# Presentation: 424352

## Tohono O’odham Nation Monsoon ClimatologyGeorge Ackerman

## Purpose 

** ****Develop monsoon climatology for TON**
-  **Identify variables to predict onset and intensity**** **
** **

**Notes:**

This summer research project was to develop a monsoon climatology for Tohono O’odham Nation and to identify some meteorological variables that can be used to predict the onset of the North American monsoons, also referred to as the Arizona monsoons or Mexican monsoons 

## Monsoon start
The word monsoon
How the monsoon develops
Subtropical Ridge moves north
Wind shift from westerly to southerly/easterly
Moisture inflow / surges
Convective thunderstorms

- Monsoon start
- The word monsoon
- How the monsoon develops
- Subtropical Ridge moves north
- Wind shift from westerly to southerly/easterly
- Moisture inflow / surges
- Convective thunderstorms

**Notes:**
Typically, the Arizona monsoons start sometime in July and ends sometime in September. The word monsoon comes from the Arab term mausin or the season of winds. 
During the month of June as the westerly winds travel inland from the Pacific they begin to shift to a southeast direction as a direct result of the northward movement of the subtropical ridge in northwestern Mexico.  By July the subtropical ridge positions it self over Texas and New Mexico, this causes a more southerly shift in the wind. By then, the wind is caught up in the clockwise rotation of the ridge. Then for a couple a months as this circulation continues it also transports cool moist air from the Gulf of  Mexico and California into Arizona. As it passes across  areas of high convection, the air rises, then we  begin to see the thunder storms develop. We usually see the thunder storms develop in the late afternoon and early evening hours.

## TON Location Map

- Generations
- Traditional crops
- Tepary, 60 d corn
- Runoff agriculture
- Diabetes
- Return to diet
- Return to Runoff
- Clim help Ag
-  Study Location

**Notes:**
For many generations the Tohono O’odham people of the southwestern Arizona deserts have depended on the associated rainy season, which we call Jukiabig Masad or the month of the big rains. This used to be the time to grow traditional crops. The crop fields were in areas were there was runoff from the washes. The traditional diet consisted of tapary beans, squash, melon and others. Today the high incedence of type II diabetes among many native people has prompted the return to the traditional diets. Runoff agriculture is a way that still could be used. By developing a monsoon climatology for the Tohono O’odham Nation we could use this to improve our planting efforts.  The study area is here within this red box,which is 113 to 111 west longitude and 31 to 33 north latitude.

## Data

- North American Regional Reanalysis (NARR) DVD, 1979-2002, daily and monthly
- Monsoon onset dates from Marlow, daily data
- Antecedent (mam) dataset, monthly data
- Monsoon onset +/- 30,60,90 day composite dataset, daily data

**Notes:**
1. The data that was used to create the climatology for the Tohono O’odham Nation was from the newly released, North American Regional Reanalysis DVD dataset. Data for 1979 through 2002 was available on the DVD, so these are the years that I experimented with.

2. The monsoon onset dates were calculated and provide to me by Dr. Marlow

## Methodology

- Climatology- onset dates, composite dataset & Grads were used
- By using the monsoon onset date
- Also maps were constructed showing correlation
- MAM and TON

**Notes:**
The onset dates were used to prepare composite data sets for 60 days before and 60 days after the onset. Then the composites were used to compared the averages.

First I developed a basic working knowledge of the command based grads computer software. With this basic knowledge I was able to modify previously made grad scripts to display maps and graphs of interest to me. I experimented with scripts using the daily and monthly control files and the variables that were available in each file, of the  North American Regional Reanalysis Dataset NARR. During this time I studied a text in weather and climate and studied previous publications on the North American monsoons.

Next, I used the onset dataset that Dr. Marlow and Dr. Mike Bilosivich created for the Tohono O’odham Nation and for Arizona and New Mexico to look at the spacial and temporal averages of each variable that were of interest to me. 

## Climatology: Relative Humidity

**Time series**

## Climatology: Precipitation

**Time series**

## Slide 9

## Slide 10

## Slide 11

## Slide 12

## Tmp2m correlation

## Tmp2m  onset correlation

- Tmp2m  onset correlation

## Summary

- Developed pre monsoon and monsoon climatology for the TON
- Examine the 1984 wet year compared to the climatology
- Examine antecedent variables for prediction of onset & intensity
- NARR dataset was very useful
- More research is needed to identify variables to predict onset and intensity
- Talk to the elders about monsoon