NOAA's Arctic Report: "Warming Accelerating"
By ROB MAYEDA
Updated 8:45 AM PST, Fri, Oct 22, 2010
The National Oceanic and Atmospheric Administration's latest Arctic Report card is out and the grades don't look so good.
While some sea ice is being replaced during Winter months, the new ice is thinner year to year, reinforcing an overall decreasing trend in sea ice coverage and depth during the last decade.
On land where more soil and rock is being exposed to sunlight, this is aiding in the warming process by absorbing more solar energy over time, especially during the late Spring through Summer months. Ice is one of the planet's best reflectors of solar energy, helping to regulate heat in the Arctic region. As darker land and waterways open up due to ice melt, these areas work the opposite way, as absorbers of incoming sun energy = warming.
Here's how this change is impacting us here in Bay Area and the rest of the country.
Temperature/pressure patterns in the Arctic are believed to be changing upper air flow / jet stream patterns over the mid-latitudes, including North America and the Bay Area.
Scientists noted here how the reduction in the usual westerly flow of the upper level winds across the southern boundary of the Arctic, may have played a role in some cooler than average air settling into Canada and the upper Northeast last year.This coincided with heavy snow events in China, northern Europe and the US Northeast.
This begs the obvious question, "How can we have higher than average snowfall totals in the Northeast if global warming is happening?"
The above referenced study shows the answer looks to be areas that normally would see mostly rain at different times of the year are now having colder air spilling down from the Arctic that can support snowfall vs. rain drops. Relatively warmer weather systems moving across the country meet up with these much colder than average pockets of air and yield higher snowfall totals (thanks to moisture-rich warmer air meeting up with the colder Arctic air).
What's interesting about this is how temperature / ice-coverage changes in the Arctic can lead to weather pattern changes well south.
Here are some of the other impacts:
First Published: Oct 22, 2010 6:38 AM PST