diff --git a/.DS_Store b/.DS_Store
index f27572d..4611e70 100644
Binary files a/.DS_Store and b/.DS_Store differ
diff --git a/pyatmos/.DS_Store b/pyatmos/.DS_Store
index e8941bc..6fc0733 100644
Binary files a/pyatmos/.DS_Store and b/pyatmos/.DS_Store differ
diff --git a/pyatmos/__init__.py b/pyatmos/__init__.py
index 45a9379..83f49a7 100644
--- a/pyatmos/__init__.py
+++ b/pyatmos/__init__.py
@@ -6,7 +6,7 @@ estimation of atmospheric properties for various atmospheric models, such
 as exponential, coesa76, nrlmsise00, and jb2008. 
 
 '''    
-
+import os
 from .standardatmos.expo import expo
 from .standardatmos.coesa76 import coesa76
 
@@ -15,7 +15,9 @@ from .jb2008.spaceweather import download_sw_jb2008,read_sw_jb2008
 
 from .msise.nrlmsise00 import nrlmsise00
 from .jb2008.jb2008 import jb2008
+
 from .utils import data_prepare
 
-# Load and update the EOP file and Leap Second file
-data_prepare.iers_load() 
\ No newline at end of file
+# Load IERS data based on environment variable
+enable_iers_load = os.getenv("ENABLE_IERS_LOAD", "true").lower() == "true"
+data_prepare.iers_load(enable_iers_load)
\ No newline at end of file
diff --git a/pyatmos/utils/data_prepare.py b/pyatmos/utils/data_prepare.py
index 371c621..45b42f6 100644
--- a/pyatmos/utils/data_prepare.py
+++ b/pyatmos/utils/data_prepare.py
@@ -2,11 +2,16 @@ from astropy.utils import iers as iers_astropy
 
 from .data_download import download_iers
 
-def iers_load():
-
-    # load the EOP file
-    dir_iers,eop_file,leapsecond_file = download_iers() 
-    iers_astropy.conf.auto_download = False
-    iers_a = iers_astropy.IERS_A.open(eop_file)
-    leapsecond = iers_astropy.LeapSeconds.from_iers_leap_seconds(leapsecond_file)
-    eop_table = iers_astropy.earth_orientation_table.set(iers_a)
\ No newline at end of file
+def iers_load(enable_iers_load=True):
+    """
+    Loads the EOP (Earth Orientation Parameters) and Leap Second files from IERS.
+    This function downloads the necessary files if they are not found locally, and then sets up the Astropy libraries to use this data.
+    """
+    if enable_iers_load:
+        # Download the EOP and Leap Second files
+        dir_iers,eop_file,leapsecond_file = download_iers()
+        # Load IERS data for Astropy
+        iers_astropy.conf.auto_download = False # Prevent automatic IERS download by Astropy
+        iers_a = iers_astropy.IERS_A.open(eop_file) # Load IERS data
+        leapsecond = iers_astropy.LeapSeconds.from_iers_leap_seconds(leapsecond_file) # Load Leap Second data
+        eop_table = iers_astropy.earth_orientation_table.set(iers_a) # Configure Astropy to use IERS data