advancing techniques for informing terrestrial ecosystem models
TRANSCRIPT
Advancing Techniques for Informing Terrestrial Ecosystem Models with Leaf and Imaging Spectroscopy to
Improve the Representa?on and Predic?on of Vegeta?on Dynamics and Carbon Cycling
Ankur R. Desai, Sean DuBois, Shawn P. Serbin, Toni T. Viskari, Michael C. Dietze, and
Philip A. Townsend
#EuroSpec2013 Final Conference, Nov 6-‐8 2013, Trento, Italy
Terrestrial carbon cycle feedback is a leading order uncertainty for climate simula5on
IPCC AR5 WG1 CH6 (draB)
This is true at the site level, too! Willow Creek EC Tower Site, Wisconsin
www.pecanproject.org
NEE
GPP
Reco
Leaf and canopy high-‐spa5al and spectral resolu5on spectroscopy to the rescue?
(a) Fresh (b) Dry
Acer saccharum
Imaging spectroscopy has a wealth of underu5lized observa5ons for ecosystem models!
nm
nm
TAFKAA
Raw DN
Cal. Radiance
Reflectance
ER-‐2 AVIRIS AVIRIS Image Cube
il menu del giorno
• Two possible pathways: – Data products assimila5on – Direct op5cal proper5es assimila5on
• Based on results from two field projects: – ChEAS Ameriflux Cluster – NASA HyspIRI prep mission
• With one assimila5on system / model: – PEcAn with ED2
PEcAn: Predic5ve Ecosystem Analayzer is a workflow for model-‐data assimila5on
Ecosystem C / H20 / E
ED2 is a dynamic ecosystem model and already includes broadband radia5ve transfer
Medvigy et al 2009
PEcAn variance decomposi5on provides informa5on on sensi5vity of a model output variable (e.g., NPP) to uncertainty in input data
(CV), model sensi5vity (elas5city), and joint variance
165 Plots 120+ AVIRIS Scenes NASA FFT Project NASA HyspIRI Campaign
Two study regions in US
2013-‐2014 Spring Summer Fall
Singh, Serbin, McNeil, Townsend. (in prep) Eco. Apps.
ChEAS
Of a total of 145 scenes, 26 in ChEAS: All midsummer (July/August) images 7.0m -‐ 16.8m resolu?on (low/high alt. ER-‐2)
ChEAS: AVIRIS over 4 Ameriflux sites
DATA PRODUCT ASSIMILATION
MODIS LAI + Flux tower ver5cal PAR profile tames model phenology
Viskari et al., (in prep)
Prior Posterior
Filled dot = MODIS LAI, open dot = LAI from flux tower profile FaPAR
2002
2003
2004
2005
SPRING FALL
AVIRIS products generated with PLSR technique and leaf-‐level spectroscopy calibra5on
Serbin et al., 2012 J Exp Botany
Where we are today:
Standardized algorithms to predict foliar cons5tuents (%C,%N,LMA,…) using spectroscopy across diverse forest types w/ uncertainty es5amtes.
• Our scaling methods propagate the uncertain5es at the leaf-‐level through the canopy PLSR modeling to produce es5mates of foliar traits (i.e. trait maps) with an es5mate of the associated retrieval uncertainty (pixel by pixel). • Thus, we can u5lize these products in a model DA framework given that we have quan5fied uncertainty in retrievals.
Model-‐data Assimila5on: AVIRIS Willow Creek EC Tower Site, Wisconsin
www.pecanproject.org
Working toward the assimila5on of AVIRIS-‐derived products. These include foliar chemistry (e.g. N, C, CN, lignin) and morphology (SLA).
Model-‐data Assimila5on: AVIRIS Willow Creek EC Tower Site, Wisconsin
www.pecanproject.org
• Of course this requires uncertainty for proper DA. Otherwise too much weight given to the RS es5mates causing overconfidence. Therefore, our methods u5lize the genera5on of AVIRIS retrieval uncertainty to properly assimilate datasets!
DIRECT OPTICAL ASSIMILATION
Scalering elements, LADF, LAI
Absorp5on
Transmilance
Reflectance
Canopy Reflectance Variability 241
and transmittance properties, quantification of the rela- 1400 nm and 1900 nm were due to water vapor, pre-venting measurements and subsequent modeling of thesetive importance of water, carbon, and nitrogen continues
to be difficult (Curran et al., 1992; Fourty et al., 1996). spectral regions. Soil reflectance variability was highestin the SWIR2 (c.v.!18–20%) and lowest in the VISStanding litter and woody stem optical properties
were generally more variable compared to leaves (Fig. (c.v.!14–16%).2). Litter reflectance and transmittance c.v.’s were 8–35% (lowest in VIS, highest in SWIR2) and 23–51% Leaf Optical Variability at Canopy Scales(lowest in NIR, highest in SWIR2), respectively. These For analyses in this and the following two sections, leafresults were similar to those found for the Texas data set and NPV optical properties were taken from Figures 1(Asner et al., 1998b). The wide-ranging litter optical val- and 2 unless noted otherwise. The darkest soil spectrumues are primarily due to differences in residual water from the field data (Fig. 3) was used to better isolate thecontent as well as species-specific differences in carbon effects of changing leaf and canopy structural conditions(e.g., lignin, cellulose) concentration (Murray and Wil- (to minimize soil effects). Figure 4 shows the role of leafliams, 1987; Asner, unpub. data). optical variability (4 s.d. in Fig. 1) on nadir-viewed canopy
Coefficients of variation for woody stem reflectance reflectance as simulated for a canopy of low and high LAIranged from 20% to 45% (highest in NIR region near 900 (1.5 and 6.0). The former is a common LAI scenario fornm, lowest in VIS). This high variability likely occurred grasslands, while the latter is typical of forest canopiesfrom differences in surface moisture and carbon constit- (Table 4). In the low LAI scenario, leaf optical variabilityuents of the outermost bark (Asner and Wessman, 1997); played a relatively small role in driving canopy reflectancehowever; stem spectral–biochemical relationships have not variation (Fig. 4a). The total range in canopy reflectancebeen quantitatively established. In general, woody stem resulting from leaf optical variation was "1% in the VISand litter spectra showed fewer water absorption features and a maximum of 4% in the NIR (Fig. 4c). At high can-than green leaf material, allowing the features associated opy LAI, the effects of leaf optical variability were morewith lignin and other organic compounds (at roughly pronounced, causing maximum variation in canopy re-1700 nm, 2000 nm, and 2200 nm) to emerge in the spec- flectance in the NIR (14–18%; Fig. 4b). In the VIS andtra (Curran et al., 1992; Verdebout et al., 1994; Jacque- along the “red edge” (!700 nm), effects of leaf-levelmoud et al., 1996). variation were still extremely small ("0.5%; Figs. 4b,c).
Mean (#1 s.d.) soil reflectance is shown in Figure 3. Leaf effects at canopy scales were greater in the SWIR1Strong atmospheric absorption features centered near than in the SWIR2 because the single scattering albedo
(reflectance$transmittance) of fresh green leaves ishigher in the SWIR1.Figure 2. A) Mean (#1 s.d.) standing litter reflec-
tance (solid lines) and transmittance (dotted lines)Structural Effects on Canopy Reflectance Propertiesproperties collected from sites in the United States
and Brazil; B) mean (#1 s.d.) woody stem reflec- Canopy LAI variation had a strong influence on reflec-tance. tance signatures (Fig. 5a), with the most pronounced ef-
fect in the NIR and the smallest effect in the VIS region.Structure enhances canopy reflectance in spectral regionswhere the scatterers are “bright” (e.g., NIR for green
Figure 3. Mean (#1 s.d.) soil reflectance spectracollected at sites in the United States and Brazil.Strong atmospheric water absorption near 1400nm and 1900 nm prevented measurements inthose spectral regions.
Asner et al. (1998) RSE
Canopy Reflectance Variability 241
and transmittance properties, quantification of the rela- 1400 nm and 1900 nm were due to water vapor, pre-venting measurements and subsequent modeling of thesetive importance of water, carbon, and nitrogen continues
to be difficult (Curran et al., 1992; Fourty et al., 1996). spectral regions. Soil reflectance variability was highestin the SWIR2 (c.v.!18–20%) and lowest in the VISStanding litter and woody stem optical properties
were generally more variable compared to leaves (Fig. (c.v.!14–16%).2). Litter reflectance and transmittance c.v.’s were 8–35% (lowest in VIS, highest in SWIR2) and 23–51% Leaf Optical Variability at Canopy Scales(lowest in NIR, highest in SWIR2), respectively. These For analyses in this and the following two sections, leafresults were similar to those found for the Texas data set and NPV optical properties were taken from Figures 1(Asner et al., 1998b). The wide-ranging litter optical val- and 2 unless noted otherwise. The darkest soil spectrumues are primarily due to differences in residual water from the field data (Fig. 3) was used to better isolate thecontent as well as species-specific differences in carbon effects of changing leaf and canopy structural conditions(e.g., lignin, cellulose) concentration (Murray and Wil- (to minimize soil effects). Figure 4 shows the role of leafliams, 1987; Asner, unpub. data). optical variability (4 s.d. in Fig. 1) on nadir-viewed canopy
Coefficients of variation for woody stem reflectance reflectance as simulated for a canopy of low and high LAIranged from 20% to 45% (highest in NIR region near 900 (1.5 and 6.0). The former is a common LAI scenario fornm, lowest in VIS). This high variability likely occurred grasslands, while the latter is typical of forest canopiesfrom differences in surface moisture and carbon constit- (Table 4). In the low LAI scenario, leaf optical variabilityuents of the outermost bark (Asner and Wessman, 1997); played a relatively small role in driving canopy reflectancehowever; stem spectral–biochemical relationships have not variation (Fig. 4a). The total range in canopy reflectancebeen quantitatively established. In general, woody stem resulting from leaf optical variation was "1% in the VISand litter spectra showed fewer water absorption features and a maximum of 4% in the NIR (Fig. 4c). At high can-than green leaf material, allowing the features associated opy LAI, the effects of leaf optical variability were morewith lignin and other organic compounds (at roughly pronounced, causing maximum variation in canopy re-1700 nm, 2000 nm, and 2200 nm) to emerge in the spec- flectance in the NIR (14–18%; Fig. 4b). In the VIS andtra (Curran et al., 1992; Verdebout et al., 1994; Jacque- along the “red edge” (!700 nm), effects of leaf-levelmoud et al., 1996). variation were still extremely small ("0.5%; Figs. 4b,c).
Mean (#1 s.d.) soil reflectance is shown in Figure 3. Leaf effects at canopy scales were greater in the SWIR1Strong atmospheric absorption features centered near than in the SWIR2 because the single scattering albedo
(reflectance$transmittance) of fresh green leaves ishigher in the SWIR1.Figure 2. A) Mean (#1 s.d.) standing litter reflec-
tance (solid lines) and transmittance (dotted lines)Structural Effects on Canopy Reflectance Propertiesproperties collected from sites in the United States
and Brazil; B) mean (#1 s.d.) woody stem reflec- Canopy LAI variation had a strong influence on reflec-tance. tance signatures (Fig. 5a), with the most pronounced ef-
fect in the NIR and the smallest effect in the VIS region.Structure enhances canopy reflectance in spectral regionswhere the scatterers are “bright” (e.g., NIR for green
Figure 3. Mean (#1 s.d.) soil reflectance spectracollected at sites in the United States and Brazil.Strong atmospheric water absorption near 1400nm and 1900 nm prevented measurements inthose spectral regions.
Canopy Refl: f(Incident rad, leaf op5cs, stem/soil/liler op5cs, stem density, crown structure, LADF, LAI, dispersion of leaves, [e.g. random or clumped])
Asner et al. (1998) RSE
Diffuse rad penetra5on
Direct rad penetra5on
Soil Reflectance
NPV
Canopy RTM Inversion RMSE = 0.015 LAI = 4.89
PROSPECT Inversion (Modeled Op5cs) Cab = 58.3 EWT = 0.020 cm SLA = 18.4 m2 / kgC
Single Scalering Albedo Update Eco. Model leaf op5cs (refl. / trans)
AVIRIS
Albedo
*constrained by data
*
* *
*
*
*
*
Tsoil
*
* *
*
*
*
*
*constrained by data
GPP
*
* *
*
*
*
*
*constrained by data
Pros and Cons: Product assimila5on
• Product assimila5on typically requires less modifica5on of most ecosystem models – Tradeoff is uncertainty of product directly propagates into uncertainty in model
– Model and product make different assump5on about canopy architecture – bias is likely if the two are fundamentally different (also scale dependent)
– Computa5onal cost for radia5ve transfer based parameter inversion is done at product stage instead of during model execu5on
– Characterizing product uncertainty as important as actual value for data assimila5on approaches
Pros and Cons: Direct op5cal assimila5on
• Op5cal assimila5on requires iden5fica5on of proper canopy radia5ve transfer model – Increases parameters, but possibly allows for op5cs to directly guide model improvement without a priori assump5ons of what spectral signatures mean
– Similarly, no bias from difference in assump5on of canopy architecture
– Easily extendable to many remote sensing plasorms – Ini5al model investment is high and model canopy may not be well suited for radia5ve transfer
A look forward • HyspIRI (hlp://hyspiri.jpl.nasa.gov/) or similar future
satellites (EnMAP; hlp://www.enmap.org/) along with con5nuous canopy spectral measurements (SpecNet) will drama5cally increase the volume of spectral informa5on in Visible, near IR, and thermal wavelengths
• We can do more than just make prely pictures and poorly validated “products” -‐ need to move away from exclusively using vegeta5on indices
• The need to reduce terrestrial carbon cycle model parameters is urgent and methods to assimilate spectral informa5on directly into models is limited to date
• Spectral databases (e.g. EcoSIS, SPECCHIO) can be mined for key PFT-‐level informa5on useful for constraining model projec5ons
!"#$ %&'( )#*!%+*%! , #* %-( #./(. #0 123 !2 4-( !"#$ %&'(5.(!6#*!( #0 %-( !(*!#.! 7!(/ 89 :(!;+./&*! < =('#*>?@ABC 6.#'6%(/ D+..+%% >?@A3C %# ).&%&E7( %-#!( '(+!7.(5'(*%! +*/ )#*)"7/( %-+% %-( FGH 0"7I(! !700(.(/ 0.#'"+.J( (..#.! >!B1KC 8()+7!( %-(9 $(.( 7*+8"( %# !+'6"(%-( -&J- 0.(E7(*)9 6#.%&#* #0 %-( 0"7I )#!6()%.7'24-( *(I% $+L( #0 %()-*#"#J&)+" &'6.#L('(*%! )+'(
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
/+%+ +)E7&!&%&#* !9!%('! .(!%.&)%(/ %-( /7.+%&#* #0 %-((//9 )#L+.&+*)( !%7/&(! %# !-#.% )+'6+&J*! /7.&*J %-(J.#$&*J !(+!#* >(2J2 V*/(.!#* !" #$2M ?@OBP W(.'+ !" #$2M?@OXC2 U78!(E7(*% 6.#/7)%&#* #0 )#''(.)&+" &*0.+.(/!6()%.#'(%(.!M %-+% $(.( !%+8"( +*/ -+/ !-#.% %&'( )#*5!%+*%!M (*+8"(/ !)&(*%&!%! %# )#*/7)% (//9 )#L+.&+*)('(+!7.('(*%! HB - + /+9M !(L(* /+9! + $((RM 3H$((R!+ 9(+.2 Y#0!9 !" #$2 >?@@ZC +.( ).(/&%(/ $&%- )#*/7)%&*J%-( 0&.!% 9(+."#*J !%7/9 #0 FGH (I)-+*J( $&%- %-( (//9)#L+.&+*)( %()-*&E7(P %-(!( '(+!7.('(*%! $(.( '+/(#L(. + /()&/7#7! 0#.(!%M !%+.%&*J &* ?@@1M +*/ )#*%&*7(%# %-&! /+92 N9 ?@@ZM + -+*/07" #0 +//&%&#*+" (//9 )#L+.5&+*)( !%7/&(!M '(+!7.&*J FGH +*/ $+%(. L+6#. (I)-+*J(M8(J+* #6(.+%&*J #L(. 0#.(!%! &* ]#.%- V'(.&)+ >N"+)R!" #$2M ?@@XP D#7"/(* !" #$2M ?@@X+M 8P D.()# < N+"/#))-&M?@@XCM Q+6+* >^+'+'#%# !" #$2M ?@@@CM +*/ _7.#6( >W+"(*5%&*& !" #$2M ?@@XC2 V*/ 89 ?@@AM .(J&#*+" *(%$#.R! #0 0"7I'(+!7.('(*% !&%(! $(.( #6(.+%&*J &* _7.#6( >F+.8#_7.#50"7IM V78&*(% !" #$2M H111P W+"(*%&*& !" #$2M H111C +*/ ]#.%-V'(.&)+ >V'(.&\"7IM `7**&*J !" #$2M ?@@@P =+$ !" #$2M!78'&%%(/C2 F7..(*%"9M %-( (//9 )#L+.&+*)( '(%-#/ &!8(&*J 7!(/ +% #L(. ?O1 !&%(! $#."/$&/(M +! 6+.% #0 %-(\=ab]_4 6.#J.+' >N+"/#))-& !" #$2M H11?+C +*/ &*L#"L(!*($ .(J&#*+" *(%$#.R! &* ]#.%- V'(.&)+ >\"7I*(%M
F+*+/+CM N.+c&"M V!&+ >V!&+\"7ICM V7!%.+"&+ >Gc\"7IC +*/V0.&)+2
!"#$%#&'() *$+ %,$%(&-)
4-( +%'#!6-(.( )#*%+&*! %7.87"(*% '#%&#*! #0 76$+./+*/ /#$*$+./ '#L&*J +&. %-+% %.+*!6#.% %.+)( J+!(!!7)- +! FGH2 4-( (//9 )#L+.&+*)( %()-*&E7( !+'6"(!%-(!( %7.87"(*% '#%&#*! %# /(%(.'&*( %-( *(% /&00(.(*)(#0 '+%(.&+" '#L&*J +).#!! %-( )+*#695+%'#!6-(.( &*%(.50+)(2 d* 6.+)%&)(M %-&! %+!R &! +))#'6"&!-(/ 89 !%+%&!%&)+"+*+"9!&! #0 %-( &*!%+*%+*(#7! L(.%&)+" '+!! 0"7I /(*!&%9>%"&!)M !'#"'#H !#?CM 7!&*J `(9*#"/!e .7"(! #0 +L(.5+J&*J >`(9*#"/!M ?O@3CM $-&)- +.( /(!).&8(/ 8("#$2 4-(6.#/7)% #0 %-&! #6(.+%&#* &! + .("+%&#*!-&6 %-+% (I6.(!!(!%-( '(+* 0"7I /(*!&%9 #0 FGH +L(.+J(/ #L(. !#'( %&'(!6+* >!7)- +! +* -#7.C +! %-( )#L+.&+*)( 8(%$((* 0"7)%75+%&#*! &* L(.%&)+" L("#)&%9 >&C +*/ %-( FGH '&I&*J .+%&#>'" !)f!+ $-(.( !+ &! +&. /(*!&%9 +*/ !) &! FGH /(*!&%9Cg
% " !!!+ $ &%'%" &?'
d* _E* ?M %-( #L(.8+.! /(*#%( %&'( +L(.+J&*J +*/ 6.&'(!.(6.(!(*% 0"7)%7+%&#*! 0.#' %-( '(+* >(2J2 '"" '# !'' C2V 6#!&%&L("9 !&J*(/ )#L+.&+*)( .(6.(!(*%! *(% FGH %.+*!50(. &*%# %-( +%'#!6-(.( +*/ + *(J+%&L( L+"7( /(*#%(! %-(.(L(.!(2
()"!*+*!",)- !../ '01#*,#)'! 2!#34*!2!)"3
4-( (E7+%&#* /(0&*&*J %-( )#*!(.L+%&#* #0 '+!! 6.#L&/(!%-(#.(%&)+" J7&/+*)( 0#. &'6"('(*%&*J %-( (//9 )#L+.5&+*)( %()-*&E7( >N+"/#))-& !" #$2M ?@OOP T+$ !" #$5M H111PS+!!'+* < =((M H11HC2 F#*)(6%7+""9M %-( 6.#8"(' 8(&*J+*+"9!(/ &! +*+"#J#7! %# %-( )+!( #0 '+&*%+&*&*J + )(.%+&*$+%(. "(L(" &* + 8+%-%78 89 J#L(.*&*J %-( 0"#$ #0 $+%(. &*+*/ #7% #0 %-( %78P $-(* %-( $+%(. "(L(" &! !%(+/9M $(R*#$ %-+% %-( .+%( #0 $+%(. "(+L&*J %-( %78 (E7+"! %-( .+%((*%(.&*J !# $( #*"9 *((/ %# '(+!7.( #*( #0 %-( 0"#$!2Y&%- %-( )+!( #0 +!!(!!&*J %7.87"(*% %.+*!0(. #0 FGH &* %-(+%'#!6-(.(M $( 7!( %-( )#*!(.L+%&#* (E7+%&#* %# /(/7)(%-( (I)-+*J( #0 )+.8#* &* +*/ #7% #0 %-( 6"+*%5!#&" !9!%('#* %-( 8+!&! #0 (//9 )#L+.&+*)( '(+!7.('(*%! '+/( &*%-( !7.0+)( 8#7*/+.9 "+9(. !(L(.+" '(%(.! +8#L( + 6"+*%)+*#692 h#$ %-&! 6.#)(!! &! +))#'6"&!-(/ &! /&!)7!!(/*(I%2\#. %-( )+!( #0 FGHM %-( )#*!(.L+%&#* #0 '+!! !%+%(!
%-+% %-( !7' #0 %-( "#)+" %&'( .+%( #0 )-+*J( #0 %-( FGH
'&I&*J .+%&# >%(.' dCM 'M +*/ +/L()%&#* >%(.' ddC &! 8+"5+*)(/ 89 %-( !7' #0 %-( 0"7I /&L(.J(*)( #0 FGH &* %-(L(.%&)+" >6CM "+%(.+" >/C +*/ "#*J&%7/&*+" >7C /&.()%&#*!>%(.' dddC +*/ %-( 8&#"#J&)+" !#7.)( !&*R5!%.(*J%- >8NC>%(.' dWCg
! H11Z N"+)R$("" T78"&!-&*J =%/M 9$0:#$ ;<#)-! =,0$0-/M ./ BA@,B@H
012 : 2 : 2 N V =:GFFh d
Net CO2 Flux (mmol m-2 s-1)
Param Est.
Es5mates of Vcmax and Jmax derived from imaging spectroscopy will be compared with those inverted from flux tower data at each site using a coupled 2-‐layer (sunlit-‐shaded canopy) FvCB ecosystem model. Uncertainty will be assessed using Bayesian parameter inversion.
NASA HyspIRI California Campaign Eddy Covariance
HyspIRI overflies a range of Mediterranean and Western Pine ecosystem flux tower sites
• Clima5c & topographic varia5on in fluxes • Water availability is key
Subalpine Forest (high eleva?on) Mixed Conifer Forest (high eleva?on)
Ponderosa Pine Forest (mid eleva?on) Oak-‐pine Woodland (low eleva?on)
Coastal Sage (low eleva?on) Coastal Grassland (low eleva?on)
Desert Chaparral (low eleva?on)
Thank you
• Many collaborators in the field in Wisconsin and California, ED2 model developers, PEcAn data assimila5on crew, NASA AVIRIS team
• More: hlp://pecanproject.org/ • Funding: NASA ROSES Hyspiri Preparatory NNX12AQ28G, NSF Advances in Biological Informa5cs DBI-‐1062204.