6/9/2010Monarch-A, Hamburg, H. Skourup1 DTU Space, Technical University of Denmark

WP 2.6 Improved estimate sea ice fluxes and the freshwater cycle in the Arctic

D 2.6.1: Sea ice Thickness and SSH 2003-2008 based on ICESat – month 18

D 2.6.2: Ice volume flux through Fram Strait, Nares and Bering Strait based on ice thickness and drift - month 18

D 2.6.4 Computed time series of GRACE signals from freshwater flux pulses and compared to satellite data - month 36

D 2.6.3 Freshwater flux time series grids for the Arctic Ocean based on modelled Greenland fresh water output (WP 2.3), river discharge (WP 1.2) and sea ice flux and melt (WP 2.6) - month 18

MONTH 18 = end of August 2011

6/9/2010Monarch-A, Hamburg, H. Skourup2 DTU Space, Technical University of Denmark

Sea ice freeboard heights

Sea ice freeboard heights and dynamic topography of the Arctic Ocean observed from ICESat altimetry 2003-2008 release 28 are available in grids of resolution 0.1°x0.2°

ICESat freeboard heights October 2005

blue: February – Marchgreen: October - November

6/9/2010Monarch-A, Hamburg, H. Skourup3 DTU Space, Technical University of Denmark

Conversion of freeboard to thickness

Conversion of measured sea ice free-board heights (hf) into ice thicknesses (tice) depends on:

- Snowdepth- Density of the ice, water and snow

)()(

*)1(

swsiwi

ssii

fice

hh

hhR

hRt

Wadhams et al, 1992

Recent studies suggest to use a

R = 3 - 3.5

for conversion of ICESat freeboard heights into thicknesses. The study is based co-incident measurements of draft by AUV and freeboard by airborne laser

Doble et al. 2011, JGR SEDNA, submitted

6/9/2010Monarch-A, Hamburg, H. Skourup4 DTU Space, Technical University of Denmark

First results of CryoSat-2

STINE results CryoSat-2

6/9/2010Monarch-A, Hamburg, H. Skourup5 DTU Space, Technical University of Denmark

ESA CryoVEx 2011: underflight of CryoSat-2

Photo by Jóhannes Stefánsson

Credits: www.esa.int/esaLP/

6/9/2010Monarch-A, Hamburg, H. Skourup6 DTU Space, Technical University of Denmark

CryoVEx 2011: DTU Space airborne activities

EGIG-line

Austfonna

Devon

Alert

Charter Norlandair Twin Otter: April 7 - May 10, 2011

April 7 – 8 Installation and test flight Kangerlussuaq

April 10 – 19 CryoVEx (sea ice program Alert)

April 20 – 25 PROMICE (Southern Greenland)

April 26 – May 6 CryoVEx (EGIG-line, Austfonna ice cap, sea ice work from RV Lance north of Svalbard, Devon ice cap)

May 7 – 8 Spare/Dismount of instruments

6/9/2010Monarch-A, Hamburg, H. Skourup7 DTU Space, Technical University of Denmark

Noget om GRACE ... Indridi ?!?

6/9/2010Monarch-A, Hamburg, H. Skourup8 DTU Space, Technical University of Denmark

WP 2.6: Status and questions

Lead beneficiary: DTU Space

D 2.6.1: Time series grids of sea ice thickness, and improved SSH measurements, 2003-2008 (for the 3-yearly laser periods), with comparisons to selected ocean models and field-calibrated satellite data

 

This deliverable is almost ready

 

Lead beneficiary: NERSC

D 2.6.2: Ice volume flux time series across the Fram Strait and other outlets (Bering Strait, Nares Strait) based on satellite data (2003-)

 

To solve this we need ice thicknesses and ice drift. DTU Space has the ice thickness fields from D 2.6.1, do NERSC have ice drift ? More important who will actually calculate the flux rates, DTU Space or NERSC ?

 

6/9/2010Monarch-A, Hamburg, H. Skourup9 DTU Space, Technical University of Denmark

WP 2.6: Status and questions - continued

Lead beneficiary: NERSC

D 2.6.3: Freshwater flux time series grids for the Arctic Ocean based on:

Modeled Greenland freshwater output

River discharge

sea ice flux

sea ice melt

 

Who will provide the modeled freshwater output from the Greenland ice sheet ?

Who will provide the river discharge ?

We already have the sea ice flux from D 2.6.2

Who will provide an estimate of the sea ice melt ? Is this provided from the model of University of Hamburg ?

 

Last but not the least we need to agree on data format and grid definitions.