Report of the SRNWP Lead Centre on Surface Processes

Report of the SRNWP Lead Centre on Surface Processes José A. García-Moya (on behalf of Ernesto Rodríguez & Stefan Gollvik) SMNT – INM & SMHI 27th EWGLAM & 12th SRNWP Meetings Ljubljana, October 2005

Outline • 4th Workshop on Surface issues: main conclusions • Activities at different centres • Recent comparison and evaluation exercises • Main fields of activity for the near future 27th EWGLAM & 12th SRNWP Meetings

4th SRNWP/HIRLAM workshop on surface processes and assimilation (15-17 Sept 2004, SMHI) • The importing option from global models is not a viable solution for surface variables with model transferability problems (eg soil moisture). It is required a synchronous development of land surface models in both LAM and global models. • Assimilation of ice-free ocean SST. The main requirement of this variable is resolution. GODAE (Global Ocean Data Assimilation Experiment) has the mandate to supply high temporal and spatial resolution using visible and microwave sensors. It is recommended to participate in GODAE meetings and to follow data availability. • Assimilation of sea ice. Some SSM/I products, such as the NCEP gridded version, do not have the required resolution and suffer from coastline problems (land contamination). Use of ocean SAF products is encouraged (and feedback to the SAF). In case of incompatibility between SST and sea ice, the ice cover product should prevail over the SST product. Large gradients of SST at the ice edge might be an issue in (small) geographical areas. • Assimilation of lake temperature and ice cover. It is very relevant to Northern countries. Current methods of initialization based on pseudo-climatology are very crude. Dedicated retrieval of lake temperature based on AVHRR and/or AATSR is possible. Some issues flagged are: (a) atmospheric absorption over mountain areas will require algorithm modifications; (b) bulk versus skin and calibration with in situ data; (c) resolution is probably adequate. • Assimilation of soil temperature. The currently used simple methods are probably adequate. Layers with daily time scales need to be initialised. The degree of coupling of soil temperature increments to those of the surface air temperature should decrease with depth. 27th EWGLAM & 12th SRNWP Meetings

Assimilation of snow mass. Although snow cover is the most reliable information, it still carries ambiguity. The NOASS/NESDIS cover product is the only timely one. Use of MODIS for independent validation is encouraged. Snow depth observations, to be used with a realistic density, are still essential for the analysis. Analysis of snow depth based on OI should be implemented as soon as possible due to its superiority over the successive corrections option. Special attention should be paid to observation practices and SYNOP (lack of) conventions. • Assimilation of soil moisture. The current magnitude of increments is unrealistic large in many implementations and hampers model development. Variational methods are a step in the right direction: (a) increments are several times smaller; (b) flexible introduction of new observations. The current size of perturbations (for gradient estimations) should be revised. The long term goal should be to further reduce the increments, while still controlling model drifts. Monitoring (weekly?) of accumulated model increments side-by-side with precipitation is encouraged. In the longer term, soil moisture assimilation systems should make use of IR brightness temperature heating rates and/or microwave (passive and active C-, L-band) observations. • Physiographic databases. The move to ECOCLIMAP should be encouraged. There is nothing comparable to ECOCLIMAP for NWP purpose. Albedo can be taken from other sources (eg LandSAF). • Code externalization. Code externalization is the creation of a dedicated, portable library, including all surface related routines and allowing for all needed functionalities of the surface code. It should be considered if usage off-line versions of the code (eg forcing with observed precipitation such as NIMROD) become a significant activity. The coupling algorithm developed by Best et al . (2004) is recommended. 27th EWGLAM & 12th SRNWP Meetings

The need of a realistic modelled soil moisture should be pursued by improving both model and assimilation formulations. It is recommended the evaluation of surface schemes driven by observations paying special attention to the water budget. The current ISBA surface scheme with only two layers for describing soil moisture evolution hinders a realistic representation of this variable. • Improvement of snow formulation. The current simple description of snow covered surfaces should be upgraded with more physical schemes implying the introduction of predictive equations for additional variables, eg snow albedo, snow density, liquid water retained by the snow package, etc • Challenges in the fine-scale (non-hydrostatic) domain. Surface parameterizations within the kilometre-scale range need deep revision. Equilibrium assumption between surface and atmosphere is no longer valid at these scales. Horizontal interactions are no more negligible. The whole tiling approach should be possibly revised, including possibly interactions between tiles, tiling affecting lower atmospheric layers, role of 3D turbulence, role of slopes for radiation, etc 27th EWGLAM & 12th SRNWP Meetings

27th EWGLAM & 12th SRNWP Meetings

RECENT COMPARISON AND EVALUATION EXERCISES • Rhone AGGregation experiment (http://www.cnrm.meteo.fr/mc2/projects/rhoneagg/) • ELDAS (http://www.knmi.nl/samenw/eldas/) 27th EWGLAM & 12th SRNWP Meetings

ELDAS Observations driving soil moisture correction evaporation precipitation METEOSAT or MSG radiation Synops data Land surface parameterization scheme Soil moisture content Soil moisture correction scheme (sub)surface runoff 27th EWGLAM & 12th SRNWP Meetings

Land SAF Objectives (http://www.meteo.pt/landsaf) The main purpose is to increase the benefits from MSG and EPS data related to land, land-atmosphere interactions and biophysical applications, namely by developing techniques, products and algorithms that will allow a more effective use of data from the two planned EUMETSAT satellites. Although directly designed to improve the observation of meteorological systems, the spectral characteristics, time resolution and global coverage offered by MSG and EPS allow for their use in a broad spectrum of other applications, namely within the scope of land biophysical applications. Activities to be performed within the framework of the Land SAF shall involve the development of products that are especially relevant in the following fields of application: • Weather forecasting and climate modelling, which require detailed information on the nature and properties of land. Highest Land SAF priority should be towards the meteorological community and, within that community, NWP has been already identified as the one that has the greatest potential of fully exploit the products; • Natural hazards management, which requires frequent observations of terrestrial surfaces in both the solar and thermal bands; • Climatological applications and climate change detection. • Environmental management and land use, which require information on land cover type and land cover changes (e.g. provided by biophysical parameters or thermal characteristics); 27th EWGLAM & 12th SRNWP Meetings

The project is organised into nine sub-tasks: Regional services focussed on the implementation of newly established European Directives structured into • a Nature Protection Observatory addressing the Habitats and Bird Directive, the Ramsar Convention, the Convention on Biological Diversity; • a Water and Soil Observatory addressing the Thematic Strategy for Soil Protection, and the Water Framework Directive; • a Spatial Planning Observatory addressing the European Spatial Development Perspective, and the European Spatial Observatory Network; • a Core Service Land Cover supporting the Observatories with cross-cutting land cover and land cover change products. All activities take into account the 6th Environmental Action Programme, the Sustainable Development Strategy, the Environmental Impact Assessment Directive, the Strategic Environmental Assessment Directive, INSPIRE, and ESDI. Global services directed towards the support of policies addressing Global Change and Sustainable Development, structured into a • Natural Carbon Fluxes Observatory addressing the UN Framework Convention on Climate Change, • Global Land Cover and Forest Change Observatory addressing the UN Forum on Forest, and the Forest and Development Communication of the Commission, • Food Security and Crop Monitoring Observatory addressing the council regulations on Food Aid Policy, Environmental Measure in Developing Countries, • Core Service Bio-geophysical Parametres supporting the observatories with cross-cutting parametre products. Operational Scenario development, including service infrastructure design and implementation planning. The geoland products and services will be designed to provide the sustainability, availability, reliability and cost efficiency that public authorities have long desired. geoland provides an interdisciplinary integration which embraces 56 partners, comprising user organisations, private and public service providers, and researchers from 15 European member- and accession states 27th EWGLAM & 12th SRNWP Meetings

Report of the SRNWP Lead Centre on Surface Processes