The ESA SnowPex project and an introduction to the … · The ESA SnowPex project and an...
Transcript of The ESA SnowPex project and an introduction to the … · The ESA SnowPex project and an...
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
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.
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014
Maximum Snow Extent: 1-7 March 2010
MOD10
GlobSnow
IMS
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014
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?
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014
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
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014
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
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014
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.)
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014
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)
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014
Part 2 – with Yves Creview (CSA): The
Arctic and high-latitude Products
Validation and Evolution workshop
(APVE)
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014
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
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014
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
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014
APVE Motivation (iv)
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014
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.)
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014
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
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014
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
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014
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
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014
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!
B. Bojkov - SnowPEX/APVE: NASA/GSFC, 29 September 2014