NASA GPM-Ground Validation: Integrated Precipitation and Hydrology Experiment 2014 Science Plan

Abstract

SummaryGround validation (GV) campaigns before and after the launch of NASA's Global Precipitation Measurement Mission (GPM) Core satellite in early 2014 have been planned to collect targeted observations to support precipitation retrieval algorithm development, to improve the science of precipitation processes, and to demonstrate the utility of GPM data for operational hydrology and water resources applications. The Integrated Precipitation and Hydrology Experiment (IPHEx) centered in the Southern Appalachians and spanning into the Piedmont and Coastal Plain regions of North Carolina seeks to characterize warm season orographic precipitation regimes, and the relationship between precipitation regimes and hydrologic processes in regions of complex terrain.Since 2007, a high elevation tipping bucket rain gauge network has been in place in the Pigeon River Basin (PRB) in the Southern Appalachians and intensive observing periods (IOPs) have been conducted in this and surrounding river basins to characterize ridgeridge and ridge-valley variability of precipitation using radiosondes, tethersondes, MicroRain Radars (MRRs), automatic weather stations and optical disdrometers. Important results from these analyses include the importance of light (<3 mm/hr) rainfall as a baseline freshwater input to the region especially in the cold season, and the high frequency of heavy rainfall and severe weather in the warm season, and illuminate the significant spatio-temporal variability of rainfall in this region.IPHEX will consist of two activities: 1) an extended observing period (EOP) from October 2013 through October 2014 including a science-grade raingauge network of 60 stations, half of which will be equipped with multiple raingauge platforms, in addition to the fixed regional observing system; a disdrometer network consisting of twenty separate clusters; and two mobile profiling facilities including MRRs; and 2) an intense observing period (IOP) from May-July of 2014 post GPM launch focusing on 4D mapping of precipitation structure during which NASA's NPOL S-band scanning dual-polarization radar, the dual-frequency Ka-Ku, dual polarimetric, Doppler radar (D3R), four additional MRRs, and the NOAA NOXP radar ) will be deployed in addition to the long-term fixed instrumentation. During the IOP, the NASA ER-2 and the UND Citation aircraft will be used to conduct high altitude and "in the column" measurements.The ER-2 will be equipped with multi-frequency-radiometers (AMPR and CoSMIR), the dual-frequency Ka-Ku band, HIWRAP Ka-Ku band, CRS W-band, and EXRAD X-band radars. The ER-2 instrument complement collectively functions as an expanded GPM Core "satellite proxy". The UND Citation instruments will be dedicated to microphysical 3 characterization. The ground-based instrumentation sites were selected to collect extensive samples of orographic effects on microphysical properties of precipitation, specifically DSDs, for the dominant warm season precipitation regimes in the region: 1) westerly systems including Mesoscale Convective...

Understanding aerosol–cloud interactions through modeling the development of orographic cumulus congestus during IPHEx

“…A study of thermally driven orographic clouds over a tropical island during the Dominica Experiment (DOMEX) field campaign found that atmospheric moisture was the predominant constraint in cloud and precipitation formation over the aerosol effect, and the surface aerosol source has the strongest influence on precipitation under unfavorable environmental conditions for cloud growth (Nugent et al, 2016). Barros et al (2018) showed that model simulations using aerosol activation spectra from local sources and activation spectra from remote aerosol sources resulted in a significant spatial and temporal redistribution of precipitation in the central Himalayas, including changes in cloud dynamics and the vertical distribution of hydrometeors. The latter is the basis for remote sensing measurements of precipitation, and therefore understanding how ACIs modify precipitation structure is key to improving retrievals in mountainous regions (e.g., Duan et al, 2015).…”

Measurement uncertainty in rainfall kinetic energy and intensity relationships for soil erosion studies: An evaluation using PARSIVEL disdrometers in the Southern Appalachian Mountains

“…In order to understand instrumental difference alone, both sensors were evaluated under laboratory controlled conditions. Data were collected in preparation for IPHEx2014 (Integrated Precipitation and Hydrology Experiment, Barros et al 2014), a Global Precipitation Mission ground validation field campaign (GPM-GV), taking place during 2014 in the Southern Appalachians and the Southeast Region of the USA. Here, we report how the instrument error affects the relationship between rainfall kinetic energy and intensity as a function of the hydrometeorological regime towards a framework to estimate rainfall kinetic energy from intensity records independently of sensor type.…”

Understanding aerosol-cloud interactions in the development of orographic cumulus congestus during IPHEx

“…May-June 2014 in the complex terrain of the SAM (Barros et al 2014). Because measurements of key input parameters are not available from the campaign, or cannot be resolved by current sampling techniques, there is a pressing need to investigate the physical space of such parameters (e.g., condensation coefficient, entrainment, and scale height) and their interdependencies, which ultimately govern ACI in cloud formation and development.…”

“…1). IPHEx was one of the ground validation campaigns after the launch of NASA's Global Precipitation Mission (GPM) core satellite, and details about this campaign can be found in the science plan (Barros et al 2014). During the IPHEx IOP, measurements of aerosol concentrations and size distributions ranging from 0.01 to 10 μm were collected at the ground level.…”

“…Observations collected over complex terrain during IPHEx (Integrated Precipitation and Hydrology Experiment; Barros et al, 2014) provide a great opportunity to investigate ACI in an orographic context of the Southern Appalachian 15 Mountains (SAM). Previous research (Wilson and Barros 2014) showed that seeder-feeder interactions among multilayer clouds generally, and between locally initiated or propagating convective clouds and low-level boundary layer clouds in particular, can increase the intensity of rainfall by one order of magnitude in the SAM and explain the observed peak midday peak in rainfall.…”