Ken Minschwaner

Research Interests

I've worked on research projects in climate, stratospheric and tropospheric ozone, photochemistry, and physics of the upper atmosphere.

Climate: My first research involved the development of computer codes for calculating infrared and solar heating in the atmosphere. These codes were incorporated into radiative-convective models to run simple climate simulations and for assessing the climate feedback by water vapor. Later on, I was able to collaborate with Andy Dessler at Texas A&M to further investigate water vapor and climate. Here are some links to our 2004 paper on the water vapor feedback, a 2006 analysis of climate models, and a 2007 paper on the regulation of tropical upper tropospheric water vapor.

A related research area involves the effect of trace greenhouse gases on the Earth's radiation budget. The first project used data from the Upper Atmosphere Research Satellite (UARS) to calculate the radiative forcing of climate by methane, nitrous oxide, and CFC-12. We also calculated global lifetimes of nitrous oxide and CFC-12 based on their photochemical destruction rates in the stratosphere. The lifetime estimates were updated (and CFC-11 lifetime added) in a 2013 study, where we used a combination of satellite measurements and radiative/photochemical models. Here is a link to some of the calculations involved in the trace gas lifetimes reevaluation, as well as a SPARC assessment in which I was involved.

Stratospheric ozone: The composition and dynamics of the Earth's stratosphere has been an interest since 1986, when I became involved with hydroxyl column abundance measurements started by Clyde Burnett at Fritz Peak, Colorado. Hydroxyl (OH) is generally regarded as one of the key reactive trace gases in the atmosphere, and an important player in ozone chemistry. We set up a second instrument on campus at New Mexico Tech and made OH measurements during a span of 5 years in the 1990's (observations page). These measurements were also used to validate satellite measurements of stratospheric OH (paper link) from the Microwave Limb Sounder (MLS). Since 2004, a large fraction of my research has involved the use of MLS measurements; collaborations with Gloria Manney and others on the MLS instrument team have been essential to this work.

Related areas of study are the modeling of the absorption and scattering of solar ultraviolet radiation as it relates to the ozone budget (including analysis of balloon measurements). We also had set up a measurement/monitoring program involving biologically active UV-B and total column ozone, which operated until the equipment was destroyed in the 2004 hailstorm. I've worked on simple models and data analysis to better understand transport dynamics in the stratosphere, such as a study concerning the isentropic mixing of midlatitude air into the tropical lower stratosphere, and the upward branch of the Brewer-Dobson circulation.

Tropospheric ozone: Ozone in the troposphere is a fairly recent (and ongoing) area of interest for me, starting in 2006 with the IONS-06 ozonesonde campaign. Measurements inside an electrically active storm near campus suggested the direct production of ozone by corona discharges. We also did some follow-up work up at Langmuir lab, and in 2014 participated in the SEACIONS campaign. One result from that work was identifying the signature of a Pacific hurricane in the upper troposphere over Socorro.

Photochemistry: My interest in photochemistry revolves mostly around molecular spectroscopy, such as oxygen ultraviolet absorption cross sections, and photodissociation of nitric oxide and water vapor. The photochemistry of carbon monoxide was also investigated using my radiative codes coupled with MLS measurements.

Upper Atmosphere: I've studied physics and chemistry of the lower thermosphere region, from about 90 to 200 km altitude, using data primarily from satellite and rocket soundings. The ultraviolet solar fluorescence from nitric oxide, ionized metal vapors, and nightglow from oxygen are areas of particular interest (ISAAC paper 1, paper 2) .