carmas climate database j. fox l. witter s. thorisson

CARMA’s Climate databaseJ. Fox

L. Witter S. Thorisson

Why a CARMA climate database

• CARMA’s goal to monitor and assess impacts of global change on caribou

• Major approach is cross-herd comparisons• Need to compare (how are herd habitats similar)

and contrast (how are herd habitats different)• Climate plays a central role in controlling caribou

abundance and distribution• Ideal to have one source for the data – climate

data

1979 – 2010 daily data available for over 100 variables across the circumpolar north

…a few words about MERRA data

• Universal coverage for over the last 30 years• Brings together all climate data within the satellite era• Ensures that different satellite provide a consistent

measure of the environment• Data at least daily and, for example temperature, every 3

hours• 72 variables offered• Grid size ½ degree latitude by 2/3 degree longitude• Data is available to download within months• Estimate for CARMA to provide annual updates is ~ 18

hours – of which 15 hours is for MERRA data download

STEP 1. DEFINE SEASONAL RANGES

8 polygons per herd

for example – Bluenose West Herd

calving

summer

springwinter

fall

taiga

tundra

whole herd

calving summer

fall

2 types of tables created

calving summer

fall

Seasonal range tables Caribou movement tables

winter winter

104 grids PCH winter219 grids Taimyr winter

Caribou-relevant climate derivatives

winter

spring/calving

summer autumn

autumn

…a few examples:comparing years for a herd

(summer temperature)

…a few examples:comparing herds (summer

temperature)

…a few examples:snow depth comparing herds

…a few examples:snow depth comparing years

…a few examples:snow depth comparing years

…a few examples:some caribou-specific variables

How much data?

• MERRA raw data 21.5 Gbytes• Polygon focused tables 2.1 Gbytes• Caribou focused tables 138 Mbytes

• TOTAL ~ 25 GBytes

Some questions for the breakout

• Data quality?– Greenness Index, Leaf Area Index– validation

• Documentation needs?• Access?• Additional caribou related variables?• Are there basic summaries needed?• Trend analysis?• Tele-connections?• Update schedule – annual, timing?