Author Archives: gymnosperm

A River Runner’s Guide to Grand Canyon Geology VI: The Schists

Geologists have great fun with puns on the term “schist”. Technically, it refers to metamorphic rock; rock that has been altered by high temperature and pressure. There are several grades of schist, our former favorite was “blue schist” as a … Continue reading

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A River Runner’s Guide to Grand Canyon Geology V: Transects

River runners follow the water. The water is in our blood, and following it is what we do. We began this series by using the Colorado River as a transect, and following the drainages up to the South Rim as … Continue reading

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A River Runner’s Guide to Grand Canyon Geology IV: Whither the Supergroup?

We left off the last post having seen the complete Supergroup sequence of over two miles of Neoproterozoic and Mesoproterozoic sediments. The river never encounters the Neoproterozoic part, roughly half. These lie above the river on the North Rim side … Continue reading

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A River Runner’s Guide to Grand Canyon Geology III: The Supergroup

A typical visitor to the Grand Canyon looks down from the rim through about a mile of sediments to the river. Most of these are Paleozoic sediments extending back about 515 million years. They appear to be level, although in … Continue reading

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A River Runner’s Guide to Grand Canyon Geology II: Muddy Creek and the Formation Problem

One might think that by now we would understand pretty well how the Grand Canyon formed. We don’t. Central to the problems of how and when the current Grand Canyon formed is the Muddy Creek Formation, a bunch of freshwater … Continue reading

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A River Runner’s Guide To Grand Canyon Geology

River runners have a different perspective on Grand Canyon geology. Remarkably, the put in at Lee’s Ferry is above the entire Grand Canyon sequence, and all the strata seem to emerge in turn from the river. This makes sense, but … Continue reading

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The Temperature and Altitude of Radiation to Space III

We left of the last post having found that brightness temperature was hopelessly asymmetric to radiance in the main CO2 deviation from the Planck temperature. This discovery dashed all hope of using brightness temperature to determine the temperatures of the … Continue reading

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The Temperature and Altitude of Radiation to Space II

We left off the last post having accommodated MODTRAN radiance to the Planck curves, and having promised to derive the temperatures of the individual lines from an inversion of the Planck radiance formula to give the Planck brightness temperature. Unfortunately, … Continue reading

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The Temperature and Altitude of Radiation to Space

This post was begun some time ago and we experienced so much trouble replicating the MODTRAN Planck curves that two rambling subsequent posts transpired recounting the misadventure. Here, and here. We eventually concluded that the Planck curves in the MODTRAN … Continue reading

Posted in Greenhouse Spectra, MODTRAN, Radiance | 1 Comment

Alalyzing the MODTRAN Planck Curves

This post reports on some progress on resolving our difficulty replicating MODTRAN Planck curves in a prior post. In a personal communication, Dr. David Archer kindly provided the spreadsheet used to produce the MODTRAN curves. The standard wave number Planck … Continue reading

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