What are the scientific objectives of the proposed project?
The scientific questions motivating HIPPO focus on (1) understanding the global sources and sinks for CO2, CH4, and other carbon cycle gases, and more broadly (2) determining large-scale rates of tracer transport in the atmosphere. The principal questions are:
What are the hypotheses and ideas to be tested?
We will quantify the sources of major carbon cycle and greenhouse gases by region at the global scale. Hypotheses to be tested include, as examples:
What previous experiments of similar type have been performed by you or other investigators?
Our team has 15 years of experience in airborne measurement of trace gases, including CO2, CO and many other gases. The most recent was the CO2 Boundary Layer Regional Airborne Study (COBRA-Maine) in 2004, “Continental, Landscape, & Ecosystem Scale Fluxes of CO2, CO and Greenhouse Gases (NSF ATM-0221850—Biocomplexity in the Environment [BE] 1/1/03—12/31/06,) PIs: S. C. Wofsy, P. R. Moorcroft, Harvard; CO-Is: D. Hollinger (USFS), J. C. Lin (Harvard; current Colo State), C. Gerbig (Harvard; current MPI Jena), A. Andrews (NOAA ESRL). This program of observations and modeling measured a suite of gases similar to the proposed suite for HIPPO during ~200 hours of flying the Wyoming King Air over northeastern North America.
In 2003 we flew "COBRA-North America" (NASA sponsored) using the UND Citation 2, twice covering the race track pattern from Colorado to Medford, OR, Campbell River BC, Edmonton, AB, Thompson, MB, Fraserdale, ON, Yarmouth, NS, Portsmouth, NH, Teterboro, NJ, Baltimore MD, Indiana, Park Falls, WI, and return to Jeffco. In addition a number of regional flights were flown, again with a similar set of tracers compared to HIPPO.
We have also flown almost 500 hours of measurements on the NASA ER-2, WB-57F, and stratospheric balloons, making very accurate CO2 measurements.
Almost all of the instrumentation on the HIPPO payload inherit the legacies of these flight programs. Thus our sensors are automated, very robust, and require no in-flight operator. In fact, the sensors do not allow in-flight intervention. They are built to exacting specifications for high-perfomance aircraft operations.
None of the previous experiments had global extent, and consequently none could address the scientific questions of HIPPO. These measurement programs were focused on regional and continental scale observations and science questions.
The data will be analyzed using the GEOS-CHEM model, driven by assimilated wind fields: We will undertake extensive data analysis and conduct comprehensive GEOS-CHEM simulations using GEOS-5 meteorological fields for the flight years, focusing on diagnostic and inverse studies.
We will also conduct inversions using different versions of GEOS assimilated meteorology, as well as the GISS GCM transport fields, to assess sensitivity to transport parameterizations. The diverse species measured simultaneously in HIPPO offer new inversion strategies to address carbon cycle issues. For example, partitioning of thermally and biologically driven oceanic CO2 exchange can be addressed using measurements of CO2, O2/N2 and Ar/N2 in a parameter estimation analysis focused on underlying processes. Such questions will be ripe for future efforts.
What results do you expect and what are the limitations?
The deliverables for HIPPO will be:
There will be limitations imposed by our inability to measure more frequently, over a longer period, at more longitudes.
How far will the Gulfstream V travel?
The NSF/NCAR HIAPER GV will travel almost 30,000 miles (48,000 kilometers) during the 27 day mission.
Where will the GV land to refuel and resupply?
The NSF/NCAR HIAPER GV will land in a few pre-arranged locations where it can be refueled, have any needed maintenance performed, get resupplied, as well as give the flight crew and scientists a rest.
The locations are:
What is the flying altitude range of the GV?
The GV can fly up to altitudes of just over 45,000' and as low as 1000'. This ability to fly at such high and low altitudes is one of the reasons this particular type of aircraft was chosen for atmospheric studies. The range of altitude gives scientists a very broad "view" into the composition of the Earth's atmosphere.
HIPPO is supported by the National Science Foundation (NSF) and its operations are managed by the Earth Observing Laboratory (EOL) of the National Center for Atmospheric Research (NCAR). Its base of operations is EOL's Research Aviation Facility (RAF) at the Rocky Mountain Municipal Airport (RMMA) in Jefferson County, Colorado.
How can I get the data or collaborate with the PIs?
Please contact the HIPPO Principal Investigators if you would like to access the data or inquire about collaborating with them.
Featured Publications:
Atmospheric Measurement Techniques: Profiling tropospheric CO2 using Aura TES and TCCON instruments |
Geophysical Research Letters: Global-scale black carbon profiles observed in the remote atmosphere and compared to models |
Geophysical Research Letters: Tropospheric distribution and variability of N2O: Evidence for strong tropical emissions |
Principal Investigator:
Steve Wofsy Harvard/SEAS
swofsy@seas.harvard.edu
Project Manager:
Pavel Romashkin NCAR/EOL/RAF
pavel@ucar.edu
EOL Data Management:
EOL Archive NCAR/EOL/DMS
eol-archive@ucar.edu