The ESA SnowPex project and an introduction to the … · The ESA SnowPex project and an introduction to the APVE workshops . ... Introduction to the ESA SnowPEX project B. Bojkov

Bojan R. Bojkov

Head Sensor Performance, Products and Algorithms

Directorate of Earth Observation Programmes

European Space Agency – ESA/ESRIN

The ESA SnowPex project and an introduction to the APVE workshops

Part 1 – with T. Nagler (Enveo):

Introduction to the ESA SnowPEX project

B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014

Snow – an important hydrological resource


Continental to Hemispheric Satellite Snow Extent Products

Name Product

type Pixel

Spacing Frequenc

y Period

Main Sensor

Organisation

NOAA IMS Binary 4 km daily 2004 -

OPT, PMW,

+ manual

NOAA (Helfrich et

al.)

NOAA IMS Binary 24 km daily 1997 -2004 OPT, PMW NOAA

ESA GlobSnow

Fractional 1 km daily - monthly

1996-2012 ATSR2 AATSR

SYKE et al.

NASA MOD10

Fractional 0.5 km Daily 2000 -

MODIS NSIDC (Hall et al.)

AVHRR Pathfinder

Binary 5 km daily 1992 -2004 AVHRR CCRS (Zhao, et al)

CryoLand Fractional (Europe)

0.5 km daily 2000 - MODIS ENVEO / SYKE et al.


Maximum Snow Extent: 1-7 March 2010

MOD10

GlobSnow

IMS


Motivation

Requirement formulated at the First GCW Snow Watch Meeting (Toronto, January 2013): Need to develop community endorsed “best practise” to intercompare global / hemispheric (pre) operational snow products derived from different EO sensors and generated by means of different algorithms, and assess the product quality.

(Derksen & Brown 2012)

Time series of Northern Hemisphere June snow cover from NOAA snow chart CDR. Rate of Snow Extent decrease: -21.5% / decade (1979-2012)

Questions: - How large is the uncertainty in rate of

Snow Extent? - In which regions are the highest

changes?


SnowPEX Objectives

The primary objectives are

• Intercompare and evaluate global / hemispheric (pre) operational snow products derived from different EO sensors and generated by means of different algorithms, assessing the product quality by objective means.

• Evaluate and intercompare temporal trends of seasonal snow parameters from various EO based products in order to achieve well-founded uncertainty estimates for climate change monitoring.

• Elaborate recommendations and needs for further improvements in monitoring seasonal snow parameters from EO data.

The SnowPEX project aims to bring together scientists and institutions of seasonal snow pack monitoring for assessing the quality of current satellite-based snow products derived from EO data, and working out guidelines for improvement.

The project will support the setup of a consolidated operational satellite snow observation system for the WMO Global Cryosphere Watch and help to improve the snow cover data base for climate monitoring, as addressed by the WCRP-CliC programme


SnowPex Status

Consortium:

• T. Nagler (PI), Enveo (Austria); R. Fernandes, CCRS (Canada); S. Metsämäki, Syke (Finland); J. Pulliaineni/K.Luojus, FMI (Finland); C. Derksen, EC (Canada); R. Solberg, NR, (Norway)

Key elements:

• Develop community accepted “best practices” for snow product intercomparisons (satellite and in-situ) following the CEOS QA4EO (http://www.qa4eo.org) principles

• Organise two International Satellite Snow Products Intercomparison workshops (ISSPI) – first one held in 21-23 July in College Park, MD

• Coordinate with/contribute to the WMO/GCW

Duration:

• 24 months through mid-2016

Information/documentation:

• http://calvalportal.ceos.org/projects/snowpex


ISSPI-1 Highlight: in-situ

Short-term priority for EO validation by in-situ datasets however should specifically address:

1. Establish in-situ/EO inter-comparison/validation protocols

2. Define (globally) representative reference sites

3. The “point to area” representativity issue, especially in complex areas (mountains, mixed areas, etc.)


Ross Brown’s ISSPI presentation

ISSPI-1 Highlight: sat. reference scenes

Hi-resolution resolution datasets i.e. Landsat, Spot 5/6, etc., preferred for direct inter-comparisons

Need consistent L1 version (re)processing of hi-resolution satellite data reference scenes globally • At a minimum over reference

sites/regions identified in the workshop

• Orthorectified with common public DEM, using common auxiliary data (land mask, land classification, etc.), consider imprved cloud screening procedures

• Readily accessible archive (possibly need to reconcile the existing archives, for example the ESA and USGS Landsat archives)

About 400 Landsat scenes were so far identified for SE evaluation (with data currently available at ENVEO, SYKE and Rutgers University)


Part 2 – with Yves Creview (CSA): The

Arctic and high-latitude Products

Validation and Evolution workshop

(APVE)



APVE Motivation

High-latitudes areas and the Arctic are sparsely populated, extremely remote, with a challenging and harsh environment

These sensitive areas are undergoing tremendous changes – human access, exploration, environmental changes, etc.

These areas are also impacted by human activity at mid-latitudes through long-range transport

and the Arctic/sub-Arctic can be considered the Earth’s canary


1. Ocean Colour Remote Sensing: background

!! From Ocean Colour to Marine biomass (chl a)

Morel and Maritorena, JGR, 2001

!! Marine biomass and physical coastal processes

Alaskan coast, NASA EO

APVE Motivation (ii)

Lena Delta

New Siberian

MERIS RR 20080812

Space-borne Earth

Observation in the last

decades has allowed us

to witness nature in

remote areas and science

to “explore“ these

phenomena

APVE Motivation (iii)

Comparing SeaWIFS derived chlorophyll climatology to a climate

model, large differences are evident - yet the differences

seem to correlate well with the Colored Dissolved Organic

Matter (CDM) – see Spiegel, et al., 2005


APVE Motivation (iv)


Earth Observation, as illustrated here, has a tremendous potential for high-latitudes by: • Monitoring sea ice change

• Monitoring hemispheric temperature change

• Identifying land cover changes and permafrost change

• Help estimate river runoff (with models)

• etc.

but, the high-latitudes are challenging for EO, especially for optical type measurements: • Extended polar night

• Extended periods with (very) high solar zenith angles

• High cloud occurrences

• Difficult environment for validation (and few validation data)

Rationale for a Targeted Workshop

The Arctic and high-latitude Products Validation and

Evolution (APVE) workshop-series is therefore proposed:

• In response to strategic priorities common to ALL

northern-latitude and Arctic Nations and most of which

are Member States of ESA

• Earth Observation (potentially) provide stand-alone and

complementary technology for monitoring vast, harsh,

and inaccessible environments

• Both are integral part of long-term high-latitude

commitments by Arctic countries (e.g. IPY follow-on, Polar

services, etc.)


Rationale for a Targeted Workshop (ii)

(but)

"Technology and science are only as good as our ability to

use the information they provide”

(and)

"The successes are dependent on our ability to relay the

information the final mile to the people”

Unknown marine scientist

Nov. 17, 2006

Tsunami warning system


APVE Workshop Themes

1. Mapping, characterization and changes with time of high-latitude areas and the Arctic • Characterization and physical changes due to processes and

dynamics

• Collection of cartographic information (incl. land classification)

2. Environmental monitoring of land, water and atmosphere in high-latitude areas and the Arctic • Includes physical, chemical and biological parameters to detect

short-term changes and trends

• Environmental monitoring of coastal transition zone

3. Sustainable economic development of natural resources in high-latitudes and the Arctic • Mapping and monitoring to support economic activities

including the exploitation of natural resources and also transportation, by land, water and air


APVE Workshop Themes (ii)

4. Safety and emergency response in high-latitude areas and the Arctic • Monitoring to improve safety and to support emergency

response to both natural and man-made conditions

5. Security and Sovereignty in high-latitude areas and the Arctic • Monitoring to support the protection of humans, wildlife and

property and the terms of the United Nations Convention on the Law of the Sea (UNCLOS)

6. Validation capacity and infrastructure in high-latitude areas

and the Arctic • Specifically addressing the needs abd coordination of the above

points

Multi-sectorial/cross-discipline with common data needs B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014

APVE Workshop Concept

• APVE will foster the assessment, development, and exploitation of the broad spectrum of capabilities offered by Space-based Earth observation technology in response to high-latitude and Arctic stakeholders information needs

• Addressing National, Regional, and International interests

• Focus on existing agency data, and others in support of future capabilities (evolution)

• Pooling resources (systems, programmes, audience, etc.)

• Better operation support/amplified impact


APVE Workshop Status

ESA has begun the planning of two APVE workshops, similar in

format to the 2008 ESA/CSA MORSE workshop, and the

ESA ACVE (atmosphere), LPVE (land) and S3VT (Sentinel-

3) workshops

This is a collaborative effort with LOOKNorth (a CND Centre of

Excellence) and the Canadian Space Agency (CSA)

The first workshop will take place from 11-12 November in

Ottawa, Canada

• 30+ presentations addressing product evolution and validation

for land, lakes, coastal zones, snow, ice, etc.

• http://calvalportal.ceos.org/events/apve-workshop

Follow-up workshop in Sweden (SHMI) in the Spring 2015 B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014

Thank you for your attention!

[email protected]


Documents

The ESA SnowPex project and an introduction to the … · The ESA SnowPex project and an introduction to the APVE workshops . ... Introduction to the ESA SnowPEX project B. Bojkov