Cryosphere Issues

1
Cryosphere Issues

• Jens Hesselbjerg Christensen
• Danish Meteorological Institute
• Working Group on Seasonal to Interannual
  Prediction 12th Session
• Miami, USA, 12-14 January 2009

2
Overview

• Linkages with CliC
• The cryosphere in seasonal prediction
• A question of time scales
• Cryospheric processes that influence the climate
  system
• CliC modelling activities some examples
• How can CHFP be analysed regarding the
  cryosphere?
• Modelling and initialising sea-ice
• Arctic customers?

3
TFSP Hypothesis (Kirtman 2005)

• There is currently untapped seasonal
  predictability due to interactions (and memory)
  among all the elements of the climate system
  (Atmosphere-Ocean-Land-Ice)
• Seasonal Predictability Needs to be Assessed with
  Respect to a Changing Climate
• Use IPCC Class Models Relevance
• Weather Prediction Models (NWP Resolution) Should
  also Tested on Seasonal Time Scales
• Collaboration with THORPEX

4
Interactive Atmosphere-Ocean-Land-Ice Prediction
Experiment

• Best Possible Observationally Based
  Initialization of all the Components of Climate
  System
• Seven Month Lead Ensemble (10 member) Fully
  Interactive Predictions of the Climate System
• Predictions Initialized Four Times per Year for
  Each Year 1979-Present
• Some Predictions by Some Groups Extended to
  Decadal
• Interactive Model
• Ocean Open but interactive (e.g., slab mixed
  layer or GCM)
• Atmosphere Open but interactive, most likely a
  GCM
• Land Open but interactive, e.g. SSiB, Mosaic,
  BATS, CLM, Bucket
• Ice Open but interactive (e.g., thermodynamic
  or dynamic)

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Enhancing the Relevance of the WCRP Programs

• GEWEX
• Provides Guidance on How to Initialize Land
  Surface
• Proposes/Implements Diagnostic Studies and
  Numerical Experiments Understanding Land Surface
  Feedbacks
• Assessing Seasonal Forecasts
• CliC
• Provides Guidance on How to Initialize Cryosphere
• Proposes/Implements Diagnostic Studies and
  Numerical Experiments
• Assessing Seasonal Forecasts
• CLIVAR
• Provides Guidance on How to Initialize
  Ocean-Atmosphere
• Proposes/Implements Diagnostic Studies and
  Numerical Experiments Understanding
  Atmosphere-Ocean Coupling and Variability
• Assessing Seasonal Forecasts
• SPARC
• Provides Guidance on How to Prescribe Atmospheric
  Composition
• Provides Guidance on How to Initialize
  Stratosphere
• Proposes/Implements Diagnostic Studies and
  Numerical Experiments
• Assessing Seasonal Forecasts

6
CliC Goal and Objectives

• Principal Goal
• Assess and quantify the impacts of climatic
  variability and change on components of the
  cryosphere and their consequences for the climate
  system, and determine the stability of the global
  cryosphere
• Supporting Objectives
• Enhance the observation monitoring of the
  cryosphere in support of process studies, model
  evaluation and change detection
• Improve understanding of the physical processes
  and feedbacks through which the cryosphere
  interacts within the climate system
• Improve the representation of cryospheric
  processes in models to reduce uncertainties in
  simulation of climate and predictions of climate
  change

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Components of the cryosphere
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Major Cryospheric Related Issues in Climate
Research

• Arctic Ocean Sea-Ice Cover
• understanding of recent past changes and future
• Possible changes in the THC
• Mean Sea Level Rise
• Stability of the West Antarctic Ice Sheet
• Potential release of C from frozen ground to
  atmosphere
• Carbon balance, possibilities of sequestration
• Role of Tibetian Plateau in Monsoon Variability

9
Location of land ice (glaciers, ice caps, and ice
sheets) north of 60ºS
Note time scales for change but well monitored
10
Cryospheric changes

• Sea ice
• Snow cover
• Glaciers
• Ice sheets and shelves
• Permafrost

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Atlas of Canada
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September sea-ice
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Figure 8.10
September
March
Sea ice in current climate as seen by models
IPCC AR4
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A sea ice model LIM
First-year sea-ice growth and decay at Barrow
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Snow 2002/2003 MODIS
NASA
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Northern Hemisphere Satellite-Derived Snow
Extent1978 2006 Visible (NOAA) Passive
Microwave (SMMR SSM/I)
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Northern Hemisphere 1978 2006 visible and
passive microwave snow-covered area (x 106 km2)
departures from monthly means (12 month
smoothed).
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Spring duration of snow cover Trends derived
from visible satellite data, 1978-2006.
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Flato pers. Comm.
Baseline climate (19801999) terrestrial snow
cover distribution in February in the Northern
Hemisphere simulated by eight AOGCMs
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Circum-Arctic map of permafrost conditions
24.5 of Northern Hemisphere southernmost extent
28N
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Zhang 2005
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Seasonally frozen ground
Zhang 2003
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Formulation of soil processes(CCLM)
Deadhorse
Nicolsky et al. 2007
Lid at 3.43m
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Formulation of soil processes(CCLM)
Deadhorse
Nicolsky et al. 2007
Lid at 80m
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CHFP data issues as seen from CliC

• Inventory of data available
• Strong CliC component
• Should imply a justification for a WCRP data
  management approach
• Challenge uniform initialisation data set
• Specify common format for model output
• CMIP5?
• Model resolution is an issue
• Complicates comparison

31
Skill of nine ten-year-long predictions, evenly
over the period 19552005 Keenlyside et al.
Nature (2008)
32
Possible WGSIP/CliC interaction

• Interactive/prescribed snow cover
• Do we know if snow is impacting skill apart from
  Tibetan plateau?
• Role of frozen grounds
• Lower boundary conditions

33
CLIPS in Polar Regions

• WMO Climate Information and Prediction Services
  (CLIPS)
• WMO recognizes a unique opportunity for the NMHSs
  of its Members to contribute to the legacy of the
  ongoing International Polar Year 2007-2008 (IPY),
  to build collaborative mechanisms for generating
  sustained, practical, operational products and
  services, to meet user needs for climate risk
  management in Polar Regions.
• a Workshop on CLIPS in Polar Regions Climate
  Product Generation, User Liaison and Training
  was held in St Petersburg, Russian Federation
  from 8-11 September 2008

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Location of land ice (glaciers, ice caps, and ice
sheets) north of 60ºS
Note time scales for change but well monitored
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THE END