Friday, September 7, 2012
Wednesday, September 5, 2012
Sea Ice Resources
Arctic sea ice is at record low levels now, with weeks remaining in the melt season. Below are some sites where ice levels are tracked.
The best source of news and analysis probably is Neven's Arctic Sea Ice blog.
A page with gobs and gobs of graphs and maps is here.
The Cryosphere Today has good daily maps and a sea ice area plot. Here is yesterday's map.
Sea ice extent is defined as where ice covers at least 15% of the sea surface. daily values are available from the Japan Aerospace Exploration Agency (JAXA).
This is today's:
Enjoy.
The best source of news and analysis probably is Neven's Arctic Sea Ice blog.
A page with gobs and gobs of graphs and maps is here.
The Cryosphere Today has good daily maps and a sea ice area plot. Here is yesterday's map.
Sea ice extent is defined as where ice covers at least 15% of the sea surface. daily values are available from the Japan Aerospace Exploration Agency (JAXA).
This is today's:
Enjoy.
Weather Extremes
For a very long time (decades) scientists have predicted that the distribution of weather we get would shift toward higher temperatures.
Well, that has been happening:
More information about that graph, and the science behind it, can be found here.
What the graph says is that heat events that used to be very rare now are quite common. The extreme events that used to happen less than 1% of the time now are 10% and more.
There are important implications to dealing with this.
First, these events come in heat waves like the one that hit the US this spring, causing fruit trees to bloom early and then have buds killed by frost when the heat wave ended. In other words, heat waves can come at the wrong time and screw up the way nature works.
Second, the severity of the heat waves causes problems. Heat causes drying, and thus drought. Dry soils don't supply water for evaporative cooling, which drives temperatures up even further. Heat begets heat, as they say. So you end up with very intense heat waves that kill by sheer temperature. There was a "global warming type" drought, i.e., not just dry but also very hot, in the Southwest in the early 2000s which killed pinyon pines by heat, which was pretty much unheard of. It was about an 800-year drought.
Well, an 800-year drought according to the climate we used to have. There have been an awful lot of 100-year and 500-year and 1000-year events in the past several years. That's what the graph above is all about - extremely rare events now are becoming common.
Well, that has been happening:
More information about that graph, and the science behind it, can be found here.
What the graph says is that heat events that used to be very rare now are quite common. The extreme events that used to happen less than 1% of the time now are 10% and more.
There are important implications to dealing with this.
First, these events come in heat waves like the one that hit the US this spring, causing fruit trees to bloom early and then have buds killed by frost when the heat wave ended. In other words, heat waves can come at the wrong time and screw up the way nature works.
Second, the severity of the heat waves causes problems. Heat causes drying, and thus drought. Dry soils don't supply water for evaporative cooling, which drives temperatures up even further. Heat begets heat, as they say. So you end up with very intense heat waves that kill by sheer temperature. There was a "global warming type" drought, i.e., not just dry but also very hot, in the Southwest in the early 2000s which killed pinyon pines by heat, which was pretty much unheard of. It was about an 800-year drought.
Well, an 800-year drought according to the climate we used to have. There have been an awful lot of 100-year and 500-year and 1000-year events in the past several years. That's what the graph above is all about - extremely rare events now are becoming common.
Tuesday, September 4, 2012
This is Probably Bad . . .
Tell me if this doesn't sound like something from a sci-fi horror movie:
About 5 years ago most scientists thought Arctic sea ice would melt almost completely by the end of this century. That was so serious and scary NASA made videos showing how serious and scary the model results were. Pretty much no one else cared.
About 3 years ago they said it looks more like 2030-2040 or so, within the lifetimes of people alive today. A few scientists said it could be more like 2013 to 2016. Big gulp, check and recheck the math, try real hard to have faith in the models that even today are not capturing the speed with which the Arctic is melting.
A year or so ago they realized the acceleration was seriously screwing with the weather. The jet stream doesn't work like it used to. It's slower now, wavier. It stalls out, causing all manner of extremes as systems that used to pass on through sit there and build.
Now more and more scientists are saying the 2013-2016 guys are maybe right. It's pretty obvious: if you look at the amount of ice actually in the Arctic Ocean, it's falling off a cliff. From here:
That red dot is this year's minimum to date, as of late August. We still have a few weeks of ice loss left. But you can see already that the end of year-round sea ice is upon us.
No one knows exactly what that means, but chances are it will be pretty severe.
Fundamentally the way the Arctic screws up the rest of the Northern Hemisphere's weather is that it stores huge amounts of heat during the summer and releases it during the winter. All that heat makes the atmosphere circulate differently.
So we can expect more extreme weather. Possibly much more extreme weather.
About 5 years ago most scientists thought Arctic sea ice would melt almost completely by the end of this century. That was so serious and scary NASA made videos showing how serious and scary the model results were. Pretty much no one else cared.
About 3 years ago they said it looks more like 2030-2040 or so, within the lifetimes of people alive today. A few scientists said it could be more like 2013 to 2016. Big gulp, check and recheck the math, try real hard to have faith in the models that even today are not capturing the speed with which the Arctic is melting.
A year or so ago they realized the acceleration was seriously screwing with the weather. The jet stream doesn't work like it used to. It's slower now, wavier. It stalls out, causing all manner of extremes as systems that used to pass on through sit there and build.
Now more and more scientists are saying the 2013-2016 guys are maybe right. It's pretty obvious: if you look at the amount of ice actually in the Arctic Ocean, it's falling off a cliff. From here:
That red dot is this year's minimum to date, as of late August. We still have a few weeks of ice loss left. But you can see already that the end of year-round sea ice is upon us.
No one knows exactly what that means, but chances are it will be pretty severe.
Fundamentally the way the Arctic screws up the rest of the Northern Hemisphere's weather is that it stores huge amounts of heat during the summer and releases it during the winter. All that heat makes the atmosphere circulate differently.
So we can expect more extreme weather. Possibly much more extreme weather.
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