Melting trends over the Melting trends over the Greenland ice sheet (1958-Greenland ice sheet (1958-

2009) from spaceborne 2009) from spaceborne microwave data and regional microwave data and regional

climate modelsclimate models

Kelsey SimmonsKelsey SimmonsAtmospheric Science MajorAtmospheric Science Major

Published May 5, 2011

By X. Fettweis, M. Tedesco, M. van den Broeke, and J. Ettema

AuthorsAuthors

Dr. Xavier FettweisDr. Xavier Fettweis

University of Liege, BelgiumUniversity of Liege, Belgium

Email: Email: xavier.fettweis@ulg.ac.bexavier.fettweis@ulg.ac.be

Dr. Marco TedescoDr. Marco Tedesco

The City College, New York, The City College, New York, NYNY

Email: Email: mtedesco@sci.ccny.cuny.emtedesco@sci.ccny.cuny.edudu

Authors Authors

Dr. Michiel R. van den BroekeDr. Michiel R. van den Broeke

Utrecht University, The Utrecht University, The NetherlandsNetherlands

Email: Email: m.r.vandenbroeke@uu.nlm.r.vandenbroeke@uu.nl

Dr. Janneke EttemaDr. Janneke Ettema

University of Twente, The University of Twente, The NetherlandsNetherlands

Email: Email: ettema@itc.nlettema@itc.nl

OverviewOverview

DataData

Biases and LimitationsBiases and Limitations

ResultsResults

What does it What does it mean/Why does this mean/Why does this matter?matter?

Collecting DataCollecting Data

Models:RACMO2 Models:RACMO2 and MARand MAR

InstrumentsInstruments

Algorithms Algorithms

Automated Weather Station (AWS) used for the Greenland Climate Network. (GC-Net)

Algorithms Algorithms Methods for detecting wet snow

•T19H K-band horizontal polarized brightness temperature

•T19Hthsd Threshold value of T19H

•T37V K-band vertical polarized brightness temperature

• XPGR Cross-polarized gradient ratio

CP1CP1

DYEDYE

ETH-CampETH-Camp

Jar1Jar1

Melting analysisMelting analysis

Time periodTime period

Years with lower Years with lower snow melting vs. snow melting vs. years with higher years with higher snow meltingsnow melting

Regions with >100 Regions with >100 days of meltingdays of melting

Difference between Difference between models and models and satellite datasatellite data

Limitations in the Limitations in the AlgorithmsAlgorithms

T19Hmelt ExtXPGR XPGR MARRACMO2

Biases in ModelsBiases in Models

Melting areas Melting areas absent in one but absent in one but not the othernot the other

Bare ice at the Bare ice at the surfacesurface

Summer snowfallSummer snowfall

Results and ErrorsResults and Errors

Significant positive Significant positive trendtrend

Years of Max and Years of Max and Min Min

Periods of highs Periods of highs and lowsand lows

Response time to Response time to surface snow surface snow changeschanges

2-m temperature 2-m temperature vs surface vs surface temperaturetemperature

Minimum thickness Minimum thickness LWC sensitive LWC sensitive

algorithmsalgorithms

What does this mean and why What does this mean and why does it matter?does it matter?

Sea level riseSea level rise

Influence weather Influence weather patternspatterns

PaleoclimatologyPaleoclimatology

QUESTIONS?QUESTIONS?

Works CitedWorks Cited

Fettweis, Xavier, Marco Tedesco, Michiel Van Den Fettweis, Xavier, Marco Tedesco, Michiel Van Den Broeke, and Janneke Ettema. "Melting Trends Broeke, and Janneke Ettema. "Melting Trends over the Greenland Ice Sheet (1958–2009) from over the Greenland Ice Sheet (1958–2009) from Spaceborne Microwave Data and Regional Spaceborne Microwave Data and Regional Climate Models." Climate Models." TC - Abstract - Melting Trends TC - Abstract - Melting Trends over the Greenland Ice Sheet (1958–2009) from over the Greenland Ice Sheet (1958–2009) from Spaceborne Microwave Data and Regional Spaceborne Microwave Data and Regional Climate ModelsClimate Models. Copernicus Publications, 5 May . Copernicus Publications, 5 May 2011. Web. 15 Apr. 2015. 2011. Web. 15 Apr. 2015.

http://cires1.colorado.edu/steffen/gcnet/aws.htmlhttp://cires1.colorado.edu/steffen/gcnet/aws.html http://s.ngm.com/2013/09/rising-seas/gatefold/http://s.ngm.com/2013/09/rising-seas/gatefold/

RS_Web_NA_15M_v3.jpgRS_Web_NA_15M_v3.jpg