HIPPO Global Phase III

Visit the HIPPO informational website.

The “Collaborative Research: HIAPER Pole-to-Pole Observations (HIPPO) of Carbon Cycle and Greenhouse Gases Study” will measure cross sections of atmospheric concentrations approximately pole-to-pole, from the surface to the tropopause, five times during different seasons over a three year period. A comprehensive suite of atmospheric trace gases pertinent to understanding the Carbon Cycle will be measured. HIPPO missions transect the mid-Pacific ocean and return either over the Eastern Pacific, or over the Western Atlantic. The program will provide the first comprehensive, global survey of atmospheric trace gases, covering the full troposphere in all seasons and multiple years. EOL will provide the NSF/NCAR G-V for this project, and the PI is Prof. Steve Wofsy from Harvard University.

This phase of the HIPPO project is the third one of five. HIPPO Global Phase I took place in January 2009; Phase II in November 2009. Phase IV is scheduled for June 2011.

To accomplish the objectives of the third phase, the NCAR G-V will fly the following missions:

• Rocky Mountain Metropolitan Airport, CO, USA -> Anchorage, AK, USA
• Anchorage, AK to the North Pole (up to 85 degrees North) round trip
• Anchorage, AK, USA -> Kona, Hawaii, USA
• Kona, HI, USA -> Pago-Pago, Am. Samoa or Rarotonga, Cook Islands
• Pago-Pago, Am. Samoa -> Christchurch, NZ
• Christchurch, NZ -> South Pole (up to 67 degrees South) round trip

• Christchurch, NZ -> Pago-Pago, Am. Samoa
• Pago-Pago, Am. Samoa -> Kona, Hawaii
• Kona, Hawaii -> Anchorage, AK
• Anchorage, AK -> N. Pole (85N)
• Anchorage, AK -> Jeffco

This 48,600 km long route differs from the Phase 1 route, which went via Eastern Pacific and had stopovers in Tahiti, Easter Island and Costa Rica. It is also different from Phase 2 route in not going over the Western Central Pacific.

All of the flights are essentially direct point-to-point routes with ongoing altitude changes. It is planned to have two maximum altitude ascents per flight, one in the first half and one in the second half, depending on the ability of the ATC to support altitude changes. Most of the flight will be conducted below RVSM (usually 28,000 ft) in order to allow the G-V to go up and down constantly to collect data at different altitudes throughout the troposphere. Ideally the flight would take off and go to FL430 for 15 min, then descend below RVSM and proceed in a sawtooth pattern between FL270 and FL100 with a 1,500 ft/min climb/ascent rate, then climb to FL450 near the end of the flight for about 15 min, descend and proceed to the airport.

All flights will be followed by at least one no-flight, maintenance day and may be followed by a rest day ("hard down" day); see the operations schedule for details.