2011 - Cooperative Institute for Research in Environmental Sciences ...

PSD-10CloudandAerosolProcesses
FEDERAL LEADS: TANEIL UTTAL AND TIM SCHNEIDER
CIRES LEAD: MATTHEW SHUPE
NOAA Goal 2: Climate
Project Goal: Make observations of clouds, aerosols and
water vapor over a variety of ice, land and sea surfaces using
a multi-sensor, multi-platform approach to improve retrieval
techniques useful for satellite validation studies.
Milestone 1. Produce cloud macrophysical and microphysical
data sets describing the clouds at Arctic atmospheric
observatories. These data sets will include information on
cloud occurrence, vertical distribution, boundaries, phase
and microphysical properties.
There has been ongoing work to develop and evaluate
techniques for deriving cloud macrophysical, microphysical
and dynamical properties from remote sensor measurements
in order to produce continuous data sets from
ongoing Arctic observatory measurements and periodic
observational campaigns. Many of these data sets are made
available via public data archives supported by NOAA
and other agencies. During the past year, two papers were
published documenting some of these cloud data sets. The
first paper documented cloud fraction measurements from
long-term measurements (at least approximately one year
in duration) from six Arctic atmospheric observatories,
including a characterization of cloud boundaries, vertical
distribution and persistence. The second paper looked in
more detail at cloud phase occurrence at three of the observatories
with more complete and complex instrument suites.
These studies revealed important differences in the annual
distribution and occurrence of clouds at different Arctic
locations, which could be linked to processes that control
cloud phase and ultimately to the larger-scale meteorological
environment at these locations. Additionally, a new set
of comprehensive cloud measurements has been started
at Summit, Greenland, and will eventually lead to further
cloud properties data sets.
Product: Shupe, MD, VP Walden, E Eloranta, T Uttal, JR
Campbell, SM Starkweather, and M Shiobara (2011), Clouds
at Arctic Atmospheric Observatories, Part I: Occurrence and
macrophysical properties, J. Appl. Meteor. Clim., 50, 626-644.
Shupe, MD (2011), Clouds at Arctic Atmospheric Observatories,
Part II: Thermodynamic phase characteristics,
J. Appl. Meteor. Clim., 50, 645-661.
Milestone 2: Utilize ground-based, multi-instrument,
remote-sensor measurements, aircraft in situ observations
and high-resolution mesoscale models to study the role of
cloud dynamical-microphysical processes in the Arctic cloud
life cycle. Specific observations will come from various sites,
including NOAA’s Study of Arctic Environmental Change,
SEARCH; the DOE’s ARM sites, and the Surface Heat Budget
of the Arctic, SHEBA; Arctic Summer Cloud Ocean Study,
ASCOS; and Arctic Mechanisms of Interaction between the
Surface and Atmosphere, AMISA, field campaigns.
Coordinated observational and modeling efforts have
substantially enhanced our understanding of cloud microphysical
and dynamical processes that are responsible for
the persistence of Arctic stratiform clouds. Observationally,
efforts have focused on deriving detailed information on
in-cloud dynamical and microphysical properties and determining
how these interact both within the cloud and the
102 CIRES Annual Report 2011
surrounding atmosphere. These observational analyses have
led to a number of papers (in preparation or published)
that document the observed cloud and boundary layer
structure and suggest some ways in which aerosol properties
constrain the formation of ice particles in mixed-phase
clouds. The detailed observational data have also been used
to evaluate nested Weather Research and Forecasting (WRF)
model simulations, where the innermost nest is run at very
fine scale resolutions of 50 meters or less. These high-resolution
simulations, with proper large scale forcing, are able
to well capture the evolution of a stratiform, mixed-phase
cloud system, lending confidence in many of the internal
model processes. The model has then been used to examine
moisture and energy budgets within the cloud and atmosphere
that cannot be directly observed. Thus, the model
simulations have been a key tool for extending our understanding
of processes like entrainment and mixing beyond
observational capabilities. Much of this general understanding
has been synthesized in a collaborative review article on
persistent Arctic mixed-phase clouds that is currently under
review.
Product: De Boer, G, H Morrison, MD Shupe, and R Hildner
(2011), Evidence of liquid dependent ice nucleation in
high-latitude stratiform clouds from surface remote sensors,
Geophys. Res. Lett., 38, L01803, doi:10.1029/2010GL046016.
Lance, S, MD Shupe, G Feingold, CA Brock, J Cozic, JS
Holloway, RH Moore, A Nenes, JP Schwarz, JR Spackman,
KD Froyd, DM Murphy, J Brioude, OR Cooper, A Stohl, and
JF Burkhart (2011), CCN as a modulator of ice processes in
Arctic mixed-phase clouds, Atmos. Chem. Phys. Discuss., 11,
6737-6770.
Solomon, A, MD Shupe, POG Persson, and H Morrison
(2011), Moisture and dynamical interactions maintaining
decoupled Arctic mixed-phase stratocumulus in the presence
of a humidity inversion, Atmos. Chem. Phys. Discuss., 11,
13469-13524.
Morrison, H, G de Boer, G Feingold, J Harrington, MD
Shupe, and K Sulia (2011), Self-organization and resilience of
Arctic mixed-phase clouds, Nat. Geosci., submitted.
Milestone 3. Participate in the Northwest Tropical Atlantic
Salmon, NTAS; PIRATA Northeast Extension, PNE;
and CalNex research cruises in 2010. Deploy cloud radar,
radiometer and flux systems to measure key surface marine
boundary layer parameters, low cloud macrophysical,
microphysical and radiative properties. Conduct initial
analysis focused on the associations between low clouds
and the boundary layer structure.
The CIRES-NOAA team participated in the PIRATA (Prediction
and Research Moored Array in the Tropical Atlantic)
Northeast Extension (PNE; also referred to as Aerose) cruise
in May 2010. Data have been made available via the NOAA
Earth System Research Laboratory/Physical Sciences Division
data archive and ftp site. Analysis of the data has been
delayed.
PSD-11 WaterCycle
FEDERAL LEAD: MARTY RALPH
CIRES LEAD: DAVID KINGSMILL
NOAA Goal 3: Weather and Water
Project Goal: Improve weather and climate predictions