David Noone Research

Research interests

Observations of water vapour isotopes from the NASA TES instrument. See Worden, Noone, et al., Nature, 2007 for details.

David Noone's research interests are in exploring the ways large scale circulations of the atmosphere and oceans can change. I am interested in understanding the role water plays in Earth's climate; whether it be in the atmosphere as vapor and clouds, on the landscape as snow and permafrost, or on the ocean as sea ice. One way to gain insight to the dynamics of water is to investigate, with measurements and models, the isotopic composition of the water in the many places it is found. Recent advances in sattelite technology has allowed the isotopic composition of water vapour to be observed globally in the troposphere and stratosphere. This represents a substantial and exciting new database of understanding hydrology with isotopes. To understand climate variability on time scales from days to thousands of years, computer models ranging in complexity from simple to very complex models of the global climate system, are used.

Noone's research group uses climate models fitted with stable water and CO2 isotope tracers to diagnose climate system processes in ways which compliment more tradiation methods. Specific problems involve paleoclimatology and millennial scale climate variability, atmospheric biosphere exchange and the role of the land surface in controlling atmospheric hydrology, and the interaction between large-scale atmospheric circulation, cloud processes and hydrology.

Group members include:

See a brief overview presentation and a climate model animation of atmospheric water vapour (50 megabyes, mpeg).

HAVAIKI

HAwaii VApour Isotope Knowledge Intercomparison

HAVAIKI is a field experiment to make measurements of water vapor isotopologues at the NOAA observatory at Mauna Loa, Hawaii. The observations span about three weeks in October 2008, and use three different laser-based sensors and two different satellites, which will be validated against traditional mass spectrometry techniques applied to samples collected on site using vacuum flasks and cryogenic trapping. The goal of this study is to compare the different measurement techniques (traditional mass spectrometry, commercially available ground-based spectroscopic water vapor analyzers, and satellite-based spectroscopy) in order to assess the fidelity of these new measurement technologies and to provide new data on the processes that control the humidity of the subtropical Pacific.

More details, see the HAVAIKI website.

SWING

Stable Water Isotope Intercomparison Group

The general purpose of the SWING project is an international intercomparison of current state-of-the-art water isotope general circulation models and related observational isotope data.

For more than four decades the isotopic composition of water stored in various archives (e.g. ice cores, ground water) has been used to study changes in the hydrological cycle on timescales from glacial-interglacial to short term variations. Such changes of the hydrological cycle play a crucial role forcing both past and future variability of the Earth's climate system. However, the interpretation of isotopic variations in terms of climate change is often handicapped by an lack of other relevant observational climate parameters (e.g. temperature, relative humidity, precipitation) both in space and time.

The SWING web site and database.

MSPICE

Mass of the Polar Ice Sheet Experiement

Ninety-five percent of the freshwater on Earth is stored in the ice sheets of Antarctica and Greenland. Greenland ice accounts for an equivalent of seven meters of sea level, while Antarctica 60 meters . The amount of snow deposited annually on the Antarctic ice sheet is equivalent to about 6.5 mm of global sea level, which approximately equals the mean annual discharge of ice back into the ocean. Despite all available measurements of snow accumulation, ice velocities, surface altimetry, surface and basal melting, and iceberg discharge, it is still not known for certain whether the Antarctic ice sheet as a whole is growing or shrinking. On the other hand, the Greenland ice sheet is shrinking at a rate that is uncertain, and a recent study showed that the rate of shedding of icebergs has doubled in past years.

MSPICE is an international coorpative research effort which aims to evaluate the atmospheric controls on the surface mass balance via an integrative proram of field measurements, modeling, and remote sensing. MSPICE is in the planning stages and will contribute the International Polar Year reseach during 2007 and 2008.

See the evolving MSPICE white paper here.

High latitude climate

Arctic system on trajectory to new, seasonally ice-free state

At the present rate of change, a summer ice-free Arctic Ocean within a century is a real possibility, a state not witnessed for at least a million years.

ArcticSystem The Arctic system is moving toward a new state that falls outside the envelope of glacial-interglacial fluctuations that prevailed during recent Earth history. This future Arctic is likely to have dramatically less permanent ice than exists at present. At the present rate of change, a summer ice-free Arctic Ocean within a century is a real possibility, a state not witnessed for at least a million years. The change appears to be driven largely by feedback-enhanced global climate warming, and there seem to be few, if any, processes or feedbacks within the Arctic system that are capable of altering the trajectory toward this "super interglacial" state.

The figure (left) is a schematic of the essential components (or hubs) of the present Arctic System. The main interactions between hubs are denoted by arrows: single or double arrowheads indicate one or two-way interactions. Interaction strength is designated by arrow thickness, and the sign (+ or -) indicates whether a change in one component produces a change in another of the same (+) or opposite (-) sign. Numbers in parentheses within each hub indicate the number of interactions going out of, and coming into, that hub. Driver hubs are blue; recipient hubs yellow.

An Arctic climate primer (from CIRES's NSIDC)
Arctic Research Consortium of the United States (ARCUS)
Arctic Climate Impact Assessment (ACIA at UAF)

Isotope terminology

isotopes: Nuclides having the same atomic number but different mass numbers, e.g. O, ¹⁸O, H, D
isotopic tracer: A tracer which only differs in isotopic composition from the substance to be traced.
isotopologue: A molecular entity that differs only in isotopic composition (number of isotopic substitutions), e.g. H₂O, HDO, H₂¹⁸O.
isotopomer: Isomers having the same number of each isotopic atom but differing in their positions.

nuclide: A species of atom, characterized by its mass number, atomic number and nuclear energy state, provided that the mean life in that state is long enough to be observable.
tracer: A foreign substance mixed with or attached to a given substance to enable the distribution or location of the latter to be determined subsequently. ... (iii) An isotopic tracer is a unique isotope, either radioactive or an enriched, uncommon stable isotope, of the element to be traced; ...

From the IUPAC Compendium of Chemical Terminology.

The most abundant isotopologues of water are H₂O (99.7%), H₂¹⁸O (0.2%), H₂¹⁷O (0.0372%), HDO (0.0311%), HD¹⁸O (0.0000626%), HD¹⁷O (0.0000116%), and can be modelled globally.

A great over vew reference document on isotopes in the environment and climate are the IAEA volumes on Environmental Isotopes in the Hydrological Cycle