Satellite Observations of Cirrus

Cirrus frequency of occurrence over the western Pacific.

Satellite observations have revealed that cirrus is very prevalent near the tropopause throughout most of the tropics. Cirrus is formed by several processes: a) in-situ rising and freezing of a humid layer, b) blow-off by deep convection, and c) initiation of cirrus formation by the cold temperature perturbations of dynamical waves. The cirrus is of interest since the cirrus restricts the amount of water vapor that is transported from the upper troposphere into the lower stratosphere.

MOPITT multispectral CO observations

Surface CO in China.

The MOPITT team has made significant advances in demonstrating multispectral retrievals of CO (carbon monoxide) with enhanced sensitivity to near-surface CO. MOPITT, (Measurements Of Pollution In The Troposphere), on EOS-Terra, has been measuring CO since March 2000, and is the only satellite instrument with both thermal infrared (TIR) and near infrared (NIR) CO channels. The standard MOPITT V4 product uses TIR-only radiances to produce CO distributions for day/night, ocean/land observations.

First direct observations of sulfuric acid clusters associated with atmospheric nucleation

Dr. Jun Zhao and the Cluster CIMS

The production of new particles following atmospheric nucleation is a frequently-observed, worldwide phenomenon. Nanoparticles produced by atmospheric nucleation can subsequently grow to become cloud condensation nuclei (CCN) within one or two days and hence affect cloud formation, precipitation, and atmospheric radiation budgets. Bridging between molecules and nanoparticles, neutral molecular clusters are believed to play an important role in boundary layer nucleation process.

Modeling of SOA formation using an explicit gas-phase chemical mechanism

GECKO-A model prediction of organic aerosol in Mexico City

The mechanisms by which secondary organic aerosols (SOA) form in the atmosphere are a topic of much current research. Parameterizations used in air quality and climate have difficulty reproducing observed quantities of ambient aerosol, at least in part because of their inability to account for the diversity of chemical species involved in SOA formation.

Arctic pollution studied with models and satellite observations in support of the ARCTAS campaign

MOPITT retrievals of tropospheric carbon monoxide

Increasing anthropogenic pollution and wildfires are the main producers of CO (carbon monoxide) pollution in the Northern Hemisphere. During the NASA ARCTAS field campaign , the ACRESP group used models and satellite data to study the polluted air masses that are transported into the Arctic troposphere, influencing the ecosystem in high northern latitudes and the global radiation and climate.


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ACOM | Atmospheric Chemistry Observations & Modeling