Rationale for a Global Geostationary Fire Product

by the Global Change Research Community

Ivan Csiszar - UMdChris Justice - UMd

Louis Giglio –UMd, NASA, SSAI

Questions

• What is the added value of geostationary fire products (over those from polar orbiters) for global change research? (rationale)

• What are the requirements for global fire products by the global change research community? (requirements)

Suite of satellite-derived fire products

• Fire risk/fire danger assessment• Active fire mapping

– detection– characterization

• Burned area mapping– characterization?

• Post-fire impacts assessment

Geostationary fire products and global change research

• Fire activity as an indicator of global climate change (“effect”)– analysis of the spatial-temporal patters of fire activity and their

changes over time at various time scales • Fire occurrence in long-term impact studies (”cause”)

– hydrological processes• burned area mapping and assessment of the destruction vegetation

canopy• pyrogenic cloud formation and seeding

– ecosystems• better fire regime characterization: time of the day, persistence, sub-pixel

properties– atmospheric chemistry

• emissions modeling– detection and characterization of emission sources

» Active fire detection, Fire Radiative Power/Energy retrievals– a-posteriori burned area mapping

• coupling with transport monitoring and modeling– wind direction/speed, smoke

Geostationary systems• Added values

– high temporal frequency of observations: capability to monitor the diurnal cycle of fire activity – how critical is this information?

– higher chance to obtain cloud-free observations– improved potential for the use of hotspots for

aggregation, “seeding” or confirmation of burn scars• combined use of active fire and burned scar mapping

– burn scars not only from geostationary platforms

– capability for sub-pixel fire characterization and temporal integration

– validation: easier to obtain coincident reference data (in-situ or high resolution aircraft and satellite)

Wet season, 16-day composite (Jan 17-Feb 1, 2002) Dry season, swath image (Oct 24, 2003)

Amazon, Terra/MODIS 250 m

Diurnal cycle from polar orbiters: MODIS Terra and Aqua

Central Africa

Terra

Aqua

What is the optimum time to sample daily maximum?It varies in space and time.

Different local times

Different seasons

Viewing anglesTopography effects

(fixed over time)

Sun angle, glint(changes over time)

Geostationary imagery: geometrical considerations

Geostationary systems• Limitations

– lower spatial resolution in general– angular effects

• potential spatial biases• fixed viewing angles – this can be taken advantage of for long-

term analysis– potential temporal bias due to changing background

conditions within the day• algorithm performance may vary – need for validation at all local

times • Global change researchers do not necessarily

understand or care about remote sensing issues • Proper processing strategy is needed for climate

research – different from operational, near-real-time applications

Sensing system requirements for global change research

• Spatial characteristics– coverage

• gap in Central Asia• poorer coverage and topography effects at high latitudes

– homogeneity• potential dependence of product quality/detection capability

on view angle– need for algorithm corrections/adjustments

• potential inter-satellite discontinuities due to differences in sensing system specifications

– need for algorithm/product inter-calibration– overlap areas with the same view angle are optimal– use polar orbiters for reference

– Resolution• needs are application-dependent – pixel level or aggregated

gridded products

GOES-EGOES-W MSG MTSAT

Map by E. Prins, NOAA

Gap in Central Asia

Little overlapover land

Angular effects

Sensing system requirements for global change research

• Temporal characteristics– homogeneity

• potential effects from algorithm changes• potential effects from sensor changes

– continuity • long-term time series• systems need to be operated by agencies with mandate for

long-term operational climate record production – most often operational agencies

• operational R&D• continuous product validation based on agreed-upon

protocols – frequency

• needs are application-dependent – instantaneous, daily or weekly, monthly etc. summary gridded products

Product validation for global change research

• For global change research applications it is essential to– know theoretical and empirical absolute detection limits

and their variability and uncertainty– relate detection capabilities to the statistical population of

regional fire events to establish detection and false alarm rates

• Goal: “Stage 3” validation and “Validated” products– “Product accuracy has been assessed and the

uncertainties in the product well established via independent measurements in a systematic and statistically robust way representing global conditions”

Data system requirements• Easy (preferably free) access to data products

– several distribution options exist• Timeliness is less an issue• Easy access to validation datasets

– strong collaboration with local/regional partners, often within operational/management agencies

• Metadata and auxiliary data• Manageable data volumes

– but: archive at high frequency to avoid spatial biases from diurnal cycle effects

• Reprocessing capabilities• Fire Climate Data Record

– Which agency (-ies) will manage it?– What fire products from what sensors will be included?

NOAA Satellite Services Division Hazard Mapping System

http://www.firedetect.noaa.gov/viewer.htm

Primarily an operational, real-time system – climate applications?

Example: integrated multi-sensor fire data system

Fire Locating and Modeling of Burning Emissions (FLAMBE)aerosol.spawar.navy.mil/flambe/

Primarily an operational, real-time system – climate applications?

Example: fire data as input to emission/transport modeling

Conclusions• Geostationary systems offer additional

information for the monitoring of diurnal, annual, inter-annual and long-term changes in fire activity – particularly at low latitudes

• Issues exist to integrate products from individual satellites into a global system

• Data production for global change research requires specific considerations

• Stage 3 product validation is essential • No stand-alone geostationary system, but

integral part of a multi-sensor system