Support the Arctic Sea Ice Forum and Blog

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - weatherdude88

Pages: [1]
Arctic sea ice / Re: The 2019 melting season
« on: August 30, 2019, 08:06:40 PM »
I can see evidence for Arctic Sea Ice losses not being above average.
What I can't see (given +ve SST and air temp anomalies) is the evidence to show why area and extent losses should be so much below average (with unusual increases on occasion).

In my subjective view, the answer is simple.

From the start of this melt season, we had record breaking anomalous ridging and warmth over the arctic. The conditions where so anomalous, we saw record sea ice extent and area retreat through August in the peripheral and easier to melt areas. The pattern was also exporting and compacting some of the sea ice at high latitudes.

Some experienced members mentioned throughout the melt season 'The central pack was not looking like it would set a new record'. Towards the end of the melt season, we saw a calming down or reversal of the pattern. There were some areas of sea ice that just melted out, that cooled down significantly, which previously had record breaking heat for months. Additionally, these same higher latitude areas that just melted, also now had reduced solar insolation. What remained was higher latitude and more difficult to melt sea ice.

The arctic is a big area. The dynamics this year where extreme, in melting easier lower latitude sea ice in certain regions of the arctic, and not the central pack. Different weather patterns and dynamics are needed to melt more of the central pack.

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: August 25, 2019, 04:18:16 PM »
2016 loses 299,415 square kilometers of sea ice area over the next 4 days (74,853 square kilometers / day). 2019 needs to lose 214,871 square kilometers over the next 4 days to keep the pace (53,717 square kilometers / day).

It is likely 2019 will fall to the third lowest northern hemisphere NSIDC sea ice area value for the date, in the next 4 days.

Let's discuss differences in barometric pressure at polar latitudes, during different stages of the solar cycle.

"The magnitude of the change in the troposphere is large enough to
alter sea level pressure fields such that a more positive
winter Southern Annual Mode (lower pressure at higher
latitudes) is produced in about 70% of the cases (especially
with climatological and historical SST). The sea level
pressure differences are on the order of 4 mb at high
southern latitudes"

"This effect, as well as the winter zonal
wind change descending into the troposphere, is more
consistent in the Southern Hemisphere during June –August
then in the Northern Hemisphere for December–February,
most likely owing to the greater planetary wave forcing and
inherent variability during Northern Hemisphere winter"

Page 166 starts "Variations In Air Pressure And In Solar Activity"

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: June 11, 2019, 07:02:47 PM »
Is this going to be a record year for sea ice retention dude88 ? b.c.

No, sea ice extent and area values will not be in the bottom 3 for the minimum either. The constant anticyclonic weather pattern has compacted sea ice at high latitudes.

This will become especially evident, as sea ice extent and area losses will stall later this melt season when the lower latitude sea ice has melted out.

It should come as no surprise that this early spring and start of summer has been dominated by anticyclone, considering we are at the start of the solar minimum.

There has been research that concludes during the solar minimum, the summer melting season at polar latitudes ‘barometric pressure is higher’ than during other intervals of the solar cycle.
It appears we will now switch to a regime of low pressure over the arctic. I am skeptical it will last longer than several weeks.

I started a new thread, so we do not continue off topic.,2755.0.html

Arctic sea ice / Re: The 2018/2019 freezing season
« on: September 28, 2018, 08:42:24 PM »
Profuse assumptions are being made. We cannot assume the atmospheric temperature profile under areas of high pressure at 850 MB or 500 MB, will correlate to the surface being as anomalously warm, as it would during northern hemisphere summer.

It is probable, there will be a layer of closer to average temperatures near the surface, than at higher altitudes, due to less solar isolation (less surface heating) and a cooler surface.

I predict northern hemisphere sea ice extent and area will continue to increase, albeit with a slower increase than average. The 850 MB and 500 MB anomalies are not indicative of the actual surface anomaly after northern hemisphere summer.

The decrease in cloud thickness / coverage under high pressure, should also allow for more heat energy to radiate into space. This could also increase the heat anomaly at 850 MB and 500 MB.

Pages: [1]