HIPPO Draft mission summary/statement

For release Thursday, 29 January 2009

HIAPER Pole-to-Pole Observation (HIPPO) Program


*Principal Investigators


Steven C. Wofsy -- Harvard University

Ralph Keeling -- Scripps Institution of Oceanography

Britt Stephens -- NCAR

Fred Moore -- CIRES/University of Colorado

Daniel Jacob -- Harvard University

Elliot Atlas -- U Miami

NOAA-ESRL sponsored:

Jim Elkins -- ESRL/ GMD

David Fahey, Rushan Gao -- ESRL/ CSD

Stephen Montzka -- ESRL/ GMD

Dale Hurst -- ESRL/ GMD

*Instrument and Measurement Collaborators:

Mark Zondlo -- Princeton

MJ Mahoney -- JPL

*Mission Manager -- Pavel Romashkin

Science goals, societal relevance

HIPPO goals:

The motivation for HIPPO is to understand the budgets for major greenhouse gases and black carbon particles in the atmosphere. "Budget" in this context refers to quantitative knowledge of: Where are these substances coming from, what are the rates of emission, what are the removal processes and rates from the atmosphere.

HIPPO approach

HIPPO has obtained very detailed, high-accuracy measurements of greenhouse gases and black carbon particles in the atmosphere, globally, from the top of the troposphere to the earth's surface, (nearly) pole-to-pole. These measurements will reveal new information on global budgets of greenhouse agents, as discussed below (see "Why HIPPO is important scientifically").

How the HIPPO mission serves the needs of society:

Global efforts to restrain increases of greenhouse gases and black carbon particles  are coming, probably in the next few years. Planning for mitigation efforts, and future national and international programs to implement them, must be based on the best possible scientific knowledge of the sources and budgets (processes, amounts, locations, attribution) of these materials in the environment.

The effectiveness of future mitigation efforts must be assessed by comparing future emissions across the globe to sources that existed prior to implementation of control policies.

HIPPO provides important contributions both to the development of the scientific methods needed to plan and to assess mitigation efforts, and to the measurement baseline for comparing past and future atmospheric concentration patterns.

Why HIPPO is important to scientifically:

The most important greenhouse gases are carbon dioxide and methane. NOAA's Earth System Research Laboratory maintains a global network of ground stations and a smaller network of low altitude aircraft that measure these and other greenhouse gases, as well as chemical species that help interpretation of the results, at or near the surface. These data have provided scientists with information needed to make estimates of the budgets of greenhouse gases.

However, different assessments have given different answers. A key uncertainty is the way in which atmospheric motions distribute emissions with height, for which we do not have global data. The HIPPO program provides "slices of the atmosphere" that show how greenhouse agents move from their sources through the atmosphere. The HIPPO data will help identify which atmospheric models work best in simulating global distributions of greenhouse agents, allowing us to refine estimates of global budgets.

In addition, HIPPO measures an even larger suite of more than a hundred gases, including pollutants, ozone, gases emitted from the sea, etc., many of which have few prior measurements and no ongoing network data.

The AIRS instrument on the NASA Earth Observing System Aqua platform makes low-resolution measurements of carbon dioxide and methane in the upper atmosphere. The Japanese GOSAT-Ibuki mission and the NASA Orbiting Carbon Observatory (OCO) mission are just being launched to measure total CO2 column amounts. HIPPO data provide validation and calibration checks on these satellites, supplying information required to utilize these data in combination with the NOAA networks.


HIPPO mission accomplishments

The HIAPER aircraft is on the last leg of the first HIPPO global survey; four more are planned for different times of the year.

1. HIPPO successfully obtained very detailed cross sections of greenhouse gases and black carbon particles from the surface to the top of the troposphere,  (almost) pole-to-pole. The feasibility of obtaining this kind of data set  has been demonstrated for the first time--a major achievement in itself.

The data set has the highest quality, able to reveal both fine details and the large-scale picture.

2. The HIPPO data show accumulation in the Arctic of CO2, methane, sulfur hexafluoride, and other greenhouse gases, plus black carbon particles. These materials originate mainly from human activity in northern hemisphere continental regions. Carbon dioxide  emissions reflect both industrial sources and the respiration of the biosphere.

3. The HIPPO data show the inputs of oxygen and removal of CO2 by the southern ocean, and the resulting changes in atmospheric concentrations.

HIPPO has observed the large-scale effects of Southern Ocean biogeochemical exchanges  that are particularly sensitive to ongoing climate change, and that play an important role in the uptake of human CO2 emissions.

For both #2 and #3, HIPPO data show these effects globally, in their full vertical  and horizontal extent, for the first time.

The full significance of these data will not be known for some time. The data will be analyzed using global atmospheric computer models and other approaches. We are confident that the data sets will significantly reduce uncertainties and fill gaps in our understanding of global budgets  of greenhouse gases and black carbon particles.