1. NAME HYDROMETEOROLOGICAL WORKING GROUP Motivation and Coordinated Activities

2. Connecting the Hydrologic Cycle… Exploration of Terrestrial Linkages  Leverage on the body of scientific and human dimensions research currently proposed under NAME to: Improve hydrometerological and hydroclimatic process knowledge and contribute to dynamic management of water resources in the NAM region.

3. Hydroclimatic Linkages in NAME Precipitation Evaporation Deep Percolation

4. Hydroclimatic Linkages in NAME Precipitation Evaporation Intensity : Frequency : Duration : Areal Coverage : Forcing Soils : Vegetation Dynamics : Antecedent Moisture : Forcing

5. Previous Findings… (Dettinger and Diaz, JHM 1(4), 289-310; Gochis et al., 2003, JHM, in press. )  Latitudinal transition to a summer-dominated regime proceeding southward from Mogollon Rim.

6. Previous Findings…  Climatological peak flows tend to lag peak precipitation by 1-2 months (Dett.&Diaz, ibid.)  Interannual streamflow values are linked to both ENSO (Magana,1999) and PDO (Brito-Castillo et al., Atmosfera, 2002) but there exists both constructive and destructive tendencies in correlation structure.  Evidence via diagnostics and modeling results of possible feedbacks between soil moisture and snow cover and the strength of the North American Monsoon system (NAMS).

7. Previous Findings…  Existence of a midsummer drought in parts of Mexico, peripheral to the “core” monsoon region of the SMO.  Smaller scale basin responses dominated by precipitation structure: short-duration (0.5-1.0hr) high-intensity (10- 100mm/hr) storms. (Michaud et al. 2001) But…likely that many catchment-scale studies remain to be translated from Spanish- speaking literature and CNA reports !

8. Lingering Uncertainties…  How are seasonal and shorter term, higher-order precipitation characteristics related to streamflow?  Given the uncertainty in precipitation observations, what confidence is there in existing estimations of runoff fractions? What fraction is recycled to the atmosphere?  What influences do the meso-climates, terrain and vegetation of the SMO, the Mexican plateau and the coastal regions have on hydrological cycling/partitioning?

9. Meso-climate aspects of the NAM Precipitation Evaporation Intensity : Frequency : Duration : Areal Coverage : Forcing Soils : Vegetation Dynamics : Antecedent Moisture : Forcing

10. Meso-climate aspects of the NAM

11. Lingering Uncertainties…  How are seasonal and longer term, higher-order precipitation characteristics related to streamflow?  Given the uncertainty in precipitation observations, what confidence is there in existing estimations of runoff fractions? What fraction is recycled to the atmosphere?  What influences do the meso-climates, terrain and vegetation of the SMO, the Mexican plateau and the coastal regions have on hydrological cycling/partitioning?  To what extent do soil moisture and snow anomalies affect the evolution of the North American Monsoon, and can such relationships (if any) be demonstrated using long-term derived soil moisture and snow data sets?

12. Broad Goals of the NHWG:  Build relationships to Mexican and U.S. water resource managers and the NAME atmospheric research community for determination of critical information requirements necessary for dynamic water resources management.  Inventory and document availability and quality of hydrographic and physiographic data over the NAM region.  Identify critical processes and scales, which govern the generation of runoff, its movement over catchments, streamflow and moisture recycling to the atmosphere.  Improve existing frameworks for hydrologic simulation, ultimately resulting in measured increases in predictability.

13. Avenues for Opportunity…. Rainfall-Runoff Process Studies Mexican Investigators + International NAME Research Comm. Improved Process Understanding and Improved Hydrologic Predictability Land Surface Forcing/Feedback Studies

14. Building NHWG Linkages… NHWG International NAME Research Comm. intra-seasonal variability (MJO) remote forcing (SST) extreme event likelihood (T.S.’s) Mexican Investigators water user/manager informatics local practices/policies data retrieval and sharing technology transfer

15. Hydrographic Data Archive NAME NETWORKMEXICAN NETWORK Unified, Quality Controlled Dataset Standardized Data Formats w/ Metadata

16. Data Synthesis for Hydrological Modeling GIS FIELDS INITIALIZATION & FORCING DATA Unified, Quality Controlled Dataset Standardized Data Formats w/ Metadata Radiation Temperature Wind Precipitation Soil Moisture

17. Endgame: Improve Existing Frameworks in Simulation… …Resulting in Increased Predictability NHWG Increased Process Knowledge Standardized Data Archive for Simulation, Calibration and Verification Knowledge of Large- Scale Hydroclimatic Controls Increased Awareness of Water User/Manager Needs and Constraints