
Final thought: if this plays out as forecast, this tropospheric “boulder” could potentially wobble the vortex enough to make for some interesting times for the #polarvortex ahead… as indicated by the current wavenumber-1 magnitude forecast in the stratosphere. (9/9)
Still, already I’ve seen posts pop up about the “stretching” of the vortex *causing* this event. Here’s a video of the forecasted polar vortex (note: bottom layer is at the lower stratosphere, not the surface) (4/9)
December 30, 2024 at 10:53 PM
Still, already I’ve seen posts pop up about the “stretching” of the vortex *causing* this event. Here’s a video of the forecasted polar vortex (note: bottom layer is at the lower stratosphere, not the surface) (4/9)
The stratospheric #polarvortex has been roaringly fast in recent days—which, if the troposphere were listening, would lead to a +ve NAO. Instead the troposphere is predicted to heavily veer towards -ve NAO. This corresponds to a big old block over Greenland. (3/9)
December 30, 2024 at 10:52 PM
The stratospheric #polarvortex has been roaringly fast in recent days—which, if the troposphere were listening, would lead to a +ve NAO. Instead the troposphere is predicted to heavily veer towards -ve NAO. This corresponds to a big old block over Greenland. (3/9)
Interesting evolution of forecasted North American cold air outbreak over the next two weeks- is it or is it not a “#polarvortex” event? (1/9) 🧵
December 30, 2024 at 10:50 PM
Interesting evolution of forecasted North American cold air outbreak over the next two weeks- is it or is it not a “#polarvortex” event? (1/9) 🧵
What are the odds of a stratospheric #polarvortex disruption this winter? Our latest blog at #NOAA climate.gov explores two factors that seem to shift the chances of one of these extreme events occurring. www.climate.gov/news-feature...
December 19, 2024 at 10:59 PM
What are the odds of a stratospheric #polarvortex disruption this winter? Our latest blog at #NOAA climate.gov explores two factors that seem to shift the chances of one of these extreme events occurring. www.climate.gov/news-feature...
The return of the #NOAA Polar Vortex blog is here! In this post we recap what's been up with the polar stratosphere over the last few months, including high polar #ozone levels from last spring into summer. Read here: www.climate.gov/news-feature...
December 4, 2024 at 5:59 PM
The return of the #NOAA Polar Vortex blog is here! In this post we recap what's been up with the polar stratosphere over the last few months, including high polar #ozone levels from last spring into summer. Read here: www.climate.gov/news-feature...
(2/2) Unclear if the troposphere will "feel" this stratospheric influence or not; the free Arctic troposphere/lower stratosphere has been stuck in an anomalously warm, high pressure state for months, largely decoupled from surface pressure changes beneath it (as measured by the Arctic Oscillation).
November 25, 2024 at 11:24 PM
(2/2) Unclear if the troposphere will "feel" this stratospheric influence or not; the free Arctic troposphere/lower stratosphere has been stuck in an anomalously warm, high pressure state for months, largely decoupled from surface pressure changes beneath it (as measured by the Arctic Oscillation).
(1/2) After its weakest Sept wind speeds since 1979, the Arctic stratospheric #polarvortex is making up for lost time and looks to rapidly intensify into early December.
November 25, 2024 at 11:21 PM
(1/2) After its weakest Sept wind speeds since 1979, the Arctic stratospheric #polarvortex is making up for lost time and looks to rapidly intensify into early December.
November 14, 2024 at 2:25 AM