CalWater2 Gulfstream-IV Measurements Janet Intrieri NOAA/Earth System Research Laboratory April 23, 2014

G-IV The Gulfstream IV-SP (G-IV) is a high altitude, high speed, twin turbofan jet aircraft acquired by NOAA AOC in The G-IV is currently configured for operational support of the National Hurricane Center synoptic surveillance mission. This mission is designed to collect, process and transmit vertical atmospheric soundings in the environment of the hurricane. 2CalWater 2015 Planning Workshop22-24 APR 2014 Platform Altitude Range Proposed BaseOps AreasStandard Payload NOAA G-IV1,000 to 45,000 Travis AFB or Honolulu, HI Offshore Coastal CA-HI Coast Range Dropwindsonde Tail Doppler Radar (TDR) Stepped Frequency Microwave Radiometer (SFMR)

Dropwindsondes The dropsonde is released from the G-IV measuring and transmitting back the pressure, temperature, humidity, and GPS Doppler frequency shifts to the aircraft as it descends to earth. The Doppler shifts are used to compute the horizontal and vertical wind components. After analysis and processing of the dropsonde data the information is formatted into a TEMP- DROP message using the standard WMO format. The TEMP-DROP message is then transmitted to the NCEP and the NHC for inclusion into the global and hurricane model runs. The TEMP-DROP message is also provided to the hurricane forecaster providing real-time observations depicting the synoptic patterns surrounding the hurricane. 3CalWater 2015 Planning Workshop22-24 APR 2014

AVAPS Airborne Vertical Atmosphere Profiling System Operated by one person Can receive & process data from 4 dropsondes at the same time Simple Graphical User Interface (GUI) Outputs real time PTH and wind spd/dir for each channel as sondes are descending 4CalWater 2015 Planning Workshop22-24 APR 2014

CalWater 2015 Planning Workshop5 SFMR The Stepped Frequency Microwave Radiometer provides information on surface winds – Sfc winds & rain rate SFMR measures C-band microwave emission from foam (air bubbles in the ocean) First guess pre-2005: Emissivity a quadratic function of wind speed for all winds new knowledge: Emissivity a quadratic function of wind up to hurricane force only- a linear function for hurricane winds

Possible Additional Payload - Dual-Beam UV Absorption Ozone Photometer Ozone measurements (NOAA O3 aka NOAA Classic) to sample air across the subtropical jet – (Profitt and McLauglin et al., 1983) – Potential Payoffs Has already been deployed on the G-IV Significantly increase our understanding of mixing across the subtropical jet and the resulting UT/LS exchange Gain systematic knowledge of the interaction between Asia pollution and the subtropical jet, which may lead pollutants directly into the lower stratosphere Obtain O3 data in the UT/LS that can be used for improving NOAA satellite O3 retrieval POC: Rushan Gao (ESRL/CSD) 6CalWater 2015 Planning Workshop22-24 APR 2014 NOTE: CO measurements – Unlikely for 2015

TDR PPI reflectivity slice from UTC at 8.5 km from the G-IV flight on 14 FEB G-IV TDR 7CalWater 2015 Planning Workshop22-24 APR 2014

North-south vertical cross-section of a east-west wind-component analysis approximately along the flight track G-IV TDR 8CalWater 2015 Planning Workshop22-24 APR 2014

A higher-resolution vertical cross section of each flight leg G-IV TDR 9CalWater 2015 Planning Workshop22-24 APR 2014

Vertical cross-sections of total horizontal wind speed. Since the analysis isn't good near the flight level, it’s removed. The vertical cross-sections assume constant conditions well left and right of flight track, and then can do a geometric solution for u, v, and (w + VT), where VT is the fall speed of the precipitation. G-IV TDR 10CalWater 2015 Planning Workshop22-24 APR 2014