KenMankoff

Pine Island Glacier and Pine Island Bay

Pine Island Glacier and Pine Island Bay

Pine Island Bay in the southeast Amundsen Sea, Antarctica, on 16 Nov 2008. Upwelling, melt-laden outflow plumes emerge from beneath the adjacent Pine Island Glacier ice shelf (top center) and mix in the bay waters. Warm red colors show sea surface temperatures more than a degree warmer than the near-freezing dark blue color. Cyclonic circulation in the bay is framed by the ice shelf, land ice and sea ice, in gray-scale with the darker shades colder. Landsat Enhanced Thematic Mapper Plus image, thermal infrared (channel 6H), subset of scene #LE72331132008321EDC00.

@article{Mankoff:2012The-role,
	Title = {{The role of Pine Island Glacier ice shelf basal
                  channels in deep water upwelling, polynyas, and
                  ocean circulation in Pine Island Bay, Antarctica}},
	Author = {Kenneth D. Mankoff and Stanley S. Jacobs and
                  Slawek M. Tulaczyk and Sharon E. Stammerjohn},
	Journal = {Annals of Glaciology},
	Number = {60},
	Volume = {53},
	Year = {2012},
        DOI = {10.3189/2012AoG60A062}}

BUBBLES And A Fish

Bubbles is a small ROV built from a kit with a customized camera mount for looking up at ice from below and down at the bottom. Her construction was motivated by some underwater footage of bed load transport due to wave action.

BUBBLES is an acronym for some combination of the words Bubbles the Underwater Undersea Blue Bathymetric Basal Buoyant Little Liquid Exploration Submersible or Submarine.

Bubble was previously deployed in a hot-tub and in Younger Lagoon, Santa Cruz, CA, as test sites. Recently Bubbles went swimming under the ice-covered Silver Lake near Kirkwood, CA. Due to the late season, we could not walk on the ice and the shore-based deployment was complicated by the shallow waters. Nevertheless, she again proved to be liquid-worthy, and spent some time swimming in the shallow waters with some fish.

Bubbles heading under the ice. Photo by E. Lynne Harden

Bubbles operations. Photo by E. Lynne Harden

Bubbles was built by Ken Mankoff and E. Lynne Harden.

WISSARD Introduction

A video (and written) news segment on part of my PhD project:

Ice Melts

Nature’s best thermometer, perhaps its most sensitive and unambiguous indicator of climate change, is ice. Ice asks no questions, presents no arguments, reads no newspapers, listens to no debates. It is not burdened by ideology and carries no political baggage as it changes from solid to liquid. It just melts.

– Henry Pollack, PhD.  A World Without Ice.

GLIMMER Ice Shelf Modeling (OS X HowTo)

A new beta version of the Community Ice Sheet Model, Glimmer-CISM, has been released. Below are instructions to compile and run it on OS X.

# build NetCDF
export CFLAGS=-m32
export FFLAGS=-m32
./configure --prefix=/Users/mankoff/local/netcdf-4.1.1 \
          --disable-cxx --disable-curl  --disable-dap
make && make install
say netCDF done

# build GLIMMER
cd ~/local/src/
wget http://download.berlios.de/glimmer-cism/glimmer-1.7.0.tar.gz
tar zxvf glimmer-1.7.0.tar.gz
cd glimmer-1.7.0/

# OS X has issues with 32 and 64 bit libraries.
# The -m32 flag forces 32 bit compilation.
# The following should be one long line:
./configure --prefix=/Users/mankoff/local/glimmer-1.7.0 \
     --with-netcdf=/Users/mankoff/local/netcdf-4.0.1 \
     FC=gfortran F77=gfortran CFLAGS=-m32

make
make install
say GLIMMER done

There are a few ways to test the installation. The source folder provides a test folder:

export PATH=/Users/mankoff/local/glimmer-1.7.0/bin:$PATH
cd ~/local/src/glimmer-1.7.0/tests/shelf
python circular-shelf.py circular-shelf.PP.config
python confined-shelf.py confined-shelf.PP.config
say GLIMMER Test Done # Takes a while. Turn up your volume

Running the above command will result in NetCDF files being created in the output/ subdirectory. You can view the contents of example.nc with most any generic NetCDF viewer. While theses tests run over a given period of time, the output only has one time stored. If you want to see an evolution of the ice shelf, older test suites available from the previous code repository site should be used:

cd ~/tmp/
wget http://forge.nesc.ac.uk/download.php/200/glimmer-example-0.6.tar.gz
tar zxvf glimmer-example-0.6.tar.gz
cd glimmer-example-0.6/
~/local/glimmer-1.7.0/bin/glide_launch.py ./example.config
say done

Examine the output file example.nc to see ice sheet evolution over time. Basal melt is shown below:

@article{Rutt:2009,
  Author = {Ian C. Rutt and Nicholas R. J. Hulton and Antony J. Payne},
  Title = {{The Glimmer community ice sheet model}},
  Year = {2009}}
  Journal = {J. Geophys. Res.},
  Volume = {114},
  Number = {F2},

Iceland’s Root

Iceland's Root

Image appears to be related to Wolfe et al. (1997). Also available in Schubert and Turcotte below the discussion. Image found at LDEO.

More Photos from Antarctica (LMG09-09)

I’ve finally gotten around to uploading some photos from the latest trip to Antarctica. We sailed on the Laurence M. Gould through the Drake Passage and the Bellingshausen Sea, then along the Antarctic Peninsula to Palmer Station. We saw a lot of ice and some wildlife.

If you want to read about the trip you can do so here or by clicking on the LMG09-09 tag to the right.

If you were on the ship here is a GPX file so you can geotag your own photos.

Phosphorescing Sea Ice

This footage was shot by Harriet Mankoff on September 22nd 2009 in the Drake Passage near 60 degrees South. It shows what I have labeled “phosphorescing sea ice” due to the white flashes at the wave crests. The sea is covered by pancake ice and slush. At the wave crest the slush builds up enough that the water drains out of the slush and it looks brighter. The reverse happens in some of the troughs.

Pancakes

Pancake Ice on Waves, Drake Passage, Antarctica.
(61 29.95S, 62 24.68W)

Sun{rise,set} over Sea Ice

We have been sailing home at 9-10 knots for the past few days and will continue to do so for the next 130ish hours.
 
The waypoint computer shows we have about 114 hours and 1050 nautical miles to our next waypoint, which is the entrance to the Straits of Magellan, still about 24 hours from port.
 
Current location is lat: -63.427, lon: -99.812