Canada Global Precipitation Mission Paul Joe Meteorological Service of Canada

Canada Outline Global Precipitation Mission European GPM Canadian GPM Retrievals and Validation

Canada The GPM Mission Objectives International Set of Cooperative Satellite Missions & Associated Scientific Research- Applications Programs Better Understand Global Water & Energy Cycle Obtain Improvements in Prediction of Significant Climate, Weather, & Hydro- meteorological Processes  Particularly Water Cycle Accelerations/Decelerations,  Tropical Cyclones & Severe Storms,  Flood Hazards, Seasonal Flood-Drought Conditions,  Stores of Fresh Water Resources

Canada OBJECTIVES Understand horizontal & vertical structure of rainfall, its macro- & micro-physical nature, & its associated latent heating Train & calibrate retrieval algorithms for constellation radiometers Provide sufficient global sampling to significantly reduce uncertainties in short- term rainfall accumulations Extend scientific and societal applications Core Satellite Non-sun-synchronous orbit ~ 65° inclination ~400 km altitude Dual frequency radar (NASDA) X-Ka Bands ( GHz) ~ 4 km horizontal resolution ~250 m vertical resolution ~ 18 dBZ MDS (CGPM 0 dBZ ?) Multifrequency radiometer (NASA) 10.7, 19, 22, 37, 85, (150/183 ?) Constellation Satellites Pre-existing operational- experimental & dedicated satellites with PMW radiometers Revisit time 3-hour goal at ~90% of time Sun-synch & non-sun- synch orbits km altitudes Precipitation Validation Sites for Error Characterization Select/globally distributed ground validation “Super sites” (research quality radar, up looking radiometer-radar-profiler system, raingage-disdrometer network, & T-q soundings) (Snow) Dense & frequently reporting regional rain gage networks (Snow, DSDs) Microphysical aircraft measurements and field campaigns (ERAF, Cloudsat) CoreConstellation The GPM Concept

Canada Concept Implementation

Canada EGPM  Improve the accuracy of global precipitation estimates with a focus on light rain and snowfall;  Improve global and regional NWP and climate model forecasts;  Improve the near-real-time monitoring of hazardous and flash-flood producing storms. The EGPM mission goal is to retrieve precipitation with an emphasis on Europe and Canada. The EGPM mission will be an integral and essential component of the GPM constellation.

Canada EGPM/CGPM Focus on snow and light rain Increased sensitivity requirements  High Sensitivity Radar  Sounding microwave channels Ground Validation  Focus on solid precipitation

Canada EGPM/GPM and Precipitation EGPM will extend precipitation observations to high latitudes

Canada At higher latitudes: larger fraction of precipitation is 'light' percentage of solid precipitation high CDF’s of Snowfall and Light Rain Detection Requirements Snowfall Intensity Rainfall Intensity Accumulation Occurrence

Canada WMO/Eumetsat User Requirements

Canada Specific Situations Eumetsat

Canada EGPM User Requirements

Canada Observation Technique Techniques Microwave backscattering at 36 GHz Microwave imaging in 18 to 150 GHz windows Microwave sounding in GHz & 118 GHz bands Needs Horizontal fields of precipitation High Sensitivity Profiles of precipitation Accuracy enhancement for light liquid and solid precipitation Precipitation Radar Microwave radiometer EGPM instruments Active/passive microwave sensing well established Innovation: imaging + sounding + radar

Canada Retrieval Simulation 18, 23, 36 and 89 GHz: differentiation between rain and snow GHz: estimates of rain and snow and 118 GHz: quantitative retrievals + radar: accurate profile retrieval Error at surface 86% 61% 38% 13% Reference

Canada Ground Validation Objectives To scientifically verify and continuously improve satellite retrieval algorithms. To establish measurement uncertainties in precipitation retrievals. To pursue precipitation validation research -- particularly of physical kind. To advance GV measurement technologies. To serve scientific clients who depend upon GV information in their research and applications, e.g.:  near-realtime retrieval error characteristics for data assimilation  error detection/reporting in instantaneous retrievals for algorithm developers

Canada

GPM Continental Supersite Requirements & Concept Provide physical validation and error statistics for algorithms; demand error statistics for all measurements at supersite. Provide data so that algorithms can develop diagnostics to identify sources of error. Perform basic science. Initial thrust would be to identify relationship between large scale variables and precipitation regime/precipitation structure. Science thrust would relate large scale parameters (low-level wind direction, CAPE, etc.) to precipitation type (convective, stratiform, ice- based, warm rain, etc.). TRMM has taught us that biases in the satellite algorithms are not only due to systematic algorithm errors, but also by changing cloud properties. Need this information so that these types of errors can be minimized and serve as guidance for algorithms. Provide motivation for field measurements to address specific algorithms problems, biases, etc.

Canada

An Example Europe Various Precipitation Regimes Various National Weather Services Various Research Organizations Various Radar Networks Various Sites suited for Ground Validation ONE AIM: Ground Validation for GPM and EGPM Sodankylä Chilbolton Cabouw Bonn Palaiseau Oberpfaffenhofen Rome Catalunya Graz Cevennes- Vivarais

Canada Potential GV Supersites Chilbolton Cabouw Palaiseau Oberpfaffenhofen Catalunya Graz Rome

Canada Instrumentation of Supersites The proposed European supersites have excellent instrumentation and are well experienced in the development and operation of the systems and the organization of field campaigns. Radar systems (S, C, X, Ka, W - Band) (Ku ?) co-located systems, some systems are mobile (airborne, truck) Multi-frequency radiometer systems Lidar systems, ceilometers Windprofiler, RASS, Sodar Surface observations Disdrometers, rain gauges Rain gauge networks Operational radio sondes nearby Lightning detection systems Research aircraft...

Canada Spatial Representativeness Fundamental Measurement Validation Problem Radar Only Radar matched to rain gage Gage only What is the truth? Need for measurement AND physical validation of GPM!

Canada Existing or Potential GV Supersite Existing or Potential Standard GV Site U.S. -- NASA-Ocean Kawajalein/RMI Japan -- CRL-South Okinawa South Korea U.S. -- NASA-Land DOE/ARM-SGP U.K. Netherlands Current Status of Potential GPM Ground Validation Site Network France Germany Brazil U.S. -- NASA-KSC Canada South Africa Austria Israel Finland Greece Italy Spain-Catalunya Australia India Taiwan C China Japan -- CRL-North Wakkanai West Africa (AMMA)

Canada Snowfall Issues In situ - Measurements – wind effects Remote Sensing Technologies Snowfall measurement in mountainous regions; Snow bands off open water; Measurement of low intensity solid precipitation events; Solid precipitation over sea ice and ice covered Arctic Ocean; Depth & Snow Water Equivalent (Z-S relationship); Wind drift problem for snow.

Canada Snowfall Water Equivalent Analysis with Wind Corrections

Canada DSD from POSS, JW and PMS Physical Validation Drop Size Distributions

Canada Cloudsat Linkages Cloudsat Mission is CGPM Pre-launch Algorithm development Cal-val strategy development test-bed for GPM  Measurement and physical validation strategy testing Cal-Val infrastructure the same (double the investment value)  Super sites, field campaigns, people High sensitivity VPRs Same radar technology GPM Pre-Launch Activities – NAST-M

Canada Summary GPM ~2011  Global precipitation measurements  3 hour, various spatial resolutions  Constellation of radiometers, Core satellite with radar  65 o /87 o latitude EGPM/CGPM  Focus on snow and light rain  Not selected as part of Earth Explorer/Opportunity  Recommended for EarthWatch/part of GEO strategy Cal/Val  Measurement and Physical Validation  Extensive instrumentation  Focus on error characterization  Little experience with snow