September 28th, 2009 by Kevin Ward
Antarctica's Larsen Ice Shelf, viewed from NASA's DC-8 aircraft in 2004, is one target of the 2009 Operation: Ice Bridge Antarctica campaign. Credit: NASA/Jim Ross
Operation Ice Bridge, a six-year NASA field campaign, is the largest airborne survey of Earth’s polar ice ever flown. It will yield an unprecedented three-dimensional view of Arctic and Antarctic ice sheets, ice shelves and sea ice.
The team in Antarctica will be blogging about their experiences on this campaign over the next few weeks so be sure to follow them on the Operation Ice Bridge blog.
August 29th, 2009 by Joanne Howl
Merril Brook Cabins, Howland, Maine
From Dr. Jon Ranson:
I’ve shared a lot of my own experiences over the past two weeks. For the moment, I’m going to step aside and ask Sassan Saatchi to share with you his impressions of his work at Howland.
From Dr. Sassan Saatchi
This has been a very good experience and I think we’ve done well here. We came out in support of the DESDynI mission. There are a few specific goals we’re working on. One is to refine our algorithms to measure forest biomass and structure. For that reason, we flew radar that’s very close to the DESDynI radar over this area not long ago. We also flew lidar. For DESDynI we want to combine the two to make forest structure more accurate. Our measurements on the ground combined with the data from the lidar and radar flights will help us do that.
Forests can change quite quickly when under timber management. This forest was identified as a high biomass site from 2003 remote sensing data. When the scientists arrived to measure it, they found it had been logged quite recently. Photo by Sassan Saatchi.
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August 28th, 2009 by Joanne Howl
Penobscot Experimental Forest, Bradley, Maine
Temperature 71°F Humidity 65% Wind 0 mph Sunny
From Dr. Jon Ranson:
This gorgeous morning we hopped in our cars and drove back to the last site, close to Lake Chemo (you can pronounce that chee-moe). Yesterday I was impressed by the high biomass and the giant Quaking Aspen trees. Today I’ve noticed that there is a lot of fallen timber in this site. We found several really big trees lying on the ground with their root pads sticking up in the air. We also saw a lot of standing dead trees, many of which had been broken off several meters above the ground. I expect this place had taken some wind not too long ago. That would explain all this deadfall.
Our remote sensing instruments don’t measure dead trees on the ground. We also can’t separate standing deadwood from live wood, either. Intact downed wood still holds carbon we know we underestimate biomass when we don’t measure it. On the other hand, if standing trees have been dead long enough, then bugs can start to eat the wood or decay begins. In that case our instruments may over estimate biomass when they measure those trees. Overall these errors are not great but its good to be aware of this.
An old growth, high biomass site in Penobscot Experimental Forest. Note the dead wood on the ground. Such dead wood is part of the above ground biomass of the forest, but is not currently measured by remote sensing instruments. Photo by Jon Ranson.
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August 27th, 2009 by Joanne Howl
Penobscot Experimental Forest, Bradley Maine
Temperature: 71°F Humidity 29% Wind: 9 mph WNW Clear
From Dr. Jon Ranson:
The weather here is finally absolutely fabulous. It’s cool and clear today. It feels just like Maine in late August should feel. We’ve got another Hurricane out in the Atlantic coming our way, but I think Danny will wait until the weekend to bother the area. For now, it’s fine field weather.
Today’s goal was to find and measure an area we’d identified as a low biomass site. Before we came to the field the DESDynI scientists sat down and looked at data from our existing instruments. In order to thoroughly test our instruments and algorithms we need to look at a wide variety of sites, both low and high biomass. For today’s sites we relied on LVIS (NASA’s Lidar Vegetation Imaging Sensor) data, which is a laser altimeter flown by aircraft over target areas. That data showed this as a very low biomass area. We wanted to check it out.
A hemispherical photograph taken through a fisheye type lens. Such photos will be digitized and analyzed to calculate canopy cover of the forest. Photo by Sassan Saatchi.
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August 26th, 2009 by Joanne Howl
Penobscot Experimental Forest, Bradley Maine
Temperature: 80°F Humidity 74% Wind: 8 mph SW Clear with few clouds
From Dr. Ranson:
On the way to today’s site we passed a small plantation of American Chestnut trees. They are part of a program run by a nonprofit organization, The American Chestnut Foundation, to restore blight-resistant American Chestnuts to their native range. What they are doing is crossing native “Mother” Chestnuts with highly blight-resistant Chinese chestnuts. As the progeny grow they are tested for blight resistance by exposing them to the fungus. The most resistant trees are again crossed with the American trees. It’s important that the trees look and grow like American Chestnut, with the Chinese trees only conferring their resistance. It can take six generations or more before these goals are met to satisfaction. Only then will the tree be considered a candidate for planting.
Moose are often found in the Howland Forest area. This young moose was spotted by John Lee. Photo by John Lee.
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