Polar Ice for 2018

Winter solstice 2017 in Northern Hemisphere will be at 11:28 AM (EST) on Thursday, December 21. In celebration, time to start another polar ice watch:

• Daily AMSR2 sea ice maps
• NSR - Ice Concentration | Northern Sea Route Information Office
• Sea Ice Index
• Arctic Sea Ice Graphs
• CryoSat Operational Monitoring - Sea Ice

For reference, a snapshot.









The Arctic freezing season is not over nor is the Antarctic melt season.

Bob Wilson

 

Every time there is a slug of polar air over the lower 48, a similar sized slug of warm air reaches polar regions:


Bob Wilson

 

"Not in my backyard" is often used to claim today's local weather in the eastern regions of the USA is proof of no global warming. But in the meanwhile Arctic ice continues to 'less freeze'. This open paper discusses in more precise terms than my 'slug of cold weather' why this happens:
http://journals.ametsoc.org/doi/pdf/10.1175/BAMS-D-16-0259.1

21 Abstract
22 The extra-tropical stratosphere in boreal winter is characterized by a strong circumpolar
23 westerly jet, confining the coldest temperatures at high latitudes. The jet, referred to as the
24 stratospheric polar vortex, is predominantly zonal and centered around the pole; however, it
25 does exhibit large variability in wind speed and location. Previous studies showed that a
26 weak stratospheric polar vortex can lead to cold-air outbreaks in the mid-latitudes but the
27 exact relationships and mechanisms are unclear. Particularly, it is unclear whether
28 stratospheric variability has contributed to the observed anomalous cooling trends in mid-
29 latitude Eurasia. Using hierarchical clustering, we show that over the last 37 years, the
30 frequency of weak vortex states in mid to late winter (January and February) has increased
31 which were accompanied by subsequent cold extremes in mid-latitude Eurasia. For this
32 region 60% of the observed cooling in the era of Arctic amplification, i.e. since 1990, can be
33 explained by the increased frequency of weak stratospheric polar vortex states, a number
34 which increases to almost 80% when El Niño/Southern Oscillation (ENSO) variability is
35 included as well. ​

Bob Wilson

 

Thanks for the references, I look forward to learning more. Just I have a slightly different take on polar, temperature, and tropical zone temperature/heat differences.

It has been my observation with water that the greater the temperature difference, the greater the turbulence between the hot and cold regions. It is a simple experiment:

1. Fill a glass container with 77F (25C) water and put a layer of ice cubes on the top (i.e., the ratio of polar area to non-polar.). Observe the turbulence.
2. Fill a glass container with 122F (50C) water and put in ice cubes in the same shallow layer
3. Fill a glass container with 215F (100C) water and put in the same ice cubes.

It is the turbulence that reflects the brief but well documented temperature extremes. Meanwhile we can observe the reduced, polar ice because warmer air invades to replace the cold air that slings down towards the equator. Simple physics, there is a reason why I focus on polar ice.

Bob Wilson

 

We agree which is why I suspect the recent hurricanes are fueled by a different effect, higher humidity from equatorial seas. In this respect the satellite data is shallow.

We agree about the cold but I have to think about the 'upper flow weakens.' I am thinking about how a high energy vortex tends to tighten its radius while one with less energy tends to widen its radius. We see this in wing tip vortex that start with a small, intense radius but widens as it slows further beyond and behind the wing.

Bob Wilson

 

Patience, the winter winds of 2017-18 are far from over.

Bob Wilson

 

The recent bomb cyclone arrived at Camp Summit Greenland:

Almost a heat wave.

Bob Wilson

 

Interesting but it begs the question if a sounding survey could map ground level water?

Bob Wilson

 

Hummmm, if we could claim it would disprove man-made global warming.

Bob Wilson

 

Source:
How severe is Cape Town's drought? A detailed look at the data | News24

The drought, as manifested by rainfall in the region of WCWSS dams, is indeed very rare, and very severe.

Importantly, the analyses reveal that the drought was likely less severe in the coastal plains and in Cape Town itself. A possible reason for that might be a weaker penetration of cold fronts that bring winter rainfall to the region into the higher and distant inland regions.​

I bring this up because the Antarctic sea ice has some continental points close by:




What are the rainfall trends for:

• South America (?)
• Australia/Tasmania/New Zealand (?)
• South Africa (drought)

Bob Wilson