arctic requirements for high resolution reanalysis · outline (1) the increasing importance of the...

Norwegian Meteorological Institute

Arctic requirements for

high resolution reanalysis

Harald SchybergThanks to: Jun She (DMI), Malte Müller (MET Norway),

Trond Iversen (MET Norway)

h.schyberg<at>met.no

Outline

(1) The increasing importance of the Arctic: changes under

global warming, new economic activities, governance

(2) Examples of potential users/usage areas for Arctic regional

reanalysis

(3) Related projects and datasets. How can Arctic regional

reanalysis add value to already existing or planned global

reanalysis and other datasets

(4) Thoughts and suggestions on requirements for design of

Arctic reanalysis

What do we mean with «the Arctic»?

Definitions differ – there is no universally

agreed southern border:

The Arctic circle 66° 33ʹ N

From climatology: The July 10°C

isotherm (roughly coincides with N

border for forest)

Here: Will not adhere to a strict

definition, but it could be natural for C3S

to have an interest in

1. key earth system processes

2. a geographical domain

corresponding to European

economical/administrative interests Illustration: Igesund/NPI

Arctic climate – rapid change is seen

Temperatures increasing more rapidly than the global average – the

“Arctic Amplification”

Sea ice – last 20 years:

Approximately half the summer coverage

Satellite and other data indicate a reduction of the order of 50% in sea

ice thickness

Summer sea ice volume roughly reduced to ¼

Permafrost temperatures have increased in most regions since the early

1980s

Impacts on ecosystems, economic activities, climate feedbacks, …

Snow and ice data provided by the National Center for Environmental Prediction/NOAA, NSIDC, U. Bremen

Climate change: The sea ice decline

Climate change: The sea ice decline (Sept.)

Projected and hindcasted September sea ice extent (colors and shading) for

IPPC climate models and observations (black line). The shading indicates the one

standard deviation range in the hindcasts and projections.

Credit: J. Stroeve and A. Barrett, National Snow and Ice Data Center

Governance of the Arctic

Some main elements:

•National states

•International agreements

•International cooperation entities

•Arctic Council

•EU has just adapted a new policy for the Arctic

Climate monitoring is one input for Arctic governance


International legal frameworks that applies to the Arctic:

•The UN Convention on the Law of the Sea (UNCLOS), which asserts jurisdictional rights of nations in the various maritime zones.

•The Arctic Council is an international, intergovernmental forum - ”the primary body for circumpolar regional cooperation”. (The EU is an ad hoc observer to Arctic Council proceedings, 3 Member States are members of the Arctic Council, Denmark, Finland and Sweden, while seven Member States are permanent observers);


On more specialized areas:

• The Barents Euro Arctic Council (BEAC) is the forum for intergovernmental and interregional cooperation in the Barents Region. The European Commission is a full member.

• The Northern Dimension is a joint policy between the EU, Russia, Norway and Iceland. It was initiated in 1999 and aims at providing a framework to promote dialogue and concrete cooperation in issues such as economy, culture, environment and transport.

• Transatlantic Ocean Research Alliance (US-Canada-Europe), the Galway agreement on ocean research, includes the Arctic.

• The OSPAR Convention aims to protect the marine environment and ecosystems from emerging threats linked to pollution, maritime activities, together with climate change and increased human presence.

• The International Maritime Organisation (IMO), a specialisedagency of the United Nations with responsibility for the safety and security of shipping and the prevention of maritime pollution by ships. All EU Member States are IMO Members. The European Commission has an observer status.

27 April 2016: An integrated European Union

policy for the Arctic

Background: The European Parliament and the Council in

2014 asked the Commission and the High Representative to

develop an integrated policy on Arctic matters, with a more

coherent framework for EU action and funding programmes.

A policy proposal that will guide the actions of the European

Union in the Arctic region. 3 main policy objectives:

protecting and preserving the Arctic in cooperation with

the people who live there

promoting sustainable use of resources

international cooperation.

39 actions listed

An integrated EU policy for the Arctic - some of

the 39 actions:

• Maintain current funding levels for Arctic research under

Horizon 2020 (on average 20 million per year). Around 40

million has already been earmarked for 2016 and 2017 for

projects on observation, weather and climate change in the

northern hemisphere and permafrost decrease.

• Support the transnational access to research infrastructures

in the Arctic and the open access to data resources. The

EU’s Copernicus space programme is to support

international research on climate change in the Arctic.

• Enhance coordination between EU funding programmes

relevant for the Arctic, identify key investment and research

priorities as well as facilitate capacity building of

stakeholders to maximise financial support for the region.

AMAP

Arctic council has six Working Groups. One of them is Arctic

Monitoring and Assessment Programme (AMAP).

Project under AMAP:

AACA - “Adaptation Actions for a Changing Arctic” – series of reports

Example – some key messages from the draft Barents area

AACA assessment

• The Arctic will warm faster than the average global warming, and

temperature projections suggest a winter-time increase of the order 3-10 ºC

between 2015 and 2080 if the future follows the path of RCP4.5. The

RCP8.5 scenario may push the warming up to 20 ºC.

• A higher proportion of the precipitation is expected to fall as rain in the

future, amplified by the sea-ice retreat and increasing the risk of rain-on-

snow events

• A number of natural hazards are connected to synoptic storms, such as rain-

on-snow events, avalanches, and extreme wave heights, but the current

projection do not provide robust indications of a change other than a

poleward shift in the storm tracks

• Polar lows are small and violent storms that represent a risk to activities in

the Arctic, and projections for the future suggest less favourable

environment for their occurrence

13

Example – some key messages from the draft Barents area

AACA assessment (2)

• The snow cover extent has decreased most at high latitudes (60-70°N), and

the decline of snow cover in Eurasia over 2007-2014 has accelerated

compared to earlier periods

• The duration of the snow season has decreased, and the melt onset date in

spring has advanced about 1-2 weeks in the 1979-2012, and the duration of

snow-cover in 2050 will be about 30-40 % less than in 2011

• Observations of the snow quality suggests an increase in very hard snow

layers from 1961 to 2009, with harder snow in early winter, more moist snow

during spring, and future warming may bring more rain-on-snow events

• The permafrost is thawing because of the Arctic warming, and the projected

warming and increases in snow thickness will result in near-surface

permafrost degradation over large geographic area

14

Some potential use areas for reanalysis

• Economic sectors: natural resource exploitation, fisheries,

tourism, transportation

• Climate system process studies

• Climate model validation

• Climate change effect studies

• Ecosystem change studies: permafrost degradation,

increasing runoff, coastal erosion, reduced ice thickness

• Arctic Populations/communities commonly distributed

along or dependent on coastal waterways and river

systems for access and subsistence

• Input to governance and resource management

• For instance Arctic Council and its “Arctic Monitoring

and Assessment Programme”

Managing the risks in economic activities:

Reanalysis can contribute

Icing from seaspray

Sea ice, icebergs

Significant wave height

Storms

Extremely low temperature

High wind and low temperature

Currents

Sea states

Darkness 24/7

Environment

The

Northern

sea route

Arcticportal.org

Lloyds (2012): «Arctic Opening: Opportunity

and Risk in the High North» (1)

Some points from analysis of a leading international insurance company:

•“Rapid and disruptive change in the Arctic environment presents uneven prospects for investment and economic development. All across the Arctic, changes in climate will create new vulnerabilities for infrastructure and present new design challenges.

•The Arctic is likely to attract substantial investment over the coming decade, potentially reaching $100bn or more. However, given the high risk/potentially high reward nature of Arctic investment, this figure could be significantly higher or lower.

•Arctic conditions will remain challenging and often unpredictable. Many of the operational risks to Arctic economic development – particularly oil and gas developments, and shipping – amplify one another. At the same time, the resilience of the Arctic’s ecosystems to withstand risk events is weak, and political and corporate sensitivity to a disaster is high.”

18

Lloyds (2012): «Arctic Opening: Opportunity

and Risk in the High North» (2)

•“The environmental consequences of disasters in the Arctic are likely to be worse than in other regions.

•The challenges of Arctic development demand coordinated responses where viable, common standards where possible, transparency and best practice across the north. These frameworks need to be in place to enable sustainable development and uphold the public interest.

•Companies operating in the Arctic require robust risk management frameworks and processes that adopt best practice and contain worst case scenarios, crisis response plans and full-scale exercises.”

19

Economic activities in the ArcticCredit:

http://arkgis.org/


Icing (ice accretion) conditions 1958-2013.


Polar lows 2000-2013

Gunnar Noer, VNN, MET Norway


Trend in number of mild and rainy days dec.-feb.

EWWA – Changes in winter warming events in the Nordic Arctic Region

From Vikhamar-Schuler et al (2013): Snow model

assessment of grazing conditions for reindeer


Existing Arctic reanalyses/hindcasts – atmos/ocean/ice

(probably uncomplete list)

Producer/

Dataset

Variables Area Period/ resolution Obs. Used in DA Model and DA method

DMI Atmosphere Pan-

Arctic

1999-2004, hourly,

15km

Synoptic data 3DVAR with ERAI as BC and

background; HIRLAM

DMI Ocean-sea ice Pan-

Arctic

1994-2013, hourly,

10km

SST, Sea ice

concentration

Nudging, HYCOM-CICE (incl.

tide)

NERSC

(Copernicus

Marine Service)

Ocean-sea ice Pan-

Arctic

1991-2014, daily,

12.5km

Currents, T/S profiles,

SST, SIC, SLA

EnKF, Hycom/TOPAZ+NERSC

ice model (no tide)

MET Norway Atmosphere

hindcast “NORA

10”

Regional 1957-present, 10km Hindcast only ERA40 BC and background,

HIRLAM

MET Norway Atmosphere

hindcast

Local/reg

ional

Not completed,

2.5km

Hindcast only HARMONIE/AROME

SMHI Ocean-sea ice-

atmosphere

Pan-

Arctic

IPY (2005-2007),

22km

AMSU-A, SST, SIC, in-situ

atm.&ocean

HIRLAM (4D-Var), HIROMB

(OI)

USA/Ohio Univ.:

Arctic System

Reanalysis

Atmos-ocean-

ice

Pan-

Arctic

2000-2012, 3hourly,

15 and 30 km

Polar WRF (3D-Var)

US: The Arctic System Reanalysis (ASR)

Polar Meteorology Group, Ohio State Univ. (Dave Bromwich), funded by NSF and NASA

Polar WRF with 3D-Var:

• 15- and 30-km (inner domain) horizontal resolution versions

• Version 1: 30 km version is complete for 2000-2012

• Version 2: 15 km version with some model updates: available soon

Bromwich et al, QJ, 2016 – comparison of version 1 with ERA interim:

Higher resolution terrain and detailed land-surface description useful

Some verification scores better, some worse than ERAI

Improvements over ERAI in near-surface fields

Improvements in depiction of mesoscale processes

http://polarmet.osu.edu/ASR/

Hindcast partly covering Arctic: «NORA10»

Hindcast produced at MET Norway, NWP model HIRLAM is used to downscale ERA-

40 data to 0.1° resolution over Norway and adjacent sea areas incl parts of Arctic

Originally covered the ERA-40 period,until 2002, has since been extended using

ECMWF operational analyses (Reistad et al. 2011, Haakenstad et al. 2012.)

Below figure from Reistad et al, 2009:

Wind fields benefit from more resolved orography

Summary: Need for high-resolution Arctic

reanalysis vs existing datasets

Existing datasets for the atmosphere:

• Resolution down to 10-15 km

• Limited time ranges

• Limited satellite data usage

Possible added value from a new reanalysis:

• An open European dataset

• Higher horizontal resolution would add value by

• Capability to describe important mesoscale convective

phenomena in cold air outbreaks over ocean (extreme surface

heat fluxes, polar lows)

• Forcing from lower boundary (orography, sea ice, snow cover,

…)

Major challenges for Arctic atmospheric reanalyses

• Good datasets and strategies for the lower boundary:• Sea-ice with varying extent, ice concentrations and

properties that influence the surface heat and moisture fluxes.

• Snow cover/properties, glaciers (Greenland)• Coupling with sea ice/ocean model could come later

• Very stable boundary layers connected to strong surface cooling

• Vigorous convection over open ocean when air masses arrive from the sea-ice or cold land (Major Cold Air Outbreaks)

• Mesoscale phenomena in cold air outbreaks over ocean:Extreme surface heat fluxes, convective systems, polar lows

• The observing system: Use of satellite data will be important

Vigorous convection: Polar lows

Satellite image of the polar low situation 6 March 2013


Polar lows

(An unusual polar low 8 January

2010: First time a polar low has

been observed North of

Spitsbergen. Possible with

retreat of winter sea ice. Polar

lows form only over open

ocean.)

MET Norway forecasters saw a

significant improvement in

Polar Low NWP modeling

capability when resolution went

to 10-15 km and below.

Convection resolving models

an advantage.

28. april 2016Danmarks Meteorologiske Institut

Veðurstofa Íslands

Side 31

Glaciers need to be accounted for:

• No glacier surface type was defined in SURFEX

caused large drift in NWP output

• Remedies were needed to remove drift, and

turned out to make HARMONIE is able to

simulate melt area well

It is important to use correct and updated

physiography data for NWP modelling & reanalysis

• Work is done to update Greenland ice sheet

extent as included in the EcoClimap-II data set

• Data from Greenland Mapping Project used to

replace GMTED2010 topography

Some experience regarding

Greenland (DMI, IMO)

The Arctic observing system

Upper air conventional observations:

Example radiosonde (left) and aircraft coverage (right) (13 Sep 2013)

Observing system relies on remote sensing in the Arctic: Good use of remote

sensing data is important for reanalysis quality

Measuring of model quality with sea-level pressure forecasts

We chose to use pressure forecasts at coastal stations:

• strongly connected to capturing the main weather systems

• not as strongly influenced by local conditions at the measurement stations as for instance wind and temperature would be

• is thus more comparable between different observing stations as a measure of the general quality of the large-scale forecast fields

Of interest to know atmospheric pressure variability which needs to be described for reference

Left: Mean absolute day-to-day observed pressure differences in hPa


Model accuracy decrases towards the North (1)

The figures shows the RMS errors in pressure (vs observations) for forecasts in the range from 18 to 42 hours

· Left: Operational ECMWF global model (~16 km resolution)

· Right: Operational HIRLAM 12 km regional model

34

The Arctic Atmospheric observing system

Relies heavily on satellite data

A preliminary gap analysis

• gap in pressure observations over sea ice and ocean areas

• almost no coverage of near-surface wind observations over sea ice

• gaps in conventional upper air data is compensated by data from satellite

sounding instruments

• data from temperature sounding in the lower troposphere is difficult to

exploit the signals have surface contributions which are generally not

well modelled (sea ice surface)

Both wind and temperature information in the lower Arctic

troposphere is missing in the remote ocean and ice areas

(Schyberg and Randriamampianina, EU ACCESS project)

35

Some onging frameworks for enhancement and

coordination of the Arctic observing system

SAON – Sustaining Arctic Observing Networks

EU Horizon 2020 calls under «Blue Growth» (under evaluation):

· BG-9-2016: Integrated Arctic Observing System

· BG-10-2016: Impact of Arctic changes on weather/climate of Northern Hemisphere

ESA Polaris program: «… development of the next generation of space infrastructure to support both scientific and operational information needs in the rapidly evolving Polar Regions»

As well as planned polar orbiters from ESA and EUMETSAT (for instanceADM-Aeolus)

… sets the scene for increased quality and usefulness of Arctic reanalysis

36

Operational regional NWP systems in the Arctic

Upper: «AROME Arctic» of MET Norway

Lower: DMI/IMO joint project

Both are HARMONIE/AROME:

• At 2.5 km horizontal resolution

«AROME Arctic» at MET Norway:

• 3D-Var data assimilation, conventional

obs + AMSU/MHS, IASI, ASCAT

• Ongoing work on AMV implementation

• Sea ice and SST from daily OSI SAF

products. Ongoing work on updated sea

ice module in SURFEX.

37

Requirements for Arctic reanalysis could

include:

• Convection resolving?

• Not fully pan-Arctic, but cover some domains of interest for

economic activities and change processes

• Make good use of the main components of the Arctic

observing system (satellite datasets needed)

• Make good use of complementary data on surface properties

relevant in the area, such as ocean and sea ice, snow, …

• Length of time period: similar to approach for other regional

reanalysis datasets

Summary

Arctic reanalysis can contribute to

• Provide important input to studies of climate change and earth

system processes in the area

• Managing risk in emerging economic activitis in the area

• Provide knowledge input to governance towards sustainable

development of the area

Some suggestions:

• Needs a good strategy for providing a good description of the

lower boundary forcing: Sea ice, ocean, snow, glaciers

• (A fully coupled atm.-ocean-seaice reanalysis a task for the future)

• Higher resolution than global reanalysis will help description of

convective phenomena in Arctic climate, effects of small scale

orography and surface forcing

Thank you!

Backup slides follow

40


Regional downscaling - HARMONIE Climate branchCooperation MET Norway with SMHI (and KNMI)


UERRA: Uncertainties in Ensembles

of Regional ReAnalysesObjectives

• To produces ensembles of European regional meteorological

reanalyses of Essential Climate Variables for several decades

• To estimate the associated uncertainties in the data sets

• To provide more observations for reanalyses

• To provide data services and user information

Pre-operational

Copernicus Climate Change Services


44

UERRAProvide data sets and uncertainty estimates,

building from FP7 EURO4M and

extends in several dimensions:

More models and analysis systems (also gridded obs)

Ensembles

Much longer time period – 50+ years or 30 for ensemble

Higher resolution than ever before

More digitised observations rescued and provided

Quality and uncertainty measures

Comprehensive web based data and visualisation service

User guidance on user oriented products


ensemble ~1978 -2015

1 Control 12 km

70 levels

10 (20) members 24 km

ensemble

Hybrid 4D-Var,

Ensemble of 4D-VARs

Conventional obs,

satellite data, precip?

Met Office SMHI/MF

deterministic ~1961-2015

5 years ensemble

1 member 11 km

65 levels

2 members physics (5 y)

HARMONIE

3D-VAR

Conventional obs,

Large scale constraint

from ERA

Uni Bonn DWD

ensemble ~5 years

1 Control 12 km

40 levels

20 members 12 km

ensemble

Conventional obs

Radar, new in LETKF

LETKF and

Ensemble Nudging

boundary forcing from global ERA reanalyses

(ERA-40, ERA-Interim,ERA -5, incl. Ensembles, EDA)

3-D model level fields u,v,T,q,clouds, 2D fields

precipitation, surface p, T, RH, snow and more


2-D surface fields analyses driven by 3D reanalyses

SMHI

MESAN

~1982 - 2013

5 km Europe

Cloud fraction

hourly

2D advanced

Statistical

interpolation

AVHRR, METEOSAT

SEVIRI and

MVIRI

Downscaled

3D HIRLAM model

Climatological

adaptation background

MF/SMHI

MESCAN

1961 - ~2013

5 km Europe

T2m, RH, 24 h

precipitation

2D advanced

Statistical

Interpolation

Surface and climate

stations

T, Td,

precipitation

Downscaled

ALADIN model

background

SMHI

HYPE

~1979 - 2010

River discharge

35000 catchments

Europe, median

215 km2

Hydrological

physical

model

No input observations

Validation against

discharge data

ERA, EURO4M and

UERRA reanalyses

Precipitation and

temperature forcing

MF SURFEX

and TRIP

~1981 - 2010

River discharge

25 km -> rivers

Surface flux model

Hydrological physical

model

No input observations

Validation against

discharge data

MESCAN

atmospheric

variables and

precipitation


Uncertainty estimations

Evaluate ensemble reanalyses and downscaled reanalyses through

comparison to independent ECV datasets that were derived independently

Establish a consistent knowledge base on the uncertainty of reanalyses

across all of Europe through a common evaluation procedure

o Extremes, Climate Indices and Indicators of user interest, scales of

variablity

Statistically assess the provided information by applying the common

evaluation procedure on all data

User dependent parameters and language adaptation

Sea Ice Concentration Climate Data Record

1979

(sept)

1978 - 2015 : Climate Data Record 2015 - … : Interim CDR

1979

2012

2015

SIC Algorithm, Processing, and Operationality

Some unique features of the algorithm:

Dynamic adjustments of the algorithm tie-points (=> Consistency) ;

Maps of uncertainties;

Rooted in the OSISAF, consolidated by the ESA CCI Sea Ice R&D.

Processing chain:

Engineered in the OSISAF, consolidated by ESA CCI Sea Ice.

Scalable data re-processing system at MET Norway (but data volumes are small).

Operational in the sense of EUMETSAT SAF and CMEMS:

Review cycles (Req. Review, Product Consolidation Review, Delivery Readiness Review);

Traceability of requirements, CORE-Climax Maturity Matrix, CEOS ECV Inventory,...

Sea Ice Type, Sea Ice Drift, ...

S. Kern (2016)

March 2015

M. Tschudi (2014) US NSIDC

June snow cover 2012 relative to 1971-2000

Credit: James Overland

arctic requirements for high resolution reanalysis · outline (1) the increasing importance of the...

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