Noah land surface model working group meeting, Boulder, 15 July 2007 Planned Noah Changes in WRF Changes in model physics Changes in land surface fields (time-fixed and time- varying)

Noah land surface model working group meeting, Boulder, 15 July 2007 Unified Noah Land Surface Model in WRF Goal: to have one single Noah code in both ARW and NMM WRF codes (to eliminate the option 99 in WRF/NMM code) Unify or set options for different treatments of physics/parameters in two Noah codes used in ARW and NMM The unified Noah for both ARW and NMM is almost ready to be implemented in the NCAR repository Will it be the unified Noah V1.0? Most likely ready in coupled WRF for the next major release (March 2008?)

Noah land surface model working group meeting, Boulder, 15 July 2007 Future Development of Noah Land Surface Model Subsurface Flow Routing Noah-Router (NCAR Tech Note: Gochis and Chen, 2003) Saturated Subsurface Routing Wigmosta et. al, 1994 Surface Exfiltration from Saturated Soil Columns Lateral Flow from Saturated Soil Layers New Parameters: Lateral K sat, n – exponential decay coefficientNew Parameters: Lateral K sat, n – exponential decay coefficient Critical initialization value: water table depthCritical initialization value: water table depth 8-layer soil model (2m – depth)8-layer soil model (2m – depth) Quasi steady-state saturated flow model, 2-d (x-,y-configuration)Quasi steady-state saturated flow model, 2-d (x-,y-configuration) Exfiltration from fully-saturated soil columnsExfiltration from fully-saturated soil columns

Noah land surface model working group meeting, Boulder, 15 July 2007 Ball-Berry Scheme in GEM Jarvis scheme LAI – Leaf Area Index, F1 ~ f (amount of PAR) F2 ~ f(air temperature: heat stress) F3 ~ f(air humidity: dry air stress) F4 ~ f(soil moisture: dry soil stress) Ball-Berry scheme in GEM (Gas Exchange Model) hs – relative humidity at leaf surface ps – Surface atmospheric pressure An – net CO2 assimilation or photosynthesis rate Cs – CO2 concentration at leaf surface m and b are linear coeff based on gas exchange consideration Fundamental difference: evapotranspiration as an ‘inevitable cost’ the foliage incurs during photosynthesis or carbon assimilation A n : three potentially limiting factors: 1. efficiency of the photosynthetic enzyme system 2. amount of PAR absorbed by leaf chlorophyll 3. capacity of the C3 and C4 vegetation to utilize the photosynthesis products

Noah land surface model working group meeting, Boulder, 15 July 2007 Future Development of Noah Land Surface Model Ball-Berry photosynthesis-based canopy resistance (Niyogi, Kumar, Purdue U.) Ball-Berry photosynthesis-based canopy resistance (Niyogi, Kumar, Purdue U.) Test in HRLDAS for is nearly finished Test in HRLDAS for is nearly finished Responses of canopy resistance to environmental and soil conditions are fairly different in Jarvis and GEM/photosynthesis formulations. That leads to large differences in soil moisture and latent heat fluxes. Incorporation of GEM in Noah is sensitive to description of land use (C3, C4 grass) and vegetation phenology (LAI, vegetation fraction, etc). GEM model reference: Niyogi, Alapaty, Raman, Chen, 2007: JAMC, in revision.

Noah land surface model working group meeting, Boulder, 15 July 2007 Future Development of Noah Land Surface Model Multi-layer urban canopy model (Taha, Multi-layer urban canopy model (Taha, Altostratus Inc; Borenstein, SJSU; Ching, EPA) Has not yet started

Noah land surface model working group meeting, Boulder, 15 July 2007 Locations of 68 SCAN sites The HRLDAS-simulated 2006 soil temperature and moisture were verified against Soil Climate Analysis Network (SCAN) data

Averaged diurnal cycle over 6 SCAN stations in northeast domain obs 6-layers Using 1-deg 2-m air T

Noah land surface model working group meeting, Boulder, 15 July 2007 MODIS Land-use and other land/vegetation products USGS land-useMODIS Data Collection Instrument AVHRR ( Advanced Very High Resolution Radiometer) MODIS ( MODerate resolution Imaging Spectroradiometer) Channels5 channels15 land surface/vegetation dedicated channels Data Collection DatesApril 1992 – March 1993 January 2001 – December 2001 Reflecting recent land-use change Data ProviderUSGS/ORNLBoston University Classification SchemeModified USGS Modified IGBP IGBP used in NPOESS and next-generation NWP models # of Categories25*19*

Noah land surface model working group meeting, Boulder, 15 July 2007 MODIS vs AVHRR Red: urban areas in the Pearl River Delta, China 1993 USGS data 2001 MODIS data

AVHRR MODIS Water boundary mapping is different Pearl River Delta, China Houston

Noah land surface model working group meeting, Boulder, 15 July 2007 New land/vegetation Products NESDIS 20-year climatology NDVI based products: – Monthly green vegetation fraction (GVF) – Monthly albedo MODIS land products – 8-day and monthly LAI, GVF, emissivity, albedo – Monthly products Real-time vegetation products We are changing WRF Pre- prosessing System (WPS) infrastructures to handle these and future (realtime) land/vegetation data. WRF-Noah land-use based LAI, 1 July 2006 MODIS based LAI, 1 July 2006

Fine-scale Urban Data Sets Goal: Accommodate more complex urban models National Urban Database with Access Portal Tool (NUDAPT) project led by Jason Ching of EPA Plan – Consider these types of data are user specific and not to be included in WRF core data set? – However, WPS should enable an easy integration of these data. – change in WPS?

Noah land surface model working group meeting, Boulder, 15 July 2007 Link between land surface and atmospheric surface layer Coupling between skin layer and first model level (depends on roughness lengths and wind speed) Surface fluxes are more sensitive to the treatment of roughness length for heat/moisture than to M-O based surface layer schemes themselves Surface sensible heat flux Surface latent heat flux Surface exchange coefficient:

Noah land surface model working group meeting, Boulder, 15 July 2007 Link between land surface and atmospheric surface layer WRF surface layer schemes –MM5 similarity: Based on Monin-Obukhov with Carslon-Boland viscous sub-layer and standard similarity functions from look- up tables. –Eta similarity: Used in Eta model. Based on Monin-Obukhov with Zilitinkevich thermal roughness length and standard similarity functions from look-up tables. –Need to evaluate these surface layer schemes, particularly WRT to nocturnal stable regime. Data sets for such evaluation? –Other schemes in consideration?