biomass TO OBSERVE FOREST BIOMASS FOR A BETTER UNDERSTANDING OF THE CARBON CYCLE

The global carbon cycle

BIOMASS objectives and purpose Objective of BIOMASS mission: to make accurate, frequent and global measurements of the distribution of forest biomass and its changes scales comparable with forest changes, and hence unprecedented information on status and dynamics of the Earth’s forests. Crucial for: Quantifying land use change (emissions & uptake) Scientific support for international treaties Landscape scale carbon dynamics and prediction Initialising and testing the land element of ESMs Forest ecosystem services & biodiversity

How well is biomass known? Model Brown Potter Model + Satellite Interpolation44 Olson Defries Brown and Lugo Fearnside Interpolation Carbon (tC/ha) <= 100 101-150 151-171 176-200 201-225 226+ 39 < Total biomass < 93 GtC Malhi: 93 +-23 old growth only based on 227 plots Saatchi: 86 GtC +- 20% Spatial patterns completely different. Implications of this uncertainty shown on next slide ________________________________________________________ EO used to help in LC (and in SS for structural variables, such as gap fraction) 44 sites used to extrapolate to 5 km B&L: 1000s of plots, 1 km map; 63 GtC F: same db, different conversions: 93 GtC B: rule-based model, 5 km, calibrated at 44 sites O: Pre-ag veg, air survey, plots, 1 degree DF: % tree cover from AVHRR mixture model calibrated by Landsat MSS, 1km, biomass calibrated at 44 sites P: CASA, driven by NDVI (for NPP) steady state, 1 degree Land cover map Estimates of total biomass vary from 39 to 93 GtC

Tropical forest aboveground biomass maps Two recent maps of Amazonian biomass – radically different

Relation radar backscatter signal-above ground biomass at L, P, VHF bands Landes forest, France L-band SAR: RAMSES P-band SAR: AirSAR VHF SAR: Carabas

The sensitivity of P-band radar to biomass

Observation concept – P-band satellite radar Calibration, Ionospheric correction Orbit cycle n Orbit cycle n+1 Polarimetric Interferometric Phase HH HV VV Phase Polarimetric radar intensity Retrieval algorithm Geophysical products The need to map biomass drives us immediately towards radar. Optical sensors see biochemistry, radar sensitive to structure. What sort of radar? Polarimetry (figs on R) Repeat pass for interferometry Both critical as we can see Forest biomass Forest height Forest biomass change Forest disturbance

P-band forest height retrieval – tropical forest Mawas, Indonesia 50 40 30 20 10 0m e.g. of P band height in tropics Also, I should remark that another beautiful complement of the height and intensity measurements is that the height measurements get more accurate for higher biomass, compensating for the reduced sensitivity of intensity methodss.

Tomography

Forest biomass retrieval at P-band 150 Les Landes Estimated biomass (t/ha) RMSE = 9.46 t/ha 150 In situ biomass (t/ha) Biomass (t/ha) `300 Inverting general P-HV curve Note different ranges of biomass. Point out value in last plot Now we are going to add extra information Estimated biomass (t/ha) RMSE = 47.2 t/ha `300 In situ biomass (t/ha) Remningstorp

Improving biomass retrieval using polarisation & height Biomass (t/ha) Polarised intensities only Intensity retrieval RMSE= 35.6 t/ha Intensity + height Height (m) 40 30 20 10 0m Wher did we get height from? One of the beautiful features of the radar system is that it allows an independent measure of height, using interferometry, as I’ll now explain Height retrieval RMSE= 16.3 t/ha

Current status Report for Selection submitted, exception for performance chapter Ministerial conference towards the end of 2012 If (2) goes well, Consultation Meeting early 2013, selection within a couple of weeks If (2) goes badly ....