LPJ-GUESS CARBO-North Modelling Wishlist – Lund University
Paul Miller & Martin Sykes

Below is a description of the data we would like in order to be able to initialise, run and evaluate LPJ-GUESS/LPJ-DGVM, for both tree line and carbon balance studies, and at both the regional and catchment scales. Please email Paul Miller (paul.miller@nateko.lu.se), or start another thread on this Forum, should you wish to discuss any of the points in detail.

We have also attached a PDF document with this information to this Forum item.

Firstly, we need a definition of the CARBO-North (CN) study region. This may be defined by the 5 km grid defined in Workpackage 2 – see below. We would need a list of longitudes & latitudes, information on where in the gridcell the given coordinate lies (southwest corner, centre etc.), and, ideally, both the area and mean height above sea level of the cells. Area will be needed for the upscaling. The CN region should of course include the intensive study sites, as we discussed in London.

For treeline and carbon balance simulations with LPJ-GUESS, at the regional scale, we will also need as much as possible of the following:

· Climate forcing (air temperature, precipitation, sunshine% or SW radiation), plus (ideally) snow cover and albedo, at both 25 km and 5 km resolution for the whole CN region. Daily data would be great, but we can use monthly too, by linearly interpolating to daily values.
· Soil depth map at the same resolutions. We’ll have to use an uniform 2 metre standard soil depth otherwise.
· Soil texture or class map at the same resolution, and some topographical information. This is for the hydrology and soil temperature calculations. An important distinction is that between peatlands (high soil C content) and non-peatlands (i.e. mineral soils), since we will use a different hydrology scheme for peatlands. For mineral soil classes, LPJ-GUESS needs the water holding capacity at both field capacity and wilting point, percolation rates, and thermal diffusivities at different soil water contents. We currently use values for 9 global texture classes, based on the 1991 FAO soil data set, but updates specific to the CN region would be great. Something like Fig. 3 in Kuhry et al. (2002).
· Permafrost map at the same resolutions (for model input and validation). Would such a map include active layer depth information?
· A list of the main tree, shrub and plant species in the CN region and the species’ characteristics. Rather than clutter up this list with the (rather long) list of characteristics needed, we would prefer that you email us and we can send you a table. If we can acquire sufficient information on the properties of the main species, then we’ll model them individually. Otherwise, we will probably model the main plant functional types (PFTs), e.g. boreal needle-leaved summergreen/evergreen trees, flood tolerant graminoids, dwarf shrubs, peat moss etc. Or, as is most likely, we may take a mixed approach, with both species and PFTs.
· A land cover map at the same resolutions, something like Fig. 2 in Kuhry et al. (2002).

Site-Based/Catchment Tree Line Analysis

Specifically for the tree line studies, we will again need a precise definition of the study regions.

Furthermore, we will need:

· The 5 km climate data, for present day and future scenarios.
· Soil depth, soil texture/type (both Workpackage 6) and permafrost maps specific to the study regions will also be invaluable. In fact, they will probably define the geographical boundaries of the study regions.
· Information on water table depth and its variability would be useful.
· Landscape topographic information would also be useful, not least for the hydrology parameterisation/evaluation.
· Land cover classifications and phytomass measurements (Workpackages 4 and 5) from all the study regions will be invaluable, as will LAI.
· Forest disturbance, management and fire data, both quantitative and qualitative, from the taiga site.
· Finally, and if possible (!), historical maps of the above fields – these would be great for initialisation of the model, for example, if only approximately.

Soil Temperature & Permafrost Validation

We would like to be able to evaluate the model’s new soil temperature and permafrost routines. Permafrost maps from the study sites will be invaluable (Workpackage 2), but we would really appreciate access to the data that will be made available to the partners through Workpackage 2’s Objective 2 ”1D transient permafrost modelling in representative permafrost terrains.”

Carbon Flux Evaluation

To evaluate the model’s CO2 and CH4 predictions, we will need the following data:

· Daily meteorological data gathered over the observation periods: air temperature, precipitation, cloudiness or SW radiation. Maybe also wind direction, if available.
· As above, we would like soil, vegetation, land cover and permafrost classifications of the area within which the fluxes are believed to originate. Any information about the snow cover, such as depth and duration, as well as water table depth, would also be useful.
CO2 and CH4 fluxes. The model’s timestep is 1 day, so this should be the minimum resolution. Since there can be considerable fluctuations in a 24-hour period, perhaps a daily standard deviation could also be supplied?