IHOP (Soil Moisture, Soil Temperature, and Vegetation Observation Network)


The boundary-layer portion of the International H2O Experiment (IHOP_2002) supports its overall goal to improve convective precipitation prediction through better use and representation of water vapor in numerical weather prediction (NWP) models through estimating surface water vapor and sensible heat fluxes, characterizing the influence of surface properties on boundary-layer heterogeneity, and understanding the role that these play in the initiation and evolution of convective precipitation systems. Data collection and analysis were designed to provide benchmarks to enable improvements in the representation of land-surface and boundary-layer processes in NWP models. more


Surface Observations

Aircraft Observations

IHOP Workshop Summary


Land-Surface Modeling (LSM)

RAL scientists work to understand, through theoretical and observational studies, the complex biophysical, hydrological, and bio-geochemical interactions between the land-surface and the atmosphere at micro- and mesoscales. The ultimate goal is to integrate such knowledge into numerical mesoscale weather prediction and regional climate models to improve prediction of the impacts of land-surface processes on regional weather, climate, and hydrology. Land surface modeling efforts were funded in FY06 by NSF, the Air Force Weather Agency (AFWA), NOAA, NASA, and DTRA.

Weather Research and Forecast (WRF) Model

The WRF/Noah LSM Coupled system consists of a large number of comprehensive terristrial data sets, their processing onto WRF grid through WRF/SI and Real routines, and the Unified Noah LSM as part of WRF physics package.

The following documents explain how to set up the WRF/SI/Real to acquire all surface, vegetation, soil data necessary to run the WRF/Noah coupled system. These information are probably most useful for users who want to modify these routines to ingest new land data and to modify the default WRF/Noah LSM configurations.

NCAR High-Resolution Land Data Assimilation System (HRLDAS)

Although the important role of soil moisture in the development of deep-convection has been recognized, it remains the most difficult variable to obtain because there is no routine high-resolution observation of soil moisture at the continental scale. Thus, a High-Resolution Land Data Assimilation System (HRLDAS) has been developed to support the WRF/Noah coupled land surface modeling system and ATEC range forecasts. It uses observed hourly precipitation, solar radiation derived from satellite, and analyzed surface wind and temperature to force a land-surface model to simulate the evolution of soil moisture.

HRLDAS produced volumetric surface soil moisture at 4-km resolution.

Urban Modeling Effort

Our goal is to develop an integrated, multi-scale urban modeling system for the Weather Research and Forecast (WRF) model to address various urban environmental issues.

Warm-Season Quantitative Precipitation Forecast (QPF)

Land surface properties (e.g., albedo, soil moisture, vegetation) modify the partition of latent heat (evaporation) and sensible heat fluxes, and boundary layer structures and stability, which collectively impacts convection initiation and precipitation.


Reen, Brian P., David R. Stauffer and Kenneth J. Davis, 2014. Land-surface heterogeneity effects in the planetary boundary layer. Boundary-Layer Meteorology, 150, 1–31, DOI 10.1007/s10546-013-9860-8.

Kumar, A., F. Chen, D. Niyogi, J.G. Alfieri, K. Mitchell, and M. Ek, 2011: Evaluation of a photosynthesis-based canopy resistance formulation in the Noah land surface model. Boundary Layer Meteorol.,138:263–284. DOI 10.1007/s10546-010-9559-z

Trier, S.B., M. A. LeMone, F. Chen, and K. W. Manning, 2011: Effects of surface heat and moisture exchange on ARW-WRF/Noah model 0-24-h warm-season precipitation forecasts over the central United States. Wea Forecasting, 26, 3-25.

Grabon, Jeffrey S., Kenneth J. Davis, Christoph Kiemle and Gerhard Ehret, 2010. Airborne Lidar Observations of the Transition Zone Between the Convective Boundary Layer and Free Atmosphere During the International H2O Project (IHOP) in 2002. Boundary-Layer Meteorol,134, 61–83, DOI 10.1007/s10546-009-9431-1

LeMone, M., F. Chen, M. Tewari, J. Dudhia, B. Geerts, Q. Miao, R. Coulter, and R. Grossman, 2010a:  Simulating the fair-weather convective boundary layer with the coupled WRF-Noah modeling system, Part 1: Surface fluxes and CBL structure and evolution along the eastern track. Mon. Wea. Rev. 138: 722-744.

LeMone, M., F. Chen, M. Tewari, J. Dudhia, B. Geerts, Q. Miao, R. Coulter, and R. Grossman, 2010b:  Simulating the fair-weather convective boundary layer with the coupled WRF-Noah modeling system, Part 2: Convective structure and mesoscale variability. Mon. Wea. Rev. 138: 745-764.

Alfieri, J.G., X. Xiao, D. Niyogi, R.A. Pielke, F. Chen, and M.A. LeMone, 2009: Satellite-based modeling of transpiration and evaporation of grasslands and croplands in the Southern Great Plain, USA. Global Planetary Changes. 67, 78-86. doi:10.1016/j.gloplacha.2008.12.003

Alfieri, J.G., D. Niyogi, H. Zhang, M. A. LeMone, F. Chen, 2009: Quantifying the Spatial Variability of Airborne Surface Flux Measurements Using Data from the 2002 International H2O Project: Statistical Method, Boundary Layer Meteorol. 133: 323-341, DOI 10.1007/s10546-009-9406-2.

Couvreux, F., F. Guichard, P. Austino, and F. Chen, 2009: Nature of the mesoscale boundary-layer height and water-vapor variability observed the 14 June 2002 during the IHOP 2002 campaign. Mon. Wea. Rev., 137, 414-432.

Kang, S.-L., and K. J. Davis, 2009: Reply to comment by C. P. Weaver in “The effect of mesoscale surface heterogeneity on the fair-weather convective atmospheric boundary layer,” J. Atmos. Sci., 66, 3229-3232.

Alfieri, J.G., D. Niyogi, P.D. Blanken, F. Chen, M.A. LeMone, M. Ek, K. Mitchell, and A. Kumar, 2008: Estimation of the Minimum Canopy Resistance for Croplands and Grasslands Using Data from the 2002 International H2O Project. Mon. Wea. Rev., 136, 4452-4469.
LeMone, M.A., M. Tewari, F. Chen, J. Alfieri, and D. Niyogi, 2008: Evaluation of the Noah land-surface model using data from a fair-weather IHOP_2002 day with heterogeneous surface fluxes. Mon. Wea. Rev., 136, 4915–4941.

Trier, S., F. Chen, K. Manning, M.A. LeMone, C. Davis, 2008: Sensitivity of the Simulated PBL and Precipitation to Land Surface Conditions for a 12-Day Warm-Season Convection Period in the Central United State. Mon. Wea. Rev., 136, 2321-2343.

Kang S.-L., K.J. Davis, 2008. The effects of mesoscale surface heterogeneity on the fair-weather convective atmospheric boundary layer, J. Atmos. Sci., 65, 3197-3213, doi: 10.1175/2008JAS2390.1.

Alfieri, J.G., D. Niyogi, M.A. LeMone, F. Chen, and S. Fall, 2007:  A simple reclassification method for correcting uncertainty in land use/land cover datasets used with land surface models.  Pure and Appl. Geophys., 164 ,1789–1809, 0033–4553/07/091789–21, DOI 10.1007/s00024-007-0241-4.

Chen, F., K. W. Manning, M.A. LeMone, S.B. Trier, J.G. Alfieri, R. Roberts, M. Tewari, D. Niyogi, T. W. Horst, S. P. Oncley, J. Basara, and P. D. Blanken, 2007: Description and Evaluation of the Characteristics of the NCAR High-Resolution Land Data Assimilation System During IHOP-02. J. Appl. Meteorol. Climatol., 46, 694-713.

LeMone, M.A., F. Chen, J. Alfieri, M. Tewari, B. Geerts, Q. Miao, R. Grossman, and R. Coulter, 2007:  Influence of land cover, soil moisture, and terrain, on the horizontal distribution of sensible and latent heat fluxes and boundary layer structure in southeast Kansas during IHOP_2002.  J. Hydromet, 8, 68-87.

LeMone, M.A., F. Chen, J. Alfieri, R.H. Cuenca, Y. Hagimoto, P. Blanken, D. Niyogi, S Kang, K. Davis, and R.L. Grossman, 2007: NCAR/CU Surface, Soil, and Vegetation Observations during the International H2O Project 2002 Field Campaign. Bull. Amer. Meteor. Soc., 88, 65-81.

Kang, S., K.J. Davis and M.A. LeMone, 2007. Observations of the ABL structures over a heterogeneous land surface during IHOP_2002. J. Hydrometeorology, 8, 221-244, DOI: 10.1175/JHM567.1

Holt, T., D. Niyogi, F. Chen, K. Manning, M. A. LeMone, A. Qureshi, 2006:  Effect of Land - Atmosphere Interactions on the IHOP 24-25 May 2002 Convection Case. Mon. Wea. Rev., 134, 113-133.

LeMone, M.A., F. Chen, J. Alfieri, R. Cuenca, Y. Hagimoto, P. Blanken, D. Niyogi, S. Kang, K. Davis, and R. Grossman, 2006: NCAR/CU surface, soil, and vegetation observation network during the IHOP_2002 field campaign . Bull. Amer. Meteor. Soc. , in press.

Weckwerth, T.W., D.B. Parsons, S.E. Koch, J.A. Moore, M.A. LeMone, B.B. Demoz, C. Flamant, B. Geerts, J. Wang, and W. Feltz, 2004: An overview of the International H2O Project (IHOP 2002) and some preliminary highlights . Bull. Amer. Meteor. Soc. , 85, 253-277.






Please direct questions/comments about this page to:

Fei Chen

Senior Scientist/Deputy Director HAP